Researchers led by Sylvia Guendelman, professor of maternal and child health at Berkeley's School of Public Health, found in one study that women who started their leave in the last month of pregnancy were less likely to have Caesarean deliveries, while another found that new mothers were more likely to establish breastfeeding the longer they delayed their return to work.

"In the public health field, we'd like to decrease the rate of C-sections and increase the rate of breastfeeding," Guendelman said in a statement. "C-sections are really a costly procedure, leading to extended hospital stays and increased risks of complications from surgery, as well as longer recovery times for the mother. "

For babies, it is known that breastfeeding protects them from infection and may decrease the risk of Sudden Infant Death Syndrome, allergies and obesity, Guendelman said.

"What we're trying to say here is that taking maternity leave may make good health sense, as well as good economic sense," Guendelman said.

The findings are published in the journal Women's Health Issues.