Congenital malformations in Toa Payoh hospital--a 18 year experience (1972-1989).

A ten year experience (1972-1981) of congenital malformations in Toa Payoh Hospital was presented previously. The experience of birth defects of the second decade (1982-1989) is reviewed and compared. The mortality rates of babies with malformations ranged from 1.52 to 3.55 per 1000 livebirths. There was no significant increase in congenital malformation death rates over the past eight years. There was an increasing trend of malformation deaths among the total neonatal deaths from 1972-1981 (p less than 0.05), but this was not so for the period 1982-1989. The incidence of minor congenital malformations has not changed except that more cases of undescended testes were recorded (p less than 0.05). Central Nervous System (CNS) malformations, congenital heart defects and chromosomal abnormalities still remain the leading cause of malformation deaths. Neural Tube Defects (NTD) were the commonest type of CNS defect and the death rates of NTD for these two periods remain the same (about 0.65 per 1000 births). The prevalence of anencephaly at birth in Chinese and Malay from 1982-1989 is 0.45 and 0.84 per 1000 livebirths respectively. Down syndrome was the commonest type of chromosomal abnormality (63%) and coarctation of aorta (40%) was the commonest type of congenital heart disease causing death. Many congenital malformations are genetically determined. More knowledge of the aetiological factors, antenatal diagnosis of birth defects, preventive measures and genetic counselling are, therefore, important in lowering birth defect rates.