Results were considered significant whenP<0.05. == Results == The results of general and obstetric FLNA maternal characteristics according to pre-pregnancy BMI are reported inTable 1. the risks of preterm delivery (odds ratio (OR)=2.85, confidence interval (CI)=1.206.74), low-birth-weight (LBW) infants (overweight subjects: OR=5.07, CI=1.7614.63; obese subjects: OR=4.49, CI=1.5413.13) and macrosomia. In obese subjects, the average serum folate level was significantly lower than in the underweight subjects. In obese subjects, the average serum hs-CRP level was significantly higher than in the rest of our sample. == Conclusion: == Pregnancy outcomes are influenced by pre-pregnancy BMI. These findings suggest that women can minimize their risks of preterm delivery, LBW and macrosomia Deoxycholic acid sodium salt by maintaining normal pre-pregnancy BMI. Keywords:pre-pregnancy BMI, preterm delivery, low birth weight, macrosomia == Introduction == Women with low pre-pregnancy body mass index (BMI) (<19.8 kg m2) experience high risk of delivering low-birth-weight (LBW) newborns, whereas women with high pre-pregnancy BMI (>29.0 kg m2) experience increased risk of macrosomia.1LBW increases the risks of infant mortality and impaired development.2In Korea, the number of LBW infants increased from 18 532 in 1993 to 22 725 in 2008.3 A preterm birth is defined as delivery before 37 completed weeks gestation.4Preterm infants experience significant perinatal mortality.5The number of preterm infants born in Korea, increased from 40 114 in 1996 to 62 869 in 2008.3Studies suggest increased risks of preterm delivery for underweight women, whereas obese women experience significantly lower rates of preterm delivery.6,7 Several biochemical markers are considered to be associated with LBW and preterm delivery. Elevated total homocysteine concentrations in plasma or serum are associated with preeclampsia, intrauterine growth retardation, perinatal death, preterm birth and LBW.8,9,10Low-serum folate is significantly correlated with increased risks of neural tube defects, preterm birth and LBW.11Elevated levels of C-reactive protein (CRP) are associated with increased risks of preterm delivery and increasing BMI of mother.12Finally, the levels of fetal fibronectin (fFN) in Deoxycholic acid sodium salt the cervix and vagina measured between 22 and 37 weeks gestation are considered potential markers of preterm delivery13and short cervical length is associated with an increased risk of preterm delivery.14 The available data on pregnancy outcomes associated with pre-pregnancy maternal BMI are inconsistent. Some studies6,7report increased risk of preterm delivery among underweight women, whereas others15report increased risk of preterm delivery among obese women. Previous Deoxycholic acid sodium salt studies have only rarely investigated the relationships between biochemical markers such as homocysteine, folate, high sensitivity CRP, fFN or cervical length and pre-pregnancy BMI. In this study, we examined the relationships between pre-pregnancy maternal BMI, pregnancy outcomes and biochemical markers. == Subjects and methods == == Subjects == Subjects were recruited at MizMedi Hospital and Ewha Womans University Hospital, Seoul, Korea between April 2006 and April 2009. A total of 830 pregnant women in their second and third trimesters (1939 weeks) participated in this study. After excluding subjects with incomplete height and weight records, 608 subjects were included in this analyses. General and obstetric characteristics, anthropometric measurements, and information regarding health habits and nutrient intake were obtained through interviews using a standardized questionnaire. The general and obstetric questions addressed age, educational level, income level, occupation status, number of family members, gestational period at baseline, total number of pregnancies and morning sickness. Weight gain during pregnancy was calculated by subtracting the pre-pregnancy weight from weight just before delivery. Pre-pregnancy BMI was calculated using self reported height and pre-pregnancy weight. We collected information on health habits, including smoking, alcohol.