Provider-initiated delivery, late preterm birth and perinatal mortality: a secondary analysis of the WHO multicountry survey on maternal and newborn health

Stillbirth in Women Living With HIV Delivering in the United Kingdom and Ireland: 2007-2015

BACKGROUND

Women living with HIV have a higher risk of adverse birth outcomes, but questions remain regarding their specific risk factors for stillbirth and the extent to which maternal HIV is associated with stillbirth.

METHODS

Using data on pregnant women with HIV reported within population-based surveillance in the United Kingdom/Ireland, we described stillbirth rates in 2007-2015 stratified by type of antiretroviral therapy (ART) and evaluated risk factors using Poisson regression. General population stillbirth rates by maternal world region of origin were derived from national annual birth statistics, and compared with rates in women with HIV, using standardized stillbirth ratios with the general population as the reference.

RESULTS

Between 2007 and 2015, there were 10,434 singleton deliveries in 8090 women with HIV; 75% of pregnancies were in women of African origin; and 49% were conceived on ART. The stillbirth rate was 8.5 (95% confidence interval: 6.9 to 10.5) per 1000 births. Risk factors for stillbirth included pre-eclampsia, diabetes, Asian maternal origin (versus United Kingdom/Ireland), CD4 count <350 cells/mm, older maternal age, and primiparity. Conceiving on ART did not increase the risk. The stillbirth rates (per 1000 births) by type of ART were 14.3, 11.7, 8.3, and 6.0, respectively for NVP + XTC/TDF-, LPV/r + 3TC/ZDV-, NVP + XTC/ABC-, and NVP + XTC/ZDV-exposed pregnancies (P value = 0.40). The standardized stillbirth ratio was 129 (95% confidence interval: 101 to 165) in women with HIV compared with the general population.

CONCLUSION

After adjusting for maternal origin, the stillbirth rate remained higher in women with HIV than the general population. We recommend further studies to understand and prevent this excess.

Epidemiology of late preterm and early term births - An international perspective

Late preterm (34-36 weeks of gestational age (GA)), and early term (37-38 weeks GA) birth rates among singleton live births vary from 3% to 6% and from 15% to 31%, respectively, across countries, although data from low- and middle-income countries are sparse. Countries with high preterm birth rates are more likely to have high early term birth rates; many risk factors are shared, including pregnancy complications (hypertension, diabetes), medical practices (provider-initiated delivery, assisted reproduction), maternal socio-demographic and lifestyle characteristics and environmental factors. Exceptions include nulliparity and inflammation which increase risks for preterm, but not early term birth. Birth before 39 weeks GA is associated with adverse child health outcomes across a wide range of settings. International rate variations suggest that reductions in early delivery are achievable; implementation of best practice guidelines for obstetrical interventions and public health policies targeting population risk factors could contribute to prevention of both late preterm and early term births.