This study describes physiological pubic symphysis diastasis (PSD) and factors that affect PSD; whether the changes occur in pregnancy, labor or delivery; and whether postpartum regression occurs.METHODS:
This prospective cohort enrolled 91 term nulliparous, English-speaking women, age >18 into three groups: 45 vaginal deliveries, 22 labored cesarean (CS) deliveries and 24 non-labored CS deliveries. PSD was assessed via pain scores and supine radiographs within 48 hours of delivery and after 6, 12 and 24 weeks. Maternal, fetal, labor and delivery variables were recorded. Analyses were performed using SAS 9.3.RESULTS:
The overall mean PSD was 7.6 (SD 2.2). There was no difference in the mean PSD of women delivering vaginally (7.18 mm) versus CS (8.04 mm) (P=0.077). The mean PSD for labored and non-labored CS showed no difference. No intrapartum events impacted the degree of PSD. Pain scores correlated with degree of PSD (C=0.22) and regressed over time. Normalization (4–5 mm) of pregnancy PSD occurred by 6 weeks post partum. Physiological separation >10 mm was associated with increased pain scores postpartum and also occurred in patients undergoing elective cesarean.CONCLUSION:
Physiological PSD occurs during pregnancy with minimal effects of labor and delivery as assessed immediately postpartum. Cesarean delivery does not prevent physiological PSD but protects against pathological PSD. The data supports physiological PSD as a hormone-related change. We hypothesize that elastic expansion and recoil of the pubic symphysis occurs with vaginal delivery.