Influence of Sex on Gestational Complications, Fetal-to-Neonatal Transition, and Postnatal Adaptation

A genome scale transcriptional regulatory model of the human placenta

Gene regulation is essential to placental function and fetal development. We built a genome-scale transcriptional regulatory network (TRN) of the human placenta using digital genomic footprinting and transcriptomic data. We integrated 475 transcriptomes and 12 DNase hypersensitivity datasets from placental samples to globally and quantitatively map transcription factor (TF)-target gene interactions. In an independent dataset, the TRN model predicted target gene expression with an out-of-sample R2 greater than 0.25 for 73% of target genes. We performed siRNA knockdowns of four TFs and achieved concordance between the predicted gene targets in our TRN and differences in expression of knockdowns with an accuracy of >0.7 for three of the four TFs. Our final model contained 113,158 interactions across 391 TFs and 7712 target genes and is publicly available. We identified 29 TFs which were significantly enriched as regulators for genes previously associated with preterm birth, and eight of these TFs were decreased in preterm placentas.

High-throughput mRNA sequencing of human placenta shows sex differences across gestation

INTRODUCTION

Fetal sex affects fetal and maternal health outcomes in pregnancy, but this connection remains poorly understood. As the placenta is the route of fetomaternal communication and derives from the fetal genome, placental gene expression sex differences may explain these outcomes.

OBJECTIVES

We utilized next generation sequencing to study the normal human placenta in both sexes in first and third trimester to generate a normative transcriptome based on sex and gestation.

STUDY DESIGN

We analyzed 124 first trimester (T1, 59 female and 65 male) and 43 third trimester (T3, 18 female and 25 male) samples for sex differences within each trimester and sex-specific gestational differences.

RESULTS

Placenta shows more significant sexual dimorphism in T1, with 94 T1 and 26 T3 differentially expressed genes (DEGs). The sex chromosomes contributed 60.6% of DEGs in T1 and 80.8% of DEGs in T3, excluding X/Y pseudoautosomal regions. There were 6 DEGs from the pseudoautosomal regions, only significant in T1 and all upregulated in males. The distribution of DEGs on the X chromosome suggests genes on Xp (the short arm) may be particularly important in placental sex differences. Dosage compensation analysis of X/Y homolog genes shows expression is primarily contributed by the X chromosome. In sex-specific analyses of first versus third trimester, there were 2815 DEGs common to both sexes upregulated in T1, and 3263 common DEGs upregulated in T3. There were 7 female-exclusive DEGs upregulated in T1, 15 female-exclusive DEGs upregulated in T3, 10 male-exclusive DEGs upregulated in T1, and 20 male-exclusive DEGs upregulated in T3.

DISCUSSION

This is the largest cohort of placentas across gestation from healthy pregnancies defining the normative sex dimorphic gene expression and sex common, sex specific and sex exclusive gene expression across gestation. The first trimester has the most sexually dimorphic transcripts, and the majority were upregulated in females compared to males in both trimesters. The short arm of the X chromosome and the pseudoautosomal region is particularly critical in defining sex differences in the first trimester placenta. As pregnancy is a dynamic state, sex specific DEGs across gestation may contribute to sex dimorphic changes in overall outcomes.

Sex differences in the risk of retinopathy of prematurity: a systematic review, frequentist and Bayesian meta-analysis, and meta-regression

BACKGROUND

Retinopathy of prematurity (ROP) is generally considered to be more frequent in males than in females. However, it is not known whether sex differences in ROP affect all degrees of the condition, are global and have changed as neonatology has developed. We aimed to conduct a systematic review and meta-analysis of studies addressing sex differences in the risk of developing ROP.

METHODS

PubMed/MEDLINE and Embase databases were searched. The frequentist, random-effects risk ratio (RR) and 95% confidence interval (CI) were calculated. Bayesian model averaged (BMA) meta-analysis was used to calculate the Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 205 studies (867,252 infants). Frequentist meta-analysis showed a positive association between male sex and severe ROP (113 studies, RR = 1.14, 95% CI = 1.07-1.22) but no association with any ROP (144 studies, RR = 1.00, 95% CI = 0.96-1.03). BMA showed extreme evidence in favor of H1 for severe ROP (BF10 = 71,174) and strong evidence in favor of H0 for any ROP (BF10 = 0.05). The association between male sex and severe ROP remained stable over time and was present only in cohorts from countries with a high or high-middle sociodemographic index.

CONCLUSIONS

Our study confirms the presence of a male disadvantage in severe ROP but not in less severe forms of the disease. There are variations in the sex differences in ROP, depending on geographical location and sociodemographic level of the countries.

Association between foetal sex and adverse neonatal outcomes in women with gestational diabetes

AIMS

Foetal male sex is associated with adverse perinatal outcomes. However, studies evaluating the impact of foetal sex on perinatal outcomes in women with gestational diabetes (GDM) are scarce. We studied whether male new-born sex is associated with neonatal outcomes, in women with GDM.

METHODS

This is a retrospective study based on the national Portuguese register of GDM. All women with live-born singleton pregnancies between 2012 and 2017 were eligible for study inclusion. Primary endpoints under analysis were neonatal hypoglycaemia, neonatal macrosomia, respiratory distress syndrome (RDS) and neonatal intensive care unit (NICU) admission. We excluded women with missing data on the primary endpoint. Pregnancy data and neonatal outcomes between female and male new-borns were compared. Multivariate logistic regression models were built.

RESULTS

We studied 10,768 new-borns in mothers with GDM, 5635 (52.3%) male, 438 (4.1%) had neonatal hypoglycaemia, 406 (3.8%) were macrosomic, 671 (6.2%) had RDS, and 671 (6.2%) needed NICU admission. Male new-borns were more frequently small or large for gestational age. No differences were observed on maternal age, body mass index, glycated haemoglobin, anti-hyperglycaemic treatment, pregnancy complications or gestational age at delivery. In the multivariate regression analysis, male sex was independently associated with neonatal hypoglycaemia [OR 1.26 (IC 95%: 1.04-1.54), p = 0.02], neonatal macrosomia [1.94 (1.56-2.41), p < 0.001], NICU admission [1.29 (1.07-1.56), p = 0.009], and RDS [1.35 (1.05-1.73, p = 0.02].

CONCLUSIONS

Male new-borns have an independent 26% higher risk of neonatal hypoglycaemia, 29% higher risk of NICU admission, 35% higher risk of RDS, and almost twofold higher risk of macrosomia, compared to female new-borns.

Influence of fetal gender on overall perinatal outcome: a prospective observational study

BACKGROUND

Fetal gender is considered as one of significant predictors of pregnancy and perinatal outcome. The aim of this study is to assess impact of fetal gender on perinatal outcome.

METHODS

Present observational study was conducted in Obstetrics and Gynecology department of rural tertiary center of Northern India over one year (January-December 2018) on all randomly selected antenatal women at gestation ≥28 weeks, delivering by any route (cesarean/vaginal) and fulfilling inclusion criteria were enrolled. Immediately after delivery, neonatal birth weight was measured using table top beam weighing scale. Apgar scores at 1- and 5-minutes, Neonatal Intensive Care Unit admission, neonatal complications were assessed by pediatrician. Adverse perinatal outcome including neonatal morbidities (prematurity, neonatal intensive care unit admission, neonatal complications) and perinatal mortality were compared between two genders. Statistical analysis was done using SPSS 22 version software.

RESULTS

Of 3085 delivered neonates, 1450 (47%) were females, 1,633(52.9%) males and two (0.06%) had ambiguous genitalia, hence excluded. Mean values for neonatal birth weight for males was 2.77±0.540 kg and females 2.65±0.506 kg (P=0.0000). One- and 5-minute Apgar scores for male neonate were 6.81±1.565, 8.51±1.841 and for females 6.98±1.184, 8.70±1.383, respectively (P=0.001). NICU admission rate, need for oxygen and intubation, complications were significantly higher for male neonates (P<0.05) whereas females had higher incidence of intra-uterine growth restriction (P=0.000). Intra-uterine deaths were also more common with male gender (P=0.007). No significant difference was observed between two genders in relation to gestation at birth (P>0.05).

CONCLUSIONS

Male neonates had higher birth weight, but adverse perinatal outcome as compared to females.

Sex and age differences in social and cognitive function in offspring exposed to late gestational hypoxia

BACKGROUND

Gestational sleep apnea is a hypoxic sleep disorder that affects 8-26% of pregnancies and increases the risk for central nervous system dysfunction in offspring. Specifically, there are sex differences in the sensitivity of the fetal hippocampus to hypoxic insults, and hippocampal impairments are associated with social dysfunction, repetitive behaviors, anxiety, and cognitive impairment. Yet, it is unclear whether gestational sleep apnea impacts these hippocampal-associated functions and if sex and age modify these effects. To examine the relationship between gestational sleep apnea and hippocampal-associated behaviors, we used chronic intermittent hypoxia (CIH) to model late gestational sleep apnea in pregnant rats. We hypothesized that late gestational CIH would produce sex- and age-specific social, anxiety-like, repetitive, and cognitive impairments in offspring.

METHODS

Timed pregnant Long-Evans rats were exposed to CIH or room air normoxia from GD 15-19. Behavioral testing of offspring occurred during either puberty or young adulthood. To examine gestational hypoxia-induced behavioral phenotypes, we quantified hippocampal-associated behaviors (social function, repetitive behaviors, anxiety-like behaviors, and spatial memory and learning), hippocampal neuronal activity (glutamatergic NMDA receptors, dopamine transporter, monoamine oxidase-A, early growth response protein 1, and doublecortin), and circulating hormones in offspring.

RESULTS

Late gestational CIH induced sex- and age-specific differences in social, repetitive, and memory functions in offspring. In female pubertal offspring, CIH impaired social function, increased repetitive behaviors, and elevated circulating corticosterone levels but did not impact memory. In contrast, CIH transiently induced spatial memory dysfunction in pubertal male offspring but did not impact social or repetitive functions. Long-term effects of gestational CIH on social behaviors were only observed in female offspring, wherein CIH induced social disengagement and suppression of circulating corticosterone levels in young adulthood. No effects of gestational CIH were observed in anxiety-like behaviors, hippocampal neuronal activity, or circulating testosterone and estradiol levels, regardless of sex or age of offspring.

CONCLUSIONS

Our results indicate that hypoxia-associated pregnancy complications during late gestation can increase the risk for behavioral and physiological outcomes in offspring, such as social dysfunction, repetitive behaviors, and cognitive impairment, that are dependent on sex and age.

The impact of gender medicine on neonatology: the disadvantage of being male: a narrative review

This narrative non-systematic review addresses the sex-specific differences observed both in prenatal period and, subsequently, in early childhood. Indeed, gender influences the type of birth and related complications. The risk of preterm birth, perinatal diseases, and differences on efficacy for pharmacological and non-pharmacological therapies, as well as prevention programs, will be evaluated. Although male newborns get more disadvantages, the physiological changes during growth and factors like social, demographic, and behavioural reverse this prevalence for some diseases. Therefore, given the primary role of genetics in gender differences, further studies specifically targeted neonatal sex-differences will be needed to streamline medical care and improve prevention programs.

Windows of Vulnerability: Consequences of Exposure Timing during the Dutch Hunger Winter

Prior research on early-life exposures to famine has established in utero development as a critical period of vulnerability to malnutrition. Yet, previous research tends to focus narrowly on this stage, at the expense of a more comprehensive examination of childhood. As a result, the literature has yet to compare the severity of the consequences of exposure to malnutrition across developmentally salient periods. Such comparison is crucial not only in the magnitude of effects but also in the nature of outcomes. Using a restricted population registry-linked health survey, this study examines the Dutch Hunger Winter to provide a comprehensive examination of the long-term consequences of in utero, infant, childhood, and adolescent exposure to famine. The results show malnutrition leads to heterogeneous effects depending on when the exposure occurs. In utero exposure to malnutrition leads to deleterious conditions in physical health and lower socioeconomic attainment. For older cohorts, results suggest a resilience to the effects of malnutrition on physical health in late life, but a higher vulnerability to socioeconomic stunting. Furthermore, the results suggest important gender differences in the long-term impact of malnutrition. Males consistently show stronger negative consequences across a wider array of conditions.

Influence of Neonatal Sex on Breast Milk Protein and Antioxidant Content in Spanish Women in the First Month of Lactation

Breast milk (BM) is the best food for newborns. Male sex is associated with a higher risk of fetal programming, prematurity, and adverse postnatal outcome, being that BM is an important health determinant. BM composition is dynamic and modified by several factors, including lactation period, prematurity, maternal nutritional status, and others. This study was designed to evaluate the influence of sex on BM composition during the first month of lactation, focused on macronutrients and antioxidants. Forty-eight breastfeeding women and their fifty-five newborns were recruited at the Hospital Clínico San Carlos (Madrid, Spain). Clinical sociodemographic data and anthropometric parameters were collected. BM samples were obtained at days 7, 14, and 28 of lactation to assess fat (Mojonnier method), protein (Bradford method), and biomarkers of oxidative status: total antioxidant capacity (ABTS and FRAP methods), thiol groups, reduced glutathione, superoxide dismutase and catalase activities, lipid peroxidation, and protein oxidation (spectrophotometric methods). Linear mixed models with random effects adjusted by maternal anthropometry, neonatal Z-scores at birth, and gestational age were used to assess the main effects of sex, lactation period, and their interaction. BM from mothers with male neonates exhibited significantly higher protein, ABTS, FRAP, and GSH levels, while catalase showed the opposite trend. No differences between sexes were observed in SOD, total thiols, and oxidative damage biomarkers. Most changes were observed on day 7 of lactation. Adjusted models demonstrated a significant association between male sex and proteins (β = 2.70 ± 1.20; p-Value = 0.048). In addition, total antioxidant capacity by ABTS (β = 0.11 ± 0.06) and GSH (β = 1.82 ± 0.94) showed a positive trend near significance (p-Value = 0.056; p-Value = 0.064, respectively). In conclusion, transitional milk showed sex differences in composition with higher protein and GSH levels in males. This may represent an advantage in the immediate perinatal period, which may help to counteract the worse adaptation of males to adverse intrauterine environments and prematurity.

Differences in nutritional status between rural and urban Yucatec Maya children: The importance of early life conditions

Early‐life conditions shape childhood growth and are affected by urbanization and the nutritional transition. To investigate how early‐life conditions (across the “first” and “second” 1000 days) are associated with rural and urban children's nutritional status, we analyzed anthropometric data from Maya children in Yucatan, Mexico. We collected weight, height and triceps skinfold measures, then computed body mass and fat mass indices (BMI/FMI), in a cross‐sectional sample of 6‐year‐olds (urban n = 72, rural n = 66). Demographic, socioeconomic and early‐life variables (birthweight/mode, rural/urban residence, household crowding) were collected by maternal interview. We statistically analyzed rural‐urban differences in demographic, socioeconomic, early‐life, and anthropometric variables, then created linear mixed models to evaluate associations between early‐life variables and child anthropometric outcomes. Two‐way interactions were tested between early‐life variables and child sex, and between early‐life variables and rural‐urban residence. Results showed that rural children were shorter‐statured, with lower overweight/obesity and cesarean delivery rates, compared to urban children. Household crowding was a negative predictor of anthropometric outcomes; the strongest effect was in boys and in urban children. Birthweight positively predicted anthropometric outcomes, especially weight/BMI. Birth mode was positively (not statistically) associated with any anthropometric outcome. Cesarean delivery was more common in boys than in girls, and predicted increased height in urban boys. In conclusion, urbanization and household crowding were the most powerful predictors of Maya 6‐year‐old anthropometry. The negative effects of crowding may disproportionately affect Maya boys versus girls and urban versus rural children. Early‐life conditions shape Maya children's nutritional status both in the “first” and “second” 1000 days.

Regional pulmonary oxygen saturations immediately after birth

BACKGROUND

Partial oxygen saturation (SpO₂) increases within minutes during transition from the intrauterine to extrauterine life. This study aims to determine the postnatal course of pulmonary regional oxygen saturation (rSO₂) measured by Near-Infrared Spectroscopy (NIRS).

METHODS

We conducted an observational study at the delivery room in infants above 35 weeks of gestation who did not need resuscitation and did not develop respiratory distress. Preductal pulse oximetry (Covidien NellcorTM) and right pulmonary apex oxygen saturation (raSO₂) and basal oxygen saturation (rbSO₂) (Covidien INVOSTM) were measured, starting from the postnatal third minute of life, until the 15th minute. The correlations between SpO₂ and pulmonary rSO₂ were analyzed.

RESULTS

Of the 110 infants included in the study, 87 were term and 23 were late preterms. The gestational age and birth weight were 38.5 ± 1.36 weeks and 3285 ± 508 g, respectively. Median (5th-95th percentile) raSO₂ and rbSO₂ were 79% (58-95%) and 78% (46-95%) at the third minute, respectively. The rSO₂ values measured from both sides increased and reached a steady-state around postnatal 9 min, similar to SpO₂ values. The pulmonary NIRS values were significantly higher for babies born by C-Section compared to babies born by vaginal delivery (p < 0.05).

CONCLUSION

We found that rSO₂ measurements increased within minutes in the postnatal period in late preterm and term babies without respiratory distress and reached a plateau at the postnatal 9th minute. The normal values obtained from this preliminary study may be used to predict the prognosis of cases with respiratory distress.

Risk factors and bronchopulmonary dysplasia severity: data from the Spanish Bronchopulmonary Dysplasia Research Network

GEIDIS is a national-based research-net registry of patients with bronchopulmonary dysplasia (BPD) from public and private Spanish hospitals. It was created to provide data on the clinical characterization and follow-up of infants with BPD until adulthood. The purpose of this observational study was to analyze the characteristics and the impact of perinatal risk factors on BPD severity. The study included 1755 preterm patients diagnosed with BPD. Of the total sample, 90.6% (n = 1591) were less than 30 weeks of gestation. The median gestational age was 27.1 weeks (25.8-28.5) and median birth weight 885 g (740-1,070 g). A total of 52.5% (n = 922) were classified as mild (type 1), 25.3% (n = 444) were moderate (type 2), and 22.2% (n = 389) were severe BPD (type 3). In patients born at under 30 weeks' gestation, most pre-and postnatal risk factors for type 2/3 BPD were associated with the length of exposure to mechanical ventilation (MV). Independent prenatal risk factors were male gender, oligohydramnios, and intrauterine growth restriction. Postnatal risk factors included the need for FiO2 of > 0.30 in the delivery room, nosocomial pneumonia, and the length of exposure to MV. Conclusion: In this national-based research-net registry of BPD patients, the length of MV is the most important risk factor associated with type 2/3 BPD. Among type 3 BPD patients, those who required an FiO2 > .30 at 36 weeks' postmenstrual age had a higher morbidity, during hospitalization and at discharge, compared to those with nasal positive pressure but FiO2 < .30. What is Known: • BPD is a highly complex multifactorial disease associated with preterm birth. What is New: • The length of exposure to mechanical ventilation is the most important postnatal risk factor associated to bronchopulmonary severity which modulate the effect of most pre and postnatal risk factors. • Among patients with BPD, the requirement for FiO2 >.30% at 36 weeks of postmenstrual age is associated with greater morbidity during hospitalization and at discharge.

Risk of Retinopathy of Prematurity in Preterm Births with Respiratory Distress Syndrome: A Population-Based Cohort Study in Taiwan

Background

Methods

Results

Conclusion

Sex differences in microRNA expression in first and third trimester human placenta†

Maternal and fetal pregnancy outcomes related to placental function vary based on fetal sex, which may be due to sexually dimorphic epigenetic regulation of RNA expression. We identified sexually dimorphic miRNA expression throughout gestation in human placentae. Next-generation sequencing identified miRNA expression profiles in first and third trimester uncomplicated pregnancies using tissue obtained at chorionic villous sampling (n = 113) and parturition (n = 47). Sequencing analysis identified 986 expressed mature miRNAs from female and male placentae at first and third trimester (baseMean>10). Of these, 11 sexually dimorphic (FDR < 0.05) miRNAs were identified in the first and 4 in the third trimester, all upregulated in females, including miR-361-5p, significant in both trimesters. Sex-specific analyses across gestation identified 677 differentially expressed (DE) miRNAs at FDR < 0.05 and baseMean>10, with 508 DE miRNAs in common between female-specific and male-specific analysis (269 upregulated in first trimester, 239 upregulated in third trimester). Of those, miR-4483 had the highest fold changes across gestation. There were 62.5% more female exclusive differences with fold change>2 across gestation than male exclusive (52 miRNAs vs 32 miRNAs), indicating miRNA expression across human gestation is sexually dimorphic. Pathway enrichment analysis identified significant pathways that were differentially regulated in first and third trimester as well as across gestation. This work provides the normative sex dimorphic miRNA atlas in first and third trimester, as well as the sex-independent and sex-specific placenta miRNA atlas across gestation, which may be used to identify biomarkers of placental function and direct functional studies investigating placental sex differences.

Male HELLP pups experience sensorimotor delays and reduced body weight

Offspring of Preeclampsia (PreE) and HELLP Syndrome are at an increased risk of developing neurodevelopmental disorders. In the current study we sought to determine if offspring from experimental models of PreE and HELLP had evidence of early onset neurodevelopmental delay. Offspring from PreE, HELLP and normal pregnant dams were assessed in a battery of sensorimotor tests beginning on postnatal day (PND) 3. Male HELLP offspring showed altered behavior in the surface righting reflex on PND 3 and cliff avoidance task from PND 3-6 relative to other groups. Results suggest that there are sex differences in offspring born to dams with PreE and HELLP.

Male Disadvantage in Oxidative Stress-Associated Complications of Prematurity: A Systematic Review, Meta-Analysis and Meta-Regression

A widely accepted concept is that boys are more susceptible than girls to oxidative stress-related complications of prematurity, including bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and periventricular leukomalacia (PVL). We aimed to quantify the effect size of this male disadvantage by performing a systematic review and meta-analysis of cohort studies exploring the association between sex and complications of prematurity. Risk ratios (RRs) and 95% CIs were calculated by a random-effects model. Of 1365 potentially relevant studies, 41 met the inclusion criteria (625,680 infants). Male sex was associated with decreased risk of hypertensive disorders of pregnancy, fetal distress, and C-section, but increased risk of low Apgar score, intubation at birth, respiratory distress, surfactant use, pneumothorax, postnatal steroids, late onset sepsis, any NEC, NEC > stage 1 (RR 1.12, CI 1.06–1.18), any IVH, severe IVH (RR 1.28, CI 1.22–1.34), severe IVH or PVL, any BPD, moderate/severe BPD (RR 1.23, CI 1.18–1.27), severe ROP (RR 1.14, CI 1.07–1.22), and mortality (RR 1.23, CI 1.16–1.30). In conclusion, preterm boys have higher clinical instability and greater need for invasive interventions than preterm girls. This leads to a male disadvantage in mortality and short-term complications of prematurity.

Association of the dysfunctional placentation endotype of prematurity with bronchopulmonary dysplasia: a systematic review, meta-analysis and meta-regression

Background

Antenatal pathological conditions are key in the pathogenesis of bronchopulmonary dysplasia (BPD). Pathophysiological pathways or endotypes leading to prematurity and perinatal lung injury can be clustered into two groups: infection and dysfunctional placentation, which include hypertensive disorders of pregnancy (HDP) and intrauterine growth restriction (IUGR). We conducted a systematic review of observational studies exploring the association between the dysfunctional placentation endotype and BPD.

Methods

MEDLINE, Embase and Web of Science databases were searched up to February 2020 for studies reporting data on the diagnosis of HDP, IUGR or small for gestational age (SGA) and BPD risk. BPD was classified as BPD28 (supplemental oxygen on day 28), BPD36 (oxygen at 36 weeks postmenstrual age), severe BPD (≥ 30% oxygen or mechanical ventilation), BPD36/death and BPD-associated pulmonary hypertension.

Results

Of 6319 studies screened, 211 (347 963 infants) were included. Meta-analysis showed an association between SGA/IUGR and BPD36 (OR 1.56, 95% CI 1.37 to 1.79), severe BPD (OR 1.82, 95% CI 1.36 to 2.29) and BPD/death (OR 1.91, 95% CI 1.55 to 2.37). Exposure to HDP was not associated with BPD but was associated with decreased odds of BPD/death (OR 0.77, 95% CI 0.64 to 0.94). Both HDP (OR 1.41, 95% CI 1.10 to 1.80) and SGA/IUGR (OR 2.37, 95% CI 1.86 to 3.02) were associated with BPD-associated pulmonary hypertension.

Conclusion

When placental vascular dysfunction is accompanied by fetal growth restriction or being born SGA, it is associated with an increased risk of developing BPD and pulmonary hypertension. The placental dysfunction endotype of prematurity is strongly associated with the vascular phenotype of BPD.

Prospero registration number

Review protocol was registered in PROSPERO database (ID=CRD42018086877).

Human Placental Transcriptome Reveals Critical Alterations in Inflammation and Energy Metabolism with Fetal Sex Differences in Spontaneous Preterm Birth

A well-functioning placenta is crucial for normal gestation and regulates the nutrient, gas, and waste exchanges between the maternal and fetal circulations and is an important endocrine organ producing hormones that regulate both the maternal and fetal physiologies during pregnancy. Placental insufficiency is implicated in spontaneous preterm birth (SPTB). We proposed that deficits in the capacity of the placenta to maintain bioenergetic and metabolic stability during pregnancy may ultimately result in SPTB. To explore our hypothesis, we performed a RNA-seq study in male and female placentas from women with SPTB (<36 weeks gestation) compared to normal pregnancies (≥38 weeks gestation) to assess the alterations in the gene expression profiles. We focused exclusively on Black women (cases and controls), who are at the highest risk of SPTB. Six hundred and seventy differentially expressed genes were identified in male SPTB placentas. Among them, 313 and 357 transcripts were increased and decreased, respectively. In contrast, only 61 differentially expressed genes were identified in female SPTB placenta. The ingenuity pathway analysis showed alterations in the genes and canonical pathways critical for regulating inflammation, oxidative stress, detoxification, mitochondrial function, energy metabolism, and the extracellular matrix. Many upstream regulators and master regulators important for nutrient-sensing and metabolism were also altered in SPTB placentas, including the PI3K complex, TGFB1/SMADs, SMARCA4, TP63, CDKN2A, BRCA1, and NFAT. The transcriptome was integrated with published human placental metabolome to assess the interactions of altered genes and metabolites. Collectively, significant and biologically relevant alterations in the transcriptome were identified in SPTB placentas with fetal sex disparities. Altered energy metabolism, mitochondrial function, inflammation, and detoxification may underly the mechanisms of placental dysfunction in SPTB.

Plasma Adenosine Deaminase (ADA)-1 and -2 Demonstrate Robust Ontogeny Across the First Four Months of Human Life

Background

Human adenosine deaminases (ADAs) modulate the immune response: ADA1 via metabolizing adenosine, a purine metabolite that inhibits pro-inflammatory and Th1 cytokine production, and the multi-functional ADA2, by enhancing T-cell proliferation and monocyte differentiation. Newborns are relatively deficient in ADA1 resulting in elevated plasma adenosine concentrations and a Th2/anti-inflammatory bias compared to adults. Despite the growing recognition of the role of ADAs in immune regulation, little is known about the ontogeny of ADA concentrations.

Methods

In a subgroup of the EPIC002-study, clinical data and plasma samples were collected from 540 Gambian infants at four time-points: day of birth; first week of life; one month of age; and four months of age. Concentrations of total extracellular ADA, ADA1, and ADA2 were measured by chromogenic assay and evaluated in relation to clinical data. Plasma cytokines/chemokine were measured across the first week of life and correlated to ADA concentrations.

Results

ADA2 demonstrated a steady rise across the first months of life, while ADA1 concentration significantly decreased 0.79-fold across the first week then increased 1.4-fold by four months of life. Males demonstrated significantly higher concentrations of ADA2 (1.1-fold) than females at four months; newborns with early-term (37 to <39 weeks) and late-term (≥41 weeks) gestational age demonstrated significantly higher ADA1 at birth (1.1-fold), and those born to mothers with advanced maternal age (≥35 years) had lower plasma concentrations of ADA2 at one month (0.93-fold). Plasma ADA1 concentrations were positively correlated with plasma CXCL8 during the first week of life, while ADA2 concentrations correlated positively with TNFα, IFNγ and CXCL10, and negatively with IL-6 and CXCL8.

Conclusions

The ratio of plasma ADA2/ADA1 concentration increased during the first week of life, after which both ADA1 and ADA2 increased across the first four months of life suggesting a gradual development of Th1/Th2 balanced immunity. Furthermore, ADA1 and ADA2 were positively correlated with cytokines/chemokines during the first week of life. Overall, ADA isoforms demonstrate robust ontogeny in newborns and infants but further mechanistic studies are needed to clarify their roles in early life immune development and the correlations with sex, gestational age, and maternal age that were observed.

Effect of newborn gender on placental histopathology and perinatal outcome in singleton live births following IVF

RESEARCH QUESTION

Does newborn gender affect placental histopathology pattern and perinatal outcome in singleton live births following IVF treatment?

DESIGN

Retrospective cohort study evaluating data of all live births from one academic tertiary hospital following IVF treatment during 2009-2017. All patients had placentas sent for pathological evaluation irrelevant of maternal and fetal complications status. Exclusion criteria were abnormal uterine cavity findings, previous uterine surgery, in-vitro maturation cycles, gestational carrier cycles, oocyte recipient cycles, preimplantation genetic diagnosis cycles and multiple pregnancies. The primary outcomes included anatomical, inflammation, vascular malperfusion and villous maturation placental features. The secondary outcomes included fetal, maternal, perinatal and delivery complications. A multivariate analysis was conducted to adjust the results for factors potentially associated with placental pathology features.

RESULTS

A total of 1057 live births were included in the final analysis and were allocated to the study groups according to fetal gender: males (n = 527) and females (n = 530). After adjustment for potential confounding factors, male gender was significantly associated with villous agglutination (odds ratio [OR] 9.8; 95% confidence interval [CI] 1.4-78.2), avascular villi (OR 4.1; 95% CI 1.3-12.6) and maternal vascular malperfusion (OR 1.8; 95% CI 1.2-2.7). Female gender was significantly associated with bilobed placenta (OR 0.2; 95% CI 0.06-0.8) and subchorionic thrombi (OR 0.5; 95% CI 0.3-0.9). The prevalence of adverse fetal, maternal and delivery outcomes was similar between the groups.

CONCLUSIONS

Newborn gender has a significant impact on the placental histopathology pattern, which can contribute to the development of adverse perinatal outcomes.

Placental Metabolomics for Assessment of Sex-specific Differences in Fetal Development During Normal Gestation

The placenta is a metabolically active interfacial organ that plays crucial roles in fetal nutrient delivery, gas exchange and waste removal reflecting dynamic maternal and fetal interactions during gestation. There is growing evidence that the sex of the placenta influences fetal responses to external stimuli in utero, such as changes in maternal nutrition and exposure to environmental stressors. However, the exact biochemical mechanisms associated with sex-specific metabolic adaptations during pregnancy and its link to placental function and fetal development remain poorly understood. Herein, multisegment injection-capillary electrophoresis-mass spectrometry is used as a high throughput metabolomics platform to characterize lyophilized placental tissue (~2 mg dried weight) from C57BL/6J mice fed a standardized diet. Over 130 authentic metabolites were consistently measured from placental extracts when using a nontargeted metabolomics workflow with stringent quality control and robust batch correction. Our work revealed distinct metabolic phenotype differences that exist between male (n = 14) and female (n = 14) placentae collected at embryonic day E18.5. Intracellular metabolites associated with fatty acid oxidation and purine degradation were found to be elevated in females as compared to male placentae (p < 0.05, effect size >0.40), including uric acid, valerylcarnitine, hexanoylcarnitine, and 3-hydroxyhexanolycarnitine. This murine model sheds new insights into sex-specific differences in placental mitochondrial function and protective mechanisms against deleterious oxidative stress that may impact fetal growth and birth outcomes later in life.

Asphyxiated Female and Male Newborn Piglets Have Similar Outcomes With Different Cardiopulmonary Resuscitation Interventions

Background: Male newborns have a greater risk of poor cardiovascular and respiratory outcomes compared to females. The mechanisms associated with the "male disadvantage" remains unclear. We have previously shown no difference between male and female newborn piglets during hypoxia, asphyxia, resuscitation, and post-resuscitation recovery. However, it is unknown if there are differences in resuscitation outcomes between males and females during different cardiopulmonary resuscitation techniques. Intervention and Measurements: Secondary analysis of 184 term newborn mixed breed duroc piglets (1-3 days of age, weighing 2.0 (0.2) kg) from seven different studies, which were exposed to 30-50 min of normocapnic hypoxia followed by asphyxia until asystole. This was followed by cardiopulmonary resuscitation. For the analysis, piglets were divided into male and female groups, as well as resuscitation technique groups (sustained inflation, 3:1 compression-to-ventilation ratio, or asynchronous ventilations during chest compressions). Cardiac function, carotid blood flow, and cerebral oxygenation were continuously recorded throughout the experiment. Main results: Regardless of resuscitation technique, there was no significant difference between males and females in the number achieving return of spontaneous circulation (ROSC) [95/123 (77%) vs. 48/61 (79%)], the time to achieve ROSC [112 (80-185) s vs. 110 (77-186) s], and the 4-h survival rate [81/95 (85%) vs. 40/48 (83%)]. Levels of the injury markers interleukin (IL)-1ß, IL-6, IL-8, and tumor necrosis factor-α in frontoparietal cortex tissue homogenates were similar between males and females. Conclusions: Regardless of resuscitation technique, there was no significant effect of sex on resuscitation outcome, survival, and hemodynamic recovery in asphyxiated newborn piglets.

Substrates and Clearance Products of Fetal Adrenal Glucocorticoid Synthesis in Full-Term Human Umbilical Circulation

In full-term elective caesarian sections, fetal flow of adrenal substrate steroids to products differs by sex, with males (M) in molar equilibrium whereas females (F) add net molarity and synthesize more cortisol. Using the same sampling design, paired, full-term, arterial, and venous umbilical cord samples and intrapartum chart records were obtained at the time of vaginal delivery (N = 167, 85 male) or emergency C-section (N = 38, 22 male). Eight steroids were quantified by liquid chromatography coupled to tandem mass spectrometry (adrenal glucocorticoids [cortisol, corticosterone], sequential cortisol precursor steroids [17-hydroxyprogesterone, 11-deoxycortisol], cortisol and corticosterone metabolites [cortisone and 11-dehydrocorticosterone], and gonadal steroids [androstenedione, testosterone]). Fetal sex was not significant in any analytic models. Going through both phase 1 and phase 2 labor increased fetal adrenal steroidogenesis and decreased male testosterone relative to emergency C-sections that do not reach stage 2 of labor (ie, head compressions) and elective C-sections with no labor. Sum adrenal steroid molarity arriving in venous serum was almost double the equivalent metric for deliveries without labor. No effects of operative vaginal delivery were noted. Maternal regional anesthetic suppressed venous concentrations, and fetal synthesis replaced that steroid. Approximate molar equivalence between substrate pool depletion and net glucocorticoid synthesis was seen. Paired venous and arterial umbilical cord serum has the potential to identify sex differences that underlie antenatal programming of hypothalamic-pituitary-adrenal axis function in later life. However, stage 2 labor before the collection of serum, and regional anesthetic for the mother, mask those sex differences.

Manganese is associated with increased plasma interleukin-1β during pregnancy, within a mixtures analysis framework of urinary trace metals

Exposure to trace metals may impact reproductive health outcomes through perturbations in maternal immune signaling molecules. We conducted a cross-sectional study of 390 pregnant women from the LIFECODES birth cohort and investigated the associations between 17 urinary metals and five immune biomarkers measured in the 3rd trimester (median 26 weeks gestation). We used linear regression to estimate pair-wise associations and applied elastic net and Bayesian kernel machine regression to identify important contributing exposures analytes as well as non-linear effects. Maternal urinary manganese, nickel, and barium were positively associated with maternal plasma interleukin-1β (IL-1β). Elastic net and Bayesian kernel machine regression identified manganese as the dominant trace metal in association with IL-1β. An interquartile range difference in manganese (0.6 μg/L) was associated with a 29 % increase in IL-1β (95 % CI: 12.4-48.2). In conclusion, trace metal exposures were associated with biomarkers of immune perturbations, and this warrants further investigation.

Boys and girls differ in symptoms and neurodevelopmental outcome after perinatal metabolic acidosis, a population-based study

AIM

To evaluate sex differences in infants born at term with metabolic acidosis with regard to perinatal health and symptomatology, and developmental outcome.

METHODS

From a population-based cohort of infants born at term (n = 14 687), 78 were prospectively identified as having metabolic acidosis at birth. Two matched controls per case were selected. Sex differences in perinatal characteristics and in neurodevelopmental outcome at 6.5 years of age were analysed. Subgroup analysis was made based on need of neonatal care and planned follow-up.

RESULTS

Acidotic boys who appeared healthy, that is with no need of specialised neonatal care respectively only followed at ordinary health care service, have worse perinatal symptoms and less favourable neurodevelopmental outcome compared to girls. The male disadvantage concerning neurodevelopmental outcome was also indicated in children without acidosis. Outcome at 6.5 years was associated with Apgar at 10 minutes (p = 0.03), need of neonatal care (p = 0.04) and sex (p = 0.02) but not acidosis per se (p = 0.54).

CONCLUSION

Sex affected immediate symptomatology in term acidotic infants and neurodevelopmental outcome at the age of 6.5 years. The findings were seen in those who appeared healthy in the neonatal period. The results suggest that sex should be considered in assessment of acidotic children.

[Short-term neonatal outcomes of vacuum-assisted delivery. A case-control study]

INTRODUCTION

The purpose of this study was to assess the neonatal morbidity and mortality associated with vacuum-assisted vaginal deliveries compared to all other vaginal deliveries, and to identify the associated risk factors.

MATERIAL AND METHODS

We conducted a retrospective case-control study in a level iii maternity hospital between 2012 and 2016, including 1,802 vacuum-assisted vaginal deliveries and 2control groups: 1802 spontaneous deliveries and 909 forceps-assisted deliveries. We considered minor complications (soft tissue trauma, cephalohaematoma, jaundice, intensive phototherapy, transient brachial plexus injury) and major complications (hypoxic-ischaemic encephalopathy, intracranial and subgaleal haemorrhage, seizures, cranial fracture, permanent brachial plexus injury), admission to the neonatal intensive care unit and death.

RESULTS

The risk of soft tissue trauma (aOR, 2.4; P<.001), cephalohaematoma (aOR, 5.5; P<.001), jaundice (aOR, 4.4; P<.001), intensive phototherapy (aOR, 2.1; P<.001) and transient brachial plexus injury (aOR; 2.1, P=.006) was higher in vacuum deliveries compared to spontaneous deliveries. Admission to the neonatal intensive care unit was also higher in vacuum deliveries compared to spontaneous deliveries (OR, 1.9; P=.001). When we compared vacuum with forceps deliveries, we found a higher risk of soft tissue trauma (OR, 2.1; P=.004), cephalohaematoma (OR, 2.2, P=.046) and jaundice (OR, 1.4; P=.012). Major complications were more frequent in the vacuum group comparing with the control groups, but the difference was not significant. The 2deaths occurred in vacuum deliveries (1.1 per 1000).

CONCLUSION

The proportion of minor neonatal complications was higher in the vacuum-assisted delivery group. Although major complications and death were also more frequent, they were uncommon, with no significant differences compared to the other groups. There are obstetrical indications for vacuum delivery, but it should alert to the need to watch for potential neonatal complications.

The Effect of Antenatal Betamethasone on White Matter Inflammation and Injury in Fetal Sheep and Ventilated Preterm Lambs

Antenatal administration of betamethasone (BM) is a common antecedent of preterm birth, but there is limited information about its impact on the acute evolution of preterm neonatal brain injury. We aimed to compare the effects of maternal BM in combination with mechanical ventilation on the white matter (WM) of late preterm sheep. At 0.85 of gestation, pregnant ewes were randomly assigned to receive intra-muscular (i.m.) saline (n = 9) or i.m. BM (n = 13). Lambs were delivered and unventilated controls (UVCSal, n = 4; UVCBM, n = 6) were humanely killed without intervention; ventilated lambs (VentSal, n = 5; VentBM, n = 7) were injuriously ventilated for 15 min, followed by conventional ventilation for 75 min. Cardiovascular and cerebral haemodynamics and oxygenation were measured continuously. The cerebral WM underwent assessment of inflammation and injury, and oxidative stress was measured in the cerebrospinal fluid (CSF). In the periventricular and subcortical WM tracts, the proportion of amoeboid (activated) microglia, the density of astrocytes, and the number of blood vessels with protein extravasation were higher in UVCBM than in UVCSal (p < 0.05 for all). During ventilation, tidal volume, mean arterial pressure, carotid blood flow, and oxygen delivery were higher in -VentBM lambs (p < 0.05 vs. VentSal). In the subcortical WM, microglial infiltration was increased in the VentSal group compared to UVCSal. The proportion of activated microglia and protein extravasation was higher in the VentBM group compared to VentSal within the periventricular and subcortical WM tracts (p < 0.05). CSF oxidative stress was increased in the VentBM group compared to UVCSal, UVCBM, and VentSal groups (p < 0.05). Antenatal BM was associated with inflammation and vascular permeability in the WM of late preterm fetal sheep. During the immediate neonatal period, the increased carotid perfusion and oxygen delivery in BM-treated lambs was associated with increased oxidative stress, microglial activation and microvascular injury.

Sex Differences Between Female and Male Newborn Piglets During Asphyxia, Resuscitation, and Recovery

Background: Male and female newborns have differences in their fetal development, fetal-to-neonatal transition, and postnatal morbidity. However, the cardiovascular fetal-to-neonatal adaption is similar between sexes. No study has examined sex differences in newborns during hypoxia, asphyxia, cardio-pulmonary resuscitation, or post-resuscitation recovery. Methods: Secondary analysis (two previous publications and two studies currently under peer-review) of 110 term newborn mixed breed piglets (1-3 days of age, weighing 2.0 ± 0.2 kg), which were exposed to 30 min normocapnic hypoxia followed by asphyxia until asystole, which was achieved by disconnecting the ventilator and clamping the endotracheal tube. This was followed by cardio-pulmonary resuscitation. For the analysis piglets were divided into female and male groups. Cardiac function, carotid blood flow, and cerebral and renal oxygenation were continuously recorded throughout the experiment. Results: A total of 35/41 (85%) female and 54/69 (78%) male piglets resuscitated achieved ROSC (p = 0.881). The median (IQR) time to achieve return of spontaneous circulation in females and males was 111 (80-228) s and 106 (80-206) s (p = 0.875), respectively. The 4-h survival rate was similar between females and males with 28/35 (80%) and 49/54 (91%) piglets surviving (p = 0.241), respectively. Conclusions: No difference between female and male newborn piglets was observed during hypoxia, asphyxia, resuscitation, and post-resuscitation recovery.

Epidemiology of subdural haemorrhage during infancy: A population-based register study

Objectives

To analyse subdural haemorrhage (SDH) during infancy in Sweden by incidence, SDH category, diagnostic distribution, age, co-morbidity, mortality, and maternal and perinatal risk factors; and its association with accidents and diagnosis of abuse.

Methods

A Swedish population-based register study comprising infants born between 1997 and 2014, 0–1 years of age, diagnosed with SDH-diagnoses according to the (International Classification of Diseases, 10^th version (ICD10), retrieved from the National Patient Register and linked to the Medical Birth Register and the Death Cause Register. Outcome measures were: 1) Incidence and distribution, 2) co-morbidity, 3) fall accidents by SDH category, 4) risk factors for all SDHs in the two age groups, 0–6 and 7–365 days, and for ICD10 SDH subgroups: S06.5 (traumatic SDH), I62.0 (acute nontraumatic), SDH and abuse diagnosis.

Results

Incidence of SDH was 16·5 per 100 000 infants (n = 306). Median age was 2·5 months. For infants older than one week, the median age was 3·5 months. Case fatality was 6·5%. Male sex was overrepresented for all SDH subgroups. Accidental falls were reported in 1/3 of the cases. One-fourth occurred within 0–6 days, having a perinatal risk profile. For infants aged 7–365 days, acute nontraumatic SDH was associated with multiple birth, preterm birth, and small-for-gestational age. Fourteen percent also had an abuse diagnosis, having increased odds of being born preterm, and being small-for-gestational age.

Conclusions

The incidence was in the range previously reported. SDH among newborns was associated with difficult birth and neonatal morbidity. Acute nontraumatic SDH and SDH with abuse diagnosis had similar perinatal risk profiles. The increased odds for acute nontraumatic SDH in twins, preterm births, neonatal convulsions or small-for-gestational age indicate a perinatal vulnerability for SDH beyond 1st week of life. The association between prematurity/small-for-gestational age and abuse diagnosis is intriguing and not easily understood.