Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, and the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, St. Michael's Hospital, University of Toronto, Toronto, The Better Outcomes Registry & Networks (BORN) Ontario, Ottawa, and the Department of Obstetrics and Gynecology, Midwifery Education Program, and the Division of Maternal-Fetal Medicine, Departments of Obstetrics and Gynecology, Radiology and Health Research Methodology and Impact, McMaster University, Hamilton, Ontario, Canada; and the Department of Obstetrics & Gynaecology, Rotunda Hospital, Dublin, Ireland.
Obstet Gynecol. 2021 Sep 1;138(3):449-458. doi: 10.1097/AOG.0000000000004506.
To evaluate whether pregnancy outcomes associated with hypertensive disorders of pregnancy in twin pregnancies differ relatively from those in singleton pregnancy.
We conducted a retrospective, population-based cohort study of all women with a liveborn singleton or twin hospital birth in Ontario, Canada, between 2012 and 2019. Data were obtained from the Better Outcomes Registry & Network Ontario. Pregnancy outcomes were compared between women with and without hypertensive disorders of pregnancy in twin gestations, and separately in singleton gestations. Adjusted relative risks (aRRs) and 95% CIs were generated using modified Poisson regression and were compared between twins and singletons using relative risk ratios.
Overall, 932,218 women met the study criteria, of whom 917,542 (98.4%) and 14,676 (1.6%) had singleton and twin gestations, respectively. The incidence of hypertensive disorders of pregnancy was higher in women with twin compared with singleton gestations (14.4% vs 6.4%, aRR 1.85 [1.76-1.94]). Hypertensive disorders of pregnancy were associated with certain adverse outcomes in singleton gestations only and with other adverse outcomes in both the singleton and twin gestations, but the aRR was lower in twins. For example, preterm birth before 37 weeks of gestation (singletons: 15.2% [hypertensive disorders of pregnancy] vs 5.4% [no hypertensive disorders of pregnancy], aRR 2.42; twins: 67.5% [hypertensive disorders of pregnancy] vs 50.4% [no hypertensive disorders of pregnancy], aRR 1.30) and neonatal respiratory morbidity (singletons: 16.3% [hypertensive disorders of pregnancy] vs 8.7% [no hypertensive disorders of pregnancy], aRR 1.50; twins: 39.8% [hypertensive disorders of pregnancy] vs 32.7% [no hypertensive disorders of pregnancy], aRR 1.13). These findings persisted in the subgroups of women with preeclampsia and early-onset preeclampsia.
Although the absolute risk of adverse maternal and neonatal outcomes is higher in twin compared with singleton pregnancies, the incremental risk of adverse outcomes associated with hypertensive disorders in twin pregnancies is lower than the incremental risk in singleton pregnancies. These findings may be attributed in part to the higher baseline risk of preterm birth and adverse maternal and perinatal outcomes in twin compared with singleton pregnancies.
评估与双胞胎妊娠相关的妊娠高血压疾病的妊娠结局是否与单胎妊娠有相对差异。
我们对 2012 年至 2019 年期间在加拿大安大略省一家医院分娩的所有单胎或双胞胎活产的女性进行了一项回顾性、基于人群的队列研究。数据来自Better Outcomes Registry & Network Ontario。比较了双胞胎妊娠和单胎妊娠中患有妊娠高血压疾病的女性与未患有妊娠高血压疾病的女性之间的妊娠结局，并分别进行了比较。使用修正泊松回归生成调整后相对风险（aRR）和 95%置信区间（CI），并使用相对风险比（RRR）比较双胞胎和单胎之间的差异。
总体而言，有 932,218 名女性符合研究标准，其中 917,542（98.4%）和 14,676（1.6%）名女性分别为单胎和双胎妊娠。与单胎妊娠相比，双胞胎妊娠中妊娠高血压疾病的发生率更高（14.4% vs 6.4%，aRR 1.85 [1.76-1.94]）。妊娠高血压疾病仅与单胎妊娠的某些不良结局相关，且与单胎和双胎妊娠的其他不良结局相关，但双胞胎中的 aRR 较低。例如，早产至 37 周前（单胎：15.2%[妊娠高血压疾病] vs 5.4%[无妊娠高血压疾病]，aRR 2.42；双胞胎：67.5%[妊娠高血压疾病] vs 50.4%[无妊娠高血压疾病]，aRR 1.30）和新生儿呼吸窘迫（单胎：16.3%[妊娠高血压疾病] vs 8.7%[无妊娠高血压疾病]，aRR 1.50；双胞胎：39.8%[妊娠高血压疾病] vs 32.7%[无妊娠高血压疾病]，aRR 1.13）。这些发现在前子痫和早发型子痫女性亚组中仍然存在。
尽管与单胎妊娠相比，双胞胎妊娠的母婴和新生儿不良结局的绝对风险较高，但与双胞胎妊娠相关的妊娠高血压疾病的不良结局的增量风险低于单胎妊娠。这些发现部分归因于与单胎妊娠相比，双胞胎妊娠的早产和不良母婴及围产儿结局的基线风险较高。
