Sexual intercourse for cervical ripening and induction of labour

The role of sexual intercourse as a method for induction of labour is uncertain.

Human sperm contains a high amount of prostaglandin, a hormone-like substance which ripens the cervix and helps labour to start. Sometimes it is necessary to help start labour and it has been suggested that sexual intercourse may be an effective means. However, there is not enough evidence to show whether sexual intercourse is effective or to show how it compares with other methods. More research is needed.

Authors' conclusions: 

The role of sexual intercourse as a method of induction of labour is uncertain. This is an important issue to pregnant women and their partners. There is a need for well-designed randomised controlled trials to assess the impact of sexual intercourse on the onset of labour. Any future trials investigating sexual intercourse as a method of induction need to be of sufficient power to detect clinically relevant differences in standard outcomes.

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Background: 

The role of prostaglandins for cervical ripening and induction of labour has been examined extensively. Human semen is the biological source that is presumed to contain the highest prostaglandin concentration. The role of sexual intercourse in the initiation of labour is uncertain. The action of sexual intercourse in stimulating labour is unclear, it may in part be due to the physical stimulation of the lower uterine segment, or endogenous release of oxytocin as a result of orgasm or from the direct action of prostaglandins in semen. Furthermore nipple stimulation may be part of the process of initiation.

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

Objectives: 

To determine the effects of sexual intercourse for third trimester cervical ripening or induction of labour in comparison with other methods of induction.

Search strategy: 

The Cochrane Pregnancy and Childbirth Group's Trials Register (June 2007) and bibliographies of relevant papers.

Selection criteria: 

Clinical trials comparing sexual intercourse for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

Data collection and analysis: 

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

Main results: 

There was one included study of 28 women which reported very limited data, from which no meaningful conclusions can be drawn.