The association between maternal amino acids and vitamins status during early pregnancy and preterm birth

To investigate the relationship between the maternal nutritional status of multiple amino acids and vitamins during early pregnancy and the risk of preterm birth, the plasma samples of 7952 pregnant women during the 12~24 gestational weeks were enrolled, and the levels of 20 amino acids and 10 vitamins were measured. The abundance differences of representative nutrients among stratified groups of pregnant women and the potential risk of preterm birth were analyzed and evaluated. The plasma levels of aspartate, methionine, and retinol were significantly higher, and that of 4-pyridoxic acid was significantly lower in the group of preterm birth pregnancy compared to the group of full-term birth pregnancy. The odds ratios of higher levels of methionine and 4-pyridoxic acid (as compared to respective normal levels) were 2.189 (95%CI: 1.247～3.845) and 0.243 (95%CI: 0.059～0.998) in the comparison group of severe preterm birth to full-term birth pregnancy, and that of higher level of retinol (as compared to normal level) was 1.595 (95%CI: 1.162～2.190) in the comparison group of mild preterm birth to full-term birth pregnancy. It was concluded that higher levels of maternal plasma methionine and vitamin A and lower levels of vitamin B6 during early pregnancy might be significantly independent risk factors for preterm birth.