Research question

To assess whether the incidence of placental disorders of pregnancy decreases with increasing parity in repeat IVF pregnancies, in the same way as natural pregnancies.

Design

This was a retrospective cohort of deliveries between November 2008 and January 2020, in a single university-affiliated medical centre. The study included women with only IVF-attained singleton pregnancies (no natural conception) with at least two deliveries, and compared the obstetric and perinatal outcomes between first, second and third deliveries. Each woman served as her own control. The primary outcome was the incidence of placental-related disorders of pregnancy, defined as small for gestational age (SGA) neonates and/or pre-eclampsia.

Results

A total of 307 first deliveries, 307 second deliveries and 49 third deliveries by the same women were compared. A trend for a decreased rate of pre-eclampsia was noted with increased parity (P = 0.06) and a significant decrease in the rate of SGA: 11.7% for first delivery, 7.8% for second delivery and 2.0% for third (P = 0.04). This difference in SGA incidence was maintained in a matched sub-analysis of the 49 women with three deliveries (P = 0.04), and after adjustment for fresh/frozen embryo transfer (P = 0.03). Although SGA and pre-eclampsia were generally more common in IVF than natural pregnancies, their decrease with increasing parity mimicked that in natural pregnancies.

Conclusion

IVF pregnancies are associated with an increased risk of placental disorders of pregnancy. However, they exhibit a decrease in incidence with increasing parity.

中文翻译：

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后续 IVF 妊娠中的妊娠胎盘疾病——同胞队列

研究问题

评估妊娠期胎盘疾病的发生率是否随着重复 IVF 妊娠的胎次增加而降低，其方式与自然妊娠相同。

设计

这是 2008 年 11 月至 2020 年 1 月在一个大学附属医疗中心的回顾性分娩队列。该研究纳入了仅通过 IVF 获得的单胎妊娠（非自然受孕）且至少有两次分娩的女性，并比较了第一次、第二次和第三次分娩之间的产科和围产期结果。每个女人都是她自己的控制者。主要结果是胎盘相关妊娠疾病的发生率，定义为小于胎龄 (SGA) 的新生儿和/或先兆子痫。

结果

对相同女性的总共 307 次第一次分娩、307 次第二次分娩和 49 次第三次分娩进行了比较。随着胎次增加（P  = 0.06）和 SGA 率显着下降，先兆子痫的发生率呈下降趋势：第一次分娩为 11.7%，第二次分娩为 7.8%，第三次分娩为 2.0%（P  = 0.04 ）。SGA 发生率的这种差异在对 49 名产妇 ( P  = 0.04) 和新鲜/冷冻胚胎移植调整后 ( P  = 0.03)的匹配子分析中得以维持。尽管 SGA 和先兆子痫在 IVF 中通常比自然妊娠更常见，但随着胎次增加，它们的减少与自然妊娠相似。

结论

试管婴儿妊娠与妊娠期胎盘疾病风险增加有关。然而，随着胎次的增加，它们的发病率下降。