BJOG. 2021 Nov 12. doi: 10.1111/1471-0528.17005. Online ahead of print.
ABSTRACT
OBJECTIVE: To investigate the impact of uterine contractile activity on the outcome of trial of labour after caesarean section (TOLAC).
DESIGN: Secondary, blinded analyses of a prospective TOLAC cohort.
SETTING: Two labour wards, in a university tertiary hospital and a central hospital.
POPULATION: 194 TOLAC parturients with intrauterine tocodynamometry during labour.
METHODS: Analysis of intrauterine pressure, frequency of contractions and baseline tonus of uterine muscle in 30-minute periods for four hours prior to birth.
MAIN OUTCOME MEASURES: Primary Outcome: uterine contractile activity during TOLAC. Secondary aims: contributors associated with failed TOLAC and uterine rupture.
RESULTS: TOLAC succeeded in 74% of cases. Uterine contractile activity, expressed as intrauterine pressure, was significantly higher in successful compared with failed TOLAC (210 vs 170 MVU). The statistically significant risk factors of failed TOLAC, after multivariate regression analysis, were prolonged gestational age, reduced cervical dilatation at admission, and lower mean intrauterine pressure. In cases of uterine rupture contractile activity did not differ from that in failed TOLAC. Cervical ripening with a Foley catheter appeared to be a risk factor of uterine rupture, as well as cervical dilatation < 3 cm at admission. The incidence of total uterine rupture was 2.6% (n=5).
CONCLUSIONS: Parturients with successful vaginal birth had higher uterine contractile activity than those experiencing failed TOLAC or uterine rupture despite similar use of oxytocin. Induction of labour with a Foley catheter turned out to be a risk factor of uterine rupture during TOLAC among parturients with no previous vaginal delivery.
PMID:34773355 | DOI:10.1111/1471-0528.17005
