[An epidemiological study on conjoined twins in China, from 1996 to 2004].

OBJECTIVE To understand the trend of incidence of conjoined twins and its epidemiological characteristics in China during 1996 to 2004. METHODS A descriptive epidemiology of conjoined twinning in China from 1996 to 2004 was investigated by using data from National Center for Birth Defects Monitoring Program (NCBDMP). Data were collected from more than 400 hospital-based units involved in the program. The monitored subjects were the hospitalized births from 28 weeks gestation to a period within 7 days after delivery. RESULTS 122 conjoined twins were found in 4,282,536 births with an incidence rate of 0. 28 per 10,000. Incidence of conjoined twins was 0.20 per 10,000 and 0.47 per 10,000 in the rural and urban areas, respectively, and the statistical significant difference (P < 0.05) was observed., Incidence of conjoined twins was for 0.17 per 10,000 and 0.36 per 10,000 in boys and girls, respectively. Conjoined twins were more common among females than males, the live-born rate was 41.32%, and the perinatal mortality was 82.6%. 53.7% conjoined twins can be diagnosed prenatally. CONCLUSION The results indicate that the incidence of conjoined twins in China is higher than that in Western countries. It is necessary to improve the prenatal diagnostic techniques and management.