Maternal Meal Ingestion Does Not Affect Amniotic Fluid Index during Short-period Observation in Normal Pregnancy

>Objective: To determine whether maternal meal ingestion affects amniotic fluid index (AFI) over a short period after maternal meal ingestion in normal growth fetuses with normal amniotic fluid volume in uncomplicated late pregnancies.Methods: Twenty-five women with an appropriate-for-gestational-age fetus with normal AFI were included in a simple crossover, blinded study during late pregnancy. After an overnight fast, two different maternal meal states were prepared. On day A, the subjects had a standard 600-kcal breakfast at 8 a.m. On day B, the fasting state was maintained until 10 a.m. Both states were randomly assigned to each woman within 3 days. On both days, the AFI was measured at 7 a.m. (the fasting state) and at 10 a.m. (the fed state on day A and the continuous fasting state on day B). A change in AFI between 7 and 10 a.m. was compared between the days by paired t test.Results: The mean gestational age (mean +/- SD) was 37.5 +/- 1.5 weeks on day A and 37.4 +/- 1.6 weeks on day B. The change in AFI between 7 and 10 a.m. was 1.1 +/- 3.0 cm on day A (with breakfast) and 2.1 +/- 2.6 cm on day B (keeping fast). These changes were not different between the days (P = 0.19).Conclusions: Maternal meal ingestion had no apparent acute effect on AFI in normal growth fetuses with normal amniotic fluid volume.