Plasma Biopterin Levels and Depressive State in Pregnancy and the Early Puerperal Period

Abstract

Plasma total biopterin and tetrahydrobiopterin levels of 14 normal pregnant and 15 normal puerperal women (within 1 week after delivery) were measured. In the first group, total biopterin levels were already increased (average: 18.2 pmol/ml) in the second trimester and remained high until the early puerperal period. In the second trimester, the ratio of tetrahydrobiopterin to total biopterin levels decreased to 72.3% and even further to 66.1% in the third trimester. This tendency continued until the puerperal period. Compared with the control group (12 healthy nonpregnant women), total biopterin levels increased during pregnancy and the puerperal period (p < 0.001), and the ratio in the third trimester and the early puerperal period decreased (p < 0.001). The depressive state according to Zung’s score appeared most markedly in the third trimester with a mean score of 48, and tended to recover to a mean score of 36.2 in the early puerperal period. In this period, a correlation was found between Zung’s score and the total biopterin levels (r = 0.80), and the ratio of tetrahydrobiopterin levels to the total biopterin levels (r = –0.92). In the early puerperal period, total biopterin levels were higher in subjects with Zung’s scores ≧36 (p < 0.001); the ratios of this group were lower than those of subjects with Zung’s scores <36 (p < 0.001). Plasma biopterin levels in pregnancy and the early puerperal period closely resembled those of patients with mood disorders who show depressive symptoms from a psychoneurological perspective. Therefore, it seems possible that a depressive state in pregnancy and the early puerperal period has the same pathology as depression.

Pregnancy-Induced Metabolic Phenotype Variations in Maternal Plasma

“…It has been proven that 6-pyruvoyl tetrahydropterin synthase controls BH 4 biosynthesis. 32 BH 2 is an oxidation product of BH 4 , showing increased levels in the second trimester and decreased levels in the third trimester. Although the underlying mechanism of these changes is still not clearly characterized, the BH 4 /BH 2 transformation would be crucial for physiological changes in pregnant women.…”

“…Omura et al reported increased levels of total biopterin and decreased levels of BH 4 in the second trimester. It has been proven that 6-pyruvoyl tetrahydropterin synthase controls BH 4 biosynthesis . BH 2 is an oxidation product of BH 4 , showing increased levels in the second trimester and decreased levels in the third trimester.…”