Twin Growth Discordance and Risk of Postpartum Hemorrhage: A Retrospective Cohort Study

Abstract

BackgroundIn recent years, the incidence of postpartum hemorrhage has increased globally. Multiple pregnancies and cesarean sections are well-known risk factors for postpartum hemorrhage. No studies have evaluated the associations between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section. This study aimed to identify the relationship between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section.MethodsThis retrospective single-center study included 3,180 women with twin pregnancies at a tertiary hospital between August 2013 and July 2020. Singleton reference charts were used to assess fetal growth restriction at birth. Discordant growth was defined as an intertwin birth weight difference of ≥20%. Logistic regression analyses were used to evaluate the association between fetal growth anomalies and postpartum hemorrhage. Additionally, sensitivity analysis of abnormal placenta and stratification by twin chorionicity were conducted.ResultsThe overall incidence of postpartum hemorrhage was 4.3%. Twin growth discordance, especially with fetal growth restriction, was associated with an increased risk of postpartum hemorrhage (adjusted odds ratio [AOR] = 1.62, 95% confidence interval [CI], 1.05–2.51, P = 0.031; AOR = 1.71; 95% CI, 1.08–2.70, P = 0.022; AOR = 1.98, 95% CI, 1.21–3.25, P = 0.006, respectively). After stratification, this relationship persisted in dichorionic twins (OR = 1.71, 95% CI, 1.04–2.82, P = 0.036; OR = 1.90, 95% CI, 1.13–3.21, P = 0.016; OR = 2.48, 95% CI, 1.41–4.38, P = 0.002, respectively). However, no significant association was observed in monochorionic twin pregnancies.ConclusionGrowth discordance, especially complicated by fetal growth restriction, was associated with an increased risk of postpartum hemorrhage in women with twin pregnancies undergoing cesarean section, and was more evident in patients with dichorionic twins.

The role of estimated fetal weight discordance in dichorionic twin pregnancies

“…This association was especially apparent in patients with twin pregnancies complicated by FGR and sFGR, although these complications were not predictive of PPH. The authors have also found a stronger correlation between birthweight discordance and PPH in dichorionic twin pregnancies [30]. Another disorder associated with increased EFWd in early pregnancy is placenta previa.…”

“…Apart from the risk of hypertensive disorders that is rooted in the pathogenesis of sFGR, increased birthweight discordance (≥ 20%) is also associated with a higher incidence of PPH (postpartum hemorrhage). In a study by Cao et al [30], a correlation was found between increased birthweight discordance and the incidence of PPH ≥ 1000 mL [OR 1.62 (1.05-2.51)] and PPH requiring invasive treatment [OR 1.62 (1.00-2.63)]. This association was especially apparent in patients with twin pregnancies complicated by FGR and sFGR, although these complications were not predictive of PPH.…”

Risk Factors for Postpartum Hemorrhage in Severe Pre-Eclampsia: A Retrospective Single-Centre Study of 1953 Cases

“…In recent years, with the development of assisted reproductive technology and the use of ovulation-promoting drugs, the incidence of twin pregnancy has increased yearly. Twin pregnancy is susceptible to PPH due to uterine overdistension and myofibrillar hyperextension, which affects myofibrillar retraction, leading to weak uterine contractions in the postpartum period, which affects complete placental abruption and closure of blood sinuses at the abruption surface of the placenta [ 18 , 19 ]. In addition, twin fetuses have a large placental area, richer blood flow, more bleeding from small uterine arteries, and vein dissections during placental abruption, and are prone to complications of hypertensive disorders of pregnancy (especially sPE), amniotic fluid, placenta previa, and intrahepatic cholestasis in pregnancy, which increase the incidence of PPH in twin pregnancy.…”

Twin Pregnancy and Postpartum Haemorrhage: A Systematic Review and Meta-analysis

“…After removing duplicates, the articles were screened according to the inclusion and exclusion criteria yielding 398 for full-text review. Finally, 21 studies involving 23,330 pregnant patients met the eligibility criteria and were included in this study (4,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39). The PRISMA ow chart (Figure S1) illustrates the details of the study selection process.…”