The risk of prematurity and small-for-gestational-age birth in Mexico City: the effects of working conditions and antenatal leave.

Objectives: This study examined the effect of working conditions, occupational stress, and antenatal leave on risk of small-for-gestational age and premature births in Mexico City.

Methods: Over a 3-month period, 2663 (96.2%) of 2767 women who gave birth at three major hospitals and worked at least 3 months during pregnancy were interviewed shortly after delivery. After the exclusion of multiple gestations and birth defects, 261 (10.0%) small-for-gestational-age and 288 (11.0%) preterm births were identified.

Results: For small-for-gestational-age births, working more than 50 hours a week (odds ratio [OR] = 1.59), standing more than 7 hours a day (OR = 1.40), and no antenatal leave (OR = 1.55) were associated with an increased risk. Women with no antenatal leave were also much more likely to give birth prematurely (OR = 3.04).

Conclusions: In this study, arduous working conditions and lack of antenatal leave benefits were found to increase the risk of poor birth outcome in Mexican women. Enforcement of existing antenatal leave laws and provision of comparable benefits for the uninsured may reduce the incidence of small-for-gestational-age births and prematurity.