Report details causes of birth defects

Babies born as twins or to older mothers are likelier to carry congenital anomalies from birth, with the risk rising with the age of the mother, according to a report released yesterday by the Ministry for Health, Welfare and Family Affairs.

Of every 10,000 newborns in Korea, around 294 are born with congenital disorders. Babies born to older mothers, born underweight, or twins are the likeliest to have the disorders, the report said. The ministry commissioned the Korea Institute for Health and Social Affairs to conduct a survey, the first in Korea, of 883,184 babies born between 2005 and 2006.

The ministry classified congenital anomalies to include asthma and behavioral defects as well as more life-threatening genetic disorders.

The No. 1 area for congenital anomalies was the circulatory system. This accounted for 45 percent of the total while problems with muscles and bones ranked second at 18 percent.

“The cause of congenial anomalies is 25 percent genetic, 3 percent mutations, 3 percent environmental causes,” said an official at the ministry. “The cause of the remaining 69 percent is still unknown. This survey will serve as a basic-level reference in researching the cause of birth defects.”

While an average 228 babies out of 10,000 born to mothers younger than 25 years old had congenital anomalies, the number rose to 339.3 babies born to mothers over 35 years of age.

The report also said that around 928 newborns out of 10,000 who weighed less than 2.5 kilograms at birth in 2005 had congenital anomalies. However, of babies born at normal weights, only 226 out of 10,000 were born with such deficiencies.

Babies born before 37 weeks had 3.7 times more birth defects than normal-term babies, while babies born as twins were at 1.9 times greater risk.

By Cho Jae-eun [jainnie@joongang.co.kr]