UK Mother-to-Child HIV Transmission Rates Continue to Decline: 2012–2014

To the Editor—World AIDS Day provides the opportunity for the human immunodeficiency virus (HIV) community to reflect on successes and challenges in the global response to HIV, including those in preventing mother-to-child transmission (MTCT).

In 2014, we reported that the national MTCT rate in the United Kingdom and Ireland had reached the all-time low of 0.46% in 2010–2011 [1]. With this update, we show a continued decline in recent years.

Comprehensive population-based data on all HIV-infected pregnant women seen for care in the United Kingdom and Ireland are collected through active surveillance within the National Study of HIV in Pregnancy and Childhood (NSHPC) [2]. HIV-exposed infants are followed up to establish infection status.

In 2012–2014, there were 3290 singleton live birth deliveries to women diagnosed prior to delivery. Infection status was confirmed in 78% of infants (2580/3290) to date, although those with unknown status are unlikely to be at a higher risk of MTCT [3]. Overall, 73% (2360) were African-born and median maternal age was 34 years (interquartile range, 30–37 years). There were 7 transmissions among the 2580 infants, giving an MTCT rate of 0.27% (95% confidence interval [CI], 0.11%–0.56%) (Figure 1).

Figure 1.

Data on mother-to-child transmission of HIV for 2000–2011 derived from data in Townsend et al [1]; data for 2012–2014 updated from National Study of HIV in Pregnancy and Childhood reports to end of September.

Eighty-five percent of deliveries in 2012–2014 were in women diagnosed before pregnancy (2781/3290), compared with 72% in 2007–2011 (4776/6585) (P < .001). Overall, 60% of deliveries were in women conceiving on combination antiretroviral therapy (ART) in 2012–2014 (1874/3136), compared with 40% (2516/6309) in 2007–2011. Vaginal deliveries increased to 46% (1495/3268) in 2012–2014 from 37% in 2007–2011 (2425/6281) (P < .001). Overall, 87% of women delivered with HIV RNA <50 copies/mL (1749/2012) and among these the MTCT rate was 0.14% (95% CI, 0.02%–0.52%).

Among the 7 transmissions, maternal diagnosis occurred before pregnancy in 4 cases (3 women conceived on treatment); there was 1 seroconversion during pregnancy. Two infants had in utero transmission (positive polymerase chain reaction [PCR] at age ≤3 days), 4 intrapartum transmission (negative birth PCR, positive PCR at age ≤6 weeks), and 1 intrapartum/postnatal transmission (PCR negative at 6 weeks and positive at >6 weeks). Four women had an undetectable viral load close to delivery.

As a result of high rates of viral suppression in pregnancy, the management of labor for women with HIV has changed [4], with nearly half now delivering vaginally. However, women need continued support with adherence to treatment postnatally, particularly when ART is started during pregnancy [5]. Among the 15% of women diagnosed as a result of screening in pregnancy, earlier initiation of ART in recent years is likely to have contributed to the declining transmission rates, although some migrant groups and parous women continue to access services late [6]. The changing population of pregnant women with HIV in the United Kingdom, including increasing numbers of those aged ≥40 years and of vertically infected pregnant women, has additional implications for pregnancy management to optimize maternal and child health [7, 8].

The continued decline in the UK/Ireland MTCT rate from 0.46% in 2010–2011 to 0.27% in 2012–2014 demonstrates the impact of sustained efforts to provide optimal treatment and care to all women living with HIV, and their infants, before, during, and after pregnancy.

Notes

Financial support. This work was funded through grant support from Public Health England.

Potential conflicts of interest. P. A. T. has received grants from PENTA Foundation and from AbbVie. C. T. has received grants from the European Commission, Medical Research Council, PENTA Foundation, and AbbVie. The authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.

Author notes

Correspondence: H. Peters, UCL Great Ormond Street Institute of Child Health, Population Policy and Practice Programme, 30 Guilford St, London WC1N 1EH, UK ([email protected]).