Hyaluronidase for cervical priming and induction of labour.

Abstract

Dilatation and effacement of the cervix are not only a result of uterine contractions, but are also dependent upon ripening processes within the cervix. The cervix is a fibrous organ composed principally of hyaluronic acid, collagen and proteoglycan. Hyaluronic acid increases as pregnancy progresses, increases markedly after the onset of labour and decreases rapidly after birth of the infant. An increase in the level of hyaluronic acid is associated with an increase in tissue water content. Cervical ripening during labour is characterised by changes of the cervix with softening of the tissue and an increased water content. Cervical injection of hyaluronidase was postulated to increase cervical ripening. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. To determine the effects of hyaluronidase for third trimester cervical ripening or induction of labour in comparison with other methods of induction of labour The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000. (1) clinical trials comparing hyaluronidase used 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; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions. A strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involves a two-stage method of data extraction. There were no included trials. The role of hyaluronidase as a method of cervical priming or induction of labour is uncertain.