Thiamin status during pregnancy.

Thiamin status of 20 nonpregnant women and 60 pregnant women was assessed. Of the 60 pregnant women, only 49 and 25 were examined for the biochemical thiamin status in the 3rd trimester and postpartum period respectively. Thirty per cent of nonpregnant women and 28 to 39 per cent of pregnant mothers (in either the 2nd trimester, 3rd trimester, or postpartum phase of pregnancy) had a deficient thiamin status with the thiamin pyrophosphate effect (TPP effect) greater than 20 per cent. None of the pregnant subject were deficient in all the three periods. Follow up of the pregnant subjects in the 2nd trimester, 3rd trimester and postpartum period revealed that the deficiency was not necessarily established in the early pregnancy nor was aggravated with the progress of pregnancy. Thiamine intake was over 2/3 of the recommended in all the pregnant subjects and revealed no significant correlation with the biochemical indices. A history of oral contraceptive usage before conception had no significant effect on the incidence of deficiency in the 2nd or 3rd trimester. The occurrence of deficient thiamin status demonstrated an increase with number of previous pregnancies. No correlation was noted between the vitamin B1 status and anthropometric measurements of neonates.