Guidance

ISOSS Hepatitis B report (for pregnancies between 1 April 2022 to 31 March 2023)

Updated 5 August 2025

Applies to England

1. Executive Summary

ISOSS hepatitis B surveillance continues to provide a clear picture of hepatitis B in pregnancy in England and its management.

There were 1921 pregnancies in women with hepatitis B in England, with a booking date between 1 April 2022 and 31 March 2023 reported to The Integrated Screening Outcomes Surveillance Service (ISOSS), demonstrating a slight fall from the previous year (n=1988).

As reported to ISOSS, there was a small increase in cases of newly diagnosed HBV in pregnancy from 20.3% (21-22) of all diagnosis to 21.7% (based on self-report of previous diagnosis). The proportion of pregnancies with higher infectivity markers was 7.3%, the same as the previous year of ISOSS data (2021-2022)

As seen with the other screened-for infections, the highest number of pregnancies in women with HBV was in London (34.2%), and women with HBV were more likely than the general population to book for antenatal care later than advised in NICE guidance (over 10+0 weeks gestation, 43.3% of women with HBV booked before 10+0 weeks, compared with 61.3% of women in the general population).

Over 95% of women were born outside the UK, which is higher than for syphilis screen-positive pregnancies (54.4%) and women living with HIV (81.2%).Of migrants recently arriving in the UK (i.e., screen positive women who arrived in the UK either during pregnancy or up to a year prior to conception), a higher proportion were newly diagnosed in pregnancy compared to other screen positive women (46.0% versus 15.3%). Also, they were more likely to be late bookers (later than 20 weeks gestation) or present unbooked in labour (31.4% and 2.0%, respectively, compared to 6.1% and 0% among remaining pregnancies).

Complex social factors were reported for 19.1% of pregnancies, with housing concerns, immigration issues and social services involvement most reported. Mental health problems also continue to be another key issue among this population.  

Monitoring of compliance with the NHS England Infectious Diseases in Pregnancy Screening (IDPS) HBV screen positive pathway showed that 75% of women of higher infectivity and/or with new diagnosis were seen by specialist services within 6 weeks and over 90% of those with lower infectivity markers were seen within 18 weeks of their positive result being received by maternity services. ISOSS now directly provide NHS IDPS Standard 6 and 8 to closely monitor these targets for NHSE. Overall, 10% of pregnancies were in women who were treated for hepatitis B in pregnancy (80% among women with a viral load greater than 200,000 IU/mL).

ISOSS surveillance of the infant vaccination programme shows reassuring results with 98% of infants receiving the birth dose within 24 hours among pregnancies booked between 1 April 2022 and 31 March 2023.

2. Introduction

The Integrated Screening Outcomes Surveillance Service (ISOSS) is commissioned by NHS England and is part of the NHS Infectious Diseases in Pregnancy Screening (IDPS) programme. Surveillance is conducted for pregnancies in women with hepatitis B virus (HBV), human immunodeficiency virus (HIV), and syphilis, their babies and other children diagnosed with HIV, vertically acquired HBV and congenital syphilis in England. HBV maternity reporting began in 2021, and since 2023 infant follow-up has been sought through linkage with the UK Health Security Agency (UKHSA) who provide data on HBV testing for infants born to women living with hepatitis B at 12 months. ISOSS remain a key stakeholder in achieving and evidencing the WHO hepatitis B elimination of mother to child transmission targets.

This report focuses on pregnancies in women with HBV who booked for antenatal care in England from 1 April 2022 to 31 March 2023. All HBV screen positive pregnancies reported to ISOSS with data submitted by the end of June 2024 are included; this includes all pregnancies in women screening positive for HBV at any point during pregnancy and those with a known chronic HBV diagnosis.  Data on infant follow-up covers infants born to women booked in the previous year from 1 April 2021- 31 March 2022. This is because UKHSA captures infant follow-up data at 12 months of age, so this data is not yet available for infants born to women booking between 1 April 2022 and 31 March 2023.

‘Spotlight’ sections within the report highlight areas of interest/key findings and include data from the previous two years surveillance; that is, 1 April 2021 to 31 March 2023.

3. NHS IDPS programme standards summary statistics

In screening year 2022 to 2023 in England:

• 631,459 (tested) pregnant women (632,911 eligible) entered the hepatitis B antenatal screening pathway

•  coverage for antenatal HIV, HBV and syphilis screening were each 99.8%

• 3.33 eligible pregnant women per 1,000 tested received a new HBV diagnosis

Screening standards set by the NHS England IDPS programme are used to measure how well screening programmes are performing in important areas. Standards for the HBV screening programme focus on;

• screening coverage
• test turnaround time
• timeliness to result and information for women
• timeliness of specialist clinical assessment
• timely administration of neonatal hepatitis B vaccination and immunoglobulin

For 2022 to 2023, the data were submitted annually by 143 different maternity providers to NHS England. This data is collected separately from ISOSS surveillance and there are differences between the 2 data sources due to data quality issues including duplicate records and following transfers of care. The most recently published data for all standards is for screening year 2021 to 2022 (1 April 2021 to 31 March 2022).  Since April 2023, data has been submitted from maternity providers to ISOSS on behalf of the NHS IDPS and ISOSS now directly provide NHS IDPS Standard 5, 6, 7, and 8 to closely monitor these targets for NHSE.

Table 1a: trends in screen positive rates for HBV in pregnant women, England, screening year 2018 to 2019 to screening year 2022 to 2023

	2018 to 2019	2019 to 2020	2020 to 2021	2021 to 2022	2022 to 2023
Screen positive women: rate per 1,000 women tested	3.89	3.77	3.38	3.39	3.33
Newly diagnosed women: rate per 1,000 women tested	0.89	0.86	0.70	0.69	0.67

4. HBV reporting

In 2022 to 2023, 100% of maternity providers submitted their initial reports for women with screen positive results for HBV via the quarterly ‘green card’ reporting system on the ISOSS portal (572 of 572 green cards completed). Antenatal notification forms were subsequently returned for 100% of screen positive pregnancies, and pregnancy outcomes forms were submitted for 100% of pregnancies.

5. HBV overview

There were 1921 pregnancies in women with HBV with a booking date between 1 April 2022 and 31 March 2023 in England reported to ISOSS. Of these, 78.3% (1505 out of 1921) of women were known to have HBV infection before their pregnancy.  The remaining 416 (21.7%) women were diagnosed via screening in their current pregnancy. These data show no significant change from the numbers in the 2021-22 ISOSS Hepatitis B report.

Women were newly diagnosed with HBV in 21.7% of pregnancies (416 out of 1921). There was one report of a woman who initially screened negative but tested positive later in pregnancy after becoming unwell.

For women with a prior HBV diagnosis, 93.0% (1390 out of 1494) had lower infectivity markers in their current pregnancy, and 7.0% (104/1494) were found to have higher infectivity markers (Table 1/Figure 1). For those with a new diagnosis of HBV in this pregnancy, 92.5% (384/415) had lower infectivity markers, with 7.5% having markers of higher infectivity. These findings are consistent with last year’s report (where 93.5% of prior diagnoses and 89.8% of new diagnoses had lower infectivity markers).

Infectivity status is defined in line with British Association of the Study of the Liver‘s (BASL) British Viral Hepatitis Group (BVHG) pregnancy guidelines and the Green Book guidance and can be found in NHS IDPS standards 6 and 8.  

Table 1: screen positive breakdown

	Number of pregnancies	Percentage (%)
Newly diagnosed lower infectivity	384	20.1
Newly diagnosed higher infectivity	31	1.6
Previously diagnosed lower infectivity	1390	72.8
Previously diagnosed higher infectivity	104	5.4
Total screen positive pregnancies1	1909	100.0

1. Data not available for 12 pregnancies due to miscarriage or termination.

Figure 1: Percentage of 1909 screen positive pregnancies by timing of diagnosis/infectivity status

5.1 Spotlight on diagnosis of HBV in pregnancy

*This section includes data from pregnancies reported from 1 April 2021 and March 2023 (3907)

New diagnoses of HBV in pregnancy booked between 1 April 2021 and 31 March 2023 accounted for 20.9% of all reported cases in that timeframe (817 of 3907). Of women newly diagnosed, 8.8% (72/816) had higher infectivity markers, and 91.2% (744/816) had lower infectivity markers. Of those with available data:

• 97.0% (778/802) of those newly diagnosed in pregnancy were to women born abroad
• 16.9% (98/579) arrived in the UK during pregnancy.
• 15.2% (124/817) booked late - at equal to or later than 20 weeks gestation (12.9%, 105/817) or arrived unbooked in labour (2.3%, 19/817).
• 7.8% (59/757) received maternal treatment in pregnancy (commencing treatment following diagnosis in pregnancy)
• 21.7% (177/817) reported at least one complex social factor.

6. Coinfections

Overall, 3.4% of women (n=66) had one co-infection and five were reported as having two coinfections.

• 0.8% (16/1921) had a syphilis coinfection and 0.9% (18/1921) had an HIV coinfection (Table 3).

Table 2: screened-for/hepatitis co-infections in pregnancy among screen-positive pregnancies

Infection	Number of pregnancies	Percentage (%)
No coinfections	1850	96.3
HIV	18	0.9
Syphilis	16	0.8
Hepatitis C virus (HCV)	3	0.2
Hepatitis D virus (HDV)	8	0.4
All HBV screen positive pregnancies	1921	100

6.1 Spotlight on screened-for and hepatitis coinfections

Among 3,907 screen positive pregnancies booked in between 1 April 2021 and 21 March 2023,79 (2.0%) had coinfections which were screened for in pregnancy (HIV, and syphilis) or HCV/HDV (Table 4).

Table 3: prevalence of screened-for and hepatitis coinfections among 3907 HBV screen positive pregnancies booked in between 1 April 2021 and 21 March 2023

Infection	Number of pregnancies	Prevalence (%)
HIV	34	0.9
Syphilis	32	0.8
Hepatitis C virus (HCV)	8	0.2
Hepatitis D virus (HDV)	10	0.3
HCV/syphilis	2	0.1
HDV/syphilis	1	0.03
HIV/syphilis	1	0.03

64 (81.0%) women with these coinfections had a prior HBV diagnosis before conception (Figure 2). Higher infectivity markers were reported for 26.7% (4/15) and 10.9% (7/64) of women with new and prior HBV diagnosis, respectively, compared with 8.4% (68/801) and 6.6% (200/3012) of all pregnancies in mono-infected HBV screen-positive women.

Among 32 pregnancies with a syphilis coinfection, nine women had a new syphilis diagnosis requiring treatment five of whom also had a new HBV diagnosis. All new diagnoses received appropriate treatment for syphilis in pregnancy.

Among 34 with an HIV coinfection, 33 were diagnosed with HIV before this pregnancy, and one was diagnosed with HIV in this pregnancy. The new HIV diagnosis was also newly diagnosed with HBV in this pregnancy. All 34 women were on appropriate ART in pregnancy.

Figure 2: Timing of HBV diagnosis and infectivity status among screen-positive pregnancies with screened-for or hepatitis coinfections, 1 April 2021 to 31 March 2023

7. Demographics

Gestational age at booking

Fewer women with HBV booked at the recommended gestation of less than 10 weeks of pregnancy (43.4%) - (833/1921) when compared to the general population (61.3%) (Table 2)

There was also a higher rate of late bookings (over 20 weeks gestation) to women with HBV (10.9%, 209/1921) (Table 2), compared to the general population (3.7%).

6 women (0.3%) with HBV arrived unbooked in labour.

• 3 women were newly diagnosed in this pregnancy, one of whom had higher infectivity markers.
• 3 women had been previously diagnosed, (one with higher infectivity and two with lower infectivity markers).
• all 6 women were born abroad, and 4 arrived in the UK during pregnancy. Timing of arrival in the UK was unknown for the other 2 women.
• adverse social circumstances were reported in 3 cases, including social services involvement (2), uncertain immigration status (1), and issues engaging with healthcare services (1).

Among pregnancies leading to livebirths or stillbirths (pregnancy outcomes summarised in Table 21), 1.1% (19 of 1664) changed Strategic Health Authority between notification and delivery, and 101 (6.1%) transferred antenatal unit during pregnancy. 

Table 4: gestation at booking for all screen positive pregnancies

	Screen positive pregnancies
Gestational age at booking (grouped)	Number of pregnancies	Percentage (%)	General pregnant population (%)
Less than 10+0 weeks	833	43.3	61.3%
10+0 to 12+6 weeks	550	28.6	26.9%
13+0 to 19+6 weeks	323	16.8	8.1%
Equal to or more than 20 weeks	209	10.9	3.7%
Unbooked in labour	6	0.3	Data unavailable
All screen positive pregnancies	1921	100.0	NA

7.1 Region of booking

The highest number of HBV screen-positive pregnancies were in London, followed by the Midlands, and the region with the fewest HBV screen-positive pregnancies was the South West (Table 5/Figure 3).

Table 5: number of screen positive pregnancies by region of booking

Region	Number of pregnancies	Percentage (%)	General pregnant population (%)
London	657	34.2	20.7
Midlands	355	18.5	18.1
East of England	173	9.0	11.6
North East and Yorkshire	180	9.4	14.2
North West	200	10.4	12.3
South West	93	4.8	8.4
South East	263	13.7	14.7
Total screen positive pregnancies	1921	100.0	100.0

Figure 3: Percentage of screen positive pregnancies by region of booking

8. Age at delivery

The median maternal age at the expected date of delivery was 34.0 years (IQR 30.0 to 37.4) for women who screened positive for HBV, an increase compared to 2021-22 (median age 30.9).

• Only 5.5% (106/1921) of pregnancies were to women under 25 years (6 of these were aged under 20), and 12.4% (238/1921) were to women aged equal to or over 40 years (Table 6), an increase compared to 2021-22 where 10% of women were over 40.
• Compared to the general population, pregnancies in women with HBV are more common among women over 30 years (Table 6).

Of 1895 pregnancies with available information, 59 (3.1%) were in vitro fertilisation (IVF) pregnancies, 41 of which were to women over the age of 35.

Table 6: maternal age at expected date of delivery among screen-positive pregnancies

Age group	Number of screen-positive pregnancies	Percentage  (%)	General pregnant population (%)
Less than 20 years	6	0.3	3.3
20 to 24 years	100	5.2	13.3
25 to 29 years	375	19.5	27.7
30 to 34 years	612	31.9	33.9
35 to 39 years	589	30.7	17.9
Equal to or more than 40 years	239	12.4	4.0
All screen positive pregnancies	1921	100.0	NA

Figure 4. maternal age at expected date of delivery among screen-positive pregnancies compared with the general population

9. Parity

Of 19081 screen-positive pregnancies, 67.8% (1295) had a previous birth, with 35.8% reporting two or more prior births (Table 7).

Table 7: parity among screen-positive pregnancies

Parity	Number of pregnancies	Percentage (%)
0	613	32.1
1	612	32.1
Equal to or more than 2	683	35.8
Total screen positive pregnancies1	1908	100.0

1. Data not available for 13 pregnancies.

10. Ethnicity and world region of birth

About 3 in 4 (73.1%, 1393/1906) screen positive pregnancies were in women of non-white ethnic backgrounds (Table 8).

Most pregnancies (96.1%, 1811/1884) were to women born outside the UK, with over a third of these (37.2%) born in Africa, 20.3% in Eastern Europe, and 29.8% in Asia (Table 9).

Of women born outside the UK, 130 (11.4%) arrived in the UK whilst pregnant, and 153 (13.5%) arrived in the year prior to pregnancy (Table 10). Among 130 women arriving in the UK during pregnancy, 66 (50.8%) booked after 20 weeks gestation, and 4 (3.1%) were unbooked in labour.

• Of these 130 women, 58 were newly diagnosed with HBV in this pregnancy.
• Higher infectivity markers were found among 5.2% (3/58) and 7.0% (5/71) of newly and previously diagnosed women, respectively.
• Treatment was reported in pregnancy for 4.2% (5/120) of women with available data.

Table 8: maternal ethnic origin among screen-positive pregnancies

	All pregnancies	Lower infectivity	Higher infectivity
Ethnicity	Number of pregnancies	Percentage (%)	Number of pregnancies	Percentage (%)	Number of pregnancies	Percentage (%)
Black African	674	35.4	632	35.8	34
Any other white background	494	25.9	471	26.7	22	16.7
Chinese	123	6.5	104	5.9	18	13.6
Asian (excluding Chinese)	408	21.4	367	20.8	40	30.3
Other	116	6.1	109	6.2	7	5.3
Mixed	42	2.2	35	2.0	7	5.3
Any other Black background	30	1.6	30	1.7	0	0
White British	19	1.0	15	0.9	4	3.0
All screen positive pregnancies1	1906	100.0	1763	100.0	132	100.0

1. Data not available for 15 pregnancies.

Table 9: maternal world region of birth among screen-positive pregnancies

	All pregnancies	Lower infectivity	Higher infectivity
World region of birth	Number of pregnancies	Percentage (%)	Number of pregnancies	Percentage (%)	Number of pregnancies	Percentage (%)
Africa	701	37.2	657	37.8	36	26.9
China	104	5.5	88	5.1	16	11.9
Rest of Asia	458	24.3	408	23.5	47	35.1
Eastern Europe	382	20.3	363	20.9	19	14.2
UK	73	3.9	65	3.7	8	6.0
Rest of Europe	152	8.1	145	8.3	7	5.2
Other	14	0.7	13	0.7	1	0.7
All screen positive pregnancies1	1884	100.0	1739	100.0	134	100.0

1. Data not available for 37 pregnancies.

Table 10: timing of UK arrival among screen-positive pregnancies in women born outside of the UK

Timing of UK arrival	Number of pregnancies	Percentage (%)
During pregnancy	130	11.4
Equal to or less than 1 year before conception	153	13.5
1 to 5 years before conception	331	29.1
6 to 10 years before conception	205	18.0
Greater than 10 years before conception	318	28.0
All screen positive pregnancies to women born abroad1	1137	100.0

1. Data not available for 675 pregnancies.

11. Body Mass Index (BMI) at booking

Among 1266 pregnancies booked at or prior to 12 weeks of gestational age, 42.8% were at a healthy weight (BMI 18.5-24.9) and 51.7% were overweight or obese (Table 11).

Table 11: maternal BMI at booking among screen-positive pregnancies

Maternal BMI at booking	Number of pregnancies	Percentage (%)
Underweight (Less than 18.5 kg/m2)	40	3.2
Healthy weight (18.5 to 24.9 kg/m2)	542	42.8
Overweight (25 to 29.9 kg/m2)	363	28.7
Obese (30 to 39.9 kg/m2)	291	23.0
Severely obese (Equal to or less than 40 kg/m2)	30	2.4
All screen positive pregnancies booking by 12 weeks of gestational age1	1266	100.0

1. Data not available for 10 pregnancies.

12. Social circumstances

Complex social factors were reported for 20.0% of women who screened positive (363 of 1817 where data was reported) with 123 women reported to have multiple factors. Reporting of complex social factors among pregnant women in the general population was lower at 13.2%.  Most reported were housing and immigration (23 women) and housing and financial concerns (17 women)) (Table 12a/12b).

• Housing concerns were reported in 4.8% of pregnancies and 4.6% had immigration problems.
• Other commonly reported complex social factors included social services involvement (4.5%) and mental health issues (4.1%).
• “Other” factors reported included 24 reports of female genital mutilation (FGM) and 2 reports of people trafficking.

Many of these issues are likely to be underreported and only represent those known to healthcare professionals and/or disclosed by women during pregnancy.

• Among 363 women reported to have at least one complex social factor; a higher proportion were newly diagnosed with HBV (27.0% compared to 20.4% of 1454 women without any social complicating factors),
• a higher proportion classified as higher infectivity status (9.7% compared to 6.4%).
• a higher proportion of women with at least one complex social factor social booked later than 20 weeks (18.3%) compared to women without any complex social factors (9.2%).

There was not a substantial difference in the proportion of infants born to women with complex social factors who received a timely birth dose of HBV vaccine (97.2% compared to 98.4%).

Table 12: Complex social factors breakdown among screen-positive pregnancies

Issue	Number of pregnancies	Percentage (%)
Housing concerns	87	4.8
Intimate partner violence	26	1.4
Drug or alcohol misuse	8	0.4
Mental health issues	74	4.1
Immigration problems	84	4.6
Prison	1	0.1
Sex work	4	0.2
Social services involvement	82	4.5
Learning difficulties	7	0.4
Issues engaging with healthcare services	28	1.5
Financial concerns	28	1.5
Other	42	2.3

12.1 Support in pregnancy

For most women, their main support in pregnancy was a cohabiting partner (87.1%, 1598 of 1835 with available data) (Table 13).

Table 13: main support in pregnancy among screen-positive pregnancies

Main support	Number of pregnancies	Percentage (%)
Partner (cohabiting)	1597	87.1
Partner (not cohabiting)	112	6.1
Family or friend	73	4.0
Other	6	0.3
None	46	2.5
All screen positive pregnancies1	1834	100.0

1. Data not available for 87 pregnancies.

12.2 Employment status

More than half of women were reported as being employed (full or part-time) (54.8%, 1002 of 1830 with available data) (Table 14).

Of women who reported a partner in pregnancy, 90.1% (1434 of 1586) of partners were employed and 6.6% unemployed.

Table 14: woman’s employment status in pregnancy among screen-positive pregnancies

Employment status	Number of pregnancies	Percentage (%)
Employed (full or part-time)	1002	54.8
Home	465	25.4
Student	77	4.2
Sick	1	0.1
Unemployed	285	15.6
All screen positive pregnancies1	1830	100.0

1. Data not available for 91 pregnancies

12.3 Spotlight on migrants recently arriving in the UK

In order to look at trends in HBV among migrants recently arriving in the UK, we combined data from women booking into antenatal care between 1 April 2021 and 31 March 2023 (since hepatitis B surveillance started).

Of 2514 screen-positive women booking into antenatal care between 1 April 2021 and 31 March 2023 with available data on country of birth and, if relevant, timing of arrival in the UK, 22.0% (554/1960) were migrants arriving in the UK during pregnancy or within one year prior to conception (hereafter referred to as ‘recent migrants’). Infectivity status did not significantly differ between recent migrants and other pregnancies, with 10.7% (59/554) of recent migrants having higher infectivity markers, compared to 7.2% (140/1959) among other pregnancies. However, there was a higher proportion of new diagnoses among recent migrants (46.0%, 255/554) compared with other pregnancies (15.3%, 299/1960).

In terms of timing of antenatal booking, recent migrants tended to book later in pregnancy, with 31.4% (174/554) booking later than 20 weeks gestation, and 2.0% (11/554) arriving unbooked in labour, compared with 6.1% (120/1960) and 0% (0/1960), respectively, among the remaining pregnancies to women with HBV. A higher proportion of recent migrants were born in Africa (52.2%, 288/552), compared with other pregnancies (35.3%, 689/1954); however, a lower proportion of recent migrants were born in Eastern Europe (11.2%, 62/552), compared with other pregnancies (20.5%, 400/1954). Recent migrants were also more likely to experience complex social factors (reported among 28.3% of recent migrants, 143/505) compared with other pregnancies (19.3%, 331/1717). Recent migrants were also more likely to require translation services (41.0%, 227/554) and not be registered with a GP (1.6%, 9/554), compared with other pregnancies (20.3%, 400/1966; 0.1%, 2/1966).

13. Language

English was spoken by 79.8% of screen positive women (1533 of 1920). Of those who spoke English, this was a first language for 28.0% of women (426 of 1523 with available data).

• Translation services during maternity care were required for 23.8% of women (455 of 1914 with available data). Of these 455, data on which language was required was available for 136 women. The most required languages were Romanian (26), Albanian (14), and Vietnamese (10).
• For those who required translation services, 95.1% (418 of 439 with data reported) received this through formal interpretation services either by phone or in-person.
• There were 21 women who did not receive formal translation services despite it being documented that it was required. The main reasons given for this included declining formal interpretation services and opting for a friend of family member to interpret for them.

ISOSS now collects language spoken or language required from interpretation services, and this will be included in future reports.

14. Registered with a GP

Where women are not registered with a GP in pregnancy, the maternity unit is unable to notify primary care of the delivery and initial birth immunisation, which creates a risk that the infant may be unable to complete the hepatitis B vaccine schedule as required. This would put the child at increased risk of HBV infection and missing testing at 12 months of age for infection status. Women were registered with a GP in 99.4% of pregnancies (1909 of 1921) by delivery.

15. Screen positive pathway

Giving results

In 92.7% (1727 of 1863 with data reported) of pregnancies, women were seen by the screening team within 10 working days of their screen positive result being returned to maternity services; for 34 women (1.8%) the interval was more than 20 working days (Table 15/Figure 4).

Where women (n=136) were not seen within the 10 working days standard (NHS IDPS-S05), the most common reasons given included:

• Not attending/unable to contact (51)
• Clinic capacity/no available appointments (19)
• Declined (19)
• Woman abroad (16)

In April 2023 the 10 working day window for women to be seen by the screening team was reviewed as part of the IDPS major standards review and a decision made to reduce the timeframe to 5 working days.  ISOSS have been monitoring Standards directly for the IDPS programme since then so reporting will be comprehensive in future reports.

All women receiving a screen positive result should be referred to specialist services by the maternity screening team, regardless of pregnancy outcome. A referral to specialist HBV services was completed for 95.3% (1823 of 1913 with available data) of women (Table 16). For the 90 women where a referral was not made, the most common reasons (as reported by clinician) were:

• Known HBV patient, already under specialist team care (49)
• Miscarriage (23). IDPS programme Guidance has since been strengthened to ensure those who miscarry are still referred to specialist HBV services.

Table 15: days to screening team appointment from date of screen positive result among screen-positive pregnancies

Time to being seen	Number of pregnancies	Percentage (%)
0 to 10 working days	1727	92.7
11 to 20 working days	102	5.5
greater than 20 working days	34	1.8
Not seen	0	0.0
All screen positive pregnancies1	1863	100.0

1. Data not available for 58 pregnancies.

Figure 5: Percentage of screen positive pregnancies seen within 10 working days from date of screen positive result

Table 16: referral to specialist HBV services among screen-positive pregnancies

Referred to specialist services	Number of pregnancies	Percentage (%)
No	90	4.7
Yes	1823	95.3
All screen positive pregnancies1	1913	100.0

1. Data not available for 8 pregnancies.

16. UKHSA antenatal surveillance

The UKHSA introduced a comprehensive programme of enhanced surveillance of HBV screen positive women and their babies in April 2021, to evaluate the impact of the selective neonatal immunisation programme on transmission of HBV to babies born to women with HBV in pregnancy. The collection of these samples for the surveillance programme is undertaken collaboratively between UKHSA and the antenatal screening teams.  An initial blood sample is requested and sent to the Virus Reference Department from all consenting women who screen positive for HBV, with additional blood samples at delivery from women and babies considered at higher infectivity risk according to Green Book Criteria.

Antenatal surveillance samples were sent by maternity providers for 90.2% (1721 of 1909 where data was reported) of pregnancies. Where surveillance samples were not sent, the most common reasons include:

• Miscarriage/termination of pregnancy (73)
• Declined (35)
• Clinic capacity/pathway not yet offered at clinic (18)
• Late booking (17)

The aim of the UKHSA surveillance is to:

• confirm the infectivity risk
• determine if the woman’s HBV infection is a mutant strain which might evade the vaccine (vaccine escape strain) and therefore potentially affect the management of this and future pregnancies
• monitor factors associated with HBV infection in babies born to women who screen positive
• quantify the contribution of vaccine failure vs in utero transmission in HBV infections in these infants
• inform future interventions such as earlier antiviral therapy to prevent in utero transmission during pregnancy

17. Review in third trimester

The management of HBV in pregnancy is complex and involves input from a number of specialties across both secondary services during pregnancy and primary care to deliver the selective neonatal immunisation pathway. This requires a multidisciplinary approach to care and clear communication.  A third trimester review for all women was introduced as part of the new clinical care pathway as an opportunity to support the pathway by reinforcing earlier information and advice given to parents about the input their baby will require following birth. This aims to improve engagement with the vaccination programme post delivery (Guidance on the hepatitis B antenatal screening and selective neonatal immunisation pathway - GOV.UK).. The appointment should facilitate a review of the woman’s care and utilised resources to discuss:

• Prompt registration of baby with GP
• Prompt registration of the baby’s birth
• The importance of the baby completing the vaccination programme

A third trimester review was arranged with the maternity screening team for 83.7% (1598 of 1910 with available data) of pregnancies. Women attended a third trimester review in 91.2% (1344 of 1473 with available data) of pregnancies among those who arranged a review. For those who did not attend a review appointment, this was often due to a preterm delivery, to having already been seen by a specialist team, or to late booking.

18. Specialist HBV services

19. Timeliness of assessment

Where a woman receives her first diagnosis of HBV in pregnancy, or a woman with a previous diagnosis is found to have higher infectivity markers during pregnancy, they should be referred to and seen by specialist services within 6 weeks of the positive result being reported to the maternity service, in line with the higher infectivity pathway. Of the women with a new diagnosis referred to specialist services who therefore required review within 6 weeks, 74.0% (307 of 415) were seen within that timeframe (Table 17). Among women with higher infectivity markers who required review within 6 weeks (including some who were new diagnoses), 77.9% (106 of 135) were seen within that timeframe. Reasons for not meeting the referral standard and being seen over 6 weeks included:

• Clinic capacity/delayed appointment (28)
• Patient did not attend/unable to contact (25)
• Late diagnosis/booking (7)
• Transfer of care (7)
• Changed to higher infectivity later in pregnancy (2)

Table 17: time to be seen by specialist HBV services (pregnancies in women newly diagnosed and higher infectivity markers) among pregnancies

Timeframe	Higher infectivity markers	Percentage (%)	Newly diagnosed	Percentage (%)
Over 6 weeks	108	26.0	29	21.5
Equal to or less than 6 weeks	307	74.0	106	78.5
Pregnancies requiring review within 6 weeks	415	100.0	135	100.0

Women with a prior diagnosis and lower infectivity markers required review within 18 weeks, in line with the lower infectivity pathway. 90.8% (1247 of 1373 with available data) were seen within that timeframe (Table 18). 3 were not seen at all by specialist services in that pregnancy. Reasons for not being seen within 18 weeks included:

• Did not attend/unable to contact (30)
• Late booking (11)
• No clinic capacity (8)
• Known HBV patients and already under specialist team care (8)

Table 18: time to be seen by specialist HBV services (pregnancies in women previously diagnosed with lower infectivity markers) among pregnancies

Timeframe	Number of pregnancies	Percentage (%)
Over 18 weeks	126	9.2
Equal to or less than 18 weeks	1247	90.8
Lower infectivity pregnancies requiring review within 18 weeks	1368	100.0

20. Viral load testing and treatment during pregnancy

A viral load of equal to or above 200,000 IU/mL is the threshold recommend by the national British Viral Hepatitis Groups (BVHG) to commence maternal HBV treatment during pregnancy. A viral load above this threshold was reported in 55 pregnancies (3.0%) and 42 (80.8%) of these women are known to have been given treatment during pregnancy (Table 19). Viral load is typically measured when women attend a specialist HBV appointment (either within 6 weeks for higher infectivity, or within 18 weeks for lower infectivity).

Table 19: viral load in pregnancy for all screen positive pregnancies

HBV DNA viral load (IU/mL)	Number of pregnancies	Percentage (%)
Less than 200,000	1789	97.0
Between 200,000 and 1,000,000	39	2.1
More than 1,000,000	16	0.9
All screen positive pregnancies1	1844	100.0

1. Data not available for 77 pregnancies.

Women were reported to be already receiving treatment for their HBV infection at the point of conception in 95 pregnancies. Of women on treatment at conception, 40 (42.1%) were higher infectivity.

For women classed as having higher infectivity markers according to Green Book criteria during pregnancy, where a registerable birth was the pregnancy outcome, 77.8% (98 of 126) of women received treatment for HBV during the pregnancy (Table 20). For all pregnancies in women with HBV infection, regardless of pregnancy outcome, 10.2% of women received treatment during pregnancy (169 of 1664 with available data). Of 52 women with viral load greater than 200,000 IU/mL, 80.8% (42/52) received treatment during pregnancy. Of these 42, 9 (21.4%) were on treatment at conception, 2 (4.8%) started treatment at 10-12 weeks gestation, 2 (4.8%) started treatment at 13-19 weeks gestation, 22 (42.4%) started treatment at 20-29 weeks gestation, and 7 (16.7%) started treatment at 30-39 weeks gestation.

• Tenofovir disoproxil (TDF) was given in 96.4% (161/ 169) of treated pregnancies, with two of the remaining eight women on Entecavir, one on Tenofovir Alafenamide (TAF), one on Truvada (Tenofovir + FTC), and one on Eviplera (due to HIV coinfection).
• The remaining three women switched treatments in pregnancy: one conceived on Entecavir, one on TAF, and one on Telbivudine, with all three switching to TDF.

ISOSS data collection of treatment variables has been updated in 2024 and should be improved moving forward.

1 woman who was already on treatment at conception arrived in the UK during pregnancy. This woman started on and remained on TDF during pregnancy.

Among women born abroad who were classified as having higher infectivity markers, 79.7% (94 of 118) were on treatment in pregnancy, compared with 57.1% (4 of 7) of women born in the UK with higher infectivity markers. Of these women with higher infectivity markers who were born abroad, 8 (6.8%) arrived in the UK during pregnancy. Of these 8, 4 were on treatment in pregnancy, and 5 were diagnosed with HBV prior to arrival in the UK.

Table 20: treatment received in pregnancy among pregnancies

	For screen positive pregnancies resulting in a registerable birth	All screen positive pregnancies (including miscarriages, TOPs and lost to follow-up)
	Higher infectivity markers	Percentage (%)	Lower infectivity markers	Percentage (%)	All pregnancies	Percentage (%)
No treatment received	28	22.2	1461	95.7%	1495	89.8
Treatment received	98	77.8	65	4.3%	169	10.2
Number of screen positive pregnancies1	126	100.0	1526	100.0%	1664	100.0

1. Data not available for 257 pregnancies.

21. Viral load re-testing during pregnancy

Among 1529 pregnancies in women with lower infectivity markers that resulted in stillbirths or livebirths (with available data), viral loads were retested at some point during the pregnancy in 75.4% (1153/1529) pregnancies. Common reasons for not being retested included:

• not clinically indicated,
• late booking/arriving in labour unbooked
• having lower infectivity markers

Of the women retested, 8 who were originally classified as lower infectivity moved to higher infectivity status later in pregnancy.

 Of these eight women:

• All were born abroad (from different countries of birth).
• Data on time since arrival in the UK was available for four women, all of whom arrived in the UK more than one year prior to pregnancy.
• Two were under age 30 years, and the remaining six were 30 to 39 years old.
• All were diagnosed with HBV prior to this pregnancy.
• Viral load at booking (between 8-18 weeks) ranged from 14 to 56,000 and at

• Viral load at retest (retesting occurred at between 20-34 weeks), ranged between 3,400-18 million

• 5 were treated (all tenofovir)
• All 8 babies received HBIG

The true number of women who change infectivity status may be underrepresented due to varied timing of any viral load tests in the absence of any guidance on retesting currently.

22. Pregnancy outcome

Among 1921 pregnancies, 1658 resulted in livebirths (1695 infants) and 6 resulted in stillbirths (6 infants) (Figure 5/Table 21).

Figure 6: breakdown of pregnancy outcomes

*1658 livebirths resulting in 1695 liveborn infants

• Thought to have progressed to term

Table 21: pregnancy outcomes among screen positive pregnancies

Pregnancy outcome	Number of pregnancies	Percentage (%)
Livebirth	1658	86.3
Stillbirth	6	0.3
Miscarriage	138	7.2
Termination	25	1.3
Left England before delivery	43	2.2
Lost to follow up before delivery	9	0.5
Outcome report pending, thought to have continued to term	42	2.2
All screen positive pregnancies	1921	100.0

23. Registerable birth outcomes

Among the 1922 pregnancies in women with HBV, 1664 resulted in registerable births of 1695 (86.3%) liveborn babies and six stillborn babies (Table 22). Just over half (53.0%) of women had a vaginal delivery.

Table 22: mode of delivery per pregnancy (live births and stillbirths) among pregnancies progressing to registerable birth

Mode of delivery	Number of pregnancies	Percentage (%)	General population (%)
Vaginal	882	53.0	61.9%
Elective caesarean	376	22.6	16.6%
Emergency caesarean	406	24.4	21.5%
Numbers of pregnancies progressing to registerable birth	1664	100.0	NA

Among those not delivering via elective caesarean, rupture of membranes occurred at delivery or within an hour of delivery for just over half of women (66.0%, 831 of 1260 with available data) (Table 23). An invasive procedure was performed in 18.4% of pregnancies (excluding elective caesarean deliveries), with most of these being artificial rupture of membranes (221 of 225) (table 24).

Table 23: duration of membrane rupture (live births and stillbirths) among pregnancies progressing to registerable birth and membrane rupture

Duration membranes ruptured	Number of pregnancies	Percentage (%)
Less than 1 hr	125	15.3
1to 4 hrs	159	19.5
4 to 12 hrs	261	32.0
12 to 24 hrs	170	20.9
24 to 48 hrs	78	9.6
Over 48 hrs	22	2.7
Number of pregnancies with a registerable birth and membrane rupture (excluding elective caesarean deliveries) 1	815	100.0

1. Data not available for 16 pregnancies.

Table 24: invasive procedure in labour among pregnancies progressing to registerable birth

Invasive procedure	Number of pregnancies	Percentage (%)
Fetal scalp electrode	1	0.1
Artificial rupture of membranes (ARM)	221	18.1
Both ARM and scalp electrode	3	0.2
No invasive procedure	998	81.6
Number of pregnancies progressing to registerable birth (excluding elective caesarean deliveries)1	1223	100.0

1. Data not available for 65 pregnancies.

Women delivered at term in most pregnancies (90.6%) (Table 25/Table 26). 9.4% of women delivered prior to 37+0 weeks gestation, which was a slightly higher proportion than women in the general population (7.9%). Of 160 babies born preterm,

• 84 were born between 35+0 and 36+6 weeks gestation
• 42 were born between 32+0 and 34+6 weeks gestation
• 34 were born at less than 32 weeks gestation

Table 25: gestation at delivery (live births and stillbirths) among registrable births resulting from pregnancies

Gestation	Number of births	Percentage (%)	General population (%)
Equal to or more than 37 weeks	1535	90.6	92.1%
Less than 37 weeks	160	9.4	7.9%
Number of registerable births1	1695	100.0	NA

1. Data not available for 6 infants.

Table 26: birthweight at delivery (live births and stillbirths) among registrable births resulting from pregnancies

Birthweight	Number of births	Percentage (%)
2.5kg or more	1524	89.8
1.5 to 2.5kg	140	8.2
Less than 1.5kg	33	1.9
Number of registerable births1	1697	100.0

1. Data not available for 4 infants.

24. Newborn outcome

The following analysis of newborn outcomes is presented among live births and stillbirths, except where noted. Of 1695 live-born infants, 129 (7.6%) were admitted to the neonatal unit.

• Commonly reported reasons for admission included prematurity (57), sepsis (13), and breathing difficulties (11).
• Congenital conditions were reported in 36 infants (2.1%) and of these, 3 had multiple conditions reported (Table 27).
• The most frequently reported conditions included ankyloglossia (6), Down’s syndrome (3), heart defects (3), and hypospadias (3).

There were 6 neonatal deaths; 4 infants died within 24 hours and 2 died between 1 week and 1 month of age.

• 2 of these deaths were attributable to prematurity, 3 were due to congenital conditions, and one was unexplained.
• A collaboration with Mothers and Babies Reducing Risk by Audits and Confidential Enquiries (MBRRACE-UK) will look further at stillbirths, neonatal deaths and maternal deaths in women with HBV in pregnancy.

Table 27: congenital conditions (live births and stillbirths) among registrable births resulting from pregnancies

Congenital conditions	Number of infants	Percentage (%)
None	1658	97.9%
One condition	33	1.9%
Multiple conditions	3	0.2%
Number of registerable births1	1694	100.0%

1. Data not available for 7 infants.

25. Vaccination and immunoglobulin administration

All infants born to women with HBV infection should receive HBV vaccination in line with the Green Book guidance, with the first dose given within 24 hours of birth. All infants born to women on the higher infectivity pathway or weighing equal to or less than 1.5kg at delivery should also receive hepatitis B immunoglobulin (HBIG) within 24 hours of birth.

The total number of pregnancies in women with HBV booking for antenatal care between 1 April 2022 and 31 March 2023 and resulting in a live birth was 1658, with 1694 infants born and exposed to HBV in utero and at delivery.

Among all infants, 136 were born to women with higher infectivity markers at delivery or in pregnancy and so were eligible to receive HBIG in addition to HBV vaccination within 24 hours of birth

Of 1694 live born infants who required HBV vaccination, 98.1% received this in line with Green Book guidance (Table 28). Of 32 infants who did not receive HBV vaccination within 24 hours, 21 received the vaccine late (median 26 hours, ranging from 25 hours to 14 days). Reasons for receiving vaccine late included:

• Given late in error (6)
• The vaccine being unavailable (2)
• Infant being unwell (1)
• Late identification of infection (4)
• Parental vaccine hesitancy (2)
• Woman presented unbooked in labour (2)
• Unknown reason (4).

Infants did not receive the vaccine at all in 11 cases, with reasons given:

• Parental decline (7)
• Neonatal death within 24 hours of birth (3)
• Staff error (1)

There were 8 women known to have changed infectivity status from lower to higher infectivity later in their pregnancy, and therefore their infants became eligible for HBIG. Of 136 infants born to women with higher infectivity markers before delivery and in pregnancy and therefore requiring HBIG in addition to vaccination, 133 received it within 24 hours of birth. For one infant, HBIG was given after 26 hours. For the 2 infants who did not receive HBIG as required, staff error was reported as the reason for one case, and the mother arriving unbooked in labour for the other case.

In addition to 136 infants born to women with higher infectivity markers at delivery or in pregnancy, an additional 30 infants were born weighing less than or equal to 1.5 kg and therefore required HBIG in line with Green Book guidance. Of these, 27 received timely HBIG. Of 2 babies who did not receive HBIG, 1 was a staff error, and 1 was a neonatal death.

An additional 19 infants born to women with lower infectivity markers were given HBIG in addition to vaccination. Reasons reported for this include:

• Clinical decision making based on HBV markers (9)
• Mother with higher infectivity markers at repeat viral load (2)
• Staff error (1)
• Delayed results (1)
• Woman considered high risk (1)
• Offered to both twins when one was low birthweight (1)
• Unknown (2)

Table 28: HBV vaccination and HBIG administration among live births resulting from pregnancies

Given within 24 hours of birth	HBV vaccine		HBIG (higher infectivity)
	Number of infants	Percentage (%)	Number of infants	Percentage (%)
Yes within 24 hours	1662	98.1%	133	97.8
No over 24 hours	21	1.2%	1	0.7
Did not receive	11	0.6%	2	1.5
Number of livebirths1	1694	100.00%	136	100.0

1. Data not available for 1 infant.

26. UKHSA neonatal surveillance

A second maternal venous surveillance sample should be taken from women classified as being higher infectivity, following delivery. A dried blood spot test should be taken from babies born and deemed high risk of infection before administration of the vaccine and HBIG. Instructions for labour and delivery staff and equipment for obtaining samples are provided by UKHSA in a box supplied with the pre-ordered HBIG.

Of the 142 babies born to women with higher infectivity markers noted at some point in pregnancy (including 8 cases where maternal infectivity status changed from lower to higher during pregnancy), 90.0% (117 of 130 with available data) had the dried blood spot taken, and surveillance boxes were returned to UKHSA in 91.9% of deliveries (124 of 135 with available data). Where samples were not taken and/or boxes not returned, the most common reasons were:

• Staff error (8 dried blood spot and 4 surveillance box)
• Arrived unbooked in labour (1 dried blood spot and 1 surveillance box)
• Declined (1 dried blood spot)
• Unknown (2 dried blood spot and 2 surveillance box)

27.  

28. Notification of birth and vaccination

The success of the combined screening and immunisation pathway is dependent on efficient and timely communication and handover of care from maternity service providers to practice nurses, GPs, child health information services (CHIS) and health visitor services in primary care.

From a programme delivery and outcomes perspective, the handover is critical in ensuring that the four-week dose of HBV vaccine is given on time to infants. The routine childhood immunisation schedule commences at 8 weeks of age. As the dose of HBV vaccine due at four weeks of age is not part of the routine childhood immunisation schedule, and a specific appointment with primary care will need to be made to ensure that the infant does not miss the dose, it is essential that the infant receives the birth and four-week doses at the recommended age to ensure optimal benefit. Any missed or delayed doses may impact on the effectiveness of the immunisation programme in preventing the infant from becoming infected with HBV.

The GP, health visitor, and CHIS were notified of the baby’s birth and vaccination in 99.8% (1654 of 1658), 98.5 (1632 of 1657 with available data), and 99.5% (1650 of 1658) of live deliveries, respectively. Where notifications were not sent, the most common reasons included:

• Certain hospitals routinely sending notifications to GP only, rather than CHIS and health visitors (8)
• Health visitor being unknown (6)
• Baby not yet registered with GP (1)

29. Infant outcome

30. UKHSA infant surveillance at 12 months of age

Monitoring the outcome for all HBV-exposed infants is a joint project between NHS England IDPS programme and the UKHSA. It ensures any infants found to have HBV infection are promptly referred to specialist care for ongoing management of their HBV. This surveillance also provides assurances on the success of the programmes

Outcomes for all exposed infants are sought, but due to the length of time required for completion of the selective HBV immunisation programme and confirmatory testing for HBV infection at 12 months of age, follow-up of infants born to women booking between 1 April 2022 and 31 March 2023 cannot yet be reported on.

The following data includes  infants born to women who booked for antenatal care between 1 April 2021 and 31 March 2022 (previously reported by ISOSS). Infants born to women who booked in 2022 to 2023 will be reported on in subsequent reports.

Of 1799 liveborn infants born to women who booked for antenatal care between 1 April 2021 and 31 March 2022, 1786 infants in the ISOSS dataset were also included in UKHSA data. Of these infants, hepatitis B surface antigen (HBsAg) outcomes from dried blood spots were available for 77% (1378/1786). All results with available data were negative for HBsAg. Data reported may differ slightly from UKHSA reports due to booking dates differing between the datasets.

There were some key sociodemographic differences between infants with and without HBsAg status confirmation. There was a higher proportion of missing HBsAg status among the following groups:

• Infants born to women identified as having issues engaging with care (40.0% (10/25) missing UKSHA data) (p=0.04)
• Infants born in hospitals in London (37.6% (240/639) missing UKHSA data) (p<0.001)

Availability of HBsAg follow-up status did not differ by maternal region of birth (p=0.09), infectivity status and timing of diagnosis (p=0.09), maternal age group (p=0.19), or whether the mother arrived in the UK within 1 year prior to conception (p=0.53).

HBsAg confirmation is recommended to occur at 12 months of age for infants born to HBV screen-positive mothers. Of 1352 infants with available data, 68.9% (931/1352) had a sample taken at 12 months of age, and 13.1% (177/1352) had a sample taken at 13 months of age.

Data on HBV vaccination in infants has been previously reported by UKHSA, showing an increasing trend over time for vaccine coverage at 12 months and 24 months, with around 90% coverage at 12 months in 2022-23. In future reports, linkage with UKHSA data will allow us to directly report on vaccination coverage among infants included in ISOSS dataset.

31. Next steps

Ongoing surveillance by ISOSS of hepatitis B management in pregnancy, at delivery and follow up of the infant, remains vital to ensure that clinical pathways are appropriate and the needs of these women and babies are being met. Surveillance also enables monitoring of key areas of interest such as health inequalities and any emerging trends in the population.

32. Vertical transmissions

NHS England (ISOSS) has been working in partnership with UKHSA to investigate reports of vertical transmission of HBV in infants born to women booked for maternity care in England from 1st April 2021 onwards. No vertical transmissions among infants tested at 12 months (i.e. born to women booked in from 1 April 2021 to 31 March 2022) have been identified.

Where a vertical transmission is identified, the ISOSS team will interview all the clinicians involved in the care of the woman and infant during and after pregnancy (following the same established process used for both congenital syphilis reports and children found to have vertically acquired HIV). Multiple clinicians are contacted for each review, starting with the reporting paediatrician, and expanded to include maternity, specialist clinical services, and others as required. Where care was provided by multiple units, the process is repeated for each unit to make sure as much information is collected as possible. This can include contacting medical advisors, primary care and safeguarding midwives where necessary.

In the future, anonymised case summaries will be produced and reviewed by the Clinical Expert Review Panel (CERP). The panel will consist of relevant clinical specialists, including maternity, laboratory, paediatrics, specialist care services, public health specialists and other clinical specialists.

The purpose of the panel is to:

• establish the circumstances surrounding the transmission
• identify any contributing factors and learning points
• feed recommendations into the NHS IDPS programme to inform national guidelines and policy

33. ISOSS processes

ISOSS previously known as the National Surveillance of HIV in Pregnancy and Childhood (NSHPC), has been running for over 30 years and holds data on over 30,000 pregnancies to date. The programme was established initially to provide maternity surveillance of all pregnancies in women living with HIV who are diagnosed by delivery. And paediatric surveillance which includes all infants born in England to diagnosed women living with HIV, along with any children diagnosed with HIV (less than 16 years of age) who are born in England or abroad seen for paediatric care in the England.

In January 2020 Surveillance of pregnancies to women with a screen positive result for syphilis was commenced.

Surveillance for pregnancies to women with HBV in pregnancy commenced in April 2021 alongside the implementation of the HBV antenatal screening and selective neonatal immunisation pathway.

34. Data validation

The ISOSS team conduct extensive matching of infant and maternal reports across pregnancies and paediatric reports. Reports include complex clinical data and there are several data quality checks in place. Validations are in place for incoming reports, and data is checked at each stage and queried directly with respondents where inconsistencies are identified, or data is missing.

35. Reporting timeline

Figure 6 shows the timeline of data collection by ISOSS during pregnancy and after the baby is born, pregnancies. There are six data collection points.

1. Green Card reporting (from approximately 12 weeks gestation): all HIV, syphilis and HBV screen positive pregnancies booked for antenatal care in the last quarter are reported to ISOSS. The green card can be edited throughout the quarter, but the submission happens at the end of a quarter.
2. Pregnancy notification form (from approximately 12 weeks gestation): initial details of pregnant woman, care in pregnancy and pregnancy status. This form is generated for each woman following the submission of the green card.
3. Pregnancy outcome form (birth): woman’s delivery details and initial care of the infant recorded and reported. This form is available around the expected date of delivery but can be released earlier on request in cases of premature birth.
4. Paediatric notification form (one to six months after birth): initial details and test results of infants seen for HIV (three to six months) and syphilis (one to two months) paediatric follow-up. Generated using maternity reports where possible. (Diagnosed children reported to ISOSS at any age when seen for paediatric care.)
5. Paediatric syphilis follow-up form (three to six months after birth): generated for all infants born to women treated for syphilis in pregnancy and/or infants requiring treatment for syphilis until discharged.
6. Paediatric HIV follow-up form: generated for all HIV-exposed infants requesting 22-to-24-month confirmatory antibody test to establish infection status.
7. Paediatric HBV follow up: data linkage with UKHSA’s Immunisation, Hepatitis and Blood Safety team at 12-13months after birth

36. Acknowledgements

NHS England would like to thank all those involved in collecting the data and producing the report, and most of all those from the NHS who deliver the NHS IDPS programme. We would like to acknowledge the important contributions made by our colleagues at UKHSA (Virus Reference Department (VRD); Blood safety, hepatitis, STIs, and HIV (BSHSH); Immunisation and vaccine preventable diseases (Imms and VPD) divisions), members of our Clinical Expert Review Panels and NHS providers in relation to surveillance of women with HBV in pregnancy and their infants.