The uterus needs to be trained into action! Most first labours are fraught with the problem of in-coordinate contractions. That is why first labours are often longer, requiring more “inductions” or “augmentations” with “drugs”. Once the uterus has undergone “training” with the first labour, it retains the “memory” of what to do and as a result, the second and third labour are characterised by more synchronised (thus more painful but better) contractions and therefore quicker labour. When a woman had a “C-section” for her first pregnancy, especially an elective “C-section”, the uterus did not get into labour and lacked “training”. Additionally, the uterus has a scar and is therefore weaker. Doctors are therefore reluctant to give these women “drugs” to make the uterus contract better. As a result, the chance of a successful vaginal birth is lower (but still possible).
It also needs to be said that most women have Cesarean sections for medical reasons: breech presentation, placenta praevia are examples. It is generally felt that the chance of vaginal birth is higher if the previous “C-section” was done for “non-recurring” causes; for example, breech. It is unlikely the second pregnancy is also breech. However, if the previous “C-section” was done for a “recurring cause”, the chance of a successful vaginal delivery is lower; for example, big baby (CPD: cephalopelvic disproportion). This is because we tend to produce similar sized children (genetics!).
Posted in: Common Queries Regarding Obstetrics