Results
A total of 71 women were included in the study group, of whom 40
experienced complete thickness uterine rupture and 31 had uterine scar
dehiscence. They were compared to 97 cases of successful VBAC matched by
maternal age, BMI, gestational age, and neonatal birth weights of the
first and second deliveries.
The basic characteristics of the study and the control groups are shown
in Table 1. Maternal age, gravidity and parity were higher in the study
group, as expected by the study design. The study group included women
with dehiscence or asymptomatic rupture in a repeat CD, whereas the
control group included only women after their first VBAC, which means
they only had one prior CD. Although the study group was statistically
older than the control group (30.2 ± 4.8 years vs. 27.8 ± 4.6 years,
p=0), this difference is not clinically significant. There were no
significant differences between the groups regarding neonatal birth
weight at first delivery and a statistical, but not clinically
meaningful difference in birth weight at the second delivery. These
potential confounders were included in the logistic regression (Tables
2,3). Infection in the previous delivery remained statistically
significant, with odds ratio of 3.41
Sixteen of 71 (22.5%) women with uterine rupture or dehiscence during
the current birth, had an infection in proximity to their previous CD,
compared to 8 of 97 (8.2%) in the control group (p=0.01).
We also compared the group with complete uterine rupture to the control
group. Among 40 women with uterine rupture, 10 (25%) had an infection
at their first CD, as compared to 8 of 97 (8.2%) of the controls
(p=0.008). This result remained statistically significant in the
logistic regression (Table 3). There was no difference regarding the
infection rate between the uterine rupture group and the dehiscence
group (25% vs. 16%, p= 0.27).
We divided the type of infection into three groups: intrapartum fever,
postpartum fever and SSI. SSI and in particular endometritis, had the
strongest correlation to uterine rupture at subsequent delivery. None of
the control group patients had endometritis, but 7 of 71 (9.8%) in the
study group and 5 of 40 (12.8%) in the complete rupture group did. No
significant difference was found between groups in terms of intrapartum
fever (Table 4).