Stillbirth is associated with postpartum severe maternal morbidity compared to gestational age matched and term livebirths.

Background: Rates of severe maternal morbidity in the United States continue to increase. ACOG recommends close postpartum follow up for patients at increased risk for severe maternal morbidity and mortality, such as those suffering from preeclampsia or hypertension. Data exploring the association between stillbirth and severe maternal morbidity are limited.

Objective: To evaluate the association between stillbirth and severe maternal morbidity when compared to gestational age matched and term livebirths.

Study design: This was a multicenter retrospective cohort study performed at three centers within a hospital system from 2017-2023. SMM was defined with guidance from the indicators outlined by the Centers for Disease Control. Inclusion criteria for the stillbirth group was delivery of a fetus showing no signs of life at 20 weeks gestation or later. Antepartum preeclampsia, multiple pregnancies, maternal age less than 18 years old, duplicate records, and voluntary terminations of pregnancy greater than 20 weeks gestation were excluded. We selected gestational age and term matched livebirths as control groups. Logistic regression was performed to evaluate the odds of composite severe maternal morbidity in stillbirths versus gestational age matched and term matched livebirths, separately, while adjusting for potential confounders. Data were presented as adjusted Odds Ratios (aOR) with 95% confidence intervals (CI) and statistical significance set at P < 0.05.

Results: Of the 29,060 deliveries during the study period, there were 129 (0.44%) stillbirths. Stillbirth was associated with significantly higher odds of severe maternal morbidity compared to term (aOR = 4.35, 95% CI 1.75-10.84) and gestational age matched livebirths (aOR = 3.39, 95% CI 1.72-6.66). There was no significant difference in the rate of postpartum hemorrhage compared between stillbirths and gestational age matched livebirths (10.1% vs. 7.3%, p = 0.42), however there were significantly more transfusions needed in the stillbirth group (10.1% vs. 1.6%, p = 0.017). When compared to term livebirths, there were significantly more transfusions (10.1% vs. 1.6%, p <0.001), intensive care admissions (2.3% vs. 0%, p = 0.007). postpartum preeclampsia (2.3% vs. 0%, p = 0.007), and sepsis (2.3% vs. 0%, p = 0.007).

Conclusion: Stillbirth is associated with an increased risk of severe maternal morbidity compared to gestational age and term matched livebirths. Increased postpartum surveillance should be implemented into practice, and preventative interventions such as tranexamic acid administration should be further evaluated with prospective studies.