The effectiveness of antenatal care in preventing intrauterine growth retardation and low birth weight due to preterm delivery.

A case-control study was conducted to assess the effectiveness of antenatal care in preventing intrauterine growth retardation (IUGR) and low birth weight due to preterm delivery (PD), using data from 1837 births which took place in 25 hospitals in Mexico City during 1984. Women with an inadequate number of visits for gestational age had 63% greater odds of IUGR (95% CI: 1.01, 2.65) and 51% greater odds of PD (95% CI: 1.02, 2.23) than women with an adequate number. The content of antenatal visits showed no independent effect on the prevention of IUGR. Women having had poor content showed a PD OR of 1.76 (95% IC: 1.33, 2.34). An important reduction in the incidence of births with IUGR and PD could be expected if women could attend an adequate number of antenatal visits (11 and 9% reductions, respectively). Eighteen per cent of the PD births would probably be prevented if antenatal care could include at least six procedures: blood pressure, height and weight, urine and blood samples, and pelvic examination.