Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
Department of Women's Health, Division of Pregnancy and Childbirth, Karolinska University Hospital, Stockholm, Sweden.
J Matern Fetal Neonatal Med. 2024 Dec;37(1):2345855. doi: 10.1080/14767058.2024.2345855. Epub 2024 Apr 28.
Intraamniotic infection (IAI) and subsequent early-onset neonatal sepsis (EONS) are among the main complications associated with preterm prelabor rupture of membranes (PPROM). Currently used diagnostic tools have been shown to have poor diagnostic performance for IAI. This study aimed to investigate whether the exposure to IAI before delivery is associated with short-term variation of the fetal heart rate in pregnancies with PPROM.
Observational cohort study of 678 pregnancies with PPROM, delivering between 24 + 0 and 33 + 6 gestational weeks from 2012 to 2019 in five labor units in Stockholm County, Sweden. Electronic medical records were examined to obtain background and exposure data. For the exposure IAI, we used the later diagnosis of EONS in the offspring as a proxy. EONS is strongly associated to IAI and was considered a better proxy for IAI than the histological diagnosis of acute chorioamnionitis, since acute chorioamnionitis can be observed in the absence of both positive microbiology and biochemical markers for inflammation. Cardiotocography traces were analyzed by a computerized algorithm for short-term variation of the fetal heart rate, which was the main outcome measure.
Twenty-seven pregnancies were categorized as having an IAI, based on the proxy diagnosis of EONS after birth. Fetuses exposed to IAI had significantly lower short-term variation values in the last cardiotocography trace before birth than fetuses who were not exposed (5.25 vs 6.62 ms; unadjusted difference: -1.37, = 0.009). After adjustment for smoking and diabetes, this difference remained significant. IAI with a later positive blood culture in the neonate ( = 12) showed an even larger absolute difference in STV (-1.65; = 0.034), with a relative decrease of 23.5%.
In pregnancies with PPROM, fetuses exposed to IAI with EONS as a proxy have lower short-term variation of the fetal heart rate than fetuses who are not exposed. Short-term variation might be useful as adjunct surveillance in pregnancies with PPROM.
羊膜腔内感染（IAI）和随后的早发性新生儿败血症（EONS）是与早产胎膜早破（PPROM）相关的主要并发症之一。目前使用的诊断工具已被证明对 IAI 的诊断性能不佳。本研究旨在探讨分娩前是否存在 IAI 暴露与 PPROM 妊娠胎儿心率的短期变化是否相关。
这是一项观察性队列研究，纳入了 2012 年至 2019 年期间瑞典斯德哥尔摩县五个分娩单位的 678 例 PPROM 妊娠患者，分娩孕周为 24+0 至 33+6 周。检查电子病历以获取背景和暴露数据。对于暴露于 IAI，我们使用后代中 EONS 的后期诊断作为替代指标。EONS 与 IAI 密切相关，并且比急性绒毛膜羊膜炎的组织学诊断更能代表 IAI，因为即使没有阳性微生物学和炎症生化标志物，也可能观察到急性绒毛膜羊膜炎。胎儿心率的短期变化通过计算机算法分析胎儿心电图记录，这是主要的观察指标。
根据出生后 EONS 的代理诊断，有 27 例妊娠被归类为存在 IAI。与未暴露于 IAI 的胎儿相比，暴露于 IAI 的胎儿在出生前最后一次胎儿心电图记录中的短期变化值明显较低（5.25 与 6.62ms；未调整差异：-1.37， = 0.009）。调整吸烟和糖尿病后，这种差异仍然显著。新生儿血培养阳性的 IAI（ = 12）的 STV 差异更大（-1.65； = 0.034），相对减少 23.5%。
在 PPROM 妊娠中，以 EONS 为代理的 IAI 暴露的胎儿与未暴露的胎儿相比，胎儿心率的短期变化较低。短期变化可能是 PPROM 妊娠中有用的附加监测方法。
