Fetal/Placental Weight Ratio in Term Japanese Pregnancy: Its Difference Among Gender, Parity, and Infant Growth

Abstract

Purpose: The “inappropriately heavy placenta” has been considered to be associated with various pregnancy disorders; however, data is scarce what factors affect it. To determine whether the following three affect it; (1) infant gender and mother's parity, (2) growth restriction, and (3) preeclampsia.Methods: We employed fetal/placental weight ratio (F/P). Subjects consisted of 53,650 infants and their placentas from women who vaginally delivered singleton live term infants. First, we examined whether F/P differs among the infant's gender or mother's parity. We classified the population into 4 categories according to gender and parity: male, nulliparous (n=7,431), male, multiparous (n=7,859), female, nulliparous (n=7,559), female, multiparous (n=7,800), and, compared F/P among the four groups. Next, we determined whether F/P differs in “small” or “large” for gestational age (SGA or LGA) infants, compared with appropriate for gestational age infants. Last, we determined whether preeclampsia (representative disorder of SGA) affects F/P.Results: (1) F/P significantly differed according to infant gender and parity: female and nulliparity had significantly smaller F/P. F/P was significantly smaller in (2) SGA infants, and (3) infants from preeclamptic mothers.Conclusion: We for the first time showed that in Japanese term vaginally-delivered singleton population, the following three had significantly smaller F/P than controls thus had “inappropriately heavy placenta”: (1) female gender and nulliparity, (2) SGA infants, and (3) infants from preeclamptic mothers. We recommend that these factors should be taken into account in evaluating placental weight. These data may also be useful for further clarifying the fetal-placental pathophysiology in these conditions.

Differential body weight, blood pressure and placental inflammatory responses to normal versus high-fat diet in melanocortin-4 receptor-deficient pregnant rats

“…It is important to highlight that placenta dysfunction is thought to drive the pathogenesis of preeclampsia. Human studies support that preeclamptic women have ‘inappropriately heavy placentas’ resulting in reduced placental sufficiency [47], as we found in our obese pregnant rat strain. We propose that our MC4R +/− obese pregnant rats are an excellent model to examine the effects of obesity and obesity-related metabolic factors on implantation and placentation.…”

Downregulation of Placental Amino Acid Transporter Expression and mTORC1 Signaling Activity Contributes to Fetal Growth Retardation in Diabetic Rats

“…Several studies have found that fetal/placental weight ratio was reduced in rodent models of IUGR [12][13][14], suggesting an inefficient placenta that failed to adapt its nutrient supply to meet the demands of the growing fetus. Additionally, it has been observed that fetal/placental weight ratios are associated with a variety of human pregnancy syndromes, including preeclampsia, preterm birth, and IUGR [15,16]. Therefore, our findings provide evidence that decreased placental efficiency plays important role in the fetal growth delay in pregestational diabetes mellitus.…”

Relationship Between Clinical, Placentary, Obstetric and Neonatal Aspects and Intrauterine Growth in High Risk Pregnancies

“…16 A higher prevalence of calciphylaxis and fibrin on both maternal and fetal surfaces was found in analyzing maternal and fetal surfaces of pregnant women with high-risk pregnancies regarding the presence and type/characteristic of macroscopic anatomopathological changes; however, a higher prevalence of calciphylaxis (57.7%) was found on the maternal surface (p<0.0001), and fibrin on the fetal surface (78.5%) (p<0.0001).…”