Hyaluronidase for cervical priming and induction of labour
Abstract
Background
Dilatation and effacement of the cervix are not only a result of uterine contractions, but are also dependant 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.
Objectives
To determine the effects of hyaluronidase for third trimester cervical ripening or induction of labour in comparison with other methods of induction of labour
Search methods
The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000.
Selection criteria
(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.
Data collection and analysis
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.
Main results
There were no included trials.
Authors' conclusions
The role of hyaluronidase as a method of cervical priming or induction of labour is uncertain.
PICOs
Plain language summary
The role of hyaluronidase as a method of ripening the cervix and inducing labour is uncertain
The cervix is made of connective tissue which contains the enzyme hyaluronidase. Sometimes it is necessary to induce labour and there are many methods currently used. One of the methods is an injection of hyaluronidase into the cervix. This is done to help ripen the cervix and start labour. The review of trials found there is not enough evidence to show the effect of hyaluronidase or to compare it with other methods. More research is needed.
