Maternal factors associated with fetal growth and birthweight are independent determinants of placental weight and exhibit differential effects by fetal sex

Effect of Mediterranean diet or mindfulness-based stress reduction during pregnancy on placental volume and perfusion: A subanalysis of the IMPACT BCN randomized clinical trial

INTRODUCTION

The IMPACT BCN trial-a parallel-group randomized clinical trial where 1221 pregnant women at high risk for small-for-gestational age (SGA) newborns were randomly allocated at 19- to 23-week gestation into three groups: Mediterranean diet, Mindfulness-based Stress reduction or non-intervention-has demonstrated a positive effect of Mediterranean diet and Stress reduction in the prevention of SGA. However, the mechanism of action of these interventions remains still unclear. The aim of this study is to investigate the effect of Mediterranean diet and Stress reduction on placental volume and perfusion.

MATERIAL AND METHODS

Participants in the Mediterranean diet group received monthly individual and group educational sessions, and free provision of extra-virgin olive oil and walnuts. Women in the Stress reduction group underwent an 8-week Stress reduction program adapted for pregnancy, consisting of weekly 2.5-h and one full-day sessions. Non-intervention group was based on usual care. Placental volume and perfusion were assessed in a subgroup of randomly selected women (n = 165) using magnetic resonance (MR) at 36-week gestation. Small placental volume was defined as MR estimated volume <10th centile. Perfusion was assessed by intravoxel incoherent motion.

RESULTS

While mean MR placental volume was similar among the study groups, both interventions were associated with a lower prevalence of small placental volume (3.9% Mediterranean diet and 5% stress reduction vs. 17% non-intervention; p = 0.03 and p = 0.04, respectively). Logistic regression showed that small placental volume was significantly associated with higher risk of SGA in both study groups (OR 7.48 [1.99-28.09] in Mediterranean diet and 20.44 [5.13-81.4] in Stress reduction). Mediation analysis showed that the effect of Mediterranean diet on SGA can be decomposed by a direct effect and an indirect effect (56.6%) mediated by a small placental volume. Similarly, the effect of Stress reduction on SGA is partially mediated (45.3%) by a small placental volume. Results on placental intravoxel incoherent motion perfusion fraction and diffusion coefficient were similar among the study groups.

CONCLUSIONS

Structured interventions during pregnancy based on Mediterranean diet or Stress reduction are associated with a lower proportion of small placentas, which is consistent with the previously observed beneficial effects of these interventions on fetal growth.

Sociodemographic factor associations with maternal and placental outcomes: A cluster and partial least squares regression analysis

INTRODUCTION

Maternal social disadvantage adversely affects maternal and offspring health, with limited research on placental outcomes. Therefore, we examined maternal sociodemographic factor associations with placental and birth outcomes in general (Lifeways Cross-Generation Cohort) and at-risk (PEARS Study of mothers with overweight or obesity) populations of pregnant women.

METHODS

TwoStep cluster analysis profiled Lifeways mothers (n = 250) based on their age, parity, marital status, household income, private healthcare insurance, homeowner status, and education. Differences in placental and birth outcomes (untrimmed placental weight (PW), birthweight (BW) and BW:PW ratio) between clusters were assessed using one-way ANOVA and chi-square tests. Partial least squares regression analysed individual effects of sociodemographic factors on placental and birth outcomes in Lifeways and PEARS mothers (n = 461).

RESULTS

Clusters were classified as "Married Homeowners" (n = 140, 56 %), "Highest Income" (n = 58, 23.2 %) and "Renters" (n = 52, 20.8 %) in the Lifeways Cohort. Renters were younger, more likely to smoke, have a means-tested medical card and more pro-inflammatory diets compared to other clusters (p < 0.01). Compared to Married Homeowners, renters' offspring had lower BW (-259.26 g, p < 0.01), shorter birth length (-1.31 cm, p < 0.01) and smaller head circumference (-0.59 cm, p = 0.02). PLS regression analyses identified nulliparity as having the greatest negative effect on PW (Lifeways and PEARS) while being a homeowner had the greatest positive effect on PW (Lifeways).

CONCLUSION

Certain combinations of sociodemographic factors (particularly homeownership) were associated with less favourable lifestyle factors, and with birth, but not placental outcomes. When explored individually, parity contributed to the prediction of placental and birth outcomes in both cohorts of pregnant women.

Prenatal Dietary Patterns and Associations With Weight-Related Pregnancy Outcomes in Hispanic Women With Low Incomes

Background: Dietary patterns during pregnancy may contribute to gestational weight gain (GWG) and birthweight, but there is limited research studying these associations in racial and ethnic minority groups. The objective of this study was to evaluate associations between prenatal dietary patterns and measures of GWG and birthweight in a cohort of culturally diverse Hispanic women with low incomes. Methods: Data were analyzed from 500 mother-infant dyads enrolled in the Starting Early Program, a childhood obesity prevention trial. Diet over the previous year was assessed in the third trimester of pregnancy using an interviewer-administered food frequency questionnaire. Dietary patterns were constructed using the Healthy Eating Index-2015 (HEI-2015) and principal components analysis (PCA) and analyzed as tertiles. GWG and birthweight outcomes were abstracted from medical records. Associations between dietary pattern tertiles and outcomes were assessed by multivariable linear and multinomial logistic regression analyses. Results: Dietary patterns were not associated with measures of GWG or adequacy for gestational age. Greater adherence to the HEI-2015 and a PCA-derived dietary pattern characterized by nutrient-dense foods were associated with higher birthweight z-scores [β: 0.2; 95% confidence interval (CI): 0.04 to 0.4 and β: 0.3; 95% CI: 0.1 to 0.5, respectively], but in sex-specific analyses, these associations were only evident in male infants (β: 0.4; 95% CI: 0.03 to 0.7 and β: 0.3; 95% CI: 0.03 to 0.6, respectively). Conclusions: Among a cohort of culturally diverse Hispanic women, adherence to healthy dietary patterns during pregnancy was modestly positively associated with increased birthweight, with sex-specific associations evident only in male infants.

Maternal metabolic profiling across body mass index groups: An exploratory longitudinal study

INTRODUCTION

Increased BMI has been identified as a risk factor for most pregnancy complications, but the underlying metabolic factors mediating the detrimental effects of BMI are largely unknown. We aimed to compare metabolic profiles in overweight/obese women (body mass index [BMI] ≥ 25 kg/m2 ) and normal weight/underweight women (BMI < 25 kg/m2 ) across gestation. We also explored how gestational weight gain (GWG) affected maternal metabolic profiles.

MATERIAL AND METHODS

Exploratory nested case-control study based on a prospective longitudinal cohort of women who were healthy prior to pregnancy and gave birth at Oslo University Hospital from 2002 to 2008. The sample consisted of 48 women who were overweight/obese and 59 normal-weight/underweight women. Plasma samples from four time points in pregnancy (weeks 14-16, 22-24, 30-32 and 36-38) were analyzed by nuclear magnetic resonance spectroscopy and 91 metabolites were measured. Linear regression models were fitted for each of the metabolites at each time point.

RESULTS

Overweight or obese women had higher levels of lipids in very-low-density lipoprotein (VLDL), total triglycerides, triglycerides in VLDL, total fatty acids, monounsaturated fatty acids, saturated fatty acids, leucine, valine, and total branched-chain amino acids in pregnancy weeks 14-16 compared to underweight and normal-weight women. Docosahexaenoic acid and degree of unsaturation were significantly lower in overweight/obese women in pregnancy weeks 36-38. In addition, overweight or obese women had higher particle concentration of XXL-VLDL and glycoprotein acetyls (GlycA) at weeks 14-16 and 30-32. GWG did not seem to affect the metabolic profile, regardless of BMI group when BMI was treated as a dichotomous variable, ≥25 kg/m2 (yes/no).

CONCLUSIONS

Overweight or obese women had smaller pregnancy-related metabolic alterations than normal-weight/underweight women. There was a trend toward higher triglyceride and VLDL particle concentration in overweight/obese women. As this was a hypothesis-generating study, the similarities with late-onset pre-eclampsia warrant further investigation. The unfavorable development of fatty acid composition in overweight/obese women, with possible implication for the offspring, should also be studied further in the future.

A Comparative Cross-sectional Study on Prevalence of Low Birth Weight and its Anticipated Risk Factors

Objective. This study aims to highlight the low birth weight (LBW) in Taiz City (Yemen), as LBW is one of the public health challenges experiencing a profound effect on newborns. Methods. This was a cross-sectional study since the interview and medical records were the sources of data to be analyzed by SPSS. Results. The findings of this study include; a high prevalence of LBW (39.11%), the maternal age was not associated with LBW (P = .68), and education level, economic status, residence place, and health status were not associated with LBW (P < .05). Although the pre-pregnancy BMI, during-pregnancy BMI, MUAC, and gestational age were significantly associated with LBW (P < .05), the only risk factor was gestational age (OR = 9.606, CI = 3.988-23.135, P = .00). Conclusion. LBW is highly prevalent in Taiz (Yemen), so providing good healthcare services is essential to manage LBW incidence.

Maternal Iron Status Is Dynamic Throughout Pregnancy and Might Predict Birth Outcomes in a Sex Dependent Manner: Results from the Alberta Pregnancy Outcomes and Nutrition (APrON) Cohort Study

BACKGROUND

Developmental responses to nutrient deprivation may differ by fetal sex. Despite this, relationships between maternal prenatal iron biomarkers and birth outcomes when stratifying by offspring sex are poorly described, especially in healthy cohorts.

OBJECTIVES

This study aimed to determine associations between maternal iron biomarkers and birth weights (BWs) and birth head circumferences (BHCs) among female and male newborns to assess whether the potential predictive ability of iron biomarkers on birth outcomes differs by offspring sex.

METHODS

The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study recruited 2189 pregnant individuals from Calgary and Edmonton, Canada. Maternal blood was drawn at each trimester and 3 mo postpartum. Maternal serum ferritin (SF) concentrations were measured using chemiluminescent immunoassays and erythropoietin (EPO), hepcidin, and soluble transferrin receptor (sTfR) using enzyme-linked immunosorbent assays. Ratios of sTfR:SF and hepcidin:EPO were calculated and birth outcomes accessed through delivery records. Directed acyclic graphs informed multivariate regression models.

RESULTS

The risk of maternal iron deficiency increased throughout pregnancy because ∼61% showed depleted iron stores (SF < 15 μg/L) by the third trimester. Maternal hepcidin, SF, sTfR, and sTfR:SF concentrations changed across time (P < 0.01), and participants carrying female fetuses consistently (across 6 biomarkers) showed a lower iron status during the third trimester compared with those with male fetuses (P < 0.05). Higher maternal SF and hepcidin:EPO during the third trimester was associated with lower BWs in males (P = 0.006 for SF; P = 0.03 for hepcidin:EPO) and females (P = 0.02 for SF; P = 0.02 for hepcidin:EPO). There were additional inverse associations between BWs and third trimester maternal hepcidin (P = 0.03) and hemoglobin (P = 0.004) and between BHCs and maternal SF (second trimester; P < 0.05) and Hb (third trimester P = 0.02) but only in males.

CONCLUSIONS

Relationships between maternal iron biomarkers and BWs and BHCs may depend on the timing of pregnancy and offpsring sex. There was a high risk of third trimester iron storage depletion among generally healthy pregnant individuals.

The Placenta: A Maternofetal Interface

The placenta is the gatekeeper between the mother and the fetus. Over the first trimester of pregnancy, the fetus is nourished by uterine gland secretions in a process known as histiotrophic nutrition. During the second trimester of pregnancy, placentation has evolved to the point at which nutrients are delivered to the placenta via maternal blood (hemotrophic nutrition). Over gestation, the placenta must adapt to these variable nutrient supplies, to alterations in maternal physiology and blood flow, and to dynamic changes in fetal growth rates. Numerous questions remain about the mechanisms used to transport nutrients to the fetus and the maternal and fetal determinants of this process. Growing data highlight the ability of the placenta to regulate this process. As new technologies and omics approaches are utilized to study this maternofetal interface, greater insight into this unique organ and its impact on fetal development and long-term health has been obtained.

Effect of high-fructose consumption in pregnancy on the bone growth of offspring rats

Growing evidence suggests that bone health is programmed in early life. Maternal diet may influence the skeletal development of offspring. We aimed to determine the possible effects of high-fructose intake during pregnancy on different aspects of long bone morphology in the offspring of rats and to initially explore the possible mechanisms. Pregnant Sprague-Dawley rats were randomly divided into four groups and intragastrically administered the same dose of distilled water (CON, n = 12), 20 g/kg/day glucose (GLU, n = 12), 10 g/kg/day fructose (LFRU, n = 12), or 20 g/kg/day fructose (HFRU, n = 12) for 21 days during gestation. Computed tomography was used to analyze the cortical and cancellous bones of the distal femur of the offspring rats, and circulating bone metabolic biomarkers were measured using enzyme immunoassay. The results showed that high-fructose intake during pregnancy could decrease body weight, impair glucose metabolism, and increase serum leptin and uric acid in offspring. The offspring in the HFRU group had higher levels of the N-terminal propeptide of type I procollagen (PINP) and the C-telopeptide of type I collagen (CTX). The bone mean density (BMD), the total cross-sectional area inside the periosteal envelope (Tt.Ar), cortical bone area (Ct.Ar), medullary (or marrow) area (Ma.Ar), and trabecular mean density of the offspring in the HFRU group were lower than those in the CON group. Tartrate-resistant acid phosphatase (Trap) staining showed that high-fructose intake during pregnancy could increase the number of osteoclasts and increase the absorption area. Our results suggested that excessive fructose intake during pregnancy could inhibit skeletal development in offspring. Thus, attention to fructose intake during pregnancy is important for bone development in offspring.

Ferumoxytol dynamic contrast enhanced magnetic resonance imaging identifies altered placental cotyledon perfusion in rhesus macaques†

Identification of placental dysfunction in early pregnancy with noninvasive imaging could be a valuable tool for assessing maternal and fetal risk. Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) can be a powerful tool for interrogating placenta health. After inoculation with Zika virus or sham inoculation at gestation age (GA) 45 or 55 days, animals were imaged up to three times at GA65, GA100, and GA145. DCE MRI images were acquired at all imaging sessions using ferumoxytol, an iron nanoparticle-based contrast agent, and analyzed for placental intervillous blood flow, number of perfusion domains, and perfusion domain volume. Cesarean section was performed at GA155, and the placenta was photographed and dissected for histopathology. Photographs were used to align cotyledons with estimated perfusion domains from MRI, allowing comparison of estimated cotyledon volume to pathology. Monkeys were separated into high and low pathology groups based on the average number of pathologies present in the placenta. Perfusion domain flow, volume, and number increased through gestation, and total blood flow increased with gestation for both low pathology and high pathology groups. A statistically significant decrease in perfusion domain volume associated with pathology was detected at all gestational ages. Individual perfusion domain flow comparisons demonstrated a statistically significant decrease with pathology at GA100 and GA145, but not GA65. Since ferumoxytol is currently used to treat anemia during human pregnancy and as an off-label MRI contrast agent, future transition of this work to human pregnancy may be possible.

Maternal body mass index and placental weight: a role for fetal insulin, maternal insulin and leptin

PURPOSE

Placental weight (PW) has been found to mediate the main effect of maternal BMI on fetal size. Still, the BMI-PW association is poorly understood. Therefore, we aimed to explore potential explanatory variables, including gestational weight gain (GWG), early- and late-pregnancy circulating levels of maternal glucose, insulin, leptin, adiponectin, triglycerides, LDL-C, and HDL-C, and fetal insulin.

METHODS

We included two studies of pregnant women from Oslo University Hospital, Norway: the prospective STORK (n = 263) and the cross-sectional 4-vessel method study (4-vessel; n = 165). We used multiple linear regression for data analyses. A non-linear BMI-PW association was observed, which leveled off from BMI25. Therefore, BMI <25 and ≥25 were analyzed separately (n = 170/122 and 93/43 for STORK/4-vessel). Confounding variables included maternal age, parity, and gestational age.

RESULTS

PW increased significantly per kg m-2 only among BMI <25 (univariate model's std.β[p] = 0.233 [0.002] vs. 0.074[0.48]/0.296[0.001] vs. -0.030[0.85] for BMI <25 vs. ≥25 in STORK/4-vessel). Maternal early- but not late-pregnancy insulin and term fetal insulin were associated with PW. The estimated effect of early pregnancy insulin was similar between the BMI groups but statistically significant only among BMI <25 (std.β[p] = 0.182[0.016] vs. 0.203[0.07] for BMI <25 vs. ≥25). Late pregnancy leptin was inversely associated with PW with a 1.3/1.7-fold greater effect among BMI ≥25 than BMI <25 in the STORK/4-vessel.

CONCLUSIONS

The BMI-PW association was non-linear: an association was observed for BMI <25 but not for BMI ≥25. Leptin may be involved in the non-linear association through a placental-adipose tissue interplay. Maternal early pregnancy insulin and fetal insulin at term were associated with PW.

The effect of maternal anaemia on low birth weight among newborns in Northwest Ethiopia

Low birth weight is an indicator of maternal-related multifactorial problems such as malnutrition, illness, and work overload. As a result, low birth weight is associated with maternal anaemia, and both of them were significant public health issues in developing nations. Low birth weight and anaemia are caused by insufficient nutrient intake, which is especially severe during pregnancy. So, this study aimed to assess the effect of maternal anaemia during the late trimester on low birth weight among newborns in Northwest Ethiopia. A systematic random sampling technique was used to select 211 participants for the primary data collection. Face-to-face interviews were used to collect data, while blood samples were collected using standard operating procedures. For further analysis, the data file was imported into Stata version 16 (MP) software. The binary logistic regression model was used to investigate significant factors related to low birth weight. Finally, the statistical significance of the variables was determined using a p value of ≤ 0.05. The prevalence of anaemia among pregnant women in the late trimester and newborns was 34 (16.11%, 95% CI: 11.42, 21.78) and 64 (30.33%, 95% CI: 24.20, 37.01), respectively. The mean ± standard deviation of the newborn babies' weight was 3.19 ± 0.49 kg. The proportion of low birth weight among newborns was 26 (12.32%, 95% CI: 8.20, 17.53%). The independent effect of anaemia on low birth weight was 4.19 times while all other factors were constant (COR = 4.19, 95% CI: 1.70, 10.30). Maternal educational status [unable to read and write (AOR = 10.94, 95% CI: 1.74, 68.58) and attained secondary education (AOR = 8.06, 95% CI: 1.53, 42.36)], and maternal anaemia (AOR = 3.51, 95% CI: 1.29, 9.55) were associated with low birth weight after adjusting with all other variables. In this study, the proportion of low birth weight was high. Here, maternal anaemia alone had a significant independent role in the development of low birth weight. Maternal education status and anaemic conditions were associated with low birth weight among newborns. Early detection and treatment of maternal anaemia during pregnancy is crucial with the usual nutritional-related care.

Sex-Dependent Regulation of Placental Oleic Acid and Palmitic Acid Metabolism by Maternal Glycemia and Associations with Birthweight

Pregnancy complications such as maternal hyperglycemia increase perinatal mortality and morbidity, but risks are higher in males than in females. We hypothesized that fetal sex-dependent differences in placental palmitic-acid (PA) and oleic-acid (OA) metabolism influence such risks. Placental explants (n = 22) were incubated with isotope-labeled fatty acids (¹³C-PA or ¹³C-OA) for 24 or 48 h and the production of forty-seven ¹³C-PA lipids and thirty-seven ¹³C-OA lipids quantified by LCMS. Linear regression was used to investigate associations between maternal glycemia, BMI and fetal sex with ¹³C lipids, and between ¹³C lipids and birthweight centile. Placental explants from females showed greater incorporation of ¹³C-OA and ¹³C-PA into almost all lipids compared to males. Fetal sex also influenced relationships with maternal glycemia, with many ¹³C-OA and ¹³C-PA acylcarnitines, ¹³C-PA-diacylglycerols and ¹³C-PA phospholipids positively associated with glycemia in females but not in males. In contrast, several ¹³C-OA triacylglycerols and ¹³C-OA phospholipids were negatively associated with glycemia in males but not in females. Birthweight centile in females was positively associated with six ¹³C-PA and three ¹³C-OA lipids (mainly acylcarnitines) and was negatively associated with eight ¹³C-OA lipids, while males showed few associations. Fetal sex thus influences placental lipid metabolism and could be a key modulator of the impact of maternal metabolic health on perinatal outcomes, potentially contributing toward sex-specific adaptions in which females prioritize survival.

Fetal sex impacts birth to placental weight ratio and umbilical cord oxygen values with implications for regulatory mechanisms

Background

We determined the effect of fetal sex on birth/placental weight and umbilical vein and artery oxygen values with implications for placental efficiency and regulatory mechanisms underlying fetal–placental growth differences.

Methods

A hospital database was used to obtain birth/placental weight, cord PO₂ and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA > 34 weeks (N = 69,836). Oxygen saturation was calculated from the cord PO₂ and pH data, while fractional O₂ extraction was calculated from the oxygen saturation data. The effect of fetal sex on birth/placental weight, cord PO₂, O₂ saturation, and fractional O₂ extraction was examined in all patients adjusting for pregnancy and labor/delivery covariates, and in a subset of low-risk patients.

Results

Birth/placental weights were lower in females indicating decreased placental efficiency. Umbilical vein oxygen values were higher in females attributed to increased uterine blood flow, while artery oxygen values were lower in females attributed to decreased hemoglobin and umbilical blood flow, and increased oxygen consumption. Fetal O₂ extraction was increased in females confirming increased O₂ consumption relative to delivery.

Conclusions

Sex-related differences in uterine/umbilical blood flows, placental development, and fetal O₂ consumption can be linked to the differences observed in cord oxygen. The lower umbilical artery oxygen in females as a measure of systemic oxygenation signaling growth could account for their decreased birth weights, while slower development in female placentae could account for their lower placental weights, which could be differentially effected contributing to their lower birth/placental weights.

Birth/placental wt is decreased in females as a measure of placental efficiency.

Cord vein O₂ is increased in females as a measure of placental O₂ transport.

Cord artery O₂ is decreased in females as a measure of fetal systemic O₂ levels.

Sex differences in placental development link to cord O₂-birth/placental wt findings.

Gestational Diabetes Mellitus and Energy-Dense Diet: What Is the Role of the Insulin/IGF Axis?

Gestational diabetes mellitus (GDM), is one of the most important pregnancy complications affecting approximately 15% of pregnant women. It is related to several gestational adverse outcomes in the fetus, e.g., macrosomia, shoulder dystocia, stillbirth, neonatal hypoglycemia, and respiratory distress. Women with GDM have a high risk of developing type 2 diabetes in the future. The pathogenesis of GDM is not completely understood; nevertheless, two factors could contribute to its development: β-cell dysfunction and failure in insulin secretion in response to insulin resistance induced by gestation. Both processes, together with the physiological activities of the insulin-like growth factors (IGFs), play a crucial role in glucose transport to the fetus and hence, fetal growth and development. IGFs (both IGF-1 and IGF-2) and their binding proteins (IGFBPs) regulate glucose metabolism and insulin sensitivity. Maternal nutritional status determines the health of the newborn, as it has substantial effects on fetal growth and development. Maternal obesity and an energy-dense diet can cause an increase in insulin and IGF-1 serum levels, producing metabolic disorders, such as insulin resistance, GDM, and high birth weight (> 4,000 g) due to a higher level of body fat. In this way, in GDM pregnancies there is an increase in IGF-1 and IGF-2 serum levels, and a decrease in IGFBP-1 and 4 serum levels, suggesting the crucial role of the insulin/IGF system in this gestational outcome. Here, the present review tries to elucidate the role that energy-dense diets and the insulin/IGF-1 signaling pathway perform in GDM pregnancies.

Prenatal alcohol consumption and placental outcomes: a systematic review and meta-analysis of clinical studies

OBJECTIVE

A systematic review was conducted to determine placental outcomes following prenatal alcohol exposure in women.

DATA SOURCES

The search terms "maternal OR prenatal OR pregnant OR periconception" AND "placenta" AND "alcohol OR ethanol" were used across 5 databases (PubMed, Embase, Cochrane Library, Web of Science, and CINAHL) from inception until November 2020.

STUDY ELIGIBILITY CRITERIA

Articles were included if they reported placental outcomes in an alcohol exposure group compared with a control group. Studies were excluded if placentas were from elective termination before 20 weeks' gestation, animal studies, in vitro studies, case studies, or coexposure studies.

METHODS

Study quality was assessed by 2 reviewers using the Newcastle-Ottawa Quality Assessment Scale. Title and abstract screening was conducted by 2 reviewers to remove duplicates and irrelevant studies. Remaining full text articles were screened by 2 reviewers against inclusion and exclusion criteria. Placental outcome data were extracted and tabulated separately for studies of placentation, placental weight, placental morphology, and placental molecular studies. Meta-analyses were conducted for outcomes reported by >3 studies.

RESULTS

Database searching retrieved 640 unique records. Screening against inclusion and exclusion criteria resulted in 33 included studies. The quality assessment identified that 61% of studies were high quality, 30% were average quality, and 9% were low quality. Meta-analyses indicated that prenatal alcohol exposure increased the likelihood of placental abruption (odds ratio, 1.48; 95% confidence interval, 1.37-1.60) but not placenta previa (odds ratio, 1.14; 95% confidence interval, 0.84-1.34) and resulted in a reduction in placental weight of 51 g (95% confidence interval, -82.8 to -19.3). Reports of altered placental vasculature, placental DNA methylation, and gene expression following prenatal alcohol exposure were identified. A single study examined placentas from male and female infants separately and found sex-specific placental outcomes.

CONCLUSION

Prenatal alcohol exposure increases the likelihood of placental abruption and is associated with decreased placental weight, altered placental vasculature, DNA methylation, and molecular pathways. Given the critical role of the placenta in determining pregnancy outcomes, further studies investigating the molecular mechanisms underlying alcohol-induced placental dysfunction are required. Sex-specific placental adaptations to adverse conditions in utero have been well documented; thus, future studies should examine prenatal alcohol exposure-associated placental outcomes separately by sex.

Decreased head circumference at birth associated with maternal tobacco smoke exposure during pregnancy on the Japanese prospective birth cohort study

Maternal tobacco smoke exposure during pregnancy impairs fetal body size, including head circumference (HC) at birth; however, the mechanism still remains unclear. This analysis using a large prospective cohort study evaluated the impact of maternal tobacco exposure on their offspring's HC and the relationship with placental weight ratio (PWR) and placental abnormalities. Parents-children pairs (n = 84,856) were included from the 104,065 records of the Japan Environmental and Children's Study. Maternal perinatal clinical and social information by self-administered questionnaires, offspring's body size, and placental information were collected. Data were analyzed with binominal logistic regression analysis and path analysis. Logistic regression showed significantly elevated adjusted odds ratio (aOR) (1.653, 95% CI 1.387-1.969) for the impact of maternal smoking during pregnancy on their offspring's smaller HC at birth. Maternal exposure to environmental tobacco smoke in the non-smoking group did not increase aOR for the smaller HC. Path analysis showed that maternal smoking during pregnancy decreased the offspring's HC directly, but not indirectly via PWR or placental abnormalities. The quitting smoking during pregnancy group did not increase aOR for the smaller HC than the non-smoking group, suggesting that quitting smoking may reduce their offspring's neurological impairment even after pregnancy.

Association of Prepregnancy Nutritional Status and Physical Activity Levels with Birth Size Outcomes among West Sumatran Pregnant Women: Results from the Vitamin D Pregnant Mothers Cohort Study in Indonesia

Background: Maternal and neonatal morbidity is still high in developing countries like in Indonesia. There are several factors may affect maternal health during pregnancy such as physical activity level (PAL) and pre-pregnancy nutritional status. Aim: To analyze the association between maternal physical activity status (PAL) and pre-pregnancy body mass index (PP BMI) with birth size outcomes. Methods: A prospective birth cohort study, Vitamin D Pregnant Mothers (VDPM) Study, to 183 healthy singleton pregnant women. Pre-pregnancy body mass index was classified according to WHO guidelines for Asian Population. Women PAL was measured at the first trimester (T1) and third trimester (T3) during pregnancy using the Global Physical Activity Questionnaire (GPAQ). Birth size outcomes were measured immediately after birth such as birth weight, birth length, and head circumference. Results: Pregnant women at T3 had two times lower physical activity than T1 of pregnancy (OR, 2.18; CI, 1.044-4.57; p = 0.045). Maternal PAL at T1 and T3 were mostly in sedentary level (74.3% and 77.1%, respectively). There was no association between PP BMI, PAL, and birth size outcomes (p > 0.05 for all comparisons). However, the physical activity at T1 had a significant association with birth weight outcomes [MD (95%CI): 155.3 (13.8 – 296.8), p = 0.032]. There was a significant interaction between maternal PAL and PP BMI on birth weight (p interaction = 0.011) and head circumference (p interaction = 0.034). Conclusions: Our study reveals that pre-maternal nutritional status and physical activity behavior during the pregnancy associated with the head circumference and birth weight outcomes. Further large studies are needed to confirm our findings.

Circulating Insulin and IGF-1 and Frequency of Food Consumption during Pregnancy as Predictors of Birth Weight and Length

The aim of the study was to assess the relationships between maternal insulin and insulin-like growth factor-1 (IGF-1) concentration and food consumption frequency and the birth parameters of the newborn. A total of 157 mother-newborn pairs participated in the study. The study showed that more frequent consumption of sweet and salty snacks as well as fruit and fruit or vegetable juices may promote greater weight gain in pregnancy and higher newborn birth weight. A significantly higher insulin concentration was found among overweight women according to body mass index (BMI), and a significantly lower concentration of IGF-1 was demonstrated among women ≥35 years of age. There was no significant correlation between the concentration of insulin and IGF-1 in the mother’s blood plasma and the birth weight and length of the newborn. A significant relationship was only found between the concentration of IGF-1 in the mother’s blood and the Ponderal index of the newborn. A woman’s eating habits during pregnancy have a significant impact on the mother’s health and on the proper growth and development of the foetus.

Association between parental and offspring BMI: results from EPACI Portugal 2012

OBJECTIVE

To assess the longitudinal association between parental BMI and offspring's BMI, in EPACI Portugal 2012.

DESIGN

Longitudinal study with retrospective collection of children's anthropometry data since birth. Children's anthropometric data were gathered from individual child health bulletins, and parents' anthropometrics were self-reported. Children's and parents' BMI were classified according to WHO cut-offs. Linear mixed models with random intercept and slope for age were applied to quantify the association between parental BMI and children BMI Z-score (zBMI).

SETTING

EPACI Portugal 2012.

PARTICIPANTS

Representative sample from the Portuguese population (n 2230) aged from 12 to 36 months.

RESULTS

58·9 % of the fathers and 35·6 % of the mothers were overweight (OW) or obese. Prevalence of infants who were, at least, at risk of OW increased from 17·0 % to 30·3 % since birth to 12 months. About half of the mothers with pre-pregnancy OW and obesity (OB) gained gestational weight above the recommendations. The children from mothers with gestational weight gain (GWG) below the recommendations showed a -0·15 SD lower zBMI (95 % CI -0·23, -0·06) in early life, comparing with mothers within GWG recommendations. Children of obese mothers were more likely to present a higher zBMI (0·24 SD, 95 % CI 0·13, 0·35) throughout the first months of life.

CONCLUSIONS

A high prevalence of OW and OB was observed in Portuguese young adults and toddlers. Mothers' pre-pregnancy BMI and insufficient GWG had a direct effect on offspring BMI. Early effective interventions are needed in order to prevent the transgenerational transmission of OB.

Mediators Linking Maternal Weight to Birthweight and Neonatal Fat Mass in Healthy Pregnancies

CONTEXT

Lifestyle interventions have not efficaciously reduced complications caused by maternal weight on fetal growth, requiring insight into explanatory mediators.

OBJECTIVE

We hypothesized that maternal mediators, including adiponectin, leptin, insulin, and glucose, mediate effects of pregestational BMI (pBMI) and gestational weight gain (GWG) on birthweight and neonatal fat mass percentage (FM%) through placental weight and fetal mediators, including insulin levels (Ifv) and venous-arterial glucose difference (ΔGfva). Hypothesized confounders were maternal age, gestational age, and parity.

METHODS

A cross-sectional study of healthy mother-offspring-pairs (n = 165) applying the 4-vessel in vivo sampling method at Oslo University Hospital, Norway. We obtained pBMI, GWG, birthweight, and placental weight. FM% was available and calculated for a subcohort (n = 84). We measured circulating levels of adiponectin, leptin, glucose, and insulin and performed path analysis and traditional mediation analyses based on linear regression models.

RESULTS

The total effect of pBMI and GWG on newborn size was estimated to be 30 g (range, 16-45 g) birthweight and 0.17 FM% (range, 0.04-0.29 FM%) per kg∙m-2 pBMI and 31 g (range, 18-44 g) and 0.24 FM% (range, 0.10-0.37 FM%) per kg GWG. The placental weight was the main mediator, mediating 25-g birthweight and 0.11 FM% per kg∙m-2 pBMI and 25-g birthweight and 0.13 FM% per kg GWG. The maternal mediators mediated a smaller part of the effect of pBMI (3.8-g birthweight and 0.023 FM% per kg∙m-2 pBMI) but not GWG.

CONCLUSION

Placental weight was the main mediator linking pBMI and GWG to birthweight and FM%. The effect of pBMI, but not GWG, on birthweight and FM%, was also mediated via the maternal and fetal mediators.

The relationship between resited epidural catheters after secondary epidural catheter failure and vaginal delivery: A retrospective case-control study

BACKGROUND

There are cases where epidural analgesia is initially effective but subsequently fails and needs to be resited. We evaluated the rate of normal vaginal delivery and operative delivery among parturients who had resited epidurals compared to parturients with epidurals that were not resited.

METHODS

A retrospective electronic medical review of parturients with a singleton gestation attempting normal vaginal delivery under epidural analgesia between the years 2012-2016 was conducted. Resited epidurals were defined as epidurals that were considered effective but subsequently removed and reinserted. For each resited epidural, two previous and two consecutive deliveries of parturients with normally functioning epidural catheter inserted by the same anesthesiologist were matched controls (non-resited epidurals).

RESULTS

There were 35,984 attempted vaginal deliveries with 118 resited epidurals and 472 non-resited epidurals. When adjusted for nulliparity, oxytocin administration, sex and weight of the baby, and maternal BMI, labor epidural catheter replacement was not associated with need for instrumental or caesarean delivery, (OR 1.5, 95% CI 0.91-2.49, P = .11).

CONCLUSIONS

Need for labor epidural catheter replacement does not appear to be associated with need for operative delivery based on this single-centre cohort analysis.

Adiponectin as a Potential Biomarker for Pregnancy Disorders

Adiponectin is an adipocyte-derived hormone that plays a critical role in energy homeostasis, mainly attributed to its insulin-sensitizing properties. Accumulating studies have reported that adiponectin concentrations are decreased during metabolic diseases, such as obesity and type 2 diabetes, with an emerging body of evidence providing support for its use as a biomarker for pregnancy complications. The identification of maternal factors that could predict the outcome of compromised pregnancies could act as valuable tools that allow the early recognition of high-risk pregnancies, facilitating close follow-up and prevention of pregnancy complications in mother and child. In this review we consider the role of adiponectin as a potential biomarker of disorders associated with pregnancy. We discuss common disorders associated with pregnancy (gestational diabetes mellitus, preeclampsia, preterm birth and abnormal intrauterine growth) and highlight studies that have investigated the potential of adiponectin to serve as biomarkers for these disorders. We conclude the review by recommending strategies to consider for future research.

Exploring the impact of HIV infection and antiretroviral therapy on placenta morphology

INTRODUCTION

Women living with HIV experience more adverse birth outcomes; the mechanisms are not fully understood. We examined placenta morphology and associations with birth outcomes in a Canadian cohort of women living with HIV (HIV⁺) on antiretroviral therapy (ART) from conception and HIV-uninfected (HIV^-) women.

METHODS

Term placentas from 94 women (40 HIV^-, 54 HIV⁺) were studied. Trimmed placenta weight was collected. Placenta digital photos were used to compute morphometric parameters. Regression models investigated associations between log-transformed placenta parameters and birth outcomes.

RESULTS

We observed a trend towards lower placenta weight and smaller placenta area in the HIV⁺ group, both of which were significantly associated with small for gestational age births. HIV⁺ serostatus was associated with 6-fold (95%CI 2-20) greater odds of having placenta area in the lowest quartile (<236 cm²). Cord marginality (distance from the edge) was significantly lower in the HIV⁺ group (p = 0.004), with 35% of placenta having an abnormal (marginal or velamentous) cord insertion vs. 12.5% in the HIV^- group (p = 0.01). Velamentous cord insertion was seen in 13% of placentas in the HIV⁺ vs. 0% in HIV^- group (p = 0.02). A significant correlation between cord marginality and placenta thickness was observed in the HIV^- group, with a more marginal cord being associated with a thicker placenta. This correlation was not observed in the HIV⁺ group. HIV⁺ placentas exposed to protease inhibitors were significantly less circular compared to the HIV^- group (p = 0.03).

CONCLUSION

Our data suggest that HIV/ART exposure affects placenta morphology and is associated with higher rates of abnormal cord insertion.

Roles of Regulatory RNAs in Nutritional Control

Small RNAs (sRNAs), including microRNAs (miRNAs), are noncoding RNA (ncRNA) molecules involved in gene regulation. sRNAs play important roles in development; however, their significance in nutritional control and as metabolic modulators is still emerging. The mechanisms by which diet impacts metabolic genes through miRNAs remain an important area of inquiry. Recent work has established how miRNAs are transported in body fluids often within exosomes, which are small cell-derived vesicles that function in intercellular communication. The abundance of other recently identified ncRNAs and new insights regarding ncRNAs as dietary bioactive compounds could remodel our understanding about how foods impact gene expression. Although controversial, some groups have shown that dietary RNAs from plants and animals (i.e., milk) are functional in consumers. In the future, regulating sRNAs either directly through dietary delivery or indirectly by altered expression of endogenous sRNA may be part of nutritional interventions for regulating metabolism.

Changes in maternal blood glucose and lipid concentrations during pregnancy differ by maternal body mass index and are related to birthweight: A prospective, longitudinal study of healthy pregnancies

BACKGROUND

Maternal obesity is increasing worldwide but the consequences for maternal physiology and fetal growth are not fully understood.

OBJECTIVE

To study whether changes in glucose and lipid metabolism during pregnancy differ between women with normal weight and overweight/obesity, and investigate which of these metabolic factors are associated with birthweight.

DESIGN

Prospective, longitudinal study.

SETTING

Department of Obstetrics, Oslo University Hospital, Rikshospitalet.

POPULATION

1031 healthy pregnant women with singleton pregnancies.

METHODS

Blood samples from early and late pregnancy were analyzed for fasting glucose, insulin and lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides). Associations between metabolic factors and birthweight (z-scores) were explored by linear regression models. Main Outcome Measures: Group-dependent longitudinal changes in glucose and lipids and their association with birthweight (z-scores).

RESULTS

Compared to women with normal weight (BMI < 25), women with overweight (BMI 25-29.9) and obesity (BMI > 30) had significantly higher fasting glucose (4.54, 4.68 and 4.84 mmol/l), insulin (23, 33 and 50 pmol/l), total cholesterol (4.85, 4.99 and 5.14 mmol/l), LDL-C (2.49, 2.66 and 2.88 mmol/l) and triglycerides (1.10, 1.28 and 1.57 mmol/l), but lower HDL-C (1.86, 1.75 and 1.55 mmol/l). BMI (B 0.05, 95% CI 0.03-0.06, p<0.001), gestational weight gain (GWG) (B 0.06, 0.05-0.08, p<0.001) and an increase in fasting glucose (B 0.30, 0.16-0.43, p<0.001) were positively associated with birthweight, whereas a decrease in HDL-C (B -0.72, -0.96- -0.53, p<0.001) had a negative association with birthweight.

CONCLUSIONS

Overweight/obesity was associated with an unfavorable metabolic profile in early pregnancy which was associated with increased birthweight. However, modifiable factors like gestational weight gain and an increase in fasting glucose were identified and can be targeted for interventions.

Association between maternal active smoking during pregnancy and placental weight: The Japan environment and Children's study

INTRODUCTION

Maternal smoking during pregnancy is a well-known risk factor for reduced birthweight. However, research investigating the association between maternal smoking and placental weight is scarce and inconsistent. Our study was conducted to evaluate the association between maternal smoking and placental weight and placental weight/birthweight ratio (PW/BW ratio).

METHODS

We used data from a birth cohort study, the Japan Environment and Children's Study (JECS). Main outcome measures were placental weight, PW/BW ratio, and the risk of high PW/BW ratio. High PW/BW ratio was defined as PW/BW ratio above the 90th percentile for gestational age and sex of offspring. The association between maternal smoking and placental weight was estimated as crude and as adjusted beta coefficients by applying linear regression analyses. Logistic regression analyses were also performed to estimate the association between maternal smoking and the risk of high PW/BW ratio.

RESULTS

Of the 91,951 pregnant women, the mean placental weight and the mean PW/BW ratio were lowest for the group of women who had never smoked. Smokers had higher odds ratio for high PW/BW ratio compared with non-smokers. Furthermore, among smokers, the mean placental weight and mean PW/BW ratio were lowest in women who smoked less than 5 daily cigarettes, and highest in women who smoked 20 or more daily cigarettes during pregnancy.

DISCUSSION

Placental weight was greater and PW/BW ratio was higher among smokers compared with non-smokers. Moreover, the number of daily cigarettes was positively associated with heavy placental weight.

A new customised placental weight standard redefines the relationship between maternal obesity and extremes of placental size and is more closely associated with pregnancy complications than an existing population standard

Placental weight is a valuable indicator of its function, predicting both pregnancy outcome and lifelong health. Population-based centile charts of weight-for-gestational-age and parity are useful for identifying extremes of placental weight but fail to consider maternal size. To address this deficit, a multiple regression model was fitted to derive coefficients for predicting normal placental weight using records from healthy pregnancies of nulliparous/multiparous women of differing height and weight (n = 107,170 deliveries, 37-43 weeks gestation). The difference between actual and predicted placental weight generated a z-score/individual centile for the entire cohort including women with pregnancy complications (n = 121,591). The association between maternal BMI and placental weight extremes defined by the new customised versus population-based standard was investigated by logistic regression, as was the association between low placental weight and pregnancy complications. Underweight women had a greater risk of low placental weight [<10thcentile, OR 1.84 (95% CI 1.66, 2.05)] and obese women had a greater risk of high placental weight [>90th centile, OR 1.98 (95% CI 1.88, 2.10)] using a population standard. After customisation, the risk of high placental weight in obese/morbidly obese women was attenuated [OR 1.17 (95% CI 1.09, 1.25)]/no longer significant, while their risk of low placental weight was 59%-129% higher (P < 0.001). The customised placental weight standard was more closely associated with stillbirth, hypertensive disease, placental abruption and neonatal death than the population standard. Our customised placental weight standard reveals higher risk of relative placental growth restriction leading to lower than expected birthweights in obese women, and a stronger association between low placental weight and pregnancy complications generally. Further, it provides an alternative tool for defining placental weight extremes with implications for the placental programming of chronic disease.

Learning from experience: cellular and molecular bases for improved outcome in subsequent pregnancies

The frequencies of preeclampsia, fetal growth restriction, fetal demise, and low birthweight are lower in subsequent pregnancies. Enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation also have been observed in subsequent as compared with first pregnancies. We sought to investigate the cellular and molecular bases for better outcomes in subsequent pregnancies. Based on the knowledge that specialized immune cells at the maternal-fetal interface, decidual natural killer cells, promote development of the placental bed and conversion of the spiral arteries by secreting a myriad of angiogenic and growth factors, we asked whether decidual natural killer cells differ in subsequent as compared with first pregnancies. This idea stemmed from recent studies suggesting that natural killer cells, although part of the innate immune system, possess some features of adaptive immunity, including a certain type of immune cell memory, termed trained immunity. We found that decidual natural killer cells from parous women "remember pregnancy" and differ from decidual natural killer cells of primigravidae. Compared with the decidual natural killer cells of first pregnancy, these cells, that we termed pregnancy-trained decidual natural killer cells, express greater levels of the natural killer receptors NKG2C and leukocyte immunoglobulin-like receptor B1, which interact with ligands expressed on invasive trophoblasts. Furthermore, they secrete greater levels of several growth factors, including vascular endothelial growth factor α as well as interferon-γ, augmenting remodeling of the placental bed. We propose that this pregnancy-trained memory dwells in the epigenome, where memory of stimuli is known to persist even when the stimulus is no longer present. This epigenetic memory apparently resides in endometrial natural killer cells between pregnancies. We suggest that this trained memory, which we coined pregnancy-trained decidual natural killer cells, may be the missing link in the immune basis for enhanced subsequent pregnancy. Epigenetic memory (chromatin modification) also may afford a global explanation for additional findings of enhanced maternal cardiovascular adaptation, shorter first and second stages of labor, and more robust lactation. Understanding the molecular and cellular bases of improved outcomes of subsequent pregnancy may lead to the development of treatment modalities designed for women at high risk for pregnancy disorders originating at the maternal-fetal interface.

Placental metal concentrations in relation to placental growth, efficiency and birth weight

The quality of the intrauterine environment, in which the placenta plays a critical role, affects birth outcomes and lifelong health. The effect of metal contaminants on the growth and functioning of the placenta have not been widely reported but may provide insights into how metal exposures lead to these outcomes. We examined relationships between placental concentrations of cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) and measures of placental growth and functioning (placental weight, placental efficiency (the log ratio of placental weight and birth weight), chorionic disc area and disc eccentricity) as part of the New Hampshire Birth Cohort Study (N = 1159). We additionally examined whether these associations were modified by placental concentrations of essential elements zinc (Zn) and selenium (Se). Associations were evaluated using generalized linear models. Multivariable-adjusted differences in placental weight were - 7.81 g (95% CI: -15.42, -2.48) with every ng/g increase in the Cd concentration of placenta (p-Value = 0.0009). Greater decrements in placental weight and efficiency associated with placental Cd were observed for females. For placentae with below median Zn and Se concentrations, decrements in placental weight were - 8.81 g (95% CI: -16.85, -0.76) and - 13.20 g (95% CI: -20.70, -5.70) respectively. The Cd concentration of placenta was also associated with reductions in placental efficiency both overall, and in Zn- and Se-stratified models. No appreciable differences were observed with other elements (As, Hg or Pb) and with other placental measures (chorionic disc area and disc eccentricity). In structural equation models, placental weight was a mediator in the relation between placental Cd concentration and reduced birth weight. Our findings suggest a role of interacting essential and contaminant elements on birth weight that may be mediated by changes in the growth and function of the placenta.

Associations Between the Features of Gross Placental Morphology and Birthweight

The placenta plays a critical role in regulating fetal growth. Recent studies suggest that there may be sex-specific differences in placental development. The purpose of our study was to evaluate the associations between birthweight and placental morphology in models adjusted for covariates and to assess sex-specific differences in these associations. We analyzed data from the Stillbirth Collaborative Research Network's population-based case-control study conducted between 2006 and 2008, which recruited cases of stillbirth and population-based controls in 5 states. Our analysis was restricted to singleton live births with a placental examination (n = 1229). Characteristics of placental morphology evaluated include thickness, surface area, difference in diameters, shape, and umbilical cord insertion site. We used linear regression to model birthweight as a function of placental morphology and covariates. Surface area had the greatest association with birthweight; a reduction in surface area of 83 cm2, which reflects the interquartile range, is associated with a 260.2-g reduction in birthweight (95% confidence interval, -299.9 to -220.6), after adjustment for other features of placental morphology and covariates. Reduced placental thickness was also associated with lower birthweight. These associations did not differ between males and females. Our results suggest that reduced placental thickness and surface area are independently associated with lower birthweight and that these relationships are not related to sex.

Uteroplacental Glucose Uptake and Fetal Glucose Consumption: A Quantitative Study in Human Pregnancies

CONTEXT

Maternal glucose levels and body mass index (BMI) are determinants of fetal overgrowth, but their relation to fetal glucose consumption is not well characterized in human pregnancy.

OBJECTIVES

To quantify uteroplacental glucose uptake and the allocation of glucose between the placenta and fetus and to identify factors that affect fetal glucose consumption.

DESIGN

Human in vivo study in term pregnancies.

SETTING

Oslo University Hospital, Norway.

PARTICIPANTS

One hundred seventy-nine healthy women with elective cesarean section.

INTERVENTIONS

Uterine and umbilical blood flow was determined using Doppler ultrasonography. Glucose and insulin were measured in the maternal radial artery and uterine vein and the umbilical artery and vein. In a subcohort (n = 33), GLUT1 expression was determined in isolated syncytiotrophoblast basal and microvillous plasma membranes.

MAIN OUTCOME MEASURES

Uteroplacental glucose uptake and placental and fetal glucose consumption quantified by the Fick principle.

RESULTS

Median (Q1, Q3) uteroplacental glucose uptake was 117.1 (59.1, 224.9) μmol⋅min-1, and fetal and placental glucose consumptions were 28.9 (15.4, 41.8) µmol⋅min-1⋅kg fetus-1 and 51.4 (-65.8, 185.4) µmol⋅min-1⋅kg placenta-1, respectively. Fetal glucose consumption correlated with birth weight (ρ: 0.34; P < 0.001) and maternal-fetal glucose gradient (ρ: 0.60; P < 0.001), but not with maternal BMI or uteroplacental glucose uptake. Uteroplacental glucose uptake was correlated to placental glucose consumption (ρ: 0.77; P < 0.001). Fetal and placental glucose consumptions were inversely correlated (ρ: -0.47; P < 0.001), but neither was correlated with placental GLUT1 expression.

CONCLUSION

These findings suggest that fetal glucose consumption is balanced against the placental needs for glucose and that placental glucose consumption is a key modulator of maternal-fetal glucose transfer in women.

Effect of nutritional status of pregnant women on birth weight of newborns at Butajira Referral Hospital, Butajira, Ethiopia

Back ground:

Maternal nutritional status influences the developmental environment of the fetus which consequently affects the birth weight of the newborn. However, the association between maternal nutritional factors and birth weight is complex and is not well characterized in Ethiopia.

Objective:

To assess the effect of maternal anthropometry and biochemical profile on birth weight of babies at Butajira Referral Hospital, Butajira, Ethiopia.

Methods and materials:

Laboratory-based cross-sectional study was conducted among 337 pregnant women at the hospital. Socio-demographic and obstetric characteristics were collected using pre-tested questionnaires. Blood sample was collected from each pregnant women for determination of total serum protein, total serum cholesterol and hemoglobin level. However, maternal dietary habits were not assessed in this study.

Results:

A total of 337 pregnant women were involved in the study. The mean (standard deviation) birth weight of the newborns was 3.14 ± 0.46 kg. After adjusting for different maternal factors, parity (p = 0.013), hemoglobin level (p = 0.046), pre-pregnancy body mass index (p < 0.001) and weight gain during pregnancy (p < 0.001) were positively associated with birth weight of the newborns, while the associations with total protein (p = 0.822) and total cholesterol (p = 0.423) were not significant.

Conclusion:

This study has shown that nutritional status of pregnant women as indicated by maternal anthropometry and hemoglobin level was associated with birth weight of the baby. Therefore, nutritional status of the pregnant women should be improved to reduce the risk of low birth weight.

Poor maternal anthropometric characteristics and newborns' birth weight and length: a cross-sectional study in Benin

Background

Maternal undernutrition is known to negatively impact newborns' birth weight and length, but this finding is poorly documented in the Beninese population. This study aimed to assess the effect of maternal anthropometry on mean birth weight and length in a Beninese cohort of newborns.

Methods

A cross-sectional study was carried out in Tori Bossito, Republic of Benin. Pregnant women attending maternity wards between June 2007 and July 2008 were recruited. At delivery the women's characteristics, including weight and height, were gathered and newborns' birth weights and lengths were measured. Statistical analysis was performed using multiple linear regression.

Results

A total of 526 mother-infant pairs were enrolled; 29.8% of women had low weight status and 26.2% had short stature (<155 cm). The mean birth weight was 2985 g (standard deviation [SD] 384) the mean birth length was 48.7 cm (SD 2.2). Maternal low weight status (coefficient=-151.81, p<0.001) and short stature (coefficient=-135.49, p<0.001) reduced the mean birth weight. Similar results were found for mean birth length, which was decreased by maternal low weight status (coefficient=-0.42, p=0.04) and short stature (coefficient=-0.51, p=0.01).

Conclusion

Maternal undernutrition expressed by low anthropometry remains problematic in the Beninese population and induces transmission of malnutrition. Nutritional interventions are required to break this vicious cycle.

PEARLS randomized lifestyle trial in pregnant Hispanic women with overweight/obesity: gestational weight gain and offspring birthweight

BACKGROUND

Inappropriate gestational weight gain (GWG) has been associated with adverse perinatal events. High rates of GWG have been reported among Hispanic women. Observational studies indicate that dietary and physical activity interventions during the prenatal period may improve maternal and infant health, but very few randomized trials have been conducted among high-risk overweight/obese Hispanic women. Accordingly, we conducted a lifestyle intervention among high-risk pregnant women and evaluated its impact on achieving appropriate GWG and on improving birthweight.

METHODS

Eligible overweight/obese women presenting at the University Hospital in Puerto Rico with a singleton pregnancy before 16 gestational weeks were recruited and randomized to lifestyle intervention (n=15) or control group (n=16). The lifestyle intervention focused on improving physical activity and diet quality and optimizing caloric intake. We evaluated the impact of the lifestyle intervention on achieving appropriate GWG and on infant birthweight. Poisson and linear regression analyses were performed.

RESULTS

The primary intent to treat analysis showed no significant effect on achievement of appropriate GWG/week through 36 weeks in the intervention group (4/15 women) when compared with the control group (3/16 women) (adjusted incidence rate ratio =1.14; 95% CI: 0.20, 6.67). Although not statistically significant, women in the intervention group (6/15) were 1.7 times more likely to achieve appropriate weekly GWG until delivery when compared with controls (4/16 women) (adjusted incidence rate ratio = 1.67; 95% CI: 0.40, 6.94). We observed lower adjusted birthweight-for-length z-scores in the intervention compared with the control group among male newborns with z-score difference -1.74 (-3.04, -0.43), but not among females -0.83 (-3.85, 2.19). These analyses were adjusted for age and baseline body mass index.

CONCLUSION

Although larger studies are required to determine whether women with obesity may benefit from prenatal lifestyle interventions targeting GWG, our results are suggestive of the intervention improving adherence to established Institute of Medicine guidelines.

Sex Differences in Nutrition, Growth, and Metabolism in Preterm Infants

Biological differences between the sexes are apparent even from the early part of the pregnancy. The crown-rump length is larger in male fetuses compared to females in the first trimester. Placentae of male and female fetuses have different protein and gene expressions, especially in adverse conditions. Even within the intrauterine milieu, the same extracellular micro RNA may show upregulation in females and downregulation in male fetuses. There appears to be a natural survival advantage for females. Maternal glucocorticoids (GC) play an important role in fetal growth and organ maturation. However, excess glucocorticoids can not only affect growth but the response may be sex-specific and probably mediated through glucocorticoid receptors (GR) in the placenta. Mild pre-eclampsia and asthma are associated with normal growth pattern in males, but in female fetuses, they are associated with a slowing of growth rate without causing IUGR probably as an adaptive response for future adverse events. Thus, female fetuses survive while male fetuses exhibit IUGR, preterm delivery and even death in the face of another adverse event. It is thought that the maternal diet may not influence growth but may influence the programming for adult disease. There is growing evidence that maternal pre-pregnancy overweight or obesity status is directly associated with a higher risk of obesity in a male child, but not in a female child, at 1 year of age. It is observed that exposure to gestational diabetes is a risk factor for childhood overweight in boys but not in girls. It is fascinating that male and female fetuses respond differently to the same intrauterine environment, and this suggests a fundamental biological variation most likely at the cellular and molecular level.

Maternal stress and placental function, a study using questionnaires and biomarkers at birth

Background

Prenatal stress affects the health of the pregnant woman and the fetus. Cortisol blood levels are elevated in pregnancy, and fetal exposure to cortisol is regulated by the placenta enzyme 11β-HSD2. A decrease in enzyme activity allows more maternal cortisol to pass through the placental barrier. Combining the fetal and maternal cortisol to cortisone ratio into the adjusted fetal cortisol exposure (AFCE) represents the activity of the enzyme 11β-HSD2 in the placenta.

Aim

To investigate the effect of prenatal maternal stress on the ratio of cortisol and cortisone in maternal and fetal blood at birth in a normal population.

Method

Maternal self-reported stress was assessed at one time-point, as late in the pregnancy as convenient for the participant, using the Depression Anxiety Stress Scales (DASS-42), Pregnancy Related Anxiety (PRA), and Major Life Events during pregnancy. The study included 273 participants from Copenhagen University Hospital. Maternal and umbilical cord blood was sampled directly after birth and cortisol and cortisone concentrations were quantified using UPLC chromatography. Data were analyzed in a five-step regression model with addition of possible confounders. The primary outcome was AFCE, and plasma concentrations of maternal and fetal cortisol and cortisone were secondary outcomes.

Results

Significant associations were seen for the primary outcome AFCE and the plasma concentrations of maternal cortisol and fetal cortisone with exposure to Pregnancy Related Anxiety (PRA), though the associations were reduced when adjusting for birth related variables, especially delivery mode. The weight of the placenta affected the associations of exposures on AFCE, but not plasma concentrations of cortisol and cortisone in mother and fetus. Moreover, the study demonstrated the importance of delivery mode and birth strain on cortisol levels right after delivery.

Conclusion

Our main finding was associations between PRA and AFCE, which shows the effect of maternal stress on placental cortisol metabolism.

Perinatal outcome among fasting and non fasting mothers during the month of Ramadan

Objective:

To compare the perinatal outcome among fasting and non fasting pregnant mothers.

Methods:

A total of 180 women, who came for delivery in the labor suite were included, after verbal informed consent. These women were divided in two groups fasting (n=100), and non-fasting (n=80).

Results:

The mean age of the mothers was 27.16±4.27 years in the fasting group and 27.36±4.92 years in non-fasting group. The average BMI of mothers was 25.31±3.26 kg/m²in fasting group while 25.64±3.58 kg/m²in non-fasting group. Perinatal outcomes, the birth weight, head circumference and mid arm circumference were almost similar between the two groups. Weight of placenta was 537.80±80.01g in fasting group while 540.50±84.29 g in non-fasting group and height of baby was 45.79±3.07 cm in fasting group while 46.61±2.92 cm in non-fasting group. In fasting group, placenta weight was 531.5±92.80 g in boys while 544.8±62.79 g in girls and ratio of placental to birth weight was 18.8±2.28 in boys while 19.4±2.70 in girls.

Conclusion:

Maternal fasting affects placental weight and length of baby, with effect more pronounced in male babies.

Estimated fetal weight percentile as a tool to predict collection of cord blood units with higher cellular content: implications for prenatal selection of cord blood donors

BACKGROUND

The need for high-cellular-content cord blood units (CBUs) for allogenic transplantation is evident to improve clinical outcomes. In our environment and with current donation programs, very few collected units meet suggested clinical thresholds, making collection programs highly inefficient. To increase the clinical conversion rate, we have assessed factors influencing the cellular content of the cord blood collection and established the estimated fetal weight percentile (EFWp) as a tool to predict which deliveries will obtain higher cellular counts.

STUDY DESIGN AND METHODS

We conducted a retrospective analysis of 11,349 collected CBUs. An analysis of diagnostic efficiency (receiver operating characteristic [ROC] curve) was performed to establish the cutoffs of several obstetric and perinatal variables from which we would obtain more than 1500 × 106 total nucleated cells and 4 × 106 CD34 cells. We then calculated the optimal EFWp cutoff to increase efficiency.

RESULTS

In the univariate analysis, factors positively and significantly associated were a greater neonatal and placental weight and longer weeks of gestation. In the multivariate analysis only neonatal and placental weight remain significant (p < 0.001). The ROC curve analysis showed that the optimal EFWp cutoff is 60, which has the maximum area under the curve. Applying this, donations meeting clinical cellular numbers will increase more than 30% with respect to not using any threshold.

CONCLUSION

The EFWp predicts the quality of the collected CBUs and can be used to make a prenatal selection of the donors, therefore increasing the efficiency of umbilical cord blood collection programs.

The PathLink Acquired Gestational Tissue Bank: Feasibility of Project PLACENTA

BACKGROUND

The Vanderbilt Institute for Clinical and Translational Research piloted the development of Project PLACENTA (PathLink Acquired gEstatioNal Tissue bAnk). This project investigated the feasibility of a fresh gestational tissue biobank, which provides tissue linked to electronic medical records for investigators interested in maternal-fetal health.

METHODS

We developed a pipeline for collection of placental tissue from Labor and Delivery within approximately 30 minutes of delivery. An email alert was developed, to signal delivery, with the ability to specifically flag patients with certain phenotypic traits. Once collected, 4 to 8 mm punch biopsy cores were snap frozen and subsequently used for DNA, RNA and protein extraction. Tissue was also collected for Formalin Fixed Paraffin Embedded (FFPE) histology, flow cytometry, and quality control measures.

RESULTS

Of 60 deliveries using the email notification system, 25 (42%) were sent to Pathology or assigned to other research protocols and were not available for collection, 10 (16%) were discarded prior to arrival at Labor and Delivery, and 25 (42%) were available for collection. Twenty placentas were collected and averaged 38 minutes per collection. DNA extraction yielded an average of 53 µg/µl per sample and RNA extraction yielded 679 ng/µl on average per sample. Proteomic studies showed no degradation of protein, abundant and similar quantities of protein across samples and differentiation between the amnion, decidua, and villi. Histological studies showed good quality for interpretation and occasional pathology including multifocal chronic villitis, meconium laden macrophages, and Stage 2 acute chorioamnionitis. Flow cytometry demonstrated good cell viability after isolation.

Human relaxins (RLNH1, RLNH2), their receptor (RXFP1) and fetoplacental growth

Relaxin, a systemic and placental hormone, has potential roles in fetoplacental growth. Human placenta expresses two RLN genes, RLNH1 and RLNH2 Maternal obesity is common and is associated with abnormal fetal growth. Our aims were to relate systemic and cord blood RLNH2, placental RLNs and their receptor (RXFP1) with fetoplacental growth in context of maternal body mass index, and associations with insulin-like growth factor 2 (IGF2) and vascular endothelial growth factor A (VEGFA) in the same placentas. Systemic, cord blood and placental samples were collected prior to term labor, divided by prepregnancy body mass index: underweight/normal (N = 25) and overweight/obese (N = 44). Blood RLNH2 was measured by ELISA; placental RLNH2, RLNH1, RXFP1, IGF2 and VEGFA were measured by quantitative immunohistochemistry and mRNAs were measured by quantitative reverse transcription PCR. Birthweight increased with systemic RLNH2 only in underweight/normal women (P = 0.036). Syncytiotrophoblast RLNH2 was increased in overweight/obese patients (P = 0.017) and was associated with placental weight in all subjects (P = 0.038). RLNH1 had no associations with birthweight or placental weight, but was associated with increased trophoblast and endothelial IGF2 and VEGFA, due to female fetal sex. Thus, while systemic RLNH2 may be involved in birthweight regulation in underweight/normal women, placental RLNH2 in all subjects may be involved in placental weight. A strong association of trophoblast IGF2 with birthweight and placental weight in overweight/obese women suggests its importance. However, an association of only RLNH1 with placental IGF2 and VEGFA was dependent upon female fetal sex. These results suggest that both systemic and placental RLNs may be associated with fetoplacental growth.

Does Exercise During Pregnancy Affect Placental Weight?: A Randomized Clinical Trial

Placental weight (PW) is a measure commonly used to summarize growth and aspects of placental function. In a normal pregnancy, it is reasonable to assume that PW is related to aspects of the functional capacity of the placenta. The placenta, as the site for all maternal-fetal oxygen and nutrient exchange, influences birth weight and is thus central to a successful pregnancy outcome. PW is the most common way to characterize placental growth, which relates to placental function. With physical exercise becoming an integral part of life for many women, the question of whether exercise during pregnancy has an adverse effect on the growing fetus is very important. The aim was to examine the influence of an aerobic exercise program throughout pregnancy on PW among healthy pregnant women. A randomized control trial was used (registration trial number: NCT02420288). Women were randomized into an exercise group (EG; n = 33) or a control group (CG; n = 32) that received standard care. The EG trained 3 days/week (55-60 min/session) from gestational Weeks 9-11 until Weeks 38-39. The 85 training sessions involved aerobic, muscular and pelvic floor strength, and flexibility exercises. PW and other pregnancy outcomes were measured. There was high attendance to the exercise program, and no differences in the PW at delivery were observed between study groups (CG = 493.2 ± 119.6 g vs. EG = 495.4 ± 150 g, p = .95). A regular, supervised exercise program throughout pregnancy does not affect the PW in healthy pregnant women.

The associations of maternal body mass index with birthweight and placental weight. Does maternal diabetes matter? A population study of 106 191 pregnancies

INTRODUCTION

The aim of this study was to study whether the associations of maternal body mass index with offspring birthweight and placental weight differ by maternal diabetes status.

MATERIAL AND METHODS

We performed a population study of 106 191 singleton pregnancies by using data from the years 2009-2012 in the Medical Birth Registry of Norway. We estimated changes in birthweight and in placental weight (in grams) by maternal body mass index by linear regression analysis.

RESULTS

In pregnancies of women without diabetes, birthweight increased by 14.7 g (95% confidence interval 14.1-15.2) per unit increase in maternal body mass index, and the increase in placental weight was 4.2 g (95% confidence interval 4.0-4.4). In pregnancies of women with gestational diabetes, the corresponding figures were 11.8 g (95% confidence interval 8.3-15.4) and 2.9 g (95% confidence interval 1.7-4.0). In pregnancies of women with type 1 diabetes we found no significant changes in birthweight or in placental weight by maternal body mass index. Overall, mean birthweight was 513.9 g (95% confidence interval 475.6-552.1) higher in pregnancies involving type 1 diabetes than in pregnancies of women without diabetes. Mean placental weight was 102.1 g (95% confidence interval 89.3-114.9) higher. Also, in pregnancies of women with gestational diabetes, both birthweight and placental weight were higher than in women without diabetes (168.2 g and 46.5 g, respectively). Adjustments were made for maternal body mass index and gestational age at birth.

CONCLUSIONS

Birthweight and placental weight increased with increasing maternal body mass index in pregnancies of women without diabetes and in pregnancies of women with gestational diabetes, but not in pregnancies of women with type 1 diabetes. Independent of body mass index, mean birthweight and mean placental weight were highest in pregnancies of women with type 1 diabetes.

Associations of Early and Late Gestational Weight Gain with Infant Birth Size

OBJECTIVES

Associations of gestational weight gain (GWG) during specific periods of pregnancy with infant birth size have been inconsistent. Infant sex-specific differences in these associations are unknown

METHODS

Information on GWG (kg) [total, early (<20 weeks gestation), and late (≥20 weeks gestation)] and indices of infant birth size including birthweight (BW), ponderal index (PI), crown-heel length (CHL), and head circumference (HC) was collected from 3,621 pregnant women. We calculated adjusted mean differences and 95 % confidence intervals (CIs) relating total, early and late GWG to infant birth size using multivariable linear regression procedures. We used stratified analyses and interaction terms to test whether associations differed by infant sex.

RESULTS

One-kg increases in total, early or late GWG were associated with BW increases of 17.2 g (95 % CI 13.8-18.9), 14.1 g (95 % CI 10.3-18.0), and 21.0 g (95 % CI 16.7-25.4), respectively. Early GWG-BW and late GWG-BW associations were different (p = 0.026). Sex-stratified total GWG-BW associations were similar to overall results. There were sex-specific differences in early GWG-BW and late GWG-BW associations. Among females, early GWG-BW (12.0 g, 95 % CI 6.7-17.2) and late GWG-BW (24.2 g, 95 % CI 18.2-30.3) associations differed (p = 0.0042); the corresponding associations did not differ among males. Total, early, and late GWG were associated with CHL and HC, but not with PI. Associations did not differ for early or late GWG.

CONCLUSIONS FOR PRACTICE

For comparable GWG, late-GWG-related BW increase is greater than early-GWG-related BW increase, particularly among female infants.

IFPA meeting 2015 workshop report II: mechanistic role of the placenta in fetal programming; biomarkers of placental function and complications of pregnancy

Workshops are an integral component of the annual International Federation of Placenta Association (IFPA) meeting, allowing for networking and focused discussion related to specialized topics on the placenta. At the 2015 IFPA meeting (Brisbane, Australia) twelve themed workshops were held, three of which are summarized in this report. These workshops focused on various aspects of placental function, particularly in cases of placenta-mediated disease. Collectively, these inter-connected workshops highlighted the role of the placenta in fetal programming, the use of various biomarkers to monitor placental function across pregnancy, and the clinical impact of novel diagnostic and surveillance modalities in instances of late onset fetal growth restriction (FGR).

The impact of altitude on birth weight depends on further mother- and infant-related factors: a population-based study in an altitude range up to 1600 m in Austria between 1984 and 2013

OBJECTIVE

A negative impact of altitude on birth weight has been demonstrated for medium to high-altitude countries.

STUDY DESIGN

The present study aims to show a similar effect for a lower altitude range up to 1600 m in the country of Austria and to adjust for several further risk factors related to mother and infant. In addition, we analyzed whether the effect of altitude influenced birth weight independently or interacted with other factors. For the purpose of this study, almost 1.9 million individual birth certificates of Austrian newborns born between 1984 and 2013 were analyzed. In a multivariate linear regression model, birth weight was associated with altitude of living address and following variables: sex, birth length, gestational age, level of education, maternal age, year of birth, parity, time to previous birth and marital status.

RESULT

Birth weight decreased by 150 g/1000 m altitude, demonstrating a clear effect of altitude on birth weight also in a low to medium altitude level. Additionally, we could show that this effect also depends on other factors, namely gestational age, education of the mother, sex, birth length, year of birth and time to previous delivery. All variables interacted significantly (p<0.0001) with altitude.

CONCLUSION

We observed a negative effect of altitude in an altitude range up to 1600 m. Furthermore, this effect also depends on other risk factors. Therefore, unadjusted estimates as described in many studies may be biased. This population-based study describes the effect of low-to-medium altitude on birth weight in central Europe over a period of 30 years.

Glucose Homeostasis Variables in Pregnancy versus Maternal and Infant Body Composition

Intrauterine factors influence infant size and body composition but the mechanisms involved are to a large extent unknown. We studied relationships between the body composition of pregnant women and variables related to their glucose homeostasis, i.e., glucose, HOMA-IR (homeostasis model assessment-insulin resistance), hemoglobin A1c and IGFBP-1 (insulin-like growth factor binding protein-1), and related these variables to the body composition of their infants. Body composition of 209 women in gestational week 32 and of their healthy, singleton and full-term one-week-old infants was measured using air displacement plethysmography. Glucose homeostasis variables were assessed in gestational week 32. HOMA-IR was positively related to fat mass index and fat mass (r2 = 0.32, p < 0.001) of the women. Maternal glucose and HOMA-IR values were positively (p ≤ 0.006) associated, while IGFBP-1 was negatively (p = 0.001) associated, with infant fat mass. HOMA-IR was positively associated with fat mass of daughters (p < 0.001), but not of sons (p = 0.65) (Sex-interaction: p = 0.042). In conclusion, glucose homeostasis variables of pregnant women are related to their own body composition and to that of their infants. The results suggest that a previously identified relationship between fat mass of mothers and daughters is mediated by maternal insulin resistance.