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

Background: Total homocysteine (tHcy) is associated with pregnancy complications and adverse pregnancy outcomes. The associations of plasma total cysteine (tCys) with such outcomes have not been investigated in large populations. Objective: We investigated the association between plasma tCys and pregnancy complications, congenital malformations, and other adverse pregnancy outcomes. Design: The plasma tCys concentrations of 5883 women aged 40-42 y that were measured in 1992-1993 during a cardiovascular health screening were compared with the outcomes and complications of 14492 pregnancies in the same women that were registered in the Medical Birth Registry of Norway from 1967 to 1996. Results: After adjustment for parity, mother's age, tHcy, total cholesterol, body mass index, smoking, and coffee drinking, high plasma tCys concentrations (above the 95th percentile) were associated with significantly higher risks of preeclampsia [n = 342; odds ratio (OR): 1.6; 95% CI: 1.1, 2.4; P = 0.03], premature delivery (n = 774; OR: 1.8; 95% CI: 1.3, 2.5; P = 0.001), and very low birth weight (n = 175; OR: 2.0; 95% CI: 1.1, 3.9; P = 0.03) than were lower plasma tCys concentrations. tCys was not associated with the risk of placental abruption. High tCys concentrations showed a weak association with congenital malformations and stillbirths with birth weight < 1500 g. The associations were independent of the tHcy concentrations. Conclusion: High tCys concentrations were associated with risks of preeclampsia, premature delivery, and low birth weight.