With a research fund from the Korea Food and Drug Administration in 2007, a research team led by Prof. Shin Jong-chul of the Department of Obstetrics and Gynecology at Catholic University of Korea's College of Medicine conducted a study of 31,272 fetuses 20 weeks or older which had been checked and treated at 18 hospitals across the country.

The study found that 932 fetuses (2.98 percent) have congenital malformations, almost double the figure of 1995 (1.53 percent), the year when the study of congenital malformations was started.

"Over the past three to four years, the rate of congenital malformations has remained at the 3 percent range. But we can't say based only on a simple comparison of figures that the rate has doubled compared with 10 years ago," Prof. Shin said.

The latest study included many university hospitals, which are favored by women with high-risk pregnancies or with fetuses with abnormalities. Also, the techniques for finding malformations have been greatly improved. These factors may help explain the higher rate of malformations.

Down syndrome caused by a translocation of chromosomes was the largest group of fetuses with malformations, at 15.69 cases per 10,000 fetuses. Next were cleft lip and palate at 11.51 cases per 10,000, and tetralogy of Fallot, a congenital heart defect, at 10.54 per 10,000.

"The rate of fetuses with congenital malformations is roughly between 2.5 and 3 percent around the world. We need to conduct further study on relations between socio-environmental factors and congenital malformations," Shin said.

(englishnews@chosun.com )