Prepregnant reproductive risk and subsequent birth outcome among Scandinavian parous women

摘要

SUMMARYThis study examined the impact of maternal prepregnant stature, smoking, and past reproductive characteristicson gestational length, birthweight, weight-for-gestation, and crown heel length. Analyses were basedon 5722 para one and two Caucasian women in Trondheim and Bergen (Norway) and Uppsala (Sweden)who had a singleton pregnancy and who were interviewed before 20 completed weeks of gestation. Dataincluded information about previous induced and spontaneous abortions, prepregnant weight and height,smoking, course and outcome of previous pregnancies with special reference to preterm and low birthweight(LBW) births, and perinatal deaths. Number of adverse outcome predictors was counted for each woman andbirth outcomes were analysed by that number. Separate univariate and multivariate analyses examined theimpact of the individual risk characteristics. Mean birthweight, crown heel length, and gestational lengthwere significantly related to number of prepregnant risk characteristics with a dose response decrease from3750 g, 51.2 cm, and 39.6 weeks to 2955 g, 47.7 cm, and 37.7 weeks for women with zero and six riskfactors, respectively. Both univariate and multivariate analyses showed that prepregnant weight, a previousLBW birth, and cigarette smoking around conception were the strongest birthweight predictors with a meanBW reduction of 424 g (95% CI 373, 475 g) and 130 g (95% CI 112, 157 g) for a previous LBW birth and10 cigarettes per day, respectively. As 88% of birthweight variation was left unexplained by theseprepregnancy characteristics, it may be concluded that the major risk factors are either unknown or that mainpredictors of birthweight, such as life style factors, exert their effect?during gestation, or both.