The unpredictability of a planned vaginal delivery is one of the reasons that some women prefer to arrange a planned cesarean delivery for the birth of their child. The overwhelming majority of planned cesarean deliveries result in the very same outcome, while unfortunately, planning a spontaneous vaginal delivery does not guarantee a spontaneous vaginal delivery outcome.
What's the likelihood of needing forceps, ventouse or both?
In 2006-07, the NHS in England estimates that only 52% of deliveries were 'normal deliveries' (the NHS' term, not mine), defined as those 'without surgical intervention, use of instruments, induction, epidural, spinal or general anaesthetic'. Table 12 states that, "For all deliveries with a spontaneous onset of labour just over three quarters resulted in a spontaneous delivery; approximately 12% resulted in an instrumental delivery; and nearly 12% resulted in a caesarean."
This means that 1 in 4 women planning a vaginal delivery will end up needing instrumental assistance (i.e. forceps, ventouse or both) and/or an emergency cesarean delivery.
By comparison, Table 12 reveals that where a cesarean delivery was planned (see: method of onset of labour), 0.9% ended up as a vaginal delivery outcome and 99% had the outcome of cesarean delivery. Unfortunately, the table does not detail how many of these cesarean outcomes were emergency surgeries, but other studies have shown that number to be very small.
This means that 1 in 10 women planning a cesarean delivery will have an unplanned vaginal delivery outcome, and only 0.1% will need instrumental vaginal assistance.
How is this a 'benefit' with planned cesarean delivery?
The NHS Maternity Statistics summary puts the total number of instrumental deliveries at 11.5%, but again (see blog on episiotomy occurrence below), you need to look at the data a little more closely to find out what percentage of vaginal deliveries involved this type of assistance. Table 12 shows that while 12.4% of vaginal deliveries that began spontaneously required instrumental assistance, the occurrence rate rises to 14%, 16% and 17.1% for vaginal deliveries that were induced. Compare these figures with the 0.1% occurrence with a planned cesarean delivery.
Then look at the medical research on the repercussions of instrumental delivery: increased risk for pevic floor disorders, incontinence, perineal pain and other long-term health issues (see my website for listings of medical studies). Remember, it is not my aim to put women off having a vaginal delivery or in any way to criticize women who choose this birth method - but the avoidance of an instrumental delivery and its associated risks serves as another legitimate reason why some women decide to schedule a cesarean.