Role of maternal folic acid on implantation of embryos and on maternal body weight & offspring's birth weight

Introduction There has been a much debate on the role of pre-/periconceptional and prenatal folic acid (FA) supplements for the long-term health of their offspring. Maternal deficiency of FA or excess of FA would likely to affect the developing fetus at critical stages of development to cause long-lasting health consequences in their offspring. The present study aimed to know the effect of folic acid supplementation and folic acid absence diet during pregnancy on the number of implantation, endometrial changes at the implantation site and on maternal body weight & offspring's birth weight. Material & Methods Thirty-Six Wistar strained female rats were approved for experimental use by the Institutional Animal Ethical Committee. Rats were randomly divided into two groups with 18 rats in each group. Further, each group has been divided into three sets with 6 rats in each. The control set was fed a normal diet, the second set was fed a diet containing no FA. 1% Succinyl sulfathiazole was added to the diet with no FA content to reduce/ inhibit the gut flora responsible for the synthesis of FA in their body. The third set was given diet with an excess of FA (40mg/kg body weight/day). Rats were given respective diet for 4 weeks before mating, continued throughout their pregnancy and 5 weeks after the delivery of pups (weening period). All female rats were paired with males of their own strain overnight at room temperature (25°C). To check whether they mated or not, the vaginal smear was taken in the early morning and stained with methylene blue and confirmed the presence of sperm plug under microscopy. On confirmation of sperm plug, the gestational day was termed as day 1 (GD1). Rats have remained in their cage and diets until they were sacrificed during gestation from day GD6-GD9. Rats were remained in their cage and with their respective diets until they delivered the pups. Delivered pups were counted for each rat and gross malformation in each pup was noted. Immediately after the delivery, all the pups born to each rat were weighed individually in the digital weighing machine. Results Average number of pups born to pregnant dams fed with FA supplementation, FA absent diet, and in normal diet was found to be 8,8, and 9 respectively. Regarding the birth weight of pups born to pregnant dams fed with FA supplementation the average weight was found to be 6.01-5.09 gm, with evidence diet it was 5.51-5.08 gm, and least weight was observed in pups born with FA absent diet (4.74-3.31 gm). Pair-wise comparison was done to correlate the significant association between the different groups. It showed significant difference when compared with pups born to FA supplementation diet to pups born to FA absent diet. Also, significant differences were noted when compared pups born to FA absent diet mother with pups born to FA supplementation and with pups born to normal diet. Conclusion Our study provides clear evidence that FA is essential in successful implantation by providing favorable receptive environment to receive the implantation-competent blastocyst for a successful pregnancy. Birth weight of pups born to pregnant dams fed with FA supplementation was found to be significantly increased when compared to those with the diet with normal amount of FA, and least weight wasobserved in pups born with FA absent diet. As the fetal birth weight is the best predictor of pregnancy outcome as the growth restriction has been associated with high morbidity and mortality. FA supplementation is essential during the period of pregnancy to prevent untoward effects on pregnancy-related complications in mother and to prevent birth defects in fetuses. Further research from longitudinal studies is warranted to confirm these results before its recommendation to the public health.