Lee Rachel, Brandt Justin S, Ananth Cande V
Division of Epidemiology and Biostatistics, Department of Obstetrics, Gynecology, and Reproductive Sciences, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, NYU Grossman School of Medicine, New York, NY, USA.
Eur J Epidemiol. 2024 Nov;39(11):1267-1276. doi: 10.1007/s10654-024-01171-z. Epub 2024 Nov 22.
Twins suffer a disproportionately higher burden of adverse perinatal outcomes than singletons. However, the degree to which preterm delivery shapes the relationship between abruption and perinatal mortality in twins is unknown. Through causal mediation decomposition, we examine how preterm delivery mediates the effect of abruption on perinatal mortality among twins using the US-matched multiple birth data (1995-2000). We estimated the hazard ratio (HR) from Cox models with gestational age as the timescale. We decomposed the total effect (TE) into counterfactual natural direct (NDE) and natural indirect (NIE) effects. 557,220 matched twin births, 1.3% (n = 7032) resulted in abruption with higher perinatal mortality rates than non-abruption births (143 versus 36 per 1000 births, respectively) and a 4.53-fold (95% confidence interval [CI]: 4.23, 4.82) increased hazard of perinatal mortality. HRs for NDE and NIE were 3.05 (95% CI: 2.84, 3.24) and 1.49 (95% CI: 1.49, 1.47, 1.50), respectively, and the proportion mediated (PM) was 41%. PM increased as the gestational age at delivery decreased. Associations persisted after correction for unmeasured confounders. The best strategies to improve perinatal delivery are delivery when abruption complicates twin pregnancies at term gestations and expectant management (avoiding early preterm delivery), if feasible, when abruption complicates twin pregnancies at preterm gestations.
与单胎妊娠相比，双胎妊娠围产期不良结局的负担要高得多。然而，早产在双胎妊娠中胎盘早剥与围产期死亡率之间的关系中所起的作用程度尚不清楚。通过因果中介分解，我们利用美国匹配的多胎出生数据（1995 - 2000年）研究早产如何介导胎盘早剥对双胎围产期死亡率的影响。我们以胎龄为时间尺度，从Cox模型估计风险比（HR）。我们将总效应（TE）分解为反事实自然直接效应（NDE）和自然间接效应（NIE）。557220例匹配的双胎出生中，1.3%（n = 7032）发生胎盘早剥，其围产期死亡率高于未发生胎盘早剥的分娩（分别为每1000例分娩中有143例和36例），围产期死亡风险增加4.53倍（95%置信区间[CI]：4.23，4.82）。NDE和NIE的HR分别为3.05（95% CI：2.84，3.24）和1.49（95% CI：1.47，1.49，1.50），中介比例（PM）为41%。PM随着分娩时胎龄的降低而增加。在校正未测量的混杂因素后，关联依然存在。改善围产期结局的最佳策略是，当足月双胎妊娠合并胎盘早剥时进行分娩；如果可行，当早产双胎妊娠合并胎盘早剥时进行期待治疗（避免早期早产）。
