Risk factors for intrapartum stillbirth and the survival probabilities of fetuses among pregnant women with complications: Secondary analysis of data from a multicenter prospective cohort study in India.
Boo YY., Choudhury SS., Zahir F., Deka G., Bora AK., Chhabra S., Kumar P., Mahanta P., Minz B., Rani A., Rao S., Roy I., Solomi V C., Verma A., Kakoty S., Bharti OK., Deka R., Opondo C., Cheng TS., Kurinczuk JJ., Nair M., MaatHRI collaborators .
OBJECTIVE: To identify the risk factors for intrapartum stillbirth and examine whether these are different from that of antepartum stillbirth, and investigate the survival probabilities of fetuses by gestational age in high-risk pregnancies. METHODS: We conducted a secondary data analysis of a hospital-based cohort study from India, including 9774 singleton pregnancies from 13 hospitals across six states. We conducted modified Poisson regression analysis to assess associations between potential risk factors and intrapartum stillbirth. Kaplan-Meier survival curves were used to explore survival probabilities of fetuses among pregnant women who had anemia and hypertensive disorders in pregnancy (HDP) compared with those who did not have these problems. RESULTS: There were 167 intrapartum stillbirths and 9607 live births; representing an incidence of 17.1 per 1000 total births (95% confidence interval [CI]: 14.6-19.9). Risk factors identified were illiteracy (adjusted risk ratio [aRR]: 2.37, 95% CI: 1.33-4.38), age > 34 years (aRR: 3.17, 1.41-7.36), <4 antenatal check-ups (aRR: 1.90, 1.27-2.87), <100 days of iron and folic acid supplementation (aRR: 9.10, 4.15-21.05), other HDP (aRR: 2.48, 1.36-4.25), severe anemia (aRR: 3.33, 1.82-6.63), preterm birth (aRR: 3.25, 2.26-4.69) and <10th percentile birth weight-for-gestational age (aRR: 1.57, 1.14-2.17). These were similar to the risk factors for antepartum stillbirths. Survival probabilities for fetuses among women with pre-eclampsia/eclampsia and severe anemia decreased from 34 weeks' and 30 weeks' gestation, respectively. CONCLUSION: In this high-risk hospital cohort of pregnant women undergoing labor induction or augmentation, risk factors for intrapartum stillbirth overlapped substantially with those for antepartum stillbirth, although the antepartum analysis was underpowered. Targeted monitoring of women with severe anemia and HDP from 30 weeks may reduce intrapartum stillbirth risk in similar settings.