Folate Status During Labor: Relationship With Pregnancy Outcome K. Stefanidis, * T. Stefos, A. Vekris, A. Sotiriadis, N. Dalkalitsis, and D. Lolis Department of Obstetrics and Gynecology, Ioannina University Hospital, Ioannina, Greece Objective: The purpose of our study was to determine the folate status of pregnant women at labor, and to detect probable relationships with the gestational age at delivery, the birth weight of the newborns, as well as the mode of the delivery, taking into account any changes in the fetal heart rate (FHR) at labor and, subsequently, operative delivery. Methods: Maternal serum folate levels were determined using automated fluorometric enzyme-linked assays. Gestational age was determined by ultrasound in the first trimester followed by serial fetal biometry. Results: The results of our study in 101 consecutive pregnant women revealed that the mean ( SD) maternal serum concentration of the folate during labor was 12.01 ( 4.16) ng/ml (range 2.50–23). The mean ( SD) gestational age at labor was 38.5 ( 1.2) weeks (range 35–41 wks) as also the mean ( SD) birth weight of the newborns was 3.217 ( 403) g(range 2,000–4,250 g). Conclusions: No significant correlation ( p  0.05) between folate levels of the maternal serum and gestational age at delivery or birth weight was found. The mode of delivery as a result of probable relationship between operative delivery and maternal serum folate levels was also not found. J. Matern.-Fetal Med. 1999;8:61–63.  1999 Wiley-Liss, Inc. Key words: folate; pregnancy; birth weight IN TRO DUCTIO N Folate is the term commonly used for pteroylmonoglu- tamic acid. In its reduced form of tetrahydrofolate, it serves as an important mediator of many reactions involving one-carbon transfers. Important reactions include the con- version of hymocysteine to methionine, and of deoxy- uridylate to thymidylate, an important step in DNA synthe- sis [1]. Recent studies found a 60% reduction in the occurrence of neural tube defects in women who used vitamins contain- ing folate [2]. Other studies have demonstrated that low concentrations of serum folate at 28 weeks of pregnancy were also associated with a greater risk of preterm delivery and low birth weight [3]. There are also studies which are dealing with the actual, desired, or recommended folate intake [4]. T he dietary customs are different among different populations. The policy of prenatal follow-up of the folate status in different pregnant populations is also different. In Greece, the measurement of the folate levels is not a routine or necessary examination during pregnancy. Therefore, in the majority of cases, women give birth to their newborns without any information about their folate status. It is also known that nutritional influences are very important for the breast-feeding process [5,6]. On the other hand, the defi- ciency of folate, causing maternal anemia, could be one of the factors influencing the fetal heart rate, especially during labor and delivery. So, the appearance of decelerations, combined with other obstetrical indications, could increase the rate of cesarean section or other interventions at labor and delivery. This probable hypothesis is something which has never been studied. To our knowledge, there is no study in the literature evaluating the concentrations of folate in maternal serum during labor. The existing studies were conducted during pregnancy. Thus, the present study is undertaken in order to evaluate the folate concentrations in maternal serum during labor, and to detect, at that time, any probable correlation with fetal weight, gestational age, and any suspected relation- ship with changes in the fetal heart rate which could lead to operative delivery. *Correspondence to: Konstantinos Stefanidis, P .O. Box 260, Rhodes 85 100, Greece. E-mail: kstef@compulink.gr Received 4 March 1998; revised 12 August 1998; accepted 14 August 1998 The Journal of Maternal-Fetal Medicine 8:61–63 (1999)  1999 Wiley-Liss, Inc.