Research has shown that high fat diets ingested during pregnancy can impair development of the fetus as well as the placenta. The problem is that these perturbations to normal development can have life-long consequences. A new study published in Physiological Reports was interested in whether the volume of amniotic fluid can change with a high fat diet even when the mother does not develop obesity. To examine this, they used both ultrasound techniques and collected samples of the amnion (the fluid-filled sac that encloses the developing embryo) to test whether there were changes in special channels that transport water (aquaporins). Reduced amniotic fluid volume can lead to preterm birth, low birth weights as well as postpartum hemorrhage and cesarean deliveries.

      Many of the studies prior to this have used sheep as a model of pregnancy. But, because of differences between sheep and humans, the findings may not translate well to humans. This study included non-obese Japanese macaques (Macaca fuscata) that were fed either control diets or diets high in fat (36% saturated fat – like the typical Western diet) both before and during pregnancy. The researchers found that macaques expressed similar forms of aquaporins as seen in the human amnion although the various forms of aquaporins were in different ratios than observed in humans.

      Although the researchers also found variations in the expression of specific aquaporins in the amnion of macaques fed a high fat diet compared to a control diet, no differences in amniotic fluid volume were detected.  These results are interesting because amniotic fluid volume is known to decrease in animals that develop obesity from high fat intake. Therefore, the findings suggest that resistance to obesity may protect the amnion in these animals. Whether these findings translate to humans is not yet known.

Cheung CY, Roberts VHJ, Frias AE, Brace RA. High‐fat diet effects on amniotic fluid volume and amnion aquaporin expression in non‐human primates. Physiological Reports. 2018 Jul; 6(14): e13792. doi:  10.14814/phy2.13792