Postpartum hemorrhage among twin pregnancies - Medically assisted versus spontaneously conceived

Twin pregnancy and postpartum haemorrhage: a systematic review and meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) continues to stand as the primary cause of maternal morbidity and mortality post-delivery, with twin pregnancies carrying a heightened risk of PPH compared to singleton deliveries.

OBJECTIVES

To investigate the incidence of primary PPH among twin pregnancies and report on maternal and peripartum characteristics within this population.

METHODS

A literature search was conducted using data from PubMed, EMBASE, Cochrane, Scopus, and Web of Science. The search aimed to identify studies concerning mothers with twin pregnancies and postpartum haemorrhage (PPH) from the inception of each respective database to June 8th, 2023. Pooled means and proportions were analyzed using the generic inverse variance method. This review was registered prospectively with PROSPERO (CRD42023427192).

RESULTS

A total of 21 studies involving 23,330 twin pregnant patients were included. Incidence of PPH for vaginal delivery and Caesarean delivery (CS) was found to be 10.9% (95% CI: -0.017, 0.235, I2 = 96%) and 27.0% (95% CI: 0.180, 0.359, I2 = 99%) respectively. In vitro fertilization (IVF) was the most common conception method at 62.0% (95% CI: 0.448, 0.792, I2 = 100%) with 81.1% (95% CI: 0.708, 0.915, I2 = 100%) of twins being dichorionic diamniotic.

CONCLUSION

This meta-analysis demonstrated more than one in ten vaginal deliveries and over one in four cesarean sections result in PPH for twin pregnancies. IVF is the predominant method of conception in this patient group and seems to contribute to subsequent PPH risk in specific mothers. While preliminary, these findings underscore the necessity for further well-designed and high-quality studies to validate these results.

Risk factors for postpartum hemorrhage in twin pregnancies with cesarean section

The rates of twin pregnancies and cesarean section have increased in recent years, and both of them are at high risks of postpartum hemorrhage (PPH). However, few studies have concentrated on the risks of PPH in twin pregnancies and cesarean deliveries. In this study, we aimed to identify the risk factors for PPH among twin-pregnant women with cesarean section. This was a retrospective observational study including 1,649 women with twin pregnancies delivered by cesarean section from 2016 to 2022 in the Second Affiliated Hospital of Wenzhou Medical University, China. The eligible women were divided into PPH group (n = 116) and non-PPH group (n = 1,533) according to the blood loss after delivery within 24 h. The baseline maternal and perinatal characteristics were compared between the two groups. Logistic regression analysis was conducted to identify the potential risk factors for PPH. We found nulliparity, assisted reproductive technology (ART) usage, preeclampsia or HELLP syndrome, placenta previa, placenta accreta and general anesthesia were more common in PPH group than non-PPH group (P < 0.05). Women in PPH group had higher maternal body mass index at delivery and higher combined birthweight of the twins than non-PPH group, but had lower parity (P < 0.05). Seven independent risk factors for PPH were identified after logistic regression analysis: ART usage (OR 2.354 95% CI 1.357-4.083, P = 0.002), preeclampsia or HELLP syndrome (OR 2.605, 95% CI 1.471-4.616, P = 0.001), placenta previa (OR 7.325, 95% CI 3.651-14.697, P < 0.001), placenta accreta (OR 6.296, 95% CI 1.316-30.12, P = 0.021), thrombocytopenia (OR 1.636, 95% CI 1.056-2.535, P = 0.027), general anesthesia (OR 2.394, 95% CI 1.223-4.686, P = 0.011), and combined birthweight (OR 1.00032, 95% CI 1.00005-1.00059, P = 0.020). Collectively, in women with twin pregnancies delivered by cesarean section, the use of ART, preeclampsia or HELLP syndrome, placenta previa, placenta accreta, thrombocytopenia, general anesthesia and the combined birthweight were identified as independent risk factors for PPH. More attention should be paid to women with these risk factors.