From the abstract:
The health effects of antenatal maternity leave have been scarcely evaluated. In California, women are eligible for paid benefits up to 4 weeks before delivery. We explored whether leave at ≥36 weeks gestation increases gestation and birthweight, and reduces primary cesarean deliveries among full-time working women.
Maternity leave in late pregnancy shows promise for reducing cesarean deliveries and prolonging gestation in occupationally strained women.
Juggling Work and Breastfeeding: Effects of Maternity Leave and Occupational Characteristics
Source: Sylvia Guendelman, Jessica Lang Kosa, Michelle Pearl, Steve Graham, Julia Goodman and Martin Kharrazi, Pediatrics, Vol. 123 no. 1, January 2009