Foshan Institute of Fetal Medicine, Maternal & Child Health Hospital of Foshan, Foshan, Guangdong, China (Ye, Fan, Chen, Li, Rao, Zhou, Liu, Lin); Department of Obstetrics, Maternal & Child Health Hospital of Foshan, Foshan, Guangdong, China (Ye, Fan, Chen, Li, Rao, Zhou, Guo, Liu, Lin).
Medical Administration Division, People's Hospital of Huadu District, Guangzhou, Guangdong, China (Huang).
Am J Obstet Gynecol MFM. 2024 Sep;6(9):101439. doi: 10.1016/j.ajogmf.2024.101439. Epub 2024 Jul 28.
The existing evidence on the association between interpregnancy interval (IPI) and pregnancy outcomes primarily focuses on singleton pregnancies, with limited research on twin pregnancies.
This study aimed to investigate the association between IPI and adverse perinatal outcomes in twin pregnancies.
This population-based, retrospective cohort study analyzed data from the National Center for Health Statistics in the United States between 2016 and 2020. We included multiparous women aged 18 to 45 years with live-born twins without congenital anomalies, born between 26 and 42 weeks of gestation. Poisson regression models, adjusted for potential confounders, were used to evaluate the associations between IPI and adverse outcomes, including preterm birth (PTB) <36 weeks, small for gestational age (SGA), neonatal intensive care unit (NICU) admission, neonatal composite morbidity, and infant death. Missing data on covariates were managed using multiple imputations. Dose-response analyses were performed using the restricted cubic splines (RCS) approach. Subgroup analyses were stratified by maternal age, parity, and combination of neonatal sex. Sensitivity analyses were conducted using complete data and excluding pregnancies with intervening events during the IPI.
A total of 143,014 twin pregnancies were included in the analysis. Compared to the referent group (IPI of 18-23 months), an IPI of less than 6 months was associated with an increased risk of PTB<36 weeks (RR, 1.21; 95% confidence interval [95% CI]: 1.17-1.25), SGA (RR, 1.11; 95% CI: 1.03-1.18), neonatal composite morbidity (RR, 1.19; 95% CI: 1.12-1.27), NICU admission (RR, 1.18; 95% CI: 1.14-1.22), and infant death (RR, 1.29; 95% CI: 1.05-1.60). An IPI of 5 years or more was associated with an increased risk of PTB<36 weeks (RR, 1.18; 95% CI: 1.15-1.21), SGA (RR, 1.24; 95% CI: 1.18-1.30), neonatal composite morbidity (RR, 1.10; 95% CI: 1.05-1.15), and NICU admission (RR, 1.14; 95% CI: 1.11-1.17). The dose-response analyses showed that these outcomes had U-shaped or J-shaped associations with IPI. The associations between IPI and the outcomes slightly differed by advanced maternal age, parity, and combination of neonatal sex. The sensitivity analyses yielded similar results to the main findings.
Extreme IPI, less than 6 months or more than 5 years, was associated with adverse outcomes in twin pregnancies. IPI could be used as a predictor for risk stratification in high-risk twin pregnancies.
现有关于孕中期间隔（IPI）与妊娠结局之间关联的证据主要集中在单胎妊娠，对双胎妊娠的研究有限。
本研究旨在探讨 IPI 与双胎妊娠不良围产结局之间的关系。
这是一项基于人群的回顾性队列研究，分析了美国国家卫生统计中心 2016 年至 2020 年的数据。我们纳入了年龄在 18 至 45 岁之间、孕龄在 26 至 42 周之间、无先天性异常的多胎活产儿的母亲。采用泊松回归模型，调整了潜在混杂因素，评估了 IPI 与不良结局（包括<36 周的早产（PTB）、小于胎龄儿（SGA）、新生儿重症监护病房（NICU）入院、新生儿复合发病率和婴儿死亡）之间的关联。使用多重插补处理协变量缺失数据。使用受限立方样条（RCS）方法进行剂量-反应分析。按母亲年龄、产次和新生儿性别组合进行亚组分析。使用完整数据进行敏感性分析，并排除 IPI 期间发生干预事件的妊娠。
共有 143014 例双胎妊娠纳入分析。与参照组（IPI 为 18-23 个月）相比，IPI 小于 6 个月与<36 周的 PTB（RR，1.21；95%置信区间[95%CI]：1.17-1.25）、SGA（RR，1.11；95%CI：1.03-1.18）、新生儿复合发病率（RR，1.19；95%CI：1.12-1.27）、NICU 入院（RR，1.18；95%CI：1.14-1.22）和婴儿死亡（RR，1.29；95%CI：1.05-1.60）风险增加相关。IPI 为 5 年或更长时间与<36 周的 PTB（RR，1.18；95%CI：1.15-1.21）、SGA（RR，1.24；95%CI：1.18-1.30）、新生儿复合发病率（RR，1.10；95%CI：1.05-1.15）和 NICU 入院（RR，1.14；95%CI：1.11-1.17）风险增加相关。剂量-反应分析表明，这些结局与 IPI 呈 U 形或 J 形关联。IPI 与结局之间的关联在高龄产妇、产次和新生儿性别组合方面略有不同。敏感性分析得出的结果与主要发现相似。
极短的 IPI（小于 6 个月）或过长的 IPI（大于 5 年）与双胎妊娠的不良结局相关。IPI 可作为高危双胎妊娠风险分层的预测指标。
