Maternal morbidity and preterm birth in 22 low- and middle-income countries: a secondary analysis of the WHO Global Survey dataset

BACKGROUND Preterm birth (PTB) (<37weeks) complicates approximately 15 million deliveries annually, 60% occurring in low- and middle-income countries (LMICs). Several maternal morbidities increase the risk of spontaneous (spPTB) and provider-initiated (piPTB) preterm birth, but there is little data from LMICs. METHOD We used the WHO Global Survey to analyze data from 172,461 singleton deliveries in 145 facilities across 22 LMICs. PTB and six maternal morbidities (height <145 cm, malaria, HIV/AIDS, pyelonephritis/UTI, diabetes and pre-eclampsia) were investigated. We described associated characteristics and developed multilevel models for the risk of spPTB/piPTB associated with maternal morbidities. Adverse perinatal outcomes (Apgar <7 at 5 minutes, NICU admission, stillbirth, early neonatal death and low birthweight) were determined. RESULTS 8.2% of deliveries were PTB; one-quarter of these were piPTB. 14.2% of piPTBs were not medically indicated. Maternal height <145 cm (AOR 1.30, 95% CI 1.10-1.52), pyelonephritis/UTI (AOR 1.16, 95% CI 1.01-1.33), pre-gestational diabetes (AOR 1.41, 95% CI 1.09-1.82) and pre-eclampsia (AOR 1.25, 95% CI 1.05-1.49) increased odds of spPTB, as did malaria in Africa (AOR 1.67, 95%CI 1.32-2.11) but not HIV/AIDS (AOR 1.17, 95% CI 0.79-1.73). Odds of piPTB were higher with maternal height <145 cm (AOR 1.47, 95% CI 1.23-1.77), pre-gestational diabetes (AOR 2.51, 95% CI 1.81-3.47) and pre-eclampsia (AOR 8.17, 95% CI 6.80-9.83). CONCLUSIONS Maternal height <145 cm, diabetes and pre-eclampsia significantly increased odds of spPTB and piPTB, while pyelonephritis/UTI and malaria increased odds of spPTB only. Strategies to reduce PTB and associated newborn morbidity/mortality in LMICs must prioritize antenatal screening/treatment of these common conditions and reducing non-medically indicated piPTBs where appropriate.