Risk Factors for Stillbirth: Findings from a Population-Based Case-Control Study, Haryana, India

Stillbirth is a prevalent adverse outcome of pregnancy in India despite efforts to improve care of women during pregnancy. Risk factors for stillbirths include sociodemographic factors, medical complications during pregnancy, intake of harmful drugs, and complications during delivery. The objective of the study was to examine the risk factors for stillbirth with a focus on sex selection drugs (SSDs).

A population-based case-control study was undertaken in Haryana. Cases of stillbirths were identified from the Maternal Infant Death Review System portal of Haryana state for the months of August-September 2014. A consecutive birth from the same geographical area as the case was selected as the control. The sample size was 325 per group. Mothers were interviewed using a validated tool. Bivariate analyses and logistic regression were conducted to examine the association between risk factors and stillbirth. Attributable risk proportions (ARP) and population attributable risk proportions (PARP) were estimated.

The sociodemographic profiles of the cases and controls were similar. History of intake of SSDs [adjusted odds ratio (OR) 2.6, 95% confidence interval (CI) 1.5, 4.5] emerged as a risk factor. Other significant factors were preterm <37 weeks (OR 3.5, 95% CI 2.1, 6.0), history of previous stillbirths (OR 4.0, 95% CI 2.1, 7.8), and complications during labour (OR 3.3, 95% CI 2.1, 5.3). Estimates of the ARP and PARP for intake of SSDs were 0.60 (95% CI 0.32, 0.77) and 0.1 (95% CI -0.13, 0.28), respectively.

SSDs could be attributed as a risk factor in a fifth of the cases of stillbirths. The number needed to harm for the use of SSDs in causing adverse effect of stillbirths was 5, suggesting thereby that for every five mothers exposed to SSDs, one would have stillbirth. Greater efforts are required to inform people about the harmful effects of SSD consumption during pregnancy.