Women who deliver preterm are at 30% higher risk of suffering complications compared to term births. They had significantly higher rates of postpartum hemorrhage (PPH) and needed blood transfusions more than women who delivered at term. They were also more likely to have cesarean births. These findings were presented at the 2023 ACOG Annual Clinical & Scientific Meeting held last week in Baltimore in Maryland and simultaneously published in the journal Obstetrics and Gynecology.^1,2

A secondary analysis of a retrospective study of 4514 singleton deliveries at the Women & Infants Hospital of Rhode Island over a period of one year was carried out to compare the risk of maternal morbidity due to PPH in 3452 term and 1062 preterm births (PTB) defined as cut-off at 37 weeks.

The overall primary study outcome, which was a composite of blood loss ≥1000 ml, use of uterotonics, blood transfusions, uterine tamponade, surgical interventions, ICU admission, hysterectomy and death due to the hemorrhage, occurred in 23.2%. When term pregnancies were compared with preterm deliveries, it was seen in 21% of term births vs 30.4% in preterm births. After adjusting for confounding variables like age, body mass index > 30 kg/m2, nulliparity, insurance status, race, smoking status, and cesarean delivery, the overall composite maternal morbidity rate was significantly increased among women with preterm births (30.4%) compared to (21%) among term births with aRR of 1.42. More women who delivered preterm required transfusions or intensive care. The incidence of hysterectomy was also higher in this group.

Compared to term pregnancies, preterm pregnancies were associated with lower rates of vaginal deliveries (55.5% vs 41.4%), higher cesarean rates (21.5% vs 30.1%). Women with term pregnancies had higher rates of induction at term (65.9% vs 40.6%). PPH (6.2% and 12.2%), use of a uterotonic agent (16% and 19.4%) and transfusion (2.6% and 8.9%) were the most commonly occurring complications among term and preterm births.2

This study shows the higher rates of maternal morbidity due to PPH among women who delivered preterm compared to the term deliveries. “Interventional trials are needed to decrease the hemorrhagic morbidity with PTB,” concluded the authors.

References

1. Whelan A, et al. Postpartum hemorrhage: preterm versus term pregnancies [ID: 1356883]. Obstet Gynecol. 2023 May;141(5S):102S-103S. DOI: 10.1097/01.AOG.0000931264.93401.76
2. https://www.healio.com/news/womens-health-ob-gyn/20230523/significantly-higher-postpartum-hemorrhage-with-preterm-vs-term-pregnancies. May 23, 2023. Accessed on May 25, 2023.