Young maternal age and risk of intrapartum stillbirth

OBJECTIVES: To determine the risk of intrapartum stillbirth among teen mothers. METHODS: The Missouri maternally linked data containing births from 1978 to 1997 were analyzed. The study group (teen mothers) was sub-divided into younger (<15 years) and older (15-19 years) teenagers. Women aged 20-24 were the referent category. We used Kaplan-Meier product-limit estimator to calculate the cumulative probability of death for each group and the Cox Proportional Hazards Regression models to obtain adjusted hazards ratios. RESULTS: The rate of antepartum and intrapartum stillbirth among teenagers was 3.8 per 1,000 and 1.0 per 1,000, respectively, compared to 3.5 per 1,000 and 0.8 per 1,000 among the reference group. The adjusted risk of intrapartum stillbirth was more than 4 times as high among younger teens (adjusted hazard ratio AHR] 4.3 95% CI 4.0-4.7]) and 50% higher among older teens (AHR 1.5 95% CI 1.2-1.8]). The risk of intrapartum stillbirth occurred in a dose-dependent fashion, with risk increasing as maternal age decreased (P < 0.01). CONCLUSION: Teenagers are at an increased risk of stillbirth, with the greatest risk disparity occurring intrapartum, especially among younger teens. This new information is potentially useful for targeting intervention measures aimed at improving in utero fetal survival among pregnant women at the lower extreme of the maternal age spectrum.