(Xinhua)
Updated: 2007-12-04 10:58

LOS ANGELES -- More dangers including the development of high blood pressure and low-birth-weight babies could occur to both mothers and babies if the mothers give births after 40, according to the study by the Public Policy Institute of California, a nonpartisan think tank.

The shadow of a young family holding hands in London, is seen in this file photo dated September 20, 2007. [Agencies]

The study showed older mothers are more likely to develop high blood pressure and gestational diabetes and to give birth to premature and low-birth-weight babies.

Even the use of donor eggs does not guarantee a healthy child or pregnancy itself, warned the study published by the Los Angeles Times on Monday.

Although they make up only about 5 percent of overall births in California, births for US-born women ages 40 to 44 have increased three fold since 1982, according to the study.

Societal changes such as better educational and career opportunities for women are common reasons for delaying childbearing, said demographer Hans P. Johnson, the report's author.

Women begin to have fertility problems about 10 to 15 years before they experience menopause. The average age of menopause is 50 to 52, but it can range from 40 to 60. Women have no way of knowing for sure at what point in the spectrum they'll fall.

"Egg donation and fertility treatments make having children in your 40s more possible," said Dr. Ingrid A. Rodi, a fertility specialist.

But aging eggs not only contribute to infertility and miscarriages but are more likely to have chromosomal abnormalities, experts said.

Despite the advantages of using donor eggs, admitting to doing so is one of the few remaining reproductive taboos -- among celebrity and regular moms alike, said the study.