Fetal Distribution of Feto-placental Blood Flow Related to Placental Nutrient Transport and Maternal Food Intake

Aims The primary aim is to examine the relation between maternal nutrition, placental transport of nutritional substances, and fetal blood flow distribution in normal pregnancies and in pregnancies complicated by altered fetal growth. Specific aims: 1. Examine the relation between fetal glucose, amino acid and lipid consumption, and ultrasound Doppler measures of fetal cerebral vascular resistance. 2. Examine the influence of extended fasting for two hours compared to a standard meal in a group with appropriate fetal group on fetal liver blood flow and fetal cerebral vascular resistance. The examinations will be performed at approximately 36 weeks gestation. 3. Examine the influence of a standard maternal meal on fetal liver blood flow and fetal cerebral vascular resistance in pregnancies complicated by fetal growth restriction (FGR). Study 1: Investigator will use the 130 fetal-maternal pairs from the "placental 4 vessel sampling method" (see below) which includes measures on fetal blood flow distribution. Some calculations will be performed on the restricted cohort of 70 pregnancies who also includes maternal blood flow measures. Study 2: A limitation of investigators previous studies on the influence of glucose intake or a regular maternal meal on fetal blood flow distribution in healthy pregnancies with appropriate fetal growth is the lack of a control group without food intake (extended fasting for two hours). To serve as participants own control the included participants will meet for examinations at two different days (one with food intake and one with extended fasting) within a few days interval. Participants will be examined in the morning and two hours after food intake or after two hours extended fasting. The study will include 25 pregnancies with gestational age about 36 weeks Study 3: Investigator will include approximately 55 women (see power calculation below) with pregnancies complicated by FGR defined as estimated birth weight (EFW) below the 3