Persistent pelvic pain and pelvic joint instability.

As accepted as the condition of pelvic pain and pelvic joint instability (PPPJI) is in pregnancy, as controversial and doubted is the same diagnosis in non-pregnant women. Women suffering severe incapacitating PPPJI for years following parturition have recently founded an association. This offers a unique opportunity to investigate their characteristics. 153 of the 215 members answered a questionnaire. The majority (110) suffered PPPJI in first pregnancy with onset preceding 20 weeks gestation in 84 women. Onset was significantly earlier in users of oral contraceptives than in non-users (16.3 weeks and 20.5 weeks, respectively). The 153 women did not differ from the controls with regard to life-style, diseases prior to reproduction or reproduction. Their 358 deliveries were characterized by a marked excess of post-term deliveries, a raised proportion of infants of 4000 g or more, an extremely low sex-ratio of offspring (0.84) with 54.5% female births, and a significantly raised congenital hip dysplasia rate, consistent with elevated oestrogen and relaxin levels.