Risk of placental dysfunction disorders after prior miscarriages: a population-based study

Area of Science:

• Reproductive Medicine
• Maternal-Fetal Medicine
• Obstetrics

Background:

• Prior miscarriage is a common occurrence in women of reproductive age.
• Placental dysfunction disorders pose significant risks to maternal and fetal health.
• The association between recurrent miscarriage and subsequent pregnancy complications requires further elucidation.

Purpose of the Study:

• To investigate the association between the number of prior miscarriages and the risk of developing specific placental dysfunction disorders.
• To quantify the increased risks of preeclampsia, stillbirth, small for gestational age (SGA) infant, placental abruption, and spontaneous preterm birth in women with a history of miscarriages.

Main Methods:

• A large-scale, population-based cohort study involving 619,587 primiparous women.
• Risk estimation for placental dysfunction disorders based on the number of self-reported prior miscarriages (0, 1, 2, or 3+).
• Unconditional logistic regression analysis was employed, adjusting for numerous potential confounding factors.

Main Results:

• Women with one prior miscarriage showed minimal increased risk for placental dysfunction disorders.
• A history of two prior miscarriages was associated with increased risks of spontaneous preterm birth, preterm SGA infant, and placental abruption.
• Women with three or more prior miscarriages exhibited significantly higher rates of preeclampsia, stillbirth, SGA infant, placental abruption, and spontaneous preterm birth, with adjusted odds ratios around 2 for preterm complications.

Conclusions:

• A history of two or more miscarriages is a significant risk factor for placental dysfunction disorders.
• These findings underscore the necessity of incorporating prior miscarriage history into antenatal care risk assessments.
• Identifying women with a history of recurrent miscarriages can facilitate targeted monitoring and management strategies during pregnancy.