Institute of Medical Science, University of Toronto, Toronto, ON; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Sunnybrook Research Institute, Toronto, ON.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Sunnybrook Research Institute, Toronto, ON.
Am J Obstet Gynecol. 2021 Nov;225(5):532.e1-532.e12. doi: 10.1016/j.ajog.2021.04.260. Epub 2021 May 10.
Data on the optimal gestational weight gain in twin pregnancies are limited. As a result, the Institute of Medicine currently provides only provisional recommendations on gestational weight gain in this population.
This study aimed to identify the optimal range of gestational weight gain in twin pregnancies and to estimate the association between inappropriate gestational weight gain and adverse pregnancy outcomes.
This was a retrospective cohort study of all women with twin pregnancies that were followed up in a single, tertiary center between 2000 and 2014. We used 2 approaches to identify the optimal range of gestational weight gain: a statistical approach (the interquartile range of gestational weight gain in low-risk pregnancies with normal outcomes) and an outcome-based approach (by identifying thresholds of gestational weight gain below or above which the rate of adverse outcomes increases). The primary outcome was preterm birth. Associations of gestational weight gain below or above the normal range with the study outcomes were estimated using logistic regression analysis and were expressed as adjusted odds ratio with 95% confidence intervals. These associations were stratified by prepregnancy body mass index group.
A total of 1274 women with twin pregnancies met the study criteria: 43 were classified as underweight, 777 were normal weight, 278 were overweight, and 176 were obese. Our estimates of the optimal gestational weight gain range were similar to those recommended by the Institute of Medicine except for the obese category, in which our optimal gestational weight gain range at 37 weeks (9.3-16.3 kg) was lower than in the provisional Institute of Medicine recommendations (11.3-19.1 kg). Nearly half of our cohort experienced inappropriate gestational weight gain: 30% (n=381) gained weight below and 17% (n=216) gained weight above current Institute of Medicine recommendations. In the normal weight group, gestational weight gain below recommendations was associated with an increased risk of preterm birth and birthweight at the <10th centile and with a reduction in the risk of hypertensive disorders, whereas gestational weight gain above recommendations was associated with an increased risk of hypertensive disorders and a reduction in the risk of birthweight at the <10th centile. Associations were less consistent in the overweight and obese groups.
These findings identify gestational weight gain as a potentially modifiable risk factor for preterm birth and other pregnancy complications in twin gestations. Further prospective studies are needed to determine whether interventions aimed at optimizing gestational weight gain can improve the outcomes of these high-risk pregnancies.
关于双胎妊娠最佳孕期体重增加的数据有限。因此，医学研究所目前仅为此人群提供临时的孕期体重增加建议。
本研究旨在确定双胎妊娠最佳孕期体重增加范围，并估计孕期体重增加不当与不良妊娠结局之间的关系。
这是一项对 2000 年至 2014 年在一家单一的三级中心随访的所有双胎妊娠女性进行的回顾性队列研究。我们使用了两种方法来确定孕期体重增加的最佳范围：一种是统计学方法（低风险、结局正常的妊娠中孕期体重增加的四分位间距）和一种基于结果的方法（通过确定不良结局发生率增加的孕期体重增加下限和上限阈值）。主要结局是早产。采用逻辑回归分析估计孕期体重增加低于或高于正常范围与研究结局的关系，并以 95%置信区间表示调整后的比值比。这些关联按孕前体重指数组分层。
共有 1274 名双胎妊娠女性符合研究标准：43 名被归类为体重不足，777 名正常体重，278 名超重，176 名肥胖。我们对最佳孕期体重增加范围的估计与医学研究所的建议相似，除了肥胖组，我们在 37 周时的最佳孕期体重增加范围（9.3-16.3kg）低于医学研究所暂定建议（11.3-19.1kg）。我们的队列中几乎有一半的女性孕期体重增加不当：30%（n=381）体重增加不足，17%（n=216）体重增加超过医学研究所的建议。在正常体重组中，孕期体重增加低于建议与早产和出生体重低于第 10 百分位的风险增加以及高血压疾病风险降低有关，而孕期体重增加超过建议与高血压疾病风险增加和出生体重低于第 10 百分位的风险降低有关。这些关联在超重和肥胖组中不太一致。
这些发现将孕期体重增加确定为双胎妊娠中早产和其他妊娠并发症的一个潜在可改变的危险因素。需要进一步的前瞻性研究来确定旨在优化孕期体重增加的干预措施是否可以改善这些高危妊娠的结局。
