Effects of Exercise on Fetal-Placental Growth and Uteroplacental Blood Flow in the Rat

Abstract

The effects of daily maternal exercise on fetal-placental growth and development and the associated changes in uteroplacental blood flow were studied in pregnant rats. Pregnant females were exercised for 1 h (0% grade at 28 m/min) daily between either days 1 and 12, 1 and 18, 1 and 22, 12 and 18, or 12 and 22 of gestation and compared with nonexercised controls. Exercise between days 1 and 12 of pregnancy had no effect on fetal-placental parameters (i.e., fetal weight or gestation length) relative to controls. In contrast, exercise between days 1 and 22 and 12 and 22 resulted in a lower number of live pups born, an increase in gestational length, and an increased birth weight of the live pups relative to controls. Exercise between days 1 and 18 or 12 and 18 induced a significant (p ≤ 0.05) suppression of uteroplacental blood flow, the number of viable fetuses, and placental weights as compared with controls. Daily exercise had no effect on ovarian function as indicated by the comparable serum progesterone levels in all groups. These data indicate that an exercised-induced depression of uteroplacental blood flow is related to impaired fetal-placental growth and development during pregnancy in the rat.

The effects of aerobic exercise on the pregnant woman, fetus, and pregnancy outcome A review

“…Studies of the relationship between maternal exercise and birth‐weight have produced conflicting results. In pregnant animals, exercise has been reported to (1) not influence birthweight, 32,92,93 (2) decrease birthweight 5,30,94 or (3) decrease litter size 93 . Hohimer et al 32 speculate that discrepancies in the results of animal studies may be due to the methods used to train animals to exercise.…”

Adherence to ACOG Guidelines on Exercise During Pregnancy: Effect on Pregnancy Outcome

“…Animal studies concerning the effects of exercise on pregnancy imply that intensive exercise is harmful to a developing fetus (Bonds & Delivoria-Papadopoulos, 1985;Garris, Kasperek, Overton, & Alligood, 1985). Garris et al (1985) noted decreased uteroplacental blood flow, as well as a decreased incidence of live births, in rats exercised from 1 to 18 days or 12 to 18 days during gestation.…”

“…Animal studies concerning the effects of exercise on pregnancy imply that intensive exercise is harmful to a developing fetus (Bonds & Delivoria-Papadopoulos, 1985;Garris, Kasperek, Overton, & Alligood, 1985). Garris et al (1985) noted decreased uteroplacental blood flow, as well as a decreased incidence of live births, in rats exercised from 1 to 18 days or 12 to 18 days during gestation. Bonds and Delivoria-Papadopoulos (1985) reviewed the literature on animal studies related to uterine and umbilical blood flow and maternal and fetal effects of exercise and noted decreased uterine blood flow and increased maternal hemoglobin concentrations in sheep and pygmy goats.…”