SARS-CoV-2 infection during pregnancy leads to low for gestational age placenta and elevated birthweight-placental weight ratio

The placental weight ratio (PWR) is a health indicator that reflects the balance between fetal and placental growth. The PWR is defined as the placental weight divided by the birth weight, and it changes across gestation. Its ranges are not well established. We aimed to establish PWR distributions by gestational age and to investigate whether the PWR distributions vary by fetal growth adequacy, small, average, and large for gestational age (SGA, AGA, and LGA). The data came from a hospital based retrospective cohort, using all births at two London, Ontario hospitals in the past 10 years. All women who delivered a live singleton infant between 22 and 42 weeks of gestation were included(n=41441). Nonparametric quantile regression was used to fit the curves. The results demonstrate decreasing PWR and dispersion, with increasing gestational age. A higher proportion of SGA infants have extreme PWRs than AGA and LGA, especially at lower gestational ages. On average, SGA infants had higher PWRs than AGA and LGA infants. The overall curves offer population standards for use in research studies. The curves stratified by fetal growth adequacy are the first of their kind, and they demonstrate that PWR differs for SGA and LGA infants.Corrigendum to “Population-Based Placental Weight Ratio Distributions”

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Maternal Marijuana Exposure, Feto-Placental Weight Ratio, and Placental Histology

American Journal of Perinatology ◽

10.1055/s-0040-1717092 ◽

2020 ◽

Author(s):

Torri D. Metz ◽

Amanda A. Allshouse ◽

Halit Pinar ◽

Michael Varner ◽

Marcela C. Smid ◽

...

Keyword(s):

Tobacco Use ◽

Fetal Growth ◽

Statistical Significance ◽

Weight Ratio ◽

Marijuana Use ◽

Placental Weight ◽

Self Report ◽

Serum Cotinine ◽

Fetal Sex ◽

Live Births

Objective Marijuana use is associated with placenta-mediated adverse pregnancy outcomes including fetal growth restriction, but the mechanism remains uncertain. The objective was to evaluate the association between maternal marijuana use and the feto-placental weight ratio (FPR). Secondarily, we aimed to compare placental histology of women who used marijuana to those who did not. Study Design This was a secondary analysis of singleton pregnancies enrolled in a multicenter and case–control stillbirth study. Prior marijuana use was detected by electronic medical record abstraction or cord homogenate positive for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid. Prior tobacco use was detected by self-report or presence of maternal serum cotinine. Stillbirths and live births were considered separately. The primary outcome was FPR. Association of marijuana use with FPR was estimated with multivariable linear modeling adjusted for fetal sex, preterm birth, and tobacco use. Comparisons between groups for placental histology were made using Chi-square and stratified by live birth and stillbirth, term and preterm deliveries, and fetal sex. Results Of 1,027 participants, 224 were stillbirths and 803 were live births. Overall, 41 (4%) women used marijuana during the pregnancy. The FPR ratio was lower among exposed offspring but reached statistical significance only for term stillbirths (mean 6.84 with marijuana use vs. mean 7.8 without use, p < 0.001). In multivariable modeling, marijuana use was not significantly associated with FPR (p = 0.09). There were no differences in histologic placental features among those with and without marijuana use overall or in stratified analyses. Conclusion Exposure to marijuana may not be associated with FPR. Similarly, there were no placental histologic features associated with marijuana exposure. Further study of the influence of maternal marijuana use on placental development and function is warranted to better understand the association between prenatal marijuana use and poor fetal growth. Key Points

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Mean Placental Birth Weight Ratio at Term in Primigravidae

10.53350/pjmhs2115113496 ◽

2021 ◽

Vol 15 (11) ◽

pp. 3496-3498

Author(s):

Nazia Muneer ◽

Shamaila Shamaun ◽

Afshan Shahid ◽

Riffat Jaleel ◽

Mehreen Iqbal ◽

...

Keyword(s):

Birth Weight ◽

Maternal Age ◽

Weight Ratio ◽

Operational Definition ◽

Cross Sectional Study ◽

Placental Weight ◽

Sectional Study ◽

Inclusion Criteria ◽

Cross Sectional ◽

The Mean

Objective: To determine the mean placental birth weight ratio at term in primigravidae Study design: Cross-sectional study Place and Duration: Department of Obstetrics and Gynecology, Civil Hospital Karachi, duration was six months after the approval of synopsis from 1st January 2016 to 30th June 2016 Subjects and Methods: A total of pregnant women who fulfill the inclusion criteria were included in this study. After delivery, baby was weighed by using weight machine and weight of baby was also noted (as per operational definition). After expulsion of complete placenta, placental weight was measured by using weight machine. The placental-birth weight ratio (PBWR) were calculated as ratio of placental weight to neonatal weight multiplied by 100. Results: Mean ± SD of maternal age was 24.77±4.04 with C.I (24.11----25.42) years. Mean ± SD of placental weight was 505.84±99.97 with C.I (489.71----521.97) grams. Out of 150 neonatal babies 101 (67.3%) were male and 49 (32.7%) were female. Mean placental birth weight ratio was found to be 16.82±2.63 with C.I (16.39----17.24). Conclusion: It is to be concluded that placental weight increased according to the birth weight. The placental weight to birth weight ratio decreased slightly with advancing gestational age. Keywords: Placental weight, Birth weight ratio, Labour at term, Primigravidae

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126. IMPLICATIONS FOR FETAL AND PLACENTAL DEVELOPMENT FOLLOWING MITOCHONDRIAL PERTURBATION IN THE EMBRYO

Reproduction Fertility and Development ◽

10.1071/srb09abs126 ◽

2009 ◽

Vol 21 (9) ◽

pp. 45

Author(s):

S. Wakefield ◽

M. Lane ◽

M. Mitchell

Keyword(s):

Mitochondrial Function ◽

Weight Ratio ◽

Threshold Effect ◽

Blastocyst Stage ◽

Placental Weight ◽

Placental Development ◽

Cell Stage ◽

Crown Rump Length ◽

Fetal Survival ◽

Placental Efficiency

The environment an embryo is exposed to can profoundly influence peri- and post-natal development despite having some capacity to adapt. Whilst the mechanisms responsible remain largely unknown, mitochondria are a likely target. In this study we deliberately perturbed mitochondrial function in the mouse embryo, using a model we have established that shows step-wise changes in embryo metabolism and development. The aim of this study was to provide direct evidence implicating mitochondrial dysfunction in the embryo with perturbed fetal and placental development. Zygote stage embryos were recovered from superovulated female mice and cultured in control conditions to the 2-cell stage. Embryos were then allocated to one of three treatments; control media (0μM-AOA), 5μM or 50μM of the known mitochondrial inhibitor, Amino-Oxyacetate, in the absence of pyruvate (5μM-AOA, 50μM-AOA). Embryos were cultured to the blastocyst stage, then transferred to pseudopregnant recipients, with fetal and placental parameters measured on day 18 of pregnancy. Implantation rates and fetal survival for both 5μM-AOA and 50μM-AOA was comparable to control embryos. For 5μM-AOA there was a significant reduction in placental weight (P=0.02) but normal fetal weight, and a significant increase in fetal: placental weight ratio (P=0.002) relative to the control, suggesting increased placental efficiency. When mitochondria were further perturbed (50μM-AOA), the fetuses and placentas were both considerably compromised: that is, decreased fetal and placental weights (P=0.002), reduced placental diameter (P=0.03) and decreased fetal crown rump length (P=0.07). This study demonstrates that mitochondrial function in the embryo impacts on peri-natal development, providing compelling evidence for mitochondrial function involvement in the mechanisms underpinning “embryo programming”. This data suggests a threshold effect, whereby embryos can only adapt up until a point after which development is compromised. Further elucidating these mechanisms is important for understanding how maternal environments and embryo culture systems determine development of future offspring.

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