Racial disparity in the prevalence of thyroid disorder during pregnancy.

A study to determine the prevalence of goitre and abnormal thyroid status during pregnancy in Malaysian women was conducted. Two hundred and three women (Malay = 85, Chinese = 47 and Indian = 71) in the third trimester and with no known thyroid disease were studied. There was a marked racial disparity in the prevalence of goitre: Indian 61%, Malay 28% and Chinese 29% (p = 0.001). The serum thyrotropic hormone (TSH) was significantly higher in Indians (median: 1.36 uIU/ml) compared to Malays (1.14 uIU/ml, p = 0.009). The serum albumin was also significantly lower in Indians (mean +/- sd; 36.12 +/- 3.9 mmol/l) compared to Malays (39.3 +/- 4.8 mmol/l) or Chinese (39.1 +/- 5.2) (p < 0.001). Thyroid antibody was detected in 14.6% of these women with no significant racial difference in its prevalence. Three women were found to be thyrotoxic but none were hypothyroid. This study found a high prevalence of goitre among the pregnant Indian women, probably related to the protein malnutrition state. The high prevalence of positive thyroid antibody in our population indicates that a high percentage of women are at risk of developing postpartum thyroiditis.