Multivariate analysis of determinants of fetal growth retardation

Objective: To analyse the relative effect of the risk factors related to fetal growth retardation (FGR) in the central area of Spain. Study design: This is a case-control survey of 370 full-term gestations. Of the 370 women, 185 were diagnosed with intrauterine growth retardation, and 185 were in the normal group. All came from a central region of Spain. We took into account 25 possible risk factors. Results: In the FGR group we found 12 risk factors with statistical significance in the univariate analysis (tobacco, drugs, low pre-pregnancy weight, low maternal height, little gestational weight gain, excessive physical activity during pregnancy, low socioeconomic status, low educational level, unmarried, urinary infection, mother's haematological changes, and previous infertility). After the multiple logistic regression analysis, five factors were shown to exist as independent risks (tobacco: OR, 23.50; 95% CI, 3.01–183.18; P < 0.01; low pre-pregnancy weight: OR, 4.01; 95% CI, 2.14–7.51; P < 0.001; low socioeconomic status: OR, 2.91; 95% CI, 1.72–4.90; P < 0.001; little gestational weight gain: OR, 2.52; 95% CI, 1.21–5.22; P < 0.05; and urinary infection: OR, 3.83; 95% CI, 1.49–9.87; P < 0.01). Conclusions: (i) Tobacco, low pre-pregnancy weight and low socioeconomic status are the three main cause-effect factors of relative importance in our sanitary zone for FGR. (ii) Disproportionate FGR is related more to older mothers and maternal previous illness than to the proportionate FGR.