Stillbirth associated with increased severe maternal morbidity risk 1 year postpartum

Key takeaways:

• Stillbirth deliveries had a higher likelihood for pregnancy complications vs. live births.
• Stillbirth deliveries were linked to severe maternal morbidity during delivery and up to 1 year postpartum.

Stillbirth was associated with an increased risk for severe maternal morbidity during delivery hospitalization and up to 1 year postpartum, researchers reported in the American Journal of Obstetrics & Gynecology.

“While a growing body of research has examined severe maternal morbidity and associated maternal characteristics, limited studies have examined severe maternal morbidity rates among stillbirth vs. live births,” Samuel H. Nyarko, PhD, research fellow in the department of epidemiology and biostatistics at the Arnold School of Public Health at the University of South Carolina, and colleagues wrote. “Existing research on this topic is limited to two states in the United States. Thus, these studies may not provide a broader understanding of severe maternal morbidity among individuals who have a stillbirth.”

Nyarko and colleagues conducted a retrospective cohort study of 8,694,912 deliveries using birth and fetal death certificate data linked to hospital discharge records from California, Michigan, Missouri, Pennsylvania and South Carolina. Researchers examined the risk for severe maternal morbidity among women with stillbirth compared with live birth deliveries.

In the cohort, 0.4% of deliveries were stillbirth deliveries. Women with stillbirth deliveries were more likely to have the following characteristics compared with women with live births:

• being non-Hispanic Black (20.5% vs. 10.8%);
• being on Medicaid (52% vs. 46.5%);
• having pregnancy complications, including preexisting diabetes (4.3% vs. 1.1%);
• preexisting hypertension (6.2% vs. 2.3%);
• preeclampsia (8.4% vs. 4.4%);
• having multiple gestations (6.2% vs. 1.6%); and
• living in South Carolina (11.6% vs. 7.4%).

The prevalence of severe maternal morbidity during delivery hospitalization for stillbirth was 791 per 10,000 deliveries compared with 154 per 10,000 deliveries for women with live births. In addition, the prevalence for non-transfusion severe maternal morbidity among women with stillbirths was 502 per 10,000 deliveries compared with 68 per 10,000 deliveries for women with live births.

Among women with stillbirth deliveries, the crude RR for severe maternal morbidity was 5.1 and the RR was 1.6 after adjusting for an obstetric comorbidity index, whereas the crude RR for non-transfusion severe maternal morbidity was 7.4 and the adjusted RR was 2 compared with live birth deliveries.

Researchers observed an elevated risk for severe maternal morbidity among women with stillbirth deliveries not only during the delivery hospitalization, but also throughout the first postpartum year for severe maternal morbidity (aRR = 1.3; 95% CI, 1.1-1.4) and for non-transfusion severe maternal morbidity (aRR = 1.2; 95% CI, 1.1-1.3).

“Our findings indicate that stillbirth delivery is associated with elevated risk of severe maternal morbidity and its indicators not only during the delivery hospitalization but also at any time during the prenatal period and up to 1 year postpartum,” the researchers wrote.