More women than ever are giving birth after age 50, thanks to the increasing use of infertility treatments.

Just how risky are these late-life pregnancies for both mother and baby? Riskier than giving birth even a few years earlier, according to findings from one of the first studies to address the issue.

Women in the Israeli study who gave birth in their sixth decade and beyond had a much higher risk of pregnancy- and delivery-related complications than women who gave birth in their mid- to late 40s.

The older women in the study were hospitalized during pregnancy almost three times as often as the 45- to 49-year-old women, and twice as many delivered low-birth-weight babies.

Researchers from Israel’s Sheba Medical Center characterized the findings among women 50 and older as “disturbing,” but they also found reason for optimism.

“It was encouraging to see that the pregnancy outcome in our (45-plus) population was generally good,” they wrote.

Childbirth After Menopause

Giving birth after age 50 is not common. Of the roughly 12 million births in the U.S. between 1997 and 1999, only about 500 involved women who were 50 or older.

The vast majority of these births involved donor eggs from younger women, a practice that has made childbirth among menopausal women possible.

Twenty-four women who gave birth between the ages of 50 and 64 were included in the new study. All the women conceived via in vitro fertilization using donor eggs, and all delivered at the Sheba Medical Center between January 1999 and June 2004.

Their pregnancy outcomes were compared with those of 99 women between the ages of 45 and 49, who also gave birth at the center during the same period.

Well over half of the age 50-plus mothers-to-be (63 percent) were hospitalized during pregnancy, compared with 22 percent of the women who were younger than 50.

And 61 percent of the age 50-plus women delivered low-birth-weight babies, compared with 32 percent of women between the ages of 45 and 49.

The average gestational age at birth for single babies born to the older mothers was 36.9 weeks, compared with 38.4 weeks among the younger women.

The incidence of pregnancy-related diabetes and hypertension was high overall -- 21 percent and 28 percent respectively. But the complications occurred with the same frequency in both age groups.

The study is published in the November issue of the journal Obstetrics and Gynecology.

How Babies Fared

The good news from the study was that despite a high rate of pregnancy complications, birth outcomes were generally good.

No severe birth defects related to premature delivery occurred among the babies born to the women in the study, even though the premature birth rate was high.

Russell Kirby, PhD, of the University of Alabama at Birmingham, was a researcher on one of the few other published studies to examine birth outcomes among women 50 and older.

Kirby and colleagues’ review of birth records among babies in the U.S. born between 1997 and 1999 also indicated that the risk to both the mother and baby increases as the age of the mother increased.

“Women who contemplate a pregnancy in their 50s need to be made aware that they face increased risk and so do their babies,” Kirby tells WebMD. “But that doesn’t mean that [late-life] pregnancies should not be attempted. I would be a strong advocate of patient choice in this matter, but women have to know the risks.”

By Salynn Boyles, reviewed by Brunilda Nazario, MD

SOURCES: Simchen, M.J. Obstetrics and Gynecology, November 2006; vol 108: pp 1084-1088. Russell Kirby, PhD, department of maternal and child health, School of Public Health, University of Alabama at Birmingham. WebMD Medical News: “Late Pregnancies Put Mom and Baby at Risk.”