Pregnancy hazards associated with low maternal body mass indices

Analysis of the obstetric records of 41,955 public patients with singleton pregnancies at the Mater Misericordiae Mothers' Hospital, South Brisbane, showed a significant association (increased odds ratio) between Low Maximum Pregnancy Maternal Body Mass Index (Quetelets Index 20-24.6 and maternal anaemia, the use of intravenous tocolysis, low birth-weight (< 1,500 g and < 2,500 g), low Apgar score (< 7 at 5 minutes) and perinatal mortality. Parturients with a Very Low Body Mass Index (Quetelets Index < 20) had even greater odds ratios in respect of the above obstetric hazards. Both the Low and Very Low Body Mass Index cohorts had significantly reduced risks of having hypertension (both essential and preeclamptic) or having their labours induced or augmented. The results are presented as odds ratios with confidence limits after controlling for the potentially confounding covariables of maternal age, parity, smoking habits and gestational age.