Maternal prostaglandin levels after vaginal examination in two pregnancy.

Plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) levels were measured in patients with twin pregnancies in come of whom the cervix was dilated and effaced. Significant rises in PGF M values were observed 5 and 10 minutes after vaginal examination in those patients who had a negative cervical score; these changes were abolished by prophylactic oral use of the beta-sympathomimetic drug fenoterol (Berotec; Boehringer Ingelheim). Patients who went into labour within 72 hours of examination had a greater percentage rise in PGFM levels than those in whom the onset of labour was delayed. Beta-sympathomimetic drugs such as fenoterol may be of value in preventing prostaglandin release and delaying the onset of labour.