In Vitro Fertilization increases Scope of Birth Defects

In what may be disappointing news for many would-be parents, U.S. researchers said on Monday that babies conceived using in vitro fertilization are two to four times more likely to have certain birth defects than those conceived naturally.

Cardiac defects involving a hole in the heart are two to three times more likely to be seen in the in vitro babies, as per findings of a team of researchers led by epidemiologist Jennita Reefhuis of the U.S. Centers for Disease Control and Prevention.

That is not all; these babies are also twice as likely to be born with a cleft lip and four times as likely to be born with certain gastrointestinal defects, the researchers maintain. The study could not account for the increased risks of birth defects. However, the researchers concluded that even as it stands, birth defects are rare in the in vitro babies.

The findings have been published in the journal Human Reproduction. The researchers also established that in vitro fertilization did not significantly increase the chances of birth defects among the multiple-birth children.

The study involved 281 babies conceived using in vitro fertilization Some of them were products of a lesser-known technique called intra-cytoplasmic sperm injection. The comparative study was made with 14,095 babies conceived without the aid of infertility treatments.

The babies under the study were single births, as opposed to twins or other multiple births. It is known that multiple birth babies are at higher risk for birth defects.

In vitro fertilization, where natural conception is aided in the laboratory, has carried hope to many homes. It involves the creation of an embryo in the laboratory with egg and sperm cells. The resulting embryo is then transferred into a woman's uterus.

Many infertile couples take resort to in vitro fertilization and about 50,000 such infants are born each year in the United States. The popularity of the technique has virtually doubled over the past decade. About 1 percent of U.S. babies are conceived using the technique, the researchers said.

Explaining the aim of the study, Reefhuis said: "Any couple who is considering these treatments wants to be aware of all the pros and cons of the treatment. And, so far, the main cons that have been known have been the increased risk of having twins and other higher multiples, which has its own share of problems.”

“I think it's important for couples to be aware that there may be some increased risk for birth defects as well,” she added.

The compass of the study, however, does not cover babies born to women after ovulation-stimulating drugs or artificial insemination.