Study: Birth Defects Decrease Survival, Childbirth, Boost Risk Of Similar Defects

April 08, 1999

CHAPEL HILL - A new study of nearly a half million girls and women shows that those born with birth defects are less likely to survive, especially during the first years of life, than others born without them. Survival is lowest for such catastrophic conditions as anencephaly, hydrocephalus, other syndromes and central nervous system irregularities and highest for cleft palate and lip, clubfoot and malformations of skin, hair, nails and genitals.

Women with birth defects also are generally less likely to have children than others but face an increased risk of bearing offspring with the same problem, the research shows. Investigators found no higher-than-normal chance that an infant would have a different birth defect from his or her mother.

A report on the findings appears in Thursday's issue (April 8) of the New England Journal of Medicine. Authors are Drs. Rolv Skjaerven and Rolv T. Lie of the University of Bergen and Dr. Allen Wilcox, chief of the National Institute of Environmental Health Sciences' epidemiology branch and a University of North Carolina at Chapel Hill School of Public Health faculty member..

The three studied 8,192 women and adolescent girls with birth defects and 451,241 others listed in the Medical Birth Registry of Norway as being born between 1967 and 1982. Although impaired physical development during pregnancy is known to boost a baby's chance of death after birth and during infancy, investigators conducted their analysis since less is known about later survival and reproduction. Also, no one has assessed the risk of dissimilar defects in the children of such women in detail.

Among subjects with defects, 80 percent survived to age 15 compared with 98 percent of those without birth anomalies, researchers found. Among surviving subjects, 53 percent of those with defects bore at least one infant by age 30 compared with 67 percent of those born normal.

Affected women were a third less likely to give birth by age 30 than unaffected women. Children of subjects with birth defects overall faced a 60 percent higher risk of having birth defects themselves.

"This increased risk was confined entirely to the specific defect carried by the mother, with the relative risk of recurrence varying from 5.5 to 82 (times) according to the defect," the authors wrote. "In contrast, there was no increase in the risk of having an infant with a different type of defect."

Deaths among those with birth defects were 15 times as high in the first year of life and 12 times as high in the second year as among the others, they said. The relative risk decreased with age but was still more than four times higher among children ages 10 to 14.

"Although the subjects with birth defects had a risk of bearing children with birth defects that was 1.6 times the risk among those without birth defects, these subjects constituted only about 1 percent of the women who gave birth, the scientists said. "Thus, the higher risk among the subjects with birth defects accounted for only 5 of 1,000 birth defects in the next generation, according to an estimate."

Twenty-six women with birth defects had infants with the same defects as compared with an expected number of just under four, they found. Maternal defects that recurred in the children were cleft palate, cleft lip, clubfoot and malformed limbs.

"Among the children of the mothers with these birth defects as compared with the children of the mothers with no defects, the relative risks were as follows: cleft palate, 82; cleft lip, 38; clubfoot, 5.5; and limb defects, 5.6," the authors wrote.

The Norwegian Research Council supported the new study.
-end-
Note: Wilcox can be reached at 919-541-4660 until Tuesday night when he will be gone for a week.



University of North Carolina at Chapel Hill

Related Birth Defects Articles from Brightsurf:

Assessing cancer diagnosis in children with birth defects
In this study, led by Baylor College of Medicine and Texas Children's Hospital, researchers provide a better understanding of cancer risk in children with birth defects.

Some antibiotics prescribed during pregnancy linked with birth defects
Children of mothers prescribed macrolide antibiotics during early pregnancy are at an increased risk of major birth defects, particularly heart defects, compared with children of mothers prescribed penicillin, finds a study published by The BMJ today.

Weight-loss surgery cuts risk of birth defects
Children born to women who underwent gastric bypass surgery before becoming pregnant had a lower risk of major birth defects than children born to women who had severe obesity at the start of their pregnancy.

Defective cilia linked to heart valve birth defects
Bicuspid aortic valve (BAV), the most common heart valve birth defect, is associated with genetic variation in human primary cilia during heart valve development, report Medical University of South Carolina researchers in Circulation.

Findings shed new light on why Zika causes birth defects in some pregnancies
A new study shows that the risk of giving birth to a child with microcephaly might be related to how the immune system reacts against the Zika virus -- specifically what kind of antibodies it produces.

Severe air pollution can cause birth defects, deaths
In a comprehensive study, researchers from Texas A&M University have determined that harmful particulate matter in the atmosphere can produce birth defects and even fatalities during pregnancy using the animal model.

Famous cancer-fighting gene also protects against birth defects
New research has revealed how the famous tumour suppressor gene p53 is surprisingly critical for development of the neural tube in female embryos.

Biomarkers may predict Zika-related birth defects
The highest risk of birth defects is from Zika virus infection during the first and second trimester.

After 60 years, scientists uncover how thalidomide produced birth defects
More than 60 years after the drug thalidomide caused birth defects in thousands of children whose mothers took the drug while pregnant, scientists at Dana-Farber Cancer Institute have solved a mystery that has lingered ever since the dangers of the drug first became apparent: how did the drug produce such severe fetal harm?

Antiepileptic drug induces birth defects in frogs
A common drug for treating epileptic seizures may lead to birth defects if used during pregnancy by interfering with glutamate signaling in earliest stages of nervous system development, finds a study in frogs published in JNeurosci.

Read More: Birth Defects News and Birth Defects Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.