Causes and associated risk factor of retained placenta: a case control study

ABSTRACT

To determine the causes and to evaluate the significance of various associated risk factors of retained placenta in the study population. A retrospective case control study was carried out between June 1992 and May 1996 on 101 patients with retained placenta. The controls were randomly selected, 202 parturients delivered vaginally and had normal separation and expulsion of placenta. Epidemiological variables, relevant risk factors and selected parameters of index labour and delivery were studied. Retained placenta was more common both in primiparas and in grandmultiparas. Significant association was found between the occurrence of retained placenta and previous history of retained placenta, induced abortion, uterine instrumentation and scarred uterus. Important causative and associated factors identified in index labour and delivery included home delivery by Traditional Birth Attendants, prolonged labour, mismanaged third stage of labour, uterine atonia and morbid adherence of placenta and / or membranes. In the study population underlying causative and associated risk factors were identified as compared to a matchable control group