UK and Ireland guidelines state that all pregnant women should have their first antenatal care appointment by 13 weeks of pregnancy (antenatal booking). We present the results of an analysis looking at the association between maternal ethnicity and late antenatal booking in HIV-positive
women in the UK and Ireland. We analysed data from the National Study of HIV in Pregnancy and Childhood (NSHPC). We included all pregnancies in women who were diagnosed with HIV before delivery and had an estimated delivery date between 1 January 2008 and 31 December 2009. Late booking was
defined as antenatal booking at 13 weeks or later. The baseline reference group for all analyses comprised women of “white” ethnicity. Logistic regression models were fitted to estimate adjusted odds ratios (AOR). There were 2721 eligible reported pregnancies; 63% (1709) had data
available on antenatal care booking date. In just over 50% of pregnancies (871/1709), the antenatal booking date was ≥13 weeks of pregnancy (i.e., late booking). Women diagnosed with HIV during the current pregnancy were more likely to present for antenatal care late than those previously
diagnosed (59.1% vs. 47.5%, p<0.001). Where women knew their HIV status prior to becoming pregnant, the risk of late booking was raised for those of African ethnicity (AOR 1.80; 95% confidence interval (CI) 1.14, 2.82; p=0.011). In women diagnosed with HIV during pregnancy,
the risk of late booking was also higher for women of African ethnicity (AOR 2.98: 95% CI 1.45, 6.11; p=0.003) and for women of other black ethnicity (AOR 3.74: 95% CI 1.28, 10.94; p=0.016). Overall, women of African or other black ethnicity were more likely to book late for
antenatal care compared with white women, regardless of timing of diagnosis. This may have an adverse effect on maternal and infant outcomes, including mother-to-child transmission of HIV.