Mode of Delivery

Singletons

In singleton births, spontaneous vertex (normal vaginal) deliveries and forceps deliveries have fallen steadily since 1976 from (75.8% to 64.0%) and (13.3% to 7.1%) respectively. This is mirrored by the rise in other modes of delivery, in particular caesarean section. However long term follow up of large cohorts of women suggests that the optimal mode of delivery is usually a normal vaginal birth, with both caesarean section and instrumental delivery more likely to be associated with residual morbidity at one year (1). 

The chart below illustrates the changes in mode of delivery since 1976.

Elective  and emergency caesarean section rates have both increased steadily since 1976 (from 4.7% to 9.0% and 3.9% to 14.9% respectively). The overall caesarian section rate has risen from 8.6% in 1976 to 23.9% in 2005. 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 women's 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 (2).

Ventouse (vacuum extraction) was less than 1% until 1989 and has risen to around 5% in recent years.  Surveys in the UK and USA in 1996 suggested that ventouse was becoming popular and this is certainly borne out in the trends seen in Scotland  (2). Vaginal breech delivery has fallen slowly but steadily from 2% to under 1%. 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 slight decline over the last two years, with a rate of 24% in 2005.  Population studies have shown a rise in perinatal and neonatal morbidity and mortality in pregnancies of more than 42 weeks gestation which has led to current recommendations for induction of labour between 41 and 42 completed weeks. In 1976 rates of induction of labour were 47.6%. They fell steadily to reach a low of 20.3% in 1989 but have since risen and fluctuated at around 26% in the last 6 years. Population studies have shown a rise in perinatal and neonatal morbidity and mortality in pregnancies of more than 42 weeks gestation which has led to current recommendations for induction of labour between 41 and 42 completed weeks (3).

Multiple births