Guidance

ISOSS Hepatitis B report 2023

Published 19 October 2023

Applies to England

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 to women with human immunodeficiency virus (HIV), hepatitis B virus (HBV) and syphilis, their babies and other children diagnosed with HIV, vertically acquired HBV and congenital syphilis in England.

This report focuses on pregnancies to women who screened positive for HBV and booked for antenatal care in England from 1 April 2021 to 31 March 2022. All screen positive pregnancies reported to ISOSS with data submitted by the end of December 2022 are included; this includes all pregnancies to women screening positive for HBV at any point during pregnancy or those with a known chronic HBV diagnosis.  

IDPS programme standards summary statistics

Screening standards data are submitted by maternity providers to the IDPS programme. This data is collected separately from ISOSS surveillance. The most recently published data is for screening year 2020 to 2021 (1 April 2020 to 31 March 2021).  

In screening year 2020 to 2021 in England:

• approximately 650,000 pregnant women entered the antenatal screening pathway
• individual infection coverage for antenatal HIV, HBV and syphilis screening was 99.8%
• 0.69 eligible pregnant women per 1,000 tested received a new HBV diagnosis

Table 1: trends in screen positive rates for HBV in pregnant women, England, screening year 2017 to 2018 to screening year 2020 to 2021

	2018 to 2019	2019 to 2020	2020 to 2021	2021 to 2022
Returns included/expected	144/146	140/143	139/142	142/142
Screen positive women: rate per 1,000 women tested	3.89	3.77	3.38	3.39
Newly diagnosed women: rate per 1,000 women tested	0.89	0.86	0.70	0.69

Table 1 note 1: known false positive results are not included in the number of screen positives.

Table 1 note 2: the rate for total screen positive women is based on a count that has been rounded to the nearest multiple of 5 for data for 2018 to 2019, 2019 to 2020 and 2020 to 2021, to prevent disclosure by comparison with other published data.

HBV reporting

Data is reported to ISOSS by 154 different maternity providers, some of which are part of bigger NHS providers that report their screening standards data in a combined format published in IDPS programme screening annual standards reports.

In 2021 to 2022, 100% of maternity providers in England submitted their initial reports for women with screen positive results for HBV via the quarterly green card reporting system on the ISOSS portal (616 of 616 green cards completed). Antenatal notification forms were subsequently returned for 99.5% of screen positive pregnancies, and pregnancy outcomes forms were submitted for 98.8% of pregnancies.

HBV overview

There were 1988 pregnancies to women with HBV with a booking date between 1 April 2021 and 31 March 2022 in England reported to ISOSS. Of these, 79.8% (1585 out of 1988) of women were known to have HBV infection before pregnancy. The remaining 402 women were diagnosed via screening in their current pregnancy.

London had the highest number of pregnancies in women with a screen positive result for HBV, and the lowest number of pregnancies with a screen positive result were reported from the South West of England.

Booking for antenatal care by 10 weeks gestation happened for 43.3% of pregnancies, compared to 65.0% in the general population. Women who booked for antenatal care after 20 weeks gestation accounted for 10.3% of pregnancies, compared to 5.9% in the general population. There were 13 women (0.7%) who screened positive for HBV who presented to maternity services in labour having received no antenatal care in the UK. Women transferred their care to another maternity provider during pregnancy or for birth in 82 (4.1%) pregnancies.

Women were newly diagnosed with HBV in 20.3% of pregnancies (402 out of 1988), and 41 women were reported as having acute HBV in pregnancy, as determined by clinicians. Acute hepatitis B is a short-term illness that occurs within the first six months after someone is exposed to HBV. Future data sharing with the UK Health Security Agency (UKHSA) will be able to confirm rates of acute HBV in pregnancy as the reported rate here is higher than expected.  There were no reports of women becoming infected with HBV during pregnancy after an initial negative screen result. 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 IDPS standards 6 and 8.  

For women with a prior diagnosis of HBV, 93.5% had lower infectivity markers in the current pregnancy, and 6.5% were found to have higher infectivity markers. For women with a new diagnosis of HBV in this pregnancy, 89.8% were found to have lower infectivity markers and 10.2% were found to have higher infectivity markers.

Table 2: screen positive breakdown

	Number of pregnancies	Percentage (%)
Previous diagnosis (lower infectivity markers)	1482	74.6
Previous diagnosis (higher infectivity markers)	103	5.2
New diagnosis (lower infectivity markers)	361	18.2
New diagnosis (higher infectivity markers)	41	2.1
Total screen positive pregnancies	1987	100

Table 2 note 1: data not reported for 1 pregnancy

Table 2 note 2: due to rounding, percentage total does not equal 100%

Table 3: number of screen positive pregnancies by region of booking

Region	Number of pregnancies	Percentage (%)
London	735	37.0
Midlands	355	17.9
East of England	176	8.9
North East and Yorkshire	198	10.0
North West	203	10.2
South East	232	11.7
South West	89	4.5
Total screen positive pregnancies	1988	100

Table 3 note 1: due to rounding, percentage total does not equal 100%

Table 4: gestation at booking for all screen positive pregnancies

Gestation	Number of  pregnancies	Percentage (%)	General population (%) (NHS Digital maternity statistics 2021 to 2022)
Less than 10+0 weeks	861	43.3	70.7
10+0 to 12+6 weeks	592	29.8	25.5
13+0 to 19+6 weeks	318	16.0	6.7
Equal to or more than 20 weeks	204	10.3	3.3
Unbooked in labour	13	0.7	Data unavailable
All screen positive pregnanices	1988	100	NA

Table 4 note 1: due to rounding, percentage total does not equal 100%

Table 5: parity

Parity	Number of pregnancies	Percentage (%)
0	495	26.2
1	676	35.7
Equal to or more than 2	720	38.1
Total screen positive pregnancies	1891	100

Table 5 note 1: data not reported for 97 pregnancies

Co-infections

Overall, 3.1% of the women (n=45) had 1 co-infection and 1 woman was reported as having two co-infections. In total, 0.9% of women had syphilis co-infection and 0.8% were co-infected with HIV.

Table 6: co-infections in pregnancy

Infection	Number of pregnancies	Percentage of all pregnancies (%)
No coinfection	1949	98.0
HIV	16	0.8
Syphilis	17	0.9
Hepatitis C	6	0.3
All screen positive pregnancies	1988	100

Demographics

Age at delivery

The median age at the expected date of delivery was 30.9 years (IQR 29.8 to 37.0) for women who screened positive for HBV. Only 6.7% of pregnancies were to women under 25 years, and nearly 10% to women over 40. Pregnancies to women with hepatitis B are more common in women over the age of 30 when compared to the general population.  

Table 7: maternal age at expected date of delivery

Age group	Number of pregnancies	Percentage of pregnancies (%)	Percentage of pregnancies general   population (2021 - 2022 data from NHS digital)
Less than 20 years	14	0.7	2.3
20 to 24 years	120	6.0	11.9
25 to 29 years	393	19.8	25.5
30 to 34 years	689	34.7	33.1
35 to 39 years	586	29.5	18.7
Equal to or more than 40 years	186	9.4	4.4
All screen positive pregnancies	1988	100	NA

Table 7 note 1: Due to rounding, percentage total does not equal 100%

Ethnicity and world region of birth

Almost three quarters (71.1%) of pregnancies were in women of minority ethnic backgrounds. Over 95% of women were born outside of the UK, with just over a third of women born in Africa, a quarter born in Asia and just under a quarter born in Eastern Europe. Of the women born outside the UK, 106 (8.7%) arrived during pregnancy and a further 165 (13.6%) arrived in the year before conception.

Table 8: ethnic origin

Ethnicity	Number of pregnancies	Percentage of pregnancies (%)
Asian	365	18.5
Black African	705	35.6
Any other Black background	44	2.2
Mixed	49	2.5
White British	19	1.0
Any other white background	541	27.4
Other	255	12.9
All screen positive pregnancies	1978	100

Table 8 note 1: data not reported for 10 pregnancies

Table 8 note 2: due to rounding, percentage total does not equal 100%

Table 9: maternal world region of birth

World region of birth	Number of pregnancies	Percentage of pregnancies (%)
Africa	722	37.5
Asia	497	25.8
Eastern Europe	459	23.8
UK	90	4.7
Rest of Europe	142	7.4
Other	17	0.9
All screen positive pregnancies	1927	100

Table 9 note 1: data not reported for 61 pregnancies

Table 9 note 2: Due to rounding, percentage total does not equal 100%

Table 10: timing of UK arrival

Timing of UK arrival	Number of pregnancies	Percentage of pregnancies (%)
Greater than 10 years before conception	345	28.4
6 to 10 years before conception	207	17.0
1 to 5 years before conception	392	32.3
Equal to or less than 1 year before conception	165	13.6
During pregnancy	106	8.7
All  screen positive pregnancies	1215	100

Table 10 note 1: data not reported for 773 pregnancies

Table 10 note 2: due to rounding, percentage total does not equal 100%

Social circumstances

Socially complicating issues were reported for 18.1% of women who screened positive (320 of 1959 where data was reported) with 100 women reported to have multiple issues. Housing concerns issues were reported in 5.2% of pregnancies and 4.1% had immigration problems. Included in the ‘Other’ category were 21 reports of female genital mutilation (FGM) and seven reports of people trafficking.

Table 11a: socially complicating issues

Issue	Number of pregnancies	Percentage of pregnancies (%)
None	1440	81.9
At least one social issue	320	18.1
All screen positive pregnancies	1760	100

Table 11a note 1: data not reported for 228 pregnancies

Table 11b: socially complicating issues   breakdown

Issue	Number of pregnancies	Percentage of pregnancies (%)
Housing concerns	92	5.2
Intimate partner violence	28	1.6
Drug or alcohol misuse	9	0.5
Mental health issues	65	3.7
Immigration problems	72	4.1
Prison	2	0.1
Sex work	5	0.3
Social services involvement	67	3.8
Learning difficulties	2	0.1
Issues engaging with healthcare services	23	1.3
Financial concerns	9	0.5
Other	111	6.4

Table 11b note 1: more than one issue reported for some pregnancies

Support in pregnancy

For the majority of women, their main support during pregnancy was a cohabiting partner (88.5%, 1671 of 1888 women where data was reported); 4.8% of women’s main support was a family member or a friend and 4.6% of women’s main support was a non-cohabiting partner.

Table 12: main support in pregnancy

Main support	Number of pregnancies	Percentage of pregnancies (%)
Partner (cohabiting)	1671	88.5
Partner (not cohabiting)	86	4.6
Family or friend	90	4.8
Other	4	0.2
None	37	2.0
All screen positive pregnancies	1888	100

Table 12 note 1: data not reported for 100 pregnancies

Table 12 note 2: due to rounding, percentage total does not equal 100%

Employment status

Over half of women were reported as being employed (53.5%, 1012 of 1890 where data was reported). Over a quarter of women were reported as homemakers and 16.0% were reported as being unemployed. Women were reported to be students in 3.0% of pregnancies.

For women who reported they had a partner during pregnancy, 90.0% of the partners were employed (1478 of 1639 women where data was reported) and 6.0% unemployed.

Table 13: women’s employment status in pregnancy

Employment status	Number of pregnancies	Percentage of pregnancies (%)
Employed (full or part-time)	1012	53.5
Home	518	27.4
Student	57	3.0
Sick	1	0.1
Unemployed	302	16.0
All screen positive pregnancies	1890	100

Table 13 note 1: data not reported for 98 pregnancies

Language

English was spoken by 77.7% of women (1545 of 1988). Of those who spoke English, this was the first language for only 26.6% of women (410 of 1539 where data reported).

Translation services during maternity care were required for 25.9% of women (515 of 1985 where data was reported). For those who required translation services, 95.8% (480 of 501 where data was reported) received this through formal interpretation services. There were 14 women who did not receive formal translation services despite it being documented that it was required. The main reason reported for this was declining formal interpretation services and opting for a friend or family member to interpret for them. ISOSS does not currently capture language spoken or language required from interpreting services.

Registered with a GP

Not having a registered GP means that the maternity unit cannot notify primary care of the  delivery and initial birth immunisation and creates a risk that the infant might not complete the hepatitis B vaccine schedule as required. This would put the child at risk of HBV infection and missing testing at 12 to 13 months of age for infection status. Women were registered with a GP in 98.9% of pregnancies by the point of delivery.

Screen positive pathway

Giving results

In 92.0% (1795 of 1952 where data was reported) of pregnancies, women were seen by the screening team within 10 working days to discuss their screen positive result. For 39 women (2.0%), this was more than 20 working days after their screen positive result was returned to maternity services.

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

• 24 women where there was no service capacity (availability of staff and clinic appointments)
• 17 women who were not contactable
• 15 women who declined the appointment
• 14 women who were abroad when the result was received

For some women, there was more than one reason why the appointment was delayed.

All women receiving a screen positive result should be referred on to specialist services by the maternity screening team, regardless of pregnancy outcome. A referral to specialist HBV services was completed for 95.1% (1887 of 1985 where data was reported) of women. Where a referral was not made, reasons included:

• 58 women were already under the care of specialist HBV services (unclear if an appointment during pregnancy was already arranged in these cases, or if specialist services were aware that the woman was pregnant)
• 32 women miscarried or underwent a termination of pregnancy (TOP) before referral
• 3 women left the country before referral or before the referral could be actioned
• 2 women booked late for antenatal care and delivered before referral or before the referral could be actioned

Table 14: days to screening team appointment from date of screen positive result

Time to being seen	Number of pregnancies	Percentage of pregnancies (%)
0 to 10 working days	1797	92.1
11 to 20 working days	97	5.0
Greater than 20 working days	39	2.0
Not seen	19	1.0
All screen positive pregnancies	1952	100

Table 14 note 1: data not reported for 36 pregnancies

Table 14 note 2: due to rounding, percentage total does not equal 100%

Table 15: referral to specialist HBV services

Referred to specialist services	Number of pregnancies	Percentage of pregnancies (%)
No	97	4.9
Yes	1887	95.1
Not known	1	0.1
All screen positive pregnancies	1985	100

Table 15 note 1: data not reported for 3 pregnancies

UKHSA surveillance

A comprehensive programme of enhanced surveillance of HBV screen positive women and their babies was introduced in April 2021. The purpose of the surveillance is to evaluate the impact of the selective neonatal immunisation programme on transmission of HBV to babies born to women with HBV in pregnancy. As part of the surveillance programme a blood sample is sent to the national Virus Reference Department from all women who screen positive for HBV, , and additional blood samples at delivery from women and babies considered at higher infectivity risk according to Green Book Criteria.

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

Antenatal surveillance samples were sent for 91.7% (1816 of 1981 where data was reported) of pregnancies. Where surveillance samples were not sent, the most common reasons reported include:

• 62 women had a pregnancy loss (miscarriage or TOP) before the sample could be taken
• 23 women declined additional samples to be sent for surveillance
• 10 women transferred their care to another maternity provider before the sample could be taken
• 8 women where clinicians reported they forgot to obtain the sample
• 7 women were seen at maternity providers who were not able to implement the new HBV pathway in line with the national roll out in April 2021 (all maternity units in England had implemented the pathway by April 2023)

Review in third trimester

All pregnancies to women with HBV require multidisciplinary team input, with care for the infant continuing past the point of maternity services input. A third trimester review for all women was introduced as a part of the new clinical care pathway as an opportunity for a reinforcement of the advice that the infant(s) require an accelerated course of HBV vaccination to protect them from HBV infection at birth. The appointment should facilitate a review of the woman’s care and utilise 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

Women attended a third trimester review with the maternity screening team in 88.0% of pregnancies (1286 of 1462 where data was reported). For women who did not attend an appointment, this was often due to this function being delivered by the specialist HBV services team, late booking in the third trimester, not attending scheduled appointments or capacity of the screening team during the COVID-19 pandemic. However, several reasons reported indicate a lack of understanding about the importance of the appointment for all women with HBV, including:

• low risk or low viral load
• not local policy
• to be reviewed three months postnatally
• screening team input not required
• viral load already taken

Specialist HBV services

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 six weeks of the positive result being reported to the maternity service, in line with the higher infectivity pathway.  Of the women referred to specialist services who required review within six weeks, 79.9% (429 of 537) were seen within that timeframe. This was 77.0% (305 of 395) among newly diagnosed women, and 88.0% (125 of 142) among women of higher infectivity. Reasons for not meeting the referral standard and being seen over six weeks included:

• DNA initial appointment (39)
• pregnancy loss (TOP or miscarriage) (10)
• staff/clinic capacity (20)
• woman no longer in the country (6)

Of the women referred to specialist services who required review within 18 weeks,  (those found to be lower infectivity and previously known positive, in line with the lower infectivity pathway), 90.0% (1298 of 1443) were seen within that timeframe, but 10.0% (145 of 1443) were not seen at all by specialist services during the pregnancy. Reasons for not being seen within 18 week specialist appointments included:

• did not attend appointment (55),
• pregnancy loss (miscarriage or TOP) (40),
• accessing antenatal care late in pregnancy (8),
• woman presented unbooked in labour (4)
• declined appointment (2),
• woman already known to specialist team (unclear if these women were reviewed during pregnancy or if specialist team were aware of the woman’s pregnancy) (2),
• transfer of care to another maternity provider (2),

Table 16: time to be seen by specialist HBV services (pregnancies to women newly diagnosed and higher infectivity markers)

Timeframe	Prior known diagnosis and higher infectivity markers	Percentage (%)	Newly diagnosed in this pregnancy (regardless of infectivity markers)	Percentage (%)	All pregnancies	Percentage (%)
Equal to or less than 6 weeks	125	88.0	304	77.0	429	79.9
Over 6 weeks	17	12.0	91	23.0	108	20.1
Pregnancies requiring review within 6 weeks	142	100	395	100	537	100

Table 16 note 1: data not reported for 1 pregnancy for prior known diagnosis and higher infectivity markers

Table 16 note 2: data not reported for 7 pregnancies for newly diagnosed in this pregnancy

Table 16 note 3: data not reported for 8 pregnancies in total for all pregnancies

Table 17: time to be seen by specialist HBV services (pregnancies to women previously diagnosed with lower infectivity markers)

Timeframe	number of pregnancies	Percentage (%)
Equal to or less than 18 weeks	1298	90.0
More than 18 weeks but prior to delivery	0	0
Not seen during pregnancy	145	10.0
Number of pregnancies with prior known diagnosis and lower infectivity markers	1443	100

*data not reported for 39 pregnancies

Viral load and treatment during pregnancy

Women were reported to be already receiving treatment for their HBV infection at the point of conception in 67 pregnancies. A viral load of equal to or above 2x10⁵ is the national British Viral Hepatitis Group’s (BVHG) recommendation to commence HBV treatment during pregnancy. A viral load above this threshold was reported in 88 pregnancies and 72 (81.2%) of these women are known to have been given treatment during pregnancy.  For women who were classed as having higher infectivity markers according to Green Book criteria during pregnancy, where a registerable birth was the pregnancy outcome, 78.9% (101 of the 128) of women received treatment for HBV during the pregnancy. For all pregnancies to women with HBV infection, regardless of pregnancy outcome, 9.8% of women received treatment during pregnancy (194 of 1988). Treatment information was received for 181 of 194 pregnancies, with Tenofovir being given in 98.3% (178/181) of pregnancies. There were six women who arrived in the country during pregnancy who were receiving other treatment. Of these, three women remained on these alternative treatments for the duration of their pregnancy, and three were changed to Tenofovir.  

Table 18: treatment received in pregnancy

	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	27	21.1	1499	94.6	1794	90.2
Treatment received	101	78.9	85	5.4	194	9.8
Number of screen positive pregnancies	128	100	1712	100	1988	100

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

HBV DNA viral load	Number of pregnancies	Percentage (%)
Less than 2x105	1838	95.5
Between 2x105 and 1x106	14	0.7
More than x106	74	3.8
All screen positive pregnancies	1926	100

Table 19 note 1: data not reported for 62 pregnancies

Pregnancy outcome

Figure 1: breakdown of pregnancy outcomes

*number of infants born, includes multiple births

Table 20: outcome per pregnancy

Pregnancy outcome	Number of pregnancies	Percentage of pregnancies (%)
Livebirth	1707	85.9
Stillbirth	5*	0.3
Miscarriage	147	7.4
Termination	31	1.6
Left England before delivery	41	2.1
Lost to follow-up before delivery	7	0.4
Outcome report pending, thought to have continued to term	50	2.5
All screen positive pregnancies	1988	100

Table 20 note 1: a multiple pregnancy resulted in both liveborn and a stillborn infant(s); this is counted under livebirth for pregnancy outcome. A total of six babies were stillborn.

Table 20 note 2: due to rounding, percentage total does not equal 100%

Registerable birth outcomes

Among the 1988 pregnancies in women with HBV, 1712 (86.1%) resulted in the registerable births of 1741 liveborn babies and six stillborn babies.  A lower proportion of women delivered vaginally compared to the general population and elective and emergency caesarean section rates were higher for women with HBV than in the general population despite HBV infection not being an indication for caesarean section.

Table 21: mode of delivery per pregnancy (live births and stillbirths)

Mode of delivery	Number of pregnancies	Percentage (%)	Percentage of births in general population (%)
Vaginal	981	57.3	62.6
Elective caesarean	363	21.2	15.5
Emergency caesarean	368	21.5	19.7
Number of pregnancies progressing to registerable birth	1712	100	NA

Rupture of membranes happened at delivery or within an hour of delivery for over half of women (56.2%). An invasive procedure was performed in 14.6% of pregnancies (243 of 169 where data reported) with the majority of these being artificial rupture of membranes (238 of 243 procedures).

Table 22: duration of membrane rupture (live births and stillbirths)

Duration membranes ruptured	Number of pregnancies	Percentage (%)
Ruptured at delivery	778	46.4
Less than 1 hour	165	9.8
1 to 4 hours	185	11.0
4 to 12 hours	298	17.8
12 to 24 hours	153	9.1
24 to 48 hours	73	4.3
Over 48 hours	26	1.5
Number of pregnancies progressing to registerable birth	1678	100

Table 22 note 1: data not reported for 34 pregnancies

Table 23: invasive procedure in labour

Invasive procedure	Number of pregnancies	Percentage (%)
Artificial rupture of membranes	238	14.3
Fetal scalp electrode	2	0.1
Fetal blood sampling	1	Less than 0.1
No invasive procedure	1418	85.5
Number of pregnancies progressing to registerable birth	1659	100

Table 23 note 1: data not reported for 53 pregnancies

Table 23 note 2: due to rounding, percentage total does not equal 100%

Women delivered at term in the majority of pregnancies (91.0%) but had a slightly higher preterm delivery rate than the general population, with 9.0% of babies being born prior to 37+0 weeks gestation. Of the 157 babies born preterm:

• 107 were born between 35+0 and 36+6 weeks gestation
• 33 were born between 32+0 and 34+6 weeks gestation
• 17 were born at less than 32 weeks gestation

Table 24: gestation at delivery (livebirths and stillbirths)

Gestation	Number of registerable infants	Percentage of births (%)	Percentage of births in general population (%) (England 2021 ONS data)
Equal to or more than 37 weeks	1582	91.0	92.1
Less than 37 weeks	157	9.0	7.5
Number of registerable births	1739	100	NA

Table 24 note 1: data not reported for 8 infants

Table 25: birthweight at delivery (livebirths and stillbirths)

Birthweight	Number of registerable infants	Percentage of infants (%)	Percentage of births in general population (%) (England 2021 ONS data)
2.5 kg or more	1600	91.6	91.0
1.5 to 2.5 kg	131	7.5	5.6
Less than 1.5 kg	15	0.9	0.8
Number of registerable births	1746	100	NA

Table 25 note 1: data not reported for 1 infant

Newborn outcome

Neonatal outcome

Of the 1742 live infants, 122 infants (7.0%) were admitted to the neonatal unit compared to 15.1% in the general population (NHS Digital maternity statistics 2020 to 2021 data). Commonly reported reasons for admission included prematurity (40) and breathing difficulties (8). Congenital conditions were reported in 43 infants (2.5%) and of these, three had multiple conditions reported.

There were four neonatal deaths (less than 0.1%); two infants died within 24 hours and two infants died between one week and one month of age. The deaths were not thought to be associated with maternal HBV infection. 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 26: neonatal unit admission

Neonatal unit admission	Number of infants	Percentage of infants (%)
No	1611	93.0
Yes	121	7.0
Number of live births	1733	100

Table 26 note 1: data not reported for 9 infants

Table 27: congenital conditions (livebirths and stillbirths)

Congenital conditions	Number of infants	Percentage of infants (%)
None	1703	97.5
One condition	40	2.3
Multiple conditions	3	0.2
Number of registerable births	1746	100

Table 27 note 1: data not reported for 1 infant

Vaccination and immunoglobulin administration

The total number of pregnancies to women with HBV resulting in a live birth was 1707, with 1742 infants being born to those women and who were therefore exposed HBV in utero and at the time of delivery. All infants born to women with HBV infection in pregnancy should receive HBV vaccination in line with the Green Book, guidance, with the first dose being given within 24 hours of birth. All infants born to women with high risk of transmission should also receive HBIG within 24 hours of birth. For the infants born to women who booked for antenatal care in 2021 to 2022, 130 were born to women with higher infectivity markers in pregnancy and so were eligible to receive HBIG in addition to HBV vaccination with 24 hours of birth.

Of the 1742 live born infants who required HBV vaccination, 98.4% received this in line with the Green Book guidance. Infants did not receive the vaccine at all in 15 cases, with reasons being:

• parental decline (8)
• neonatal death within 24 hours of birth (3)
• woman presented unbooked in labour (1)
• unknown (3)

For 13 infants, vaccination was administered after 24 hours of age (ranging from 26 to 60 hours). Reasons for delays to vaccination include:

• mother in ITU (1)
• parental vaccine hesitancy (3)
• given late in error (3)
• woman presented unbooked in labour (2)
• unknown reason (4)

Of the 130 infants who required HBIG as well as vaccination, 123 received it with 24 hours of birth (data not reported for one infant). For four    infants, HBIG was given later than 24 hours (ranging from 36 to 144 hours). For the six infants who did not receive HBIG as required, reasons include:

• parental decline (2)
• woman presented unbooked in labour (1)
• error by clinical team (2)
• decision made by clinical team that it was not needed (1)

In addition to the 130 infants born to women with higher infectivity markers, an additional 13 liveborn infants were born weighing less than 1.5kg and therefore required HBIG in line with the Green Book guidance. Of these, nine received HBIG within 24 hours of life. For the four babies who did not receive HBIG, two were reported as screening incidents and two were neonatal deaths.

An additional 20 infants born to women with lower infectivity markers were given HBIG in addition to vaccination. Reasons reported for this include:

• change in serological markers (12)
• unavailability of full HBV results (2)
• unknown (2)
• administered in error (1)
• due to ethnicity (1) (unclear what is meant by this report as ethnicity is not an indication for HBIG administration)
• maternal request and anxiety (1)
• recently tested positive in pregnancy (1) (unclear why this was needed as woman reported as newly diagnosed but lower infectivity markers)

Table 28: HBV vaccination and HBIG administration

Given within 24 hours of birth	HBV vaccine		HBIG
	Number of infants	Percentage of infants	Number of infants	Percentage of infants
Yes within 24 hours	1710	98.4	123	95.3
No over 24 hour	13	0.7	4	3.1
Did not receive	15	0.9	2	1.6
Number of livebirths	1738	100	129	100

Table 28 note 1: data not reported for 3 infants for vaccination

Table 28 note 2: data not reported for 1 infant for HBIG

Neonatal surveillance

A second maternal venous surveillance sample should be taken from those women classified as being of higher infectivity after the woman has delivered her baby. A dried blood spot test should be taken from babies born and deemed at high risk of infection before administration of the vaccine and HBIG. Instructions for the labour and delivery staff and equipment for obtaining samples are provided by UKHSA in a box supplied with the pre-ordered HBIG. For the 130 babies born to women with higher infectivity markers, 85.4% (111 of 130) had the dried blood spot sample taken, and surveillance boxes were returned to UKHSA in 92.2% of deliveries (119 of 129 where data reported). Where samples were not taken and/or boxes not returned, the most common reasons for this were:

• delivered before boxes were able to be delivered by UKHSA early in the roll out of the new pathway (4)
• preterm delivery before box and HBIG had been delivered (3)
• baby unwell in neonatal intensive care (3)
• staff error (3)

Notification of birth and vaccination

The success of the combined screening and immunisation pathways 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 vaccine is given on time to the infant. The routine childhood immunisation schedule commences at eight 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 was notified of the baby’s birth and vaccination in 99.5% of live deliveries (1699 of 1707), the health visitor was notified in 95.8% of live deliveries (1634 or 1706 where data was reported) and notification was sent to CHIS in 99.8% of live deliveries (1704 of 1707). Where notifications were not sent, reasons reported include:

• maternity unit had no named contact for health visiting services to communicate with (31)
• woman not registered with a GP (4)
• transferred area (2)
• staff error (1)

Infant outcome

Infant surveillance at 12 months of age

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

Outcomes on 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 this cohort cannot yet be reported on. The infants born to women who booked for antenatal care in 2021 to 2022 will be reported on in subsequent reports.

Summary and next steps

The first year of national maternity HBV surveillance has shown a good level of reporting by providers despite the burden of a higher number of cases to report compared to HIV and syphilis. Overall, 7.3% of pregnancies were to women with higher infectivity markers during pregnancy which is slightly lower than expected when compared with findings from NHSE annual standards data and information held by UKHSA on requests for HBIG. Future data sharing with colleagues at the UKHSA will help improve accuracy of these figures.  As seen with the other screened for infections, the largest number of pregnancies to women with HBV is in London, and women were more likely to book for antenatal care later than advised in NICE guidance (over 10+0 weeks gestation). Over 95% of women were born outside the UK, which is higher than for the other screened for infections (compared to 60% for syphilis and 80% for HIV). Socially complicating issues were reported for 18.1% of pregnancies, with housing concerns, immigration issues and mental health issues being most commonly reported.  

Outcomes

The UKHSA offers the free national dried blood spot testing service for infants at 12 months old for diagnostic testing to check if they have become infected with HBV via vertical transmission. Work is currently underway to establish data sharing agreement between NHS England and the UKHSA to ensure an outcome of infection status for every infant is sought. 

Vertical transmissions

NHS England (ISOSS) is working in partnership with the 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. It is thought that approximately three infants per year born to women deemed to be of higher infectivity acquire persistent infection despite receiving HBIG and vaccine. However, only half of the higher risk infants are reported as being tested at 12 months for evidence of HBV infection so this number may be more. Surveillance and data linkage between ISOSS and UKHSA will allow a more accurate assessment of vertical transmission rates for all infants exposed to HBV.

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.

Anonymised case summaries are produced and reviewed by the Clinical Expert Review Panel (CERP). The panel consists of relevant clinical specialists, including maternity, laboratory, paediatrics, specialist care services 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 IDPS advisory group to inform national guidelines and policy

ISOSS background

Data-reporting processes

ISOSS HIV surveillance, 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. Maternity surveillance covers all pregnancies in women living with HIV who are diagnosed by delivery. Paediatric surveillance 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.

Routine surveillance of pregnancies to women with a screen positive result for syphilis was commenced for those who booked for antenatal care from January 2020. 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.

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 a number of 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.

Reporting timeline

Figure 2: reporting timeline for ISOSS data collection for women during pregnancy and infants after birth

Figure 2 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

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 IDPS programme. We would like to acknowledge the important contributions made by our colleagues at UKHSA, members of our Clinical Expert Review Panels and NHS providers in relation to surveillance of women with HBV in pregnancy and their infants.