Cholesterol-lowering diet may strengthen placental circulation system

Starting a low-cholesterol low-saturated fat diet in early pregnancy could have a beneficial effect on umbilical artery circulation and cause less fetal stress at mid-term, according to study findings published in the June issue of the American Journal of Obstetrics and Gynecology.

Janette Khoury, MD, of Ulleval University Hospital in Oslo, Norway, and colleagues analyzed the pulsatility index (PI) levels of both uterine and umbilical arteries of 290 white, healthy, pregnant women at gestational weeks 17 through 20, 24, 30, and 36. The study divided the women into a normal-diet control group and an intervention group who ate fish, low-fat meat, whole grains, fruits, and vegetables.

Using Doppler ultrasound velocimetry, researchers found PI levels similar in the two uterine arteries but discovered a pronounced physiologic gestational decrease in the PI in the umbilical artery from weeks 24 through 30 for women in the low-fat diet group, suggesting that nutrition could aid in placental development and function.

An accompanying editorial questions the usefulness of the study's results. Among other things, the editorialist notes that a "secondary wave of trophoblastic invasion may have been completed" by the time intervention began, therefore preventing any potential benefit of the diet in aiding fetal circulation.

Khoury J, Haugen G, Tonstad S et al. , Effect of a cholesterol-lowering diet during pregnancy on maternal and fetal Doppler velocimetry: the CARRDIP study. Am J Obstet Gynecol. 2007;196:549.e1-.e7.