Pre-natal care and prevention of low birth weight: A case-control study in southern Spain

Abstract

A national policy for improving pre-natal care was applied throughout Andalusia (southern Spain) in 1984. We report the results of an evaluation of this health care programme as regards the prevention of low birth weight. Two case-control studies in a hospital setting were performed: one before the programme was implemented (1981–1982) and the second one 6 years after the programme (1990–1993). A total of 179 cases and 395 controls for the period 1981–1982 and 251 cases and 381 controls for 1990–1993 were selected. Pre-natal care was assessed on the basis of the number of pre-natal care visits, the date of the first visit and an American composite index to adjust for gestational age. Multiple-factor adjusted odds ratios (OR) and their 95% confidence intervals (CI) were estimated using logistic regression analysis. The use of pre-natal care significantly improved overtime: the proportion of women receiving no pre-natal care decreased from over 30% to less than 5% and the proportion of women starting pre-natal care in the first trimester for 1990–1993 was 3 times the figure for 1981–1982. In the 1981–1982 case-control study, pre-natal care was not related to low birth weight risk. In the 1990–1993 case-control study, a clear and significant trend was observed between the number of pre-natal care visits and the adequacy of care according to the composite index and the risk of low birth weight. When these relationships were analysed stratifying by gestational age, a significant trend was found between pre-natal care and pre-term low birth weight. The results suggest that the present Andalusian programme helps prevent pre-term low birth weight.