Perinatal Reference Intervals for Plasma Homocysteine and Factors Influencing Its Concentration (Technical Briefs‪)‬

Moderately increased plasma total homocysteine (tHcy) concentrations have been associated with an increased risk of atherothrombotic vascular events (1). Disturbances in homocysteine metabolism have also been reported as a possible risk factor for early pregnancy loss and congenital birth defects, such as neural tube defects, as well as for maternal obstetric complications (2). Reference intervals for healthy maternal and newborn populations are scarce; in particular, we could not find data on large samples of women at delivery. Raijmakers et al. (3) reported tHcy results for samples collected at delivery or 4 h before caesarian section on 35 women. Bohles et al. (4) and Malinow et al. (5) measured tHcy at delivery in 60 and 35 women, respectively, and Bjeorke Monsen et al. (6) reported results for 169 samples collected between 96 to 108 h after birth. Available data on newborns include the results from one large study in Italy (7) and a few smaller studies (3-6), among which only one is from North America; it included 35 women and their newborns (5). Mean tHcy values were quite different among these studies.