Taking a leave of absence before childbirth sharply lowers the rate of Caesarean section deliveries, according to new research from UC Berkeley.

Women who took a break from work after their 35th week of pregnancy were four times less likely to require the costly surgery, compared with women who worked almost up to their delivery date, according the study, which appears in the January/February issue of Women's Health Issues.

Caesarean sections, or C-sections, require an incision through the mother's abdomen and uterus to deliver a child, and they typically are used when a vaginal delivery could put the life of mother or baby in jeopardy. 

Not only is the procedure more costly than normal delivery, but it leads to longer recovery times for women and increased risk of surgical complications.

The study is among the first to analyze the health effects of a work break before delivery in U.S. women. Only 28 percent of those delivering their first child took leave from full-time work before giving birth, according to the U.S. Census.

"We don't have a culture in the United States of taking rest before the birth of a child, because there is an assumption that the real work comes after the baby is born," said Sylvia Guendelman, professor of maternal and child health at UC Berkeley's School of Public Health and lead author of the study.

Many women also cite financial reasons for not taking maternity leave before delivery.

The United States, in comparison to most industrialized countries, does not provide paid maternity leave. 

While federal law requires as many as 12 weeks of job-protected leave, it mandates no pay.

California, however, is one of five states that does provide paid maternity leave, typically 55 percent to 60 percent of wages. That includes four weeks of coverage before delivery, and six weeks or longer after delivery.

Despite these benefits, Guendelman said, the number of California women taking leave before delivery still is only slightly higher than the U.S. average.

Some women also fear a work stoppage could harm career advancement, she said.

Guendelman also led a new study on the effects of maternity leave on the duration of breast-feeding, published in the January issue of Pediatrics.

The study found that women taking six to 12 weeks of leave were twice as likely to cease breast-feeding their infants, compared with women who stayed off the job.

Women who returned to work after less than six weeks of maternity leave were four times as likely to stop breast-feeding.

The American Academy of Pediatrics advises feeding a newborn exclusively on breast milk for the first four to six months, which studies show protects them from infection, Sudden Infant Death Syndrome, allergies and obesity.

Reach Suzanne Bohan at 510-262-2789 or sbohan@bayareanewsgroup.com.