The usefulness of initial risk assessment as a predictor of pregnancy complications and premature delivery

Abstract

Risk assessment is an essential component of all programs for surveillance of pregnancy. The objective of the study is to assess the usefulness of initial risk status as predictor for pregnancy complications and premature delivery. A retrospective, area-based study including all women giving birth at Västerås Central Hospital, Sweden in 1990 (2,008) and 1992 (1,874). Data was collected before and after the introduction of a reduced routine surveillance program. The study populations were classified in a low-risk group and three risk groups according to presence of risk factors at booking (initial risk factors), development of pregnancy complications (later risk factors) or a combination of both. Relative risk for premature delivery and predictive value of initial risk factors for pregnancy complications were analyzed. The relative risk for premature delivery was significantly increased in all three risk categories both years except for the group with only initial risk factors in 1990. Risk factors were present at booking in 27% (1990) and 26% (1992). Pregnancy complications developed in 35% and 28%, respectively. The positive predictive value of initial risk factors for pregnancy complications was 40% and 33%, adding little useful information. The relative risk for premature delivery was correlated to obstetric risk but was moderately increased with initial risk factors only. The initial risk status is a poor predictor of pregnancy complications and cannot alone be used for individual planning of surveillance during pregnancy. Even for low risk women routine programs must be structured to secure adequate identification of current complications.