Plasma zinc levels during pregnancy and its relationship to maternal and neonatal characteristics: a longitudinal study

Forty consecutive healthy pregnant women aged 17-38 yr who attended the antenatal clinic of the Department of Obstetrics and Gynecology, Ankara University in their first trimester participated in the study. The pregnant women were followed up longitudinally until the end of their pregnancy. Forty healthy age-matched nonpregnant women were used as a control group. Each pregnant woman was interviewed and a special questionnaire recording dietary history (3-d recall) and socioeconomic status (SES) was used. Birth weight, height, and head circumference of the newborn were measured and a complete physical examination was done for each neonate by the same observer. Blood samples were obtained at each trimester and zinc determinations were made using flame atomic absorption spectrophotometer. The results of plasma Zn measurements were available in 39 pregnant women. There were 23 women of low SES (mean plasma Zn level: 59.0 +/- 6.9 microg/dL) and 16 of high SES (mean plasma Zn: 70.3 +/- 5.2 microg/dL). The difference between the mean plasma Zn levels of these two groups was significant (p < 0.001). The nutritional status in our study appeared to be an important factor responsible for low plasma Zn levels during pregnancy. However, we did not find any correlation between plasma Zn levels and anthropometric parameters of the newborn and pregnancy outcome. Further studies using larger sample sizes are needed to clarify the role of plasma Zn levels on maternal features and fetal outcomes in Turkey.