Uterine rupture: Results from a prospective population-based study in Italy

To determine the incidence of uterine rupture (UR), and evaluate risk factors, management, and associated maternal and perinatal outcomes.

This multicentre prospective population-based study involved six regions in Italy accounting for 49% of national births. The study population comprised all women aged 11-59 years delivering at ≥22 gestational weeks with a diagnosis of UR from September 2014 to August 2016. Maternal and pregnancy characteristics and information on potential risk factors were collected. Unadjusted relative risks (RR) and 95% confidence intervals (CI) were computed with respect to the background population.

In total, 74 cases of UR occurred among the study population (rate 0.16/1000 pregnancies; mean age 34 years; 14 perinatal deaths, one maternal death). A significantly higher risk of UR was observed for maternal age ≥ 35 years (RR = 1.58, 95% CI 1.00-2.51), multiparity (RR = 5.71, 95% CI 3.14-10.04), previous caesarean section (RR = 20.5, 95% CI 11.11-37.74) and uterine scarring (RR = 6.44, 95% CI 2.94-14.12). A significant association was observed between UR and caesarean section as the mode of delivery (RR = 27.9, 95% CI 10.2-76.5) and gestational age < 37 weeks (RR = 11.82, 95% CI 7.46-18.71).

This study found a low rate of UR compared with other European countries, probably due to the high rate of primary caesarean sections and to resistance towards trial of labour and vaginal delivery after caesarean section among obstetricians in Italy. The unforeseen increase in caesarean sections -and, as a result, an increase in placenta accreta spectrum disorders, peripartum hysterectomy and related maternal and perinatal morbidity and mortality as a consequence of previous uterine scarring - failed to ensure better maternal and perinatal outcomes.