Mode of Delivery

Singletons

In singleton births, spontaneous vertex (normal vaginal) deliveries have fallen steadily since 1976 from (75.8% to 61.8%). Forceps deliveries have fallen from 13.3% in 1976 to a low of 6.8% in 2002 then rising since then to 9.8% in 2009. This is mirrored by the rise in other modes of delivery, in particular caesarean section.

The chart below illustrates the changes in mode of delivery since 1998.

Elective  and emergency caesarean section rates have both increased steadily since 1976 (from 4.7% to 10.1% and 3.9% to 14.8% respectively). The overall caesarean section rate has risen from 8.6% in 1976 to 24.9% in 2009. Possible explanations for this rise include demographic changes, differences in clinical practice, characteristics and views of the obstetrician, the organisation and availability of resources, one to one support in labour and womens' choices. The change in practice for delivery of breech presentation, repeat caesarean section, delivery of preterm infants and twins are contributing to the overall rise. In addition maternal age and weight are rising and this has been shown to correlate with a rise in caesarean section (1).

Ventouse (vacuum extraction) was less than 1% until 1990 then rose to 5.6% in 2003.  Since then there has been a steady decline to 3.3% in 2009. Vaginal breech delivery has fallen slowly but steadily from 1.7% in 1976 to 0.2%. In 1976 rates of induction of labour were 47.6% and then fell steadily to reach a low of 20.3% in 1989.  Since 1989, rates of induction have risen and then fluctuated at around 27%, but are once again showing a steady decline over the last few years, with a rate of 21.7% in 2009.  Population studies have shown a rise in perinatal and neonatal morbidity and mortality in prolonged pregnancies which has led to current recommendations for considering induction of labour after 41 completed weeks (2, 3).

Multiple births

Multiple births are less likely to be delivered vaginally, with 29.3% being delivered by elective caesarean section (compared to 6.1% in 1976) and 35.1% by emergency section (compared to 4.5% in 1976). The incidence of multiple births is rising partly because of an older maternal population (multiple births are more common with increasing maternal age) and the use of ovulation induction and IVF (In Vitro Fertilisation).

Click below for related data:

• Live Births by Mode of Delivery  [34KB]

References:

1. National Sentinel Caesarean Section Audit Report. October 2001
2. Gülmezoglu AM, Crowther  CA, Middleton P. Induction of labour for improving birth outcomes for women at or beyond term. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945.pub2.

3. http://www.nice.org.uk/nicemedia/live/12012/41255/41255.pdf