Spontaneous cephalic version and risk factors for persistent breech presentation: a longitudinal retrospective cohort...

Area of Science:

• Obstetrics
• Fetal Medicine
• Maternal-Fetal Medicine

Background:

• Breech presentation is a common fetal malposition diagnosed in early pregnancy.
• Understanding the rate of spontaneous version and risk factors for persistent breech presentation is crucial for perinatal care.

Purpose of the Study:

• To determine the rate of spontaneous version in breech presentation from mid-pregnancy to term.
• To identify risk factors associated with persistent breech presentation diagnosed in the second trimester.

Main Methods:

• Retrospective cohort study of 25,313 pregnant women.
• Second-trimester ultrasound (22-26 weeks) for initial diagnosis.
• Cox regression analysis to assess risk factor associations.

Main Results:

• Prevalence of breech presentation was 36.8% at 22-26 weeks; 4.2% persisted to labor.
• Multiparity and later gestational age at delivery decreased persistent breech risk.
• Increased risk of persistent breech presentation was associated with female fetus, lateral/fundal placenta, and uterine malformations.

Conclusions:

• Approximately 4% of second-trimester breech presentations persist until term.
• Maternal age over 40, female fetus, placental location, and uterine anomalies are risk factors for persistent breech presentation.
• Higher educational attainment, multiparity, and later delivery gestational age are protective factors against persistent breech presentation.