INSUFFICIENT REMODELING OF THE UTERINE CONNECTIVE-TISSUE IN WOMEN WITH PROTRACTED LABOR

Objective-To investigate the association between a slow progress of labour and insufficient remodelling of the uterine connective tissue. Design-An open comparative study. Setting-Danderyd Hospital, Department of Obstetrics and Gynaecology, referral centre. Subjects-Eleven women (study group) in oxytocin augmented labour but with an unripe cervix in whom vaginal delivery could not be accomplished and 12 women (normal labour group) in normally progressing spontaneous labour and a favourable cervix but who needed to be delivered by caesarean section due to signs of fetal distress. Interventions-At caesarean section tissue specimens were obtained from the fundus, the isthmus and the cervix uteri. Main outcome measures-Collagen concentration and extractability, collagenolytic activity expressed as DNP-peptide hydrolytic activity and the concentrations of sulphated glycosaminoglycans (S-GAG) and hyaluronic acid (HA) in the tissue specimens. Results-Statistically significantly higher concentrations and lower extractability of collagen in the isthmus and the cervix uteri was found in women with slow progress of labour compared with those with normal labour. Conclusions-An insufficient remodelling of the connective tissue in the cervix and isthmus uteri may contribute to slow progress of labour.