Results
From 1 January 2012 to 31 December 2017, there were 1,776 women aged ≥ 40 years who delivered at Álvaro Cunqueiro Hospital. Women who had multiple gestations and women delivering at < 39 weeks of gestation were excluded. There were a total of 603 pregnant women in the expectant management group compared to 634 women in the induction group. Baseline characteristics were similar between the two groups (Table 1). The delivery outcomes are shown in Table 2. There was no significant difference in the rate of caesarean section between the induction and expectant management groups (24% vs. 24.4%) (p=0,971). The risk of urgent intrapartum caesarean section was 44.1% in the induction group versus 33.1% in the expectant management group; these differences were not significant (p=0,127).
A secondary analysis showed that in the group of women without any previous surgical or vaginal delivery, the distribution according to the type of labour did not show statistically significant differences between groups (p= 0,109). The rate of successful trial of labour after caesarean (TOLAC) was 57.3% in the expectant management group and 51.2% in the induction group. These differences were not statistically significant (p=0,247). There were significant between-group differences in the frequency of stained amniotic fluid (147 of 603 in the expectant management group [24.4%] versus 89/634 in the induction of labour group [10.9%] ).
The neonatal outcomes are presented in Table 3. No statistically significant differences were found for the Apgar value at 5 min and umbilical artery pH value. There were two cases of stillbirth in the expectant management group, and no intrauterine foetal deaths were registered in the induction group. These differences were not statistically significant (P =0,147). The expectant management group needed more advanced paediatric support at birth than the labour induction group. (Table 4). The rate of admission to the NICU was lower in the labour induction group (p=0,000) than that in the expectant management group.