Division of Maternal Fetal Medicine, NorthShore University Health System, Evanston, IL; Division of Maternal Fetal Medicine, University of Chicago, Chicago, IL.
Department of Obstetrics and Gynecology, NorthShore University Health System, Evanston, IL; Institute for Policy Research, Northwestern University, Evanston, IL.
Am J Obstet Gynecol. 2022 Dec;227(6):887.e1-887.e15. doi: 10.1016/j.ajog.2022.06.030. Epub 2022 Jun 25.
Histologic examination of the placenta is often performed after preterm birth. Although placental examination cannot change the index pregnancy outcome, it may inform the risk of adverse outcomes in a subsequent pregnancy. Previous research has examined the association between individual histologic lesions and pregnancy outcomes without consistent results.
This study aimed to determine the independent contributions of the major placental pathology histologic types to recurrent preterm birth.
This was a retrospective cohort study of deliveries at a tertiary care center from January 2009 to March 2018. Individuals with ≥2 births, an index birth of <37 weeks of gestation, and a placental pathology report from the index pregnancy were included. The presence of maternal vascular malperfusion, fetal vascular malperfusion, acute inflammation, and chronic inflammation was extracted from the pathology reports for each index placenta and classified as none, low grade, or high grade. A log-binomial model incorporating all 4 placental pathology histologic types, index gestational age, race, and maternal age was used to estimate the associations between each placental histologic type and risk of recurrent preterm birth. Moreover, 2-way interaction terms were studied among placental histologic types. In addition, 2 stratified analyses were completed on the basis of characteristics of the index preterm birth: (1) by late preterm (gestational age of 34-36 weeks) vs early-to-moderate preterm birth (<34 weeks) and (2) a subgroup analysis of those with spontaneous preterm birth.
A total of 924 pregnancy pairs met the inclusion criteria. Only high-grade chronic inflammation was independently associated with an increased risk of recurrent preterm birth (adjusted risk ratio, 1.37; 95% confidence interval, 1.03-1.81). Stratified analysis by gestational age group demonstrated maternal vascular malperfusion was associated with recurrent preterm birth only among those with early preterm birth (adjusted risk ratio, 1.40; 95% confidence interval, 1.01-1.93). Among participants with spontaneous preterm labor, no association was found between pathology histologic types and risk of preterm birth.
Among index preterm pregnancies, high-grade chronic placental inflammation was associated with recurrent preterm birth. Low-grade maternal vascular malperfusion was associated with recurrent preterm birth only among those with an early or moderate index preterm birth (<34 weeks of gestation). These findings may be useful in determining the risk profile for individual patients and may generate hypotheses as to the pathogenesis of recurrent preterm birth.
早产产后通常会进行胎盘组织学检查。尽管胎盘检查不能改变指数妊娠的结局，但它可能会提示后续妊娠不良结局的风险。先前的研究已经检查了单个组织学病变与妊娠结局之间的关联，但结果并不一致。
本研究旨在确定主要胎盘病理学组织类型对复发性早产的独立贡献。
这是一项回顾性队列研究，纳入了 2009 年 1 月至 2018 年 3 月在三级医疗中心分娩的患者。纳入标准为：至少有 2 次分娩，指数妊娠分娩<37 周，且有胎盘病理学报告。从每个指数胎盘的病理学报告中提取母体血管灌注不良、胎儿血管灌注不良、急性炎症和慢性炎症，并将其分为无、低级别或高级别。采用包含所有 4 种胎盘病理学组织类型、指数孕龄、种族和产妇年龄的对数二项式模型，估计每种胎盘组织学类型与复发性早产风险之间的关系。此外，还研究了胎盘组织学类型之间的 2 个双向交互项。此外，还根据指数早产的特征完成了 2 项分层分析：（1）晚期早产（孕龄 34-36 周）与早-中期早产（<34 周），以及（2）自发性早产的亚组分析。
共有 924 对妊娠符合纳入标准。只有高级别慢性炎症与复发性早产风险增加独立相关（调整风险比，1.37；95%置信区间，1.03-1.81）。按孕龄组分层分析显示，仅在早期早产患者中，母体血管灌注不良与复发性早产相关（调整风险比，1.40；95%置信区间，1.01-1.93）。在自发性早产临产患者中，病理学组织学类型与早产风险之间无关联。
在指数早产妊娠中，高级别慢性胎盘炎症与复发性早产相关。仅在早-中期指数早产（<34 周妊娠）患者中，低级别母体血管灌注不良与复发性早产相关。这些发现可能有助于确定个体患者的风险状况，并为复发性早产的发病机制提供假设。
