Plasma total homocysteine, pregnancy complications, and adverse pregnancy outcomes: the Hordaland Homocysteine Study

Abstract

Total homocysteine (tHcy) measured in serum or plasma is a marker of folate status and a risk factor for cardiovascular disease. Our objective was to investigate associations between tHcy and complications and adverse outcomes of pregnancy. Plasma tHcy values measured in 1992-1993 in 5883 women aged 40-42 y were compared with outcomes and complications of 14492 pregnancies in the same women that were reported to the Medical Birth Registry of Norway from 1967 to 1996. When we compared the upper with the lower quartile of plasma tHcy, the adjusted risk for preeclampsia was 32% higher [odds ratio (OR): 1. 32; 95% CI: 0.98, 1.77; P for trend = 0.02], that for prematurity was 38% higher (OR: 1.38; 95% CI: 1.09, 1.75; P for trend = 0.005), and that for very low birth weight was 101% higher (OR: 2.01; 95% CI: 1.23, 3.27; P for trend = 0.003). These associations were stronger during the years closest to the tHcy determination (1980-1996), when there was also a significant relation between tHcy concentration and stillbirth (OR: 2.03; 95% CI: 0.98, 4.21; P for trend = 0.02). Neural tube defects and clubfoot had significant associations with plasma tHcy. Placental abruption had no relation with tHcy quartile, but the adjusted OR when tHcy concentrations >15 micromol/L were compared with lower values was 3.13 (95% CI: 1.63, 6. 03; P = 0.001). Elevated tHcy concentration is associated with common pregnancy complications and adverse pregnancy outcomes.