Male sex and pre-existing diabetes are independent risk factors for stillbirth

Pre-existing Diabetes and Stillbirth or Perinatal Mortality: A Systematic Review and Meta-analysis

OBJECTIVE

Despite the well-recognized association between pre-existing diabetes mellitus and stillbirth or perinatal mortality, there remain knowledge gaps about the strength of association across different populations. The primary objective of this systematic review and meta-analysis was to quantify the association between pre-existing diabetes and stillbirth or perinatal mortality, and secondarily, to identify risk factors predictive of stillbirth or perinatal mortality among those with pre-existing diabetes.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials from inception to April 2022.

METHODS OF STUDY SELECTION

Cohort studies and randomized controlled trials in English or French that examined the association between pre-existing diabetes and stillbirth or perinatal mortality (as defined by the original authors) or identified risk factors for stillbirth and perinatal mortality in individuals with pre-existing diabetes were included. Data extraction was performed independently and in duplicate with the use of prespecified inclusion and exclusion criteria. Assessment for heterogeneity and risk of bias was performed. Meta-analyses were completed with a random-effects model.

TABULATION, INTEGRATION, AND RESULTS

From 7,777 citations, 91 studies met the inclusion criteria. Pre-existing diabetes was associated with higher odds of stillbirth (37 studies; pooled odds ratio [OR] 3.74, 95% CI, 3.17-4.41, I2=82.5%) and perinatal mortality (14 studies; pooled OR 3.22, 95% CI, 2.54-4.07, I2=82.7%). Individuals with type 1 diabetes had lower odds of stillbirth (pooled OR 0.81, 95% CI, 0.68-0.95, I2=0%) and perinatal mortality (pooled OR 0.73, 95% CI, 0.61-0.87, I2=0%) compared with those with type 2 diabetes. Prenatal care and prepregnancy diabetes care were significantly associated with lower odds of stillbirth (OR 0.26, 95% CI, 0.11-0.62, I2=87.0%) and perinatal mortality (OR 0.41, 95% CI, 0.29-0.59, I2=0%).

CONCLUSION

Pre-existing diabetes confers a more than threefold increased odds of both stillbirth and perinatal mortality. Maternal type 2 diabetes was associated with a higher risk of stillbirth and perinatal mortality compared with maternal type 1 diabetes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022303112.

Regulation of sexually dimorphic placental adaptation in LPS exposure-induced intrauterine growth restriction

BACKGROUND

Sexual dimorphism in placental physiology affects the functionality of placental adaptation during adverse pregnancy. Defects of placental function compromise fetal programming, affecting the offspring's adult life. However, studies focusing on the relationship between sex-specific placental adaptation and consequent fetal maldevelopment under sub-optimal uterus milieu are still elusive.

METHODS

Here, we investigated the effects of maternal lipopolysaccharide (LPS) exposure between placental sex. Pregnant ICR mice received intraperitoneal injection of phosphate-buffered saline or 100, 200, and 400 µg/kg LPS on the gestational day (GD) 15.5. To determine whether prenatal maternal LPS exposure resulted in complicated pregnancy outcomes, survival rate of embryos was calculated and the growth of embryos and placentas was examined. To elucidate global transcriptomic changes occurring in the placenta, total RNA-sequencing (RNA-seq) was performed in female and male placentas.

RESULTS

LPS administration induced placental inflammation in both sexes at GD 17.5. Prenatal infection resulted in growth retardation in both sexes of embryos, and especially more prevalently in male. Impaired placental development was observed in a sex-specific manner. LPS 400 µg/kg reduced the percentage area of the labyrinth in females and junctional zone in males, respectively. RNA-sequencing revealed widespread sexually dimorphic transcriptional changes in placenta. In particular, representative changes were involved in biological processes such as trophoblast differentiation, nutrient/ion transporter, pregnancy, and immune system.

CONCLUSIONS

Our results present the sexually dimorphic responses of placental physiology in intrauterine growth restriction model and provide tentative relationship further to be elucidated between sex-biased placental functional change and long-term effects on the offspring's later life.

The relationship of fetal sex and maternal race and ethnicity with early and late pregnancy C-reactive protein and interleukin-8

PROBLEM

Promotion of a healthy pregnancy is dependent on a coordinated immune response that minimizes inflammation at the maternal-fetal interface. Few studies investigated the effect of fetal sex on proinflammatory biomarkers during pregnancy and whether maternal race could impact this association. We aimed to examine whether fetal sex could, independently of maternal race/ethnicity and the condition of pregnancy (normal vs. complicated), impact inflammatory markers (C-reactive protein [CRP] and interleukin-8 [IL-8] levels) in early and late pregnancy.

METHODS OF STUDY

This study was a cohort analysis using prospectively collected data from pregnant women who participated in the Vitamin Antenatal Asthma Reduction Trial (VDAART, N = 816). Maternal serum CRP and IL-8 levels were measured in early and late pregnancy (10-18 and 32-38 weeks of gestation, respectively). Five hundred and twenty-eight out of 816 pregnant women who participated in the trial had available CRP and IL-8 measurements at both study time points. We examined the association of fetal sex with early and late CRP and IL-8 levels and their paired sample difference. We further investigated whether maternal race/ethnicity, pregnancy complications (i.e., preeclampsia and gestational diabetes), and early pregnancy body mass index (BMI) could affect the association between these two biomarkers and fetal sex adjusting for potential confounders. For this purpose, we used generalized linear and logistic regression models on log-normalized early and late CRP and IL-8 levels as well as their split at median to form high and low groups.

RESULTS

Women pregnant with male fetuses (266/528 = 56.5%) had higher CRP levels in early to mid-pregnancy (β = .18: 95% confidence interval [CI]: CI = 0.03-0.32; p = .02). Twenty-seven percent (143/528) of the study subjects were Hispanic. Hispanic African American [AA] women and women of races other than White and AA had higher levels of CRP at early to mid-pregnancy compared with White women (β = .57; 95% CI: 0.17-0.97; p < .01 and β = .27; 95% CI: 0.05-0.48; p = .02, respectively). IL-8 levels were not associated with fetal sex in early and late pregnancy (p's > .05). Other factors such as gestational diabetes and early pregnancy BMI were associated with higher CRP levels and higher CRP and IL-8 levels, respectively. Dichotomizing log-normalized cytokine levels at the median in a sensitivity analysis, women with male fetuses had lower odds of high (above-median) IL-8 levels at early pregnancy. Also, women with races other than AA and White carrying male fetuses had higher odds of having high (above-median) late-pregnancy CRP and early-pregnancy IL-8 levels (adjusted odds ratio [aOR] = 3.80, 95% CI: 0.24-1.23; p = .02 and aOR = 3.57; 95% CI: 0.23-1.03; p = .02, respectively). Of the pregnancy complications, women with gestational diabetes mellitus had a higher paired difference of early and late pregnancy CRP levels (β = .38; 95% CI: 0.09-0.68; p = .01), but no difference in IL-8 levels (p's > .05). No associations between the inflammatory markers and preeclampsia were found.

CONCLUSION

Fetal sex is associated with CRP in early pregnancy and an association with IL-8 in early pregnancy is implied. Our study further indicates that maternal race/ethnicity could be a contributing factor in the relationship between fetal sex and inflammatory responses during pregnancy. However, the specificity and level of the contribution might vary by type of cytokine, pregnancy stage, and other confounding factors such as BMI that may impact these associations.

Preconception stress exposure from childhood to adolescence and birth outcomes: The impact of stress type, severity and consistency

The negative effects of prenatal stress on offspring health are well established, but there remains little understanding of the influence of stress prior to conception despite known effects on biological systems that are important for a healthy pregnancy. Furthermore, operational definitions of stress vary considerably, and exposure is often characterized via summed, ordinal scales of events. We hypothesized that type, severity, and consistency of preconception stress would be associated with birthweight and gestational age (GA) at birth. Data were drawn from a subsample of participants in the 21-year longitudinal Pittsburgh Girls Study (PGS, N = 2,450) that has followed women annually since childhood. Prior work in the PGS derived three domains of stress exposure between ages 7-17 years related to subsistence (e.g., resource strain, overcrowding), safety (e.g., community violence, inter-adult aggression), and caregiving (e.g., separation, maternal depression). We tested the effects of dimensions of preconception stress on birthweight and GA among offspring of 490 PGS participants who delivered at age 18 or older (n = 490; 76% Black, 20% White, 4% Multiracial). Our hypotheses were partially supported with results varying by stress type and severity and by infant sex. Severity of preconception exposure to subsistence stress was prospectively associated with lower offspring birthweight (B = -146.94, SE = 69.07, 95% CI = -282.66, -11.22). The association between severity of caregiving stress in childhood and adolescence and GA at birth was moderated by infant sex (B = 0.85, SE = .41, 95% CI = 0.04, 1.66), suggesting greater vulnerability to this type of stress for male compared to female infants. Exposure to safety stressors did not predict birth outcomes. Infants of Black compared with White mothers had lower birthweight in all models regardless of preconception stress type, severity or consistency. However, we observed no moderating effects of race on preconception stress-birth outcome associations. Demonstrating specificity of associations between preconception stress exposure and prenatal health has the potential to inform preventive interventions targeting profiles of exposure to optimize birth outcomes.

Sex Differences Are Here to Stay: Relevance to Prenatal Care

Sex differences exist in the incidence and presentation of many pregnancy complications, including but not limited to pregnancy loss, spontaneous preterm birth, and fetal growth restriction. Sex differences arise very early in development due to differential gene expression from the X and Y chromosomes, and later may also be influenced by the action of gonadal steroid hormones. Though offspring sex is not considered in most prenatal diagnostic or therapeutic strategies currently in use, it may be beneficial to consider sex differences and the associated mechanisms underlying pregnancy complications. This review will cover (i) the prevalence and presentation of sex differences that occur in perinatal complications, particularly with a focus on the placenta; (ii) possible mechanisms underlying the development of sex differences in placental function and pregnancy phenotypes; and (iii) knowledge gaps that should be addressed in the development of diagnostic or risk prediction tools for such complications, with an emphasis on those for which it would be important to consider sex.

Sex ratios at birth in Australia according to mother's country of birth: A national study of all 5 614 847 reported live births 1997-2016

Objectives

Son preference and sex selective practices have resulted in a deficit of girls in several countries, primarily across Asia. Emerging evidence indicates that son preference survives migration to Western high-income countries. The objective of this study was to assess male-to-female (M/F) ratios at birth per mother’s country of birth in Australia 1997–2016, in total and by parity, and by states/territories and over time.

Methods

Data for this national population-based cross-sectional study were obtained from the National Perinatal Data Collection (NPDC) and included all live births in Australia 1997–2016 (N = 5 614 847). M/F ratios with 95% Confidence Intervals were estimated.

Results

The M/F ratio for births to Australian-born mothers was within the expected range (1.03–1.07) regardless of parity and time period. M/F ratios were elevated above the expected range for births to mothers born in China in the total sample (M/F ratio 1.084, 95% confidence interval 1.071–1.097) and at parity 2 (1.175, 1.120–1.231), and for births to mothers born in India at parity 2 (1.146, 1.090–1.204). Parity 2 births were the most consistently male-biased across time. Across states, elevated M/F ratios were identified for both groups in New South Wales (China parity 2: 1.182, 1.108–1.260; India parity 2: 1.182, 1.088–1.285), for births to Chinese-born mothers in Victoria (total births: 1.097, 1.072–1.123; parity 1: 1.115, 1.072–1.159) and Australian Capital Territory (total births: 1.189, 1.085–1.302) and births to Indian-born mothers Western Australia (parity 2: 1.307, 1.122–1.523).

Conclusions

Son preference persists in some immigrant communities after migration to Australia. The consistent pattern of elevated M/F ratios across the larger states indicates that sex imbalances at birth are largely independent of restrictiveness of local abortion laws. Drivers and consequences of son preference in Western high-income settings should be explored to further promote gender equality, and to strengthen support for women who may be vulnerable to reproductive coercion.

Molecular Pathways of Cellular Senescence and Placental Aging in Late Fetal Growth Restriction and Stillbirth

Abnormally accelerated, premature placental senescence plays a crucial role in the genesis of pregnancy pathologies. Abnormal growth in the third trimester can present as small for gestational age fetuses or fetal growth restriction. One differs from the other by the presence of signs of placental insufficiency and the risk of stillbirth. The majority of stillbirths occur in normally grown fetuses and are classified as "unexplained", which often leads to conclusions that they were unpreventable. The main characteristic of aging is a gradual decline in the function of cells, tissues, and organs. These changes result in the accumulation of senescent cells in mitotic tissues. These cells begin the aging process that disrupts tissues' normal functions by affecting neighboring cells, degrading the extracellular matrix, and reducing tissues' regeneration capacity. Different degrees of abnormal placentation result in the severity of fetal growth restriction and its sequelae, including fetal death. This review aims to present the current knowledge and identify future research directions to understand better placental aging in late fetal growth restriction and unexplained stillbirth. We hypothesized that the final diagnosis of placental insufficiency can be made only using markers of placental senescence.

Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis

Background

Since the placenta also has a sex, fetal sex–specific differences in the occurrence of placenta-mediated complications could exist.

Objective

To determine the association of fetal sex with multiple maternal pregnancy complications.

Search strategy

Six electronic databases Ovid MEDLINE, EMBASE, Cochrane Central, Web-of-Science, PubMed, and Google Scholar were systematically searched to identify eligible studies. Reference lists of the included studies and contact with experts were also used for identification of studies.

Selection criteria

Observational studies that assessed fetal sex and the presence of maternal pregnancy complications within singleton pregnancies.

Data collection and analyses

Data were extracted by 2 independent reviewers using a predesigned data collection form.

Main results

From 6522 original references, 74 studies were selected, including over 12,5 million women. Male fetal sex was associated with term pre-eclampsia (pooled OR 1.07 [95%CI 1.06 to 1.09]) and gestational diabetes (pooled OR 1.04 [1.02 to 1.07]). All other pregnancy complications (i.e., gestational hypertension, total pre-eclampsia, eclampsia, placental abruption, and post-partum hemorrhage) tended to be associated with male fetal sex, except for preterm pre-eclampsia, which was more associated with female fetal sex. Overall quality of the included studies was good. Between-study heterogeneity was high due to differences in study population and outcome definition.

Conclusion

This meta-analysis suggests that the occurrence of pregnancy complications differ according to fetal sex with a higher cardiovascular and metabolic load for the mother in the presence of a male fetus.

Funding

None.

Maternal stress in relation to sex-specific expression of placental genes involved in nutrient transport, oxygen tension, immune response, and the glucocorticoid barrier

INTRODUCTION

Murine models provide evidence that maternal stress during pregnancy can influence placenta morphology and function, including altered expression of genes involved in the maintenance and progression of pregnancy and fetal development. Corresponding research evaluating the impact of maternal stress on placental gene expression in humans is limited. We examined maternal stress in relation to placental expression of 17 candidate genes in a community-based sample.

METHODS

Participants included 60 mother-newborn pairs enrolled in the PRogramming of Intergenerational Stress Mechanisms pregnancy cohort based at the Mount Sinai Hospital in New York City. Placentas were collected immediately following delivery and gene expression was measured using a qPCR-based platform. Maternal experiences of traumatic and non-traumatic stress were measured using the Life Stressor Checklist-Revised (LSC-R) administered during a mid-pregnancy interview. We used multivariable linear regression to examine associations between LSC-R scores and expression of each gene in separate models in the sample overall and stratified by fetal sex.

RESULTS

Higher maternal stress was associated with significantly increased placental expression of the nutrient sensor gene OGT, the glucose transporter gene GLUT1, and the hypoxia sensor gene HIF3A. In models stratified by fetal sex, significant associations remained only among males.

DISCUSSION

This study represents one of the most comprehensive examinations of maternal lifetime traumatic and non-traumatic stress in relation to placental gene expression in human tissue. Our findings support that maternal stress may alter sex-specific placental expression of genes involved in critical developmental processes.

Healthcare factors associated with the risk of antepartum and intrapartum stillbirth in migrants in Western Australia (2005-2013): A retrospective cohort study

BACKGROUND

Migrant women, especially from Indian and African ethnicity, have a higher risk of stillbirth than native-born populations in high-income countries. Differential access or timing of ANC and the uptake of other services may play a role. We investigated the pattern of healthcare utilisation among migrant women and its relationship with the risk of stillbirth (SB)-antepartum stillbirth (AnteSB) and intrapartum stillbirth (IntraSB)-in Western Australia (WA).

METHODS AND FINDINGS

A retrospective cohort study using de-identified linked data from perinatal, birth, death, hospital, and birth defects registrations through the WA Data Linkage System was undertaken. All (N = 260,997) non-Indigenous births (2005-2013) were included. Logistic regression analysis was used to estimate odds ratios and 95% CI for AnteSB and IntraSB comparing migrant women from white, Asian, Indian, African, Māori, and 'other' ethnicities with Australian-born women controlling for risk factors and potential healthcare-related covariates. Of all the births, 66.1% were to Australian-born and 33.9% to migrant women. The mean age (years) was 29.5 among the Australian-born and 30.5 among the migrant mothers. For parity, 42.3% of Australian-born women, 58.2% of Indian women, and 29.3% of African women were nulliparous. Only 5.3% of Māori and 9.2% of African migrants had private health insurance in contrast to 43.1% of Australian-born women. Among Australian-born women, 14% had smoked in pregnancy whereas only 0.7% and 1.9% of migrants from Indian and African backgrounds, respectively, had smoked in pregnancy. The odds of AnteSB was elevated in African (odds ratio [OR] 2.22, 95% CI 1.48-2.13, P < 0.001), Indian (OR 1.64, 95% CI 1.13-2.44, P = 0.013), and other women (OR 1.46, 95% CI 1.07-1.97, P = 0.016) whereas IntraSB was higher in African (OR 5.24, 95% CI 3.22-8.54, P < 0.001) and 'other' women (OR 2.18, 95% CI 1.35-3.54, P = 0.002) compared with Australian-born women. When migrants were stratified by timing of first antenatal visit, the odds of AnteSB was exclusively increased in those who commenced ANC later than 14 weeks gestation in women from Indian (OR 2.16, 95% CI 1.18-3.95, P = 0.013), Māori (OR 3.03, 95% CI 1.43-6.45, P = 0.004), and 'other' (OR 2.19, 95% CI 1.34-3.58, P = 0.002) ethnicities. With midwife-only intrapartum care, the odds of IntraSB for viable births in African and 'other' migrants (combined) were more than 3 times that of Australian-born women (OR 3.43, 95% CI 1.28-9.19, P = 0.014); however, with multidisciplinary intrapartum care, the odds were similar to that of Australian-born group (OR 1.34, 95% CI 0.30-5.98, P = 0.695). Compared with Australian-born women, migrant women who utilised interpreter services had a lower risk of SB (OR 0.51, 95% CI 0.27-0.96, P = 0.035); those who did not utilise interpreters had a higher risk of SB (OR 1.20, 95% CI 1.07-1.35, P < 0.001). Covariates partially available in the data set comprised the main limitation of the study.

CONCLUSION

Late commencement of ANC, underutilisation of interpreter services, and midwife-only intrapartum care are associated with increased risk of SB in migrant women. Education to improve early engagement with ANC, better uptake of interpreter services, and the provision of multidisciplinary-team intrapartum care to women specifically from African and 'other' backgrounds may reduce the risk of SB in migrants.

Toll-Like Receptor-4 Antagonist (+)-Naloxone Confers Sexually Dimorphic Protection From Inflammation-Induced Fetal Programming in Mice

Inflammation elicited by infection or noninfectious insults during gestation induces proinflammatory cytokines that can shift the trajectory of development to alter offspring phenotype, promote adiposity, and increase susceptibility to metabolic disease in later life. In this study, we use mice to investigate the utility of a small molecule Toll-like receptor (TLR)4 antagonist (+)-naloxone, the nonopioid isomer of the opioid receptor antagonist (-)-naloxone, for mitigating altered fetal metabolic programming induced by a modest systemic inflammatory challenge in late gestation. In adult progeny exposed to lipopolysaccharide (LPS) challenge in utero, male but not female offspring exhibited elevated adipose tissue, reduced muscle mass, and elevated plasma leptin at 20 weeks of age. Effects were largely reversed by coadministration of (+)-naloxone following LPS. When given alone without LPS, (+)-naloxone elicited accelerated postweaning growth and elevated muscle and fat mass in adult male but not female offspring. LPS induced expression of inflammatory cytokines Il1a, Il1b, Il6, Tnf, and Il10 in fetal brain, placental, and uterine tissues, and (+)-naloxone suppressed LPS-induced cytokine expression. Fetal sex-specific regulation of cytokine expression was evident, with higher Il1a, Il1b, Il6, and Il10 induced by LPS in tissues associated with male fetuses, and greater suppression by (+)-naloxone of Il6 in females. These data demonstrate that modulating TLR4 signaling with (+)-naloxone provides protection from inflammatory diversion of fetal developmental programming in utero, associated with attenuation of gestational tissue cytokine expression in a fetal sex-specific manner. The results suggest that pharmacologic interventions targeting TLR4 warrant evaluation for attenuating developmental programming effects of fetal exposure to maternal inflammatory mediators.

Sex differences in substrates and clearance products of cortisol and corticosterone synthesis in full-term human umbilical circulation without labor: Substrate depletion matches synthesis in males, but not females

BACKGROUND

Antenatal impacts on the hypothalamus- pituitary-adrenal axis affect health throughout later life and the impacts on developing males and females often differ. The female fetus at full-term (sampled as scheduled Caesarian section without antecedent labor) both receives more cortisol in umbilical venous blood and adds more cortisol to umbilical arterial circulation than the male. The current study was designed to expand our knowledge of sex-specific, fetal, adrenal steroid synthesis and clearance pathways.

METHODS

Paired, full-term, arterial and venous umbilical cord samples were taken at the time of scheduled Caesarian delivery (N = 53, 33 male). Adrenal glucocorticoids (cortisol, corticosterone), cortisol precursor steroids (17-hydroxyprogesterone, 11-deoxycortisol), and cortisol and corticosterone metabolites (cortisone and 11-dehydrocorticosterone), as well as gonadal steroids (testosterone and androstenedione), were quantified by liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Both sexes preferentially added corticosterone. Males added more testosterone than females. The female fetus had higher umbilical cord (arterial and venous) concentrations of cortisol, as well as higher total steroid molarity summed across the six adrenal steroids, than males. Depletion of substrate pools of 17-hydroxyprogesterone, 11-deoxycortisol, and cortisone could account for only 20% of net female cortisol synthesis. In contrast, increased fetal synthesis of cortisol was balanced by equivalent molar depletion of substrate pools when the fetus was male.

CONCLUSIONS

Preferential fetal corticosterone synthesis in both sexes, and higher concentrations of cortisol in females were confirmed. Differences in adrenal steroidogenesis pathway function in full-term males and females might underlie antenatal programming of hypothalamic-pituitary-adrenal axis function in later life.

Fetal chronic hypoxia and oxidative stress in diabetic pregnancy. Could fetal erythropoietin improve offspring outcomes?

Oxidative stress is responsible for microvascular complications (hypertension, nephropathy, retinopathy, peripheral neuropathy) of diabetes, which during pregnancy increase both maternal and fetal complications. Chronic hypoxia and hyperglycemia result in increased oxidative stress and decreased antioxidant enzyme activity. However, oxidative stress induces also anti-oxidative reactions both in pregnant diabetes patients and in their fetuses. Not all type 1 diabetes patients with long-lasting disease develop microvascular complications, which suggests that some of these patients have protective mechanisms against these complications. Fetal erythropoietin (EPO) is the main regulator of red cell production in the mother and in the fetus, but it has also protective effects in various maternal and fetal tissues. This dual effect of EPO is based on EPO receptor (EPO-R) isoforms, which differ structurally and functionally from the hematopoietic EPO-R isoform. The tissue protective effects of EPO are based on its anti-apoptotic, anti-oxidative, anti-inflammatory, cell proliferative and angiogenic properties. Recent experimental and clinical studies have shown that EPO has also positive metabolic effects on hyperglycemia and diabetes, although these have not yet been fully delineated. Whether the tissue protective and metabolic effects of EPO could have clinical benefits, are important topics for future research in diabetic pregnancies.

Racial differences in placental pathology among very preterm births

INTRODUCTION

African American women are at higher risk for preterm birth compared to white women, but no placental pathology has characterized this disparity. The objective of this study was to examine the association of race with placental pathology among very preterm births.

METHODS

We conducted an eight-year retrospective cohort study of very preterm infants born at ≤32 weeks at Northwestern Prentice Women's Hospital in Chicago, Illinois. Archived placental slides underwent standardized masked histopathologic review. Logistic regression was performed for placental pathology, adjusting for available relevant covariates and stratified by infant sex and gestational age.

RESULTS

Placentas were available for 296 white and 224 African American mother-infant pairs among births at ≤32 weeks gestation. Compared to placentas from white births, the adjusted OR (aOR) for acute inflammation in placentas from African American births was 1.95 (95% CI 0.87-4.37), the aOR for chronic inflammation was 3.35 (1.49-7.54), the aOR for fetal vascular pathology was 0.82 (0.29-2.32), and the aOR for maternal vascular pathology was 1.01 (0.51-1.99). Stratified analysis showed associations between all placental pathologies and race among male births. Across gestational age groups (<28 and ≥ 28 weeks), the association between race and placental pathology was present for chronic inflammation and fetal vascular pathology.

DISCUSSION

Race is associated with placental pathology, and in particular, with chronic inflammation among very preterm births. The effect is modified by infant sex and gestational age. Placental histopathology may be useful markers for understanding the biological processes that shape disparities in pregnancy outcomes.

Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Objective Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. Methods We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. Results A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Conclusion Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.

Risk factors of stillbirths in Victoria (Australia): A case-control study

Stillbirth is one of the most adverse pregnancy outcomes. The rate of stillbirth in high income countries has remained stagnant in recent decades. This study aimed to determine the incidence and risk factors of stillbirths specific to hospital-based deliveries in a secondary level hospital in Melbourne, Australia, over a 5-year period. We conducted a case-control study from January 2007 to December 2011. Univariate and multivariate analyses were conducted in STATA 12.1. The 5-year cumulative incidence of still-birth was 5.3 per 1000 total births (95% CI 4.3, 6.5). Univariate analysis revealed that higher body-mass index, smoking during pregnancy, haemoglobin level (≥14.5 g/dl), previous stillbirth, primiparity, marital status, previous caesarean section and reduced foetal movement in the 2 weeks prior to delivery were associated with increased risk of stillbirth. However, after adjustment for confounders in a multiple-regression model, only previous caesarean section (p = 0.006), unmarried (p = 0.004), high haemoglobin level (p = 0.007) and reduced foetal movement in the 2 weeks prior to delivery (p < 0.001) remained significantly associated with increased risk of stillbirth. The characteristics of our study population was similar to the population of state-wide survey in 2009, however, the incidence in our study was slightly lower. We concluded that previous caesarean section, pregnancy while being unmarried, higher haemoglobin level and reduced foetal movement in the 2 weeks before delivery were significant predictors of stillbirth. The identified risk factors were similar to other studies and the obstetric practice at the hospital or the demographics of the study population did not add to additional risk.

Paternal obesity in a rodent model affects placental gene expression in a sex-specific manner

Fetal growth restriction (FGR) is a major obstetric complication stemming from poor placental development. We have previously demonstrated that paternal obesity in mice is associated with impaired embryo development and significantly reduced fetal and placental weights. We hypothesised that the FGR observed in our rodent model of paternal diet-induced obesity is associated with alterations in metabolic, cell signalling and stress pathways. Male C57BL/6 mice were fed either a normal or high-fat diet for 10 weeks before sperm collection for IVF and subsequent embryo transfer. On embryonic day 14, placentas were collected and RNA extracted from both male and female placentas to assess mRNA expression of 24 target genes using custom RT-qPCR arrays. Peroxisome proliferator-activated receptor alpha (Ppara) and caspase-12 (Casp12) expression were significantly altered in male placentas from obese fathers compared with normal (P<0.05), but not female placentas. PPARA and CASP12 proteins were localised within the placenta to trophoblast giant cells by immunohistochemistry, and relative protein abundance was determined by western blot analysis. DNA was also extracted from the same placentas to determine methylation status. Global DNA methylation was significantly increased in female placentas from obese fathers compared with normal (P<0.05), but not male placentas. In this study, we demonstrate for the first time that paternal obesity is associated with changes in gene expression and methylation status of extraembryonic tissue in a sex-specific manner. These findings reinforce the negative consequences of paternal obesity before conception, and emphasise the need for more lifestyle advice for prospective fathers.

Placenta expresses anti-Müllerian hormone and its receptor: Sex-related difference in fetal membranes

INTRODUCTION

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor-β superfamily, playing a role in sexual differentiation and recruitment. Since a correlation exists between AMH serum levels in cord blood and fetal sex, the present study aimed to identify mRNA and protein expression of AMH and AMHRII in placenta and fetal membranes according to fetal sex.

METHODS

Placenta and fetal membranes samples (n = 40) were collected from women with singleton uncomplicated pregnancies at term. Identification of AMH protein in placenta and fetal membranes was carried out by immunohistochemistry and AMH and AMHRII protein localization by immunofluorescence, while mRNA expression was assessed by quantitative real-time PCR.

RESULT

AMH and AMHRII mRNAs were expressed by placenta and fetal membranes at term, without any significant difference between males and females. Placental immunostaining showed a syncytial localization of AMH without sex-related differences; while fetal membranes immunostaining was significantly more intense in male than in female fetuses (p < 0,01). Immunofluorescence showed an intense co-localization of AMH and AMHRII in placenta and fetal membranes.

DISCUSSION

The present study for the first time demonstrated that human placenta and fetal membranes expresses and co-localizes AMH and AMHRII. Although no sex-related difference was found for the mRNA expression both in placenta and fetal membranes, a most intense staining for AMH in male fetal membranes supports AMH as a gender specific hormone.

Effects of maternal inflammation and exposure to cigarette smoke on birth weight and delivery of preterm babies in a cohort of indigenous Australian women

Sudden infant death syndrome (SIDS), neonatal deaths, and deaths from infection are higher among Indigenous Australians. This study aimed to determine the effects of inflammatory responses and exposure to cigarette smoke, two important factors associated with sudden death in infancy, on preterm birth, and birth weight in a cohort of Indigenous mothers. Indigenous Australian women (n = 131) were recruited as part of a longitudinal study while attending antenatal care clinics during pregnancy; blood samples were collected up to three times in pregnancy. Serum cotinine, indicating exposure to cigarette smoke, was detected in 50.4% of mothers. Compared with non-Indigenous women, the cohort had 10 times the prevalence of antibodies to Helicobacter pylori (33 vs. 3%). Levels of immunoglobulin G, antibodies to H. pylori, and C-reactive protein (CRP) were all inversely correlated with gestational age (P < 0.05). CRP levels were positively associated with maternal body mass index (BMI; ρ = 0.449, P = 0.001). The effects of cigarette smoke (cotinine) and inflammation (CRP) were assessed in relation to risk factors for SIDS: gestational age at delivery and birth weight. Serum cotinine levels were negatively associated with birth weight (ρ = −0.37, P < 0.001), this correlation held true for both male (ρ = −0.39, P = 0.002) and female (ρ = −0.30, P = 0.017) infants. Cotinine was negatively associated with gestational age at delivery (ρ = −0.199, P = 0.023). When assessed by fetal sex, this was significant only for males (ρ = −0.327, P = 0.011). CRP was negatively associated with gestational age at delivery for female infants (ρ = −0.46, P < 0.001). In contrast, maternal BMI was significantly correlated with birth weight. These data highlight the importance of putting programs in place to reduce cigarette smoke exposure in pregnancy and to treat women with chronic infections such as H. pylori to improve pregnancy outcomes and decrease risk factors for sudden death in infancy.

Fetal sex modifies effects of prenatal stress exposure and adverse birth outcomes

Prenatal maternal stress is associated with pregnancy complications, poor fetal development and poor birth outcomes. Fetal sex has also been shown to affect the course of pregnancy and its outcomes. The aim of this study was to evaluate whether fetal sex modifies the association between continuous exposure to life-threatening rocket attack alarms and adverse pregnancy outcomes. A retrospective cohort study was conducted in which the exposed group was comprised of 1846 women exposed to rocket-attack alarms before and during pregnancy. The unexposed group, with similar sociodemographic characteristics, delivered during the same period of time at the same medical center, but resided out of rocket-attack range. Multivariable models for each gender separately, controlling for possible confounders, evaluated the risk associated with exposure for preterm births (PTB), low birthweight (LBW), small for gestational age and small head circumference (HC). In both univariable and multivariable analyses exposure status was a significant risk factor in female fetuses only: PTB (adj. OR = 1.43; 1.04-1.96), LBW (adj. OR = 1.41; 1.02-1.95) and HC < 31 cm (adj. OR = 1.78; 1.11-2.88). In addition, regarding all adverse outcomes, the male-to-female ratio was higher in the exposed group than in the unexposed group. The findings support the hypothesis that male and female fetuses respond differentially to chronic maternal stress.

Effects of Fetal Sex on Expression of the (Pro)renin Receptor and Genes Influenced by its Interaction With Prorenin in Human Amnion

Males are more likely to be born preterm than females. The causes are unknown, but it is suggested that intrauterine tissues regulate fetal growth and survival in a sex-specific manner. We postulated that prorenin binding to its prorenin/renin receptor receptor (ATP6AP2) would act in a fetal sex-specific manner in human amnion to regulate the expression of promyelocytic zinc finger, a negative regulator of ATP6AP2 expression as well as 2 pathways that might influence the onset of labor, namely transforming growth factor β1 (TGFB1) and prostaglandin endoperoxide synthase 2 (PTGS2). Our findings demonstrate that there are strong interactions between prorenin, ATP6AP2, and TGFB1 and that this system has a greater capacity in female amnion to stimulate profibrotic pathways, thus maintaining the integrity of the fetal membranes. In contrast, glucocorticoids or other factors independent of the prorenin/prorenin receptor pathway may be important regulators of PTGS2 in human pregnancy.

Elevated risk of stillbirth in males: systematic review and meta-analysis of more than 30 million births

BACKGROUND

Stillbirth rates have changed little over the last decade, and a high proportion of cases are unexplained. This meta-analysis examined whether there are inequalities in stillbirth risks according to sex.

METHODS

A systematic review of the literature was conducted, and data were obtained on more than 30 million birth outcomes reported in observational studies. The pooled relative risk of stillbirth was estimated using random-effects models.

RESULTS

The crude mean rate (stillbirths/1,000 total births) was 6.23 for males and 5.74 for females. The pooled relative risk was 1.10 (95% confidence interval (CI): 1.07-1.13). The attributable fraction in the whole population was 4.2% (95% CI: 3.70-4.63), and the attributable fraction among male fetuses was 7.8% (95% CI: 7.0-8.66). Study populations from countries with known sex-biased sex selection issues had anomalous stillbirth sex ratios and higher overall stillbirth risks than other countries, reflecting increased mortality among females.

CONCLUSIONS

Risk of stillbirth in males is elevated by about 10%. The population-attributable risk is comparable to smoking and equates to approximately 100,000 stillbirths per year globally. The pattern is consistent across countries of varying incomes. Given current difficulties in reducing stillbirth rates, work to understand the causes of excess male risk is warranted. We recommend that stillbirths are routinely recorded by sex. This will also assist in exposing prenatal sex selection as elevated or equal risks of stillbirth in females would be readily apparent and could therefore be used to trigger investigation.

Inverse relationship between gestational weight gain and glucose uptake in human placenta from female foetuses

BACKGROUND

Maternal obesity and gestational weight gain (GWG) have a significant impact on the in utero environment, and thus on foetal development and the health of the offspring later in life.

OBJECTIVE

The aim of this study was to determine the effect of maternal pre-existing obesity and maternal GWG on glucose uptake from placentas from male and female offspring.

METHODS

Total glucose uptake was measured in placental explants using radio-labelled glucose.

RESULTS

In the female placentas (n = 36), GWG and glucose uptake were significantly negatively correlated (r = -0.7, P < 0.0001; n = 36), and customized birthweight centile correlated with placental glucose uptake (r = 0.36, P = 0.03) but not GWG. In the male placentas (n = 45), GWG and glucose uptake were not related, and customized birthweight centile correlated with GWG (r = 0.34, P = 0.02; n = 45), but not placental glucose uptake.

CONCLUSIONS

The female placenta can adapt glucose uptake in the face of excessive GWG. The male placenta showed no evidence of changing glucose uptake in response to maternal GWG.

Recurrent miscarriage and birth sex ratio

OBJECTIVE

To examine the relationship between birth sex ratio and unexplained recurrent miscarriage (RM).

STUDY DESIGN

Retrospective, observational study including a total of 138 women with primary recurrent miscarriage (PRM) and 170 women with secondary recurrent miscarriage (SRM) in a tertiary referral recurrent miscarriage clinic between 1992 and 2010. The sex ratio of the first birth and subsequent birth were the main outcome measures.

RESULTS

In women with SRM: (i) The male:female sex ratio of the first stillbirth was 10:2, significantly (OR=4.76) higher than the male:female sex ratio of 1.05 among all births in UK. (ii) When the first born was a male, the male:female sex ratio of the subsequent birth was 21:35, significantly (OR=0.57) lower than the sex ratio among the general population. (iii) A male firstborn did not affect the chance of a subsequent live-birth. The findings did not apply to sex ratio in primary RM.

CONCLUSION

There was a subtle relationship between the sex of the first and subsequent births and secondary recurrent miscarriage, but not primary recurrent miscarriage.

Expression of the placental transcriptome in maternal nutrient reduction in baboons is dependent on fetal sex

Maternal undernutrition increases the risk of perinatal complications and predisposes offspring to obesity, diabetes, and cardiovascular disease later in life. Emerging evidence suggests that changes in placental function play a role in linking altered maternal nutrition in pregnancy to the subsequent development of adult disease. The susceptibility for disease in response to an adverse intrauterine environment differs distinctly between boys and girls, with girls typically having better outcomes. Here, we tested the hypothesis that regulation of the placental transcriptome by maternal nutrient reduction (NR) is dependent on fetal sex. We used a nonhuman primate model of NR in which maternal global food intake was reduced by 30% in baboons starting at gestational day (GD) 30. At GD 165 (term = GD 183), placental genome expression profiling of 6 control (n = 3 females, 3 males) and 6 nutrient restricted (n = 3 females, 3 males) fetuses was carried out followed by bioinformatic analysis. Surprisingly, there was no coordinated placental molecular response to decreased nutrient availability when analyzing the data without accounting for fetal sex. In contrast, female placentas exhibited a highly coordinated response that included upregulation of genes in networks, pathways, and functional groups related to programmed cell death and downregulation of genes in networks, pathways, and functional groups associated with cell proliferation. These changes were not apparent in the male placentas. Our data support the concept that female placentas initiate complex adaptive responses to an adverse intrauterine environment, which may contribute to increased survival and better pregnancy outcomes in girls.

The human placental sexome differs between trophoblast epithelium and villous vessel endothelium

Molecular mechanisms underlying sexual dimorphism in mammals, fetal sex influences on intrauterine development, and the sex-biased susceptibility for selected diseases in adulthood are novel areas of current research. As importantly, two decades of multifaceted research has established that susceptibility to many adult disorders originates in utero, commonly secondary to the effects of placental dysfunction. We hypothesized that fetal sex influences gene expression and produces functional differences in human placentas. We thus extended previous studies on sexual dimorphism in mammals, which used RNA isolated from whole tissues, to investigate the effects of sex on four cell-phenotypes within a single key tissue, human placental villi. The cells studied included cytotrophoblasts, syncytiotrophoblast, arterial and venous endothelial cells. The cells were isolated from placentas of male or female fetuses and subjected to microarray analysis. We found that fetal sex differentially affected gene expression in a cell-phenotype dependent manner among all four cell-phenotypes. The markedly enriched pathways in males were identified to be signaling pathways for graft-versus-host disease as well as the immune and inflammatory systems that parallel the reported poorer outcome of male fetuses. Our study is the first to compare global gene expression by microarray analysis in purified, characterized, somatic cells from a single human tissue, i.e. placental villi. Importantly, our findings demonstrate that there are cell-phenotype specific, and tissue-specific, sex-biased responses in the human placenta, suggesting fetal sex should be considered as an independent variable in gene expression analysis of human placental villi.

Unexplained antepartum stillbirth: a consequence of placental aging?

Unexplained antepartum stillbirth is a major obstetric health problem. Data demonstrate a rapid rise in risk per 1000 continuing pregnancies as gestation advances beyond 40 weeks. We review the evidence that such stillbirths are a consequence of aging related changes in the late gestation placenta. We suggest that the relatively small number of continuing pregnancies after 40 completed weeks means that negative effects of genes that produce aging affect so few pregnancies that polymorphisms in genes that produce these effects are retained in the population. Aging related changes likely represent a consequence of the damaging effects of oxidative stress, increased by cigarette smoking counteracted by the mitigating effects of oxidative defence pathways. The aging related changes are likely downstream from nutrient sensing units such as mTOR and include effects on production of telomerase and consequent shortening of telomere length. The late gestation changes occur in the context of increasing fetal growth and nutrient supply demands that can produce the rapid development of a mismatch between placental supply and fetal need resulting in fetal demise. Premature aging may also play an important role in antepartum stillbirth occurring earlier in pregnancy, especially in the context of growth restriction.

Antenatal glucocorticoids reduce growth in appropriately grown and growth-restricted ovine fetuses in a sex-specific manner

Antenatal glucocorticoids are administered to mature the fetal lungs before preterm birth. Glucocorticoids also have non-pulmonary effects, including reducing fetal body and brain growth. The present study examined whether glucocorticoid administration has a sex-specific effect on growth in appropriately grown (control) and intrauterine growth-restricted (IUGR) fetal sheep. IUGR was induced at 0.7 gestation in fetal sheep by single umbilical artery ligation. On Days 5 and 6 after surgery, IUGR or control fetuses were exposed to the synthetic glucocorticoid betamethasone (BM; 11.4mg) or saline via intramuscular maternal administration. On Day 7, a postmortem was conducted to determine fetal sex and weight. Compared with control fetuses, the birthweight of male and female IUGR fetuses was significantly reduced (by 18.5±4.4% (P=0.002) and 21.7±6.0% (P=0.001), respectively). Maternal administration of BM significantly reduced bodyweight in both control and IUGR fetuses (by 11.3±2.8% and 20.5±3.6% in control male and female fetuses, respectively; and by 22.9±3.1% and 38.3±3.4% in IUGR male and female fetuses, respectively; P<0.001 for all, versus control+saline) fetuses. In control and IUGR animals the degree of growth restriction was greater in females than males (P<0.05) following administration of BM. These data suggest that antenatal glucocorticoids reduce fetal growth in a sex-specific manner, with females more growth restricted than males.

Fetal sex-related dysregulation in testosterone production and their receptor expression in the human placenta with preeclampsia

OBJECTIVE

To determine the effects of fetal sex on aromatase and androgen receptor (AR) expression in the placenta of normal and preeclamptic pregnancies.

STUDY DESIGN

Placentae from preeclamptic (five female and six male fetuses) and healthy pregnancies (seven female and seven male fetuses) were examined by immunofluorescence, western blotting and quantitative reverse transcriptase PCR.

RESULT

Placental AR levels were significantly higher (P<0.05) in placentae of both male and female fetuses compared with their respective sexes in normal pregnancies. The placental aromatase levels varied depending on fetal sex. If the fetus was female, aromatase levels were substantially higher (P<0.05) in preeclamptic than in normal placentae. If the fetus was male, the aromatase levels were significantly lower (P<0.05) in preeclamptic than in normal placentae. Placental aromatase levels were significantly higher (P<0.05) in male- than in female-bearing normal placentae.

CONCLUSION

Dysregulation in androgen production and signaling in preeclamptic placentae may contribute to placental abnormalities, increasing the frequency of maternal-fetal complications associated with preeclampsia.

Fetal sex affects expression of renin-angiotensin system components in term human decidua

The maternal decidua expresses the genes of the renin-angiotensin system (RAS). Human decidua was collected at term either before labor (i.e. cesarean delivery) or after spontaneous labor. The mRNA for prorenin (REN), prorenin receptor (ATP6AP2), angiotensinogen (AGT), angiotensin-converting enzymes 1 and 2 (ACE1 and ACE2), angiotensin II type 1 receptor (AGTR1), and angiotensin 1-7 receptor (MAS1) were measured by quantitative real-time RT-PCR. Decidual explants were cultured in duplicate for 24 and 48 h, and all RAS mRNA, and the secretion of prorenin, angiotensin II, and angiotensin 1-7 was measured using quantitative real-time RT-PCR, ELISA, and radioimmunoassay, respectively. In the decidua collected before labor, REN mRNA levels were higher if the fetus was female. In addition, REN, ATP6AP2, AGT, and MAS1 mRNA abundance was greater in decidual explants collected from women carrying a female fetus, as was prorenin protein. After 24 h, ACE1 mRNA was higher in the decidual explants from women with a male fetus, whereas after 48 h, both ACE1 and ACE2 mRNA was higher in decidual explants from women with a female fetus. Angiotensin II was present in all explants, but angiotensin 1-7 levels often registered below the lower limits of sensitivity for the assay. After labor, decidua, when compared with nonlaboring decidua, demonstrated lower REN expression when the fetus was female. Therefore, the maternal decidual RAS is regulated in a sex-specific manner, suggesting that it may function differently when the fetus is male than when it is female.

Prenatal programming of the innate immune response following in utero exposure to inflammation: a sexually dimorphic process?

Maternal infection and inflammation are common events during pregnancy. This article documents evidence that suggests such inflammation compromises the development of the fetal innate immune response, in support of an in utero origins hypothesis of neonatal and childhood inflammatory disease. The potential for this response to exhibit sex specificity is also explored, based on evidence of sexually dimorphic placental responses to maternal inflammation.

Placental abruption, offspring sex, and birth outcomes in a large cohort of mothers

OBJECTIVE

To investigate stillbirth, neonatal, and perinatal death outcomes in pregnancies complicated by placental abruption, according to fetal sex.

METHODS

We utilized maternally linked cohort data files of singleton live births to mothers diagnosed with placental abruption during the period 1989 through 2005 (n = 10,014). Logistic regression models were employed to generate adjusted odd ratios and their 95% confidence intervals. Male babies served as the referent category.

RESULTS

The sex ratio at birth was 1.18. The overall prevalence of stillbirth, neonatal mortality, and perinatal mortality was 7.2%, 4.5%, and 11.8%, respectively. Placental abruption was less likely to occur in mothers carrying female pregnancies than mothers of male infants (adjusted odds ratio [95% confidence interval] = 0.89 [0.86-0.93]). There were no significant sex differences with regards to stillbirth, neonatal mortality, and perinatal mortality. Similar findings were observed for preterm and term infants.

CONCLUSIONS

Although a preponderance of male infants was discernable among mothers with placental abruption, no sex difference in fetal survival was observed among the offspring of the mothers affected by placental abruption.

Fetal and maternal factors associated with infant mortality in vervet monkeys

BACKGROUND

Causes of infant death remain unknown in significant proportions of human and non-human primate pregnancies.

METHODS

A closed breeding colony with high rates of infant mortality had pregnancies assessed (n=153) by fetal measurements and maternal characteristics. Infant outcome was classified as neonatal death (stillborn or died <48 hours from birth), postnatal death (died 2-30 days) or surviving (alive after 30 days).

RESULTS

Fetal size did not predict outcome. Poor maternal glycemic control and low social ranking increased odds for adverse outcome (OR=3.72, P=0.01 and 2.27, P=0.04, respectively). Male sex was over-represented in stillbirths (P=0.04), and many were macrosomic, but size did not associate with maternal glycemic control measured as glycated hemoglobin A1c. Postnatally dead infants were smaller (P<0.01), which associated with behavioral factors and glycemic control.

CONCLUSIONS

Fetal growth estimates predicted gestational age but not fetal outcome. Maternal social status and metabolic health, particularly glycemic control, increased risks of adverse pregnancy outcome.

Obstetric problems in diabetic pregnancy - The role of fetal hypoxia

Perinatal mortality has not decreased over the last two decades in pregestational diabetic pregnancies. Stillbirth rate is 4-6 times and neonatal mortality 2-4 times higher in diabetic than in non-diabetic pregnancies despite modern electronic fetal surveillance methods. Majority of late stillbirths are "unexplained", many of which are presumably caused by fetal hypoxia. Both experimental and clinical studies have shown that fetal hyperglycaemia and hyperinsulinaemia can independently cause fetal hypoxia, which ultimately can lead to fetal death. Poor glycaemic control is associated with perinatal complications. Sharp increases in amniotic fluid erythropoietin levels indicate fetal hypoxia in diabetic pregnancy. Fetal erythropoietin concentrations correlate directly with maternal HbA(1c) levels. It is therefore important to maintain near-normal glycaemic level throughout pregnancy. Measurement of amniotic fluid erythropoietin level is a new way to detect fetal hypoxia antenatally. Sufficiently large controlled studies are needed before definitive answer of the clinical utility of amniotic fluid erythropoietin measurements in diabetic pregnancies can be determined.

Maternal and neonatal outcomes of pregnancies complicated by asthma in an Australian population

OBJECTIVE

To determine if there are sex differences in risk and incidence of stillbirth, preterm delivery and small-for-gestational age (SGA) in pregnancies complicated by maternal asthma relative to a non-asthmatic population.

STUDY DESIGN

Univariant and multiple regression analysis of the incidence of preterm delivery, SGA and stillbirth in singleton pregnancies complicated by asthma in Newcastle, NSW, Australia, from 1995 to 1999.

RESULTS

Asthma complicated 12% of all singleton pregnancies. The incidence of preterm delivery was not significantly different between asthmatic (13%) and non-asthmatic (11%) pregnancies. Male fetuses (53%) were more likely to deliver preterm than female fetuses (47%) in both asthmatic and non-asthmatic populations. There were significantly more male neonates of pregnancies complicated by asthma that were SGA at term relative to those of the non-asthmatic population. There were significantly more preterm female neonates that were SGA in pregnancies complicated by asthma relative to those of the non-asthmatic population. Male fetuses were more likely to be associated with a stillbirth in pregnancies complicated by asthma than female fetuses.

CONCLUSION

The presence of maternal asthma during pregnancy increases the risk of stillbirth for the male fetus and is associated with changes in fetal growth, but does not increase the incidence of a preterm delivery.

The effect of betamethasone treatment on neuroactive steroid synthesis in a foetal Guinea pig model of growth restriction

There are ongoing concerns that antenatal corticosteroids, which are administered to women at high risk of delivering preterm to reduce the incidence of respiratory distress syndrome, have adverse effects on foetal brain development and subsequent effects on behaviour and learning, when administered as repeated courses. The present study aimed to examine whether repeated betamethasone treatment alters the expression of the key-rate limiting enzyme, 5alpha-reductase, in the synthetic pathway of the potent neuroactive steroid allopregnanolone in the brain and placenta and whether this effect is potentiated in growth restricted foetuses. To investigate this, pregnant guinea pigs carrying either control (sham surgery) or growth-restricted foetuses were treated with vehicle or betamethasone (1 mg/kg/day) for 4 days prior to sacrifice (65d). Placental insufficiency was induced by the ablation of uterine artery branches supplying each placenta at mid gestation, resulting in foetal growth restriction characterised by 'brain sparing'. Real-time reverse transcriptase polymerase chain reaction was used to determine relative 5alpha-reductase type 1 and 2 mRNA expression in the placenta and brain. Immunohistochemistry was used to examine the glial fibrillary acidic protein (GFAP) expression in the subcortical white matter, CA1 and dentate regions of the hippocampus. 5alpha-reductase type 2 mRNA expression in the brain was markedly reduced by betamethasone treatment in male foetuses compared to vehicle-treated controls but not in female foetuses. In addition, 5alpha-reductase type 1 expression in the brain was increased by growth restriction and/or betamethasone treatment in female foetuses but expression in males foetuses did not increase. 5alpha-reductase type 2 expression in the placenta was markedly reduced by betamethasone treatment compared to vehicle-treated control. Intrauterine growth restriction and betamethasone treatment reduced GFAP expression in the CA1 region of the hippocampus in the brains of male but not female foetuses. These data indicate that betamethasone treatment suppresses placental expression and has sexually dimorphic effects on expression of neuroactive steroid synthetic enzymes in the brain. These actions may lead to adverse effects on the developing brain, particularly in male foetuses, such as the observed effects on GFAP expression.