The association between angiogenic markers and fetal sex: Implications for preeclampsia research

Prediction of Fetal Death in Preterm Preeclampsia Using Fetal Sex, Placental Growth Factor and Gestational Age

BACKGROUND/OBJECTIVES

Preeclampsia (PE) is a systemic disease that affects 4.6% of pregnancies. Despite the existence of a first-trimester screening for the prediction of preterm PE, no consensus exists regarding neither the right moment to end the pregnancy nor the appropriate variables to estimate the prognosis. The objective of this study was to obtain a prediction model for perinatal death in patients with preterm PE, useful for clinical practice.

METHODS

Singleton pregnant women with PE and preterm delivery were included in an observational retrospective study. Multiple maternal and fetal variables were collected, and several multivariable logistic regression analyses were applied to construct models to predict perinatal death, selecting the most accurate and reproducible according to the highest area under the curve (AUC) and the lowest Akaike Information Criteria (AIC).

RESULTS

A group of 148 pregnant women were included, and 18 perinatal deaths were registered. Univariable logistic regression selected as statistically significant variables the following: gestational age (GA) at admission, fetal sex, poor response to antihypertensive drugs, PlGF, umbilical artery (UA) pulsatility index (PI), cerebroplacental ratio (CPR), and absent/reversed ductus venosus (DV). The multivariable model, including all these parameters, presented an AUC of 0.95 and an AIC of 76.5. However, a model including only GA and fetal sex presented a similar accuracy with the highest simplicity (AUC 0.93, AIC 67.6). Finally, in fetuses with a similar GA, fetal death became dependent on PlGF and fetal sex, underlying the role of fetal sex in all circumstances.

CONCLUSIONS

Female fetal sex and low PlGF are notorious predictors of perinatal death in preterm PE, only surpassed by early GA at birth.

Fetal-origin cells in maternal circulation correlate with placental dysfunction, fetal sex, and severe hypertension during pregnancy

Fetal microchimerism (FMc) arises when fetal cells enter maternal circulation, potentially persisting for decades. Increased FMc is associated with fetal growth restriction, preeclampsia, and anti-angiogenic shift in placenta-associated proteins in diabetic and normotensive term pregnancies. The two-stage model of preeclampsia postulates that placental dysfunction causes such shift in placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFLt-1), triggering maternal vascular inflammation and endothelial dysfunction. We investigated whether anti-angiogenic shift, fetal sex, fetal growth restriction, and severe maternal hypertension correlate with FMc in hypertensive disorders of pregnancy with new-onset features (n = 125). Maternal blood was drawn pre-delivery at > 25 weeks' gestation. FMc was detected by quantitative polymerase chain reaction targeting paternally inherited unique fetal alleles. PlGF and sFlt-1 were measured by immunoassay. We estimated odds ratios (ORs) by logistic regression and detection rate ratios (DRRs) by negative binomial regression. PlGF correlated negatively with FMc quantity (DRR = 0.2, p = 0.005) and female fetal sex correlated positively with FMc prevalence (OR = 5.0, p < 0.001) and quantity (DRR = 4.5, p < 0.001). Fetal growth restriction no longer correlated with increased FMc quantity after adjustment for correlates of placental dysfunction (DRR = 1.5, p = 0.272), whereas severe hypertension remained correlated with both FMc measures (OR = 5.5, p = 0.006; DRR = 6.3, p = 0.001). Our findings suggest that increased FMc is independently associated with both stages of the two-stage preeclampsia model. The association with female fetal sex has implications for microchimerism detection methodology. Future studies should target both male and female-origin FMc and focus on clarifying which placental mechanisms impact fetal cell transfer and how FMc impacts the maternal vasculature.

Fetal Sexual Dimorphism and Preeclampsia Among Twin Pregnancies

BACKGROUND

In singleton pregnancies, fetal sexual dimorphism has been observed in hypertensive disorders of pregnancy, particularly preeclampsia, a morbid syndrome that increases the risk of adult-onset cardiovascular disease for mothers and their offspring. However, few studies have explored the effect of fetal sex on hypertensive disorders of pregnancy among twin pregnancies.

METHODS

We conducted a retrospective cohort study of 1032 twin pregnancies between 2011 and 2022 using data from a perinatal database that recruits participants from 3 hospitals in Houston, TX. We categorized pregnancies based on fetal sex pairings into female/female, male/male, and female/male. Pregnancies with female/female pairs were used as our reference group. Our primary outcomes included gestational hypertension, preeclampsia, superimposed preeclampsia, and preeclampsia subtyped by gestational age of delivery. A modified Poisson regression model with robust error variance was used to calculate the relative risk and 95% CI for the association between fetal sex pairs and hypertensive disorders of pregnancy.

RESULTS

Adjusted models of female/male pairs were associated with preterm preeclampsia (relative risk, 2.01 [95% CI, 1.15-3.53]) relative to those with female/female pairs. No associations with other hypertensive disorders of pregnancy were observed among pregnancies with male/male pairs compared with those with female/female fetal sex pairs.

CONCLUSIONS

We found some evidence of sexual dimorphism for preterm preeclampsia among female/male twin pairs. Additional research is needed to understand what biological mechanisms could explain these findings.

Fetal sexual dimorphism and preeclampsia among twin pregnancies

Background

In singleton pregnancies, fetal sexual dimorphism has been observed in hypertensive disorders of pregnancy (HDP), particularly preeclampsia, a morbid syndrome that increases risk of adult onset cardiovascular disease for mothers and their offspring. However, few studies have explored the effect of fetal sex on HDP among twin pregnancies.

Methods

We conducted a retrospective cohort study of 1,032 twin pregnancies between 2011 - 2022 using data from a perinatal database that recruits participants from three hospitals in Houston, TX. We categorized pregnancies based on fetal sex pairings into female/female, male/male, and female/male. Pregnancies with a female/female fetal sex were used as our reference group. Our primary outcomes included gestational hypertension, preeclampsia, superimposed preeclampsia, and preeclampsia subtyped by gestational age of delivery. A modified Poisson regression model with robust error variance was used to calculate the relative risk (RR) and 95% confidence interval (CI) for the association between fetal sex pairs and HDP.

Results

Adjusted models of female/male fetal sex pairs were associated with preterm preeclampsia (RR 2.01, 95% CI 1.15-3.53) relative to those with female/female fetuses. No associations with other HDP were observed among pregnancies with male/male fetal sex compared to those with female/female fetal sex pairs.

Conclusions

We found some evidence of sexual dimorphism for preterm preeclampsia among female/male twin pairs. Additional research is needed to understand what biological mechanisms could explain these findings.

The effect of nicotine-containing products and fetal sex on placenta-associated circulating midpregnancy biomarkers

Background

In utero exposure to nicotine, largely assessed by smoking, is a risk factor for impaired offspring health, while potential effects of non-combustible nicotine use such as snus (oral moist tobacco), are less well-known. Maternal serum concentrations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) may be viewed as “placenta health markers”, known to differ by fetal sex. Maternal smoking during pregnancy has been associated with lower levels of circulating sFlt-1, while the effect of snus on placenta-associated angiogenic factors is unknown. Our aim was to explore if snus and/or smoking exposure was associated with midpregnancy maternal levels of sFlt-1, PlGF and sFlt-1/PlGF ratio if these associations were modified by fetal sex.

Methods

Midpregnancy (16–22 gestational weeks) serum from 2603 Scandinavian women enrolled in the population-based multi-center PreventADALL (Preventing Atopic Dermatitis and ALLergies in children) study was analysed for sFlt-1 and PlGF concentrations by electrochemiluminescence, deriving the sFlt-1/PGF ratio. Nicotine use was assessed by electronic questionnaires at enrollment in 2278 of the women. Univariable and multivariable linear regression models on log transformed outcomes were used to assess the association between nicotine use and biomarker levels. Interaction terms were included to identify whether the associations were modified by fetal sex.

Results

Median sFlt-1, PlGF and sFlt-1/PlGF ratios among women with nicotine exposure information were similar to those of all included women and differed by fetal sex. Current snus use was significantly associated with reduced maternal circulating PlGF levels in adjusted analyses [β − 0.12, (95% CI − 0.20; 0.00) compared to never use, p = 0.020]. A significant interaction between fetal sex and snus exposure was observed for PIGF (p = 0.031). Prior or periconceptional snus use was significantly associated with PIGF in male fetus pregnancies [β − 0.05 (95% CI − 0.09 to (− 0.02)) and β − 0.07 (95% CI − 0.12 to (− 0.02)) compared to never use, p = 0.002]. Smoking was not significantly associated with any circulating biomarkers levels.

Conclusions

Midpregnancy maternal angiogenic profile differed by periconceptional snus use and fetal sex. Snus exposure, perceived as “safe” by users, before or during pregnancy seems to affect midpregnancy placental health in a sex dimorphic manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00443-1.

Association of fetal sex with angiogenic factors in normotensive and hypertensive pregnancy states

OBJECTIVES

With the incorporation of angiogenic biomarkers into clinical practice, identification of potential modifiers of the angiogenic profile, including fetal sex, is essential.

STUDY DESIGN

In this retrospective cohort analysis, patients with hypertensive disorders of pregnancy (HDP) and normotensive pregnancies were enrolled upon admission to Labor and Delivery. Blood samples for angiogenic factors were assessed using an automated platform. Clinical and demographic information was abstracted from each patient's medical records.

MAIN OUTCOME MEASURES

Soluble fms-like tyrosine kinase-1 (sFlt1) and placental growth factor (PlGF) levels and their ratio in relation to fetal sex in patients with normotensive pregnancies compared to those with HDP were evaluated.

RESULTS

A total of 617 patients were analyzed (299 normotensive, 113 gestational hypertensive, 71 chronic hypertensive, and 134 preeclamptic patients). There was no difference between the number of patients who had a male fetus among preeclampsia and normotensive parturients (56.0 % vs 50.2 %, p = 0.26). Normotensive patients carrying a male fetus had significantly higher sFlt1 (pg/ml) (3168 [IQR: 2160-4945] vs 2678 [IQR: 1752-4271]; p = 0.01) and sFlt1/PlGF ratios (18 [IQR: 7-44] vs 12 [IQR: 5-30]; p = 0.01) in comparison to pregnant patients carrying a female fetus. This difference between fetal sexes was not observed in the angiogenic profile of patients with HDP.

CONCLUSIONS

Our study of primarily Black, obese patients demonstrates that normotensive patients carrying a male fetus have a significantly higher sFlt1 and sFlt1/PlGF ratio as compared to those carrying a female fetus at term gestation. Fetal sex should be considered as a covariate when studying angiogenic factors in normotensive pregnant patients.

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 differences in uterine artery Doppler during gestation in pregnancies complicated by placental dysfunction

BACKGROUND

There is growing evidence of sex differences in placental vascular development. The objective of this study was to investigate the effect of fetal sex on uterine artery pulsatility index (PI) throughout gestation in a cohort of normal and complicated pregnancies.

METHODS

A prospective longitudinal study was conducted in 240 pregnant women. Pulsed wave Doppler ultrasound of the proximal uterine arteries was performed at a 4-weekly interval between 14 and 40 weeks of gestation. The patients were classified retrospectively as normal or complicated (one or more of maternal preeclampsia, preterm birth, or small for gestational age). To assess if the change in uterine artery PI during gestation differed between normal and complicated pregnancies and between fetal sexes, the uterine artery PI was modeled using a linear function of gestational age and the rate of change was estimated from the slope.

RESULTS

While the uterine artery PI did not differ over gestation between females and males for normal pregnancies, the trajectory of this index differed by fetal sex for pregnancies complicated by either preeclampsia, preterm birth, or fetal growth restriction (p < 0.0001). The male fetuses in the complicated pregnancy group had an elevated slope compared to the other groups (p < 0.0001), suggesting a more progressive deterioration in uteroplacental perfusion over gestation.

CONCLUSIONS

The uterine artery PI is widely used to assess uteroplacental function in clinical settings. The observation that this metric changes more rapidly in complicated pregnancies where the fetus was male highlights the importance of sex when interpreting hemodynamic markers of placental maturation.

Markers of Endothelial Injury and Dysfunction in Early- and Late-Onset Preeclampsia

With regard to differences in the clinical symptoms of preeclampsia (PE), the degree of endothelial dysfunction may differ between early and late-onset preeclampsia (EOP and LOP). The authors of this study examined it by assessing the endothelial injury level in women with EOP (20 patients) and LOP (20 patients) and in normotensive pregnant women (20 patients) in their late second and third trimesters of pregnancy, using the two markers-the serum concentration of hyaluronan (HA) and the serum level of soluble vascular cell adhesion molecule-1 (sVCAM-1). The serum concentrations of HA and sVCAM-1 did not differ significantly between the EOP and LOP patients. However, these were statistically higher than that of the control group participants (p < 0.05; p < 0.001). A significant correlation between the levels of HA and sVCAM-1 was found both in the entire group of patients with preeclampsia (p = 0.0277) and in women with late-onset disease (p = 0.0364), but not in the patients with early-onset preeclampsia (p = 0.331). The obtained results indicated a comparable level of endothelial injury in the two types of PE. The presence of a similar degree of endothelial injury in patients with EOP and LOP should create awareness among all clinicians about the possible fatal complications in both groups of patients with PE.

Blood Pressure and Angiogenic Markers in Pregnancy: Contributors to Pregnancy-Induced Hypertension and Offspring Cardiovascular Risk

Pregnancy-induced hypertension is a severe pregnancy complication, increasing risk of long-term cardiovascular disease in mothers and offspring. We hypothesized that maternal blood pressure in pregnancy associated with offspring blood pressure; that the associations were sex-specific; and that maternal circulating placental angiogenic markers (PlGF [placental growth factor] and sFlt-1 [soluble fms-like tyrosine kinase-1]) mediated this relationship. We analyzed data from 2434 women and 2217 children from the Odense Child Cohort, a prospective Danish cohort study. Offspring blood pressure trajectory from 4 months to 5 years was highly associated to maternal first, second, and third trimester blood pressure, and mean blood pressure in pregnancy, independent of maternal and offspring covariates. There were offspring sex-specific associations: Girls from mothers in the highest quartile of first and third trimester blood pressure had significantly higher systolic blood pressure at 5 years than the rest of the cohort (mean difference±SEM: 1.81±0.59 and 2.11±0.59 mm Hg, respectively, all P<0.01); whereas boys had significantly higher diastolic blood pressure at 5 years (mean difference±SEM: 1.11±0.45 and 1.03±0.45, respectively, all P<0.05). Concentrations of PlGF at gestational week 28 correlated inversely to maternal gestational blood pressure trajectory, independent of the diagnosis of pregnancy-induced hypertension, adjusted β coefficients (95% CI) for predicting systolic blood pressure (SBP): -3.18 (-4.66 to -1.70) mm Hg, for predicting diastolic blood pressure (DBP): -2.48 (-3.57 to -1.40) mm Hg. In conclusion, maternal gestational blood pressure predicted offspring blood pressure trajectory until 5 years in a sex-differential manner. Furthermore, subtle alterations in blood pressure in early pregnancy preceded hypertension or preeclampsia, and PlGF was a mediator of cardiovascular health in pregnancy.

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.

No association between early antiretroviral therapy during pregnancy and plasma levels of angiogenic factors: a cohort study

Background

Early antiretroviral therapy (ART) during pregnancy has dramatically reduced the risk of perinatal HIV transmission. However, studies have shown an association between premature delivery and the use of ART during pregnancy (particularly protease inhibitor (PI)-based therapies), which could be explained by placental dysfunction. The objective of this study was to evaluate the association of ART (class, duration of exposure and time of initiation) with placental function by using angiogenic factors placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) as biomarkers.

Methods

Clinical and biological data from 159 pregnant women living with HIV were analyzed. Levels of each biomarker were measured in the first and second trimester of pregnancy. After logarithmic transformation, we compared these using generalized estimating equations according to (a) the type of ART; (b) the duration of exposure to ART; and (c) the time of initiation of ART.

Results

After adjusting for variables such as ethnicity, maternal age, gestational age, body mass index, parity, smoking status, and sex of the fetus, we found no significant association between the class of ART (PI-based or not) and serum concentrations of PlGF or sFlt-1. Furthermore, no significant association was found between biomarker levels and the duration of ART exposure or the timing of ART initiation (pre- or post-conception).

Conclusions

This study suggests that first and second trimester angiogenic factor levels are not significantly associated with ART, regardless of the duration or type (with or without PI). These observations seem reassuring when considering the use of ART during early pregnancy.

Impact of gestational hypertension and preeclampsia on fetal gender: A large prospective cohort study in China

BACKGROUND

Recent studies suggested an association between fetal sex preponderance and hypertensive disorders during pregnancy, but the conclusions were inconsistent. Our objective was to investigate whether the occurrence of gestational hypertensive disorders would affect the possibility of delivering boys.

METHODS

Data were obtained from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included participants who were registered in 2 southern Chinese provinces, and whose information of blood pressure and sex delivery were recorded in detailed. Blood pressure was measured during pregnancy by trained health care workers and other health-related information was recorded prospectively. We used log-binomial regression to evaluate the association between gestational hypertension or preeclampsia and the chance of male delivery.

RESULTS

Among 205,605 singleton pregnancy women, the overall incidences of gestational hypertension and preeclampsia were 9.5% and 2.4%, respectively. The prevalence of male delivery was 51.1% and 50.2% in the groups of gestational hypertension and preeclampsia, while in the normotension group was 52.0%. After adjustment for the effects of the main potential confounders, women with gestational hypertension and preeclampsia both showed significantly decreased probability of giving birth to a boy. The adjusted risk ratios (RRs) were 0.98 (95% confidence interval (CI): 0.97-0.99) and 0.96 (95% CI: 0.94-0.99), respectively.

CONCLUSIONS

Our results support a slight but significant association between gestational hypertension or preeclampsia and decreased likelihood of male delivery.

Characterisation of the Selective Reduced Uteroplacental Perfusion (sRUPP) Model of Preeclampsia

Preeclampsia is a complication of pregnancy characterised by gestational hypertension, proteinuria and/or end organ disease. The reduced uteroplacental perfusion (RUPP) model, via partial occlusion of the lower abdominal aorta, mimics insufficient placental perfusion as a primary causal characteristic of preeclampsia. However, a major limitation of the RUPP model is that perfusion is reduced to the entire hindquarters of the rat resulting in hindlimb ischemia. We hypothesised that clipping the uterine and ovarian arteries in the selective (s)RUPP model would provoke signs of preeclampsia while avoiding systemic ischemia. Sham, RUPP or sRUPP procedures were performed in pregnant Sprague Dawley rats on gestational day (GD)14. On GD21 uterine blood flow was significantly reduced in both the RUPP and sRUPP models while aortic flow was reduced only in RUPP. Both models resulted in increased MAP, increased vascular oxidative stress (superoxide generation), increased pro-inflammatory (RANTES) and reduced pro-angiogenic (endoglin) mediators. Vascular compliance and constriction were unaltered in either RUPP or sRUPP groups. In summary, refinements to the RUPP model simultaneously maintain the characteristic phenotype of preeclampsia and avoid peripheral ischemia; providing a useful tool which may be used to increase our knowledge and bring us closer to a solution for women affected by preeclampsia.

The Density of Cell Nuclei at the Materno-Fetal Exchange Barrier is Sexually Dimorphic in Normal Placentas, but not in IUGR

Placental sexual dimorphism is of special interest in prenatal programming. Various postnatal diseases with gender dependent incidence, especially neuropsychiatric disorders like schizophrenia and autism spectrum disorders, have prenatal risk factors established. However, the functional relevance of placental microarchitecture in prenatal programming is poorly investigated, mainly due to a lack of statistically efficient methods. We hypothesized that the recently established 3D microscopic analysis of villous trees would be able to identify microscopic structural correlates of human placental sexual dimorphism. We analyzed the density of cell nuclei of villous trophoblast, i.e. the materno-fetal exchange barrier, in placentas from term pregnancies. The cell nuclei were grouped into proliferative and non-proliferative nuclei by detection of a proliferation marker (PCNA). Normal female placentas showed a higher density of non-proliferating nuclei (PCNA-negative) in villous trophoblast than normal male placentas. The density of PCNA-negative cell nuclei was higher in placentas of pregnancies with intrauterine growth retardation (IUGR) than in control placentas. The data of the present study shows that the density of non-proliferative cell nuclei in the syncytial layer of villous trophoblast is influenced by fetal sex and by IUGR, while proliferation remains unchanged. A novel concept of post-fusion regulation of syncytial structure and function is proposed.

Recognizing and Managing Postpartum Psychosis: A Clinical Guide for Obstetric Providers

Postpartum psychosis is a psychiatric emergency that affects 1 to 2 per 1000 women. Key clinical features include mood fluctuation, abnormal thoughts or behaviors, and confusion. Women with a history of bipolar disorder are at heightened risk, as are first-time mothers; current research on the causes focuses on biological triggers, such as immune dysregulation. Women with postpartum psychosis require inpatient hospitalization and should be treated with lithium, antipsychotics, and benzodiazepines.

Maternal serum mitochondrial DNA (mtDNA) levels are elevated in preeclampsia - A matched case-control study

OBJECTIVE

Oxidative stress and mitochondrial dysfunction may play a crucial role in preeclampsia (PE). The aim of this study was to investigate differences in maternal levels of serum-mitochondrial (mt) DNA, a proposed biomarker for mitochondrial dysfunction, in women with PE compared to healthy pregnant women.

STUDY DESIGN

Using samples obtained from the prospective Biobank study, we measured serum-mtDNA levels in pregnant women diagnosed with PE and in women with uneventful pregnancies, matched for gestational and maternal age, BMI, and smoking status. In a second step, we performed a generalized linear model to detect associations between mtDNA-serum-levels and certain conditions during pregnancy.

RESULTS

Mean mtDNA levels were significantly higher in PE (n = 20) than in matched controls (n = 20) and were 0.00767 (SD 0.00255) U/L and 0.00513 (SD 0.00458) U/L, respectively (p = 0.038). We did not find a significant correlation between higher mtDNA levels and early onset PE, IUGR, maternal age, or maternal BMI. Interestingly, increased mtDNA levels were significantly associated with female fetal sex (p = 0.003).

CONCLUSION

Our findings strengthen the hypothesis postulating that oxidative stress and mitochondrial dysfunction are key factors in the pathophysiology of PE. More prospective studies are highly warranted to further investigate the role of mtDNA in PE and assess the usefulness as a possible biomarker for PE.

Fetal sexual dimorphism in systemic soluble fms-like tyrosine kinase 1 among normotensive and preeclamptic women

PROBLEM

A handful of studies report sexual dimorphism in the maternal angiogenic profile possibly influencing placental development and preeclampsia risk. This secondary analysis explored associations between fetal sex and soluble fms-like tyrosine kinase-1 (sFLT) and endoglin (9-35 weeks gestation) using data from a nested case-control study within the Danish National Birth Cohort.

METHOD OF STUDY

A total of 448 preeclamptic women and 328 normotensive women had data on sFLT and endoglin. Preeclampsia was defined by blood pressure ≥140/90 mm Hg and proteinuria (≥0.3g or 300 mg/24 h.). Generalized linear models adjusting for gestational age of blood draw, body mass index, maternal age, and smoking determined associations between fetal sex and log-transformed biomarkers.

RESULTS

Male fetal sex is associated with 11% lower sFLT levels (β = -0.11, P = 0.03) in preeclamptic women. There were no differences observed in normotensive women. We found no statistically significant differences in endoglin by fetal sex among groups.

CONCLUSION

Our results are similar with other studies suggesting that women with female fetuses have increased sFLT levels. However, significant difference was only among women with preeclampsia. This study was exploratory and longitudinal investigations across pregnancy are required to understand the relationship between fetal sex and systemic maternal angiogenic biomarkers.

The impact of female fetal sex on preeclampsia and the maternal immune milieu

OBJECTIVE

Small studies suggest that fetal sex alters maternal inflammation. We examined the association between fetal sex, preeclampsia and circulating maternal immune markers.

METHODS

This was a secondary data analysis within a nested case-control study of 216 preeclamptic women and 432 randomly selected normotensive controls from the Collaborative Perinatal Project. All women had singleton, primiparous pregnancies without chronic health conditions. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for associations between female fetal sex and preeclampsia. Outcomes included preeclampsia, preterm preeclampsia (<37 and <34 weeks), and normotensive preterm birth <37 weeks. Associations between female fetal sex and immune markers [interleukin (IL)-6, IL4, IL5, IL12, IL10, IL8, IL1-beta, interferon (IFN)-gamma, tumor necrosis factor (TNF)-beta, and transforming growth factor-beta] were examined using a statistical method developed for large proportions of censored biomarker data. Models were adjusted for maternal age, race, body mass index, and smoking.

RESULTS

Women with early preterm preeclampsia (<34 weeks) had higher odds of having a female fetus (OR_adj. 3.2, 95% CI 1.1-9.6) and women with normotensive preterm birth had lower odds (OR_adj. 0.5, 95% CI 0.3-0.9). Female fetal sex was associated with lower first trimester pro-inflammatory IFNγ and IL-12 but higher second trimester pro-inflammatory IL1β and TNFβ, anti-inflammatory IL4r, and regulatory cytokines IL5 and IL10. Female fetal sex was associated with higher postpartum IL10 in preeclamptic women only.

CONCLUSIONS

We identified sexual dimorphism in maternal inflammation. Longitudinal studies are needed to determine if fetal sex impacts the maternal immune milieu across pregnancy.

Maternal choline supplementation during murine pregnancy modulates placental markers of inflammation, apoptosis and vascularization in a fetal sex-dependent manner

INTRODUCTION

Normal placental vascular development is influenced by inflammatory, angiogenic and apoptotic processes, which may be modulated by choline through its role in membrane biosynthesis, cellular signaling and gene expression regulation. The current study examined the effect of maternal choline supplementation (MCS) on placental inflammatory, angiogenic and apoptotic processes during murine pregnancy.

METHOD

Pregnant dams were randomized to receive 1, 2 or 4 times (X) the normal choline content of rodent diets, and tissues were harvested on embryonic day (E) 10.5, 12.5, 15.5 or 18.5 for gene expression, protein abundance and immunohistochemical analyses.

RESULTS

The choline-induced changes in the inflammatory and angiogenic markers were a function of fetal sex. Specifically, 4X (versus 1X) choline reduced the transcript (P ≤ 0.05) and protein (P ≤ 0.06) expression of TNF-a and IL-1β in the male placentas at E10.5 and E18.5, respectively. In the female placentas, 4X (versus 1X) choline modulated the transcript expression of Il1b in a biphasic pattern with reduced Il1b at E12.5 (P = 0.045) and E18.5 (P = 0.067) but increased Il1b at E15.5 (P = 0.031). MCS also induced an upregulation of Vegfa expression in the female placentas at E15.5 (P = 0.034; 4X versus 2X) and E18.5 (P = 0.026; 4X versus 1X). MCS decreased (P = 0.011; 4X versus 1X) placental apoptosis at E10.5. Additionally, the luminal area of the maternal spiral arteries was larger (P ≤ 0.05; 4X versus 1X) in response to extra choline throughout gestation.

DISCUSSION

MCS during murine pregnancy has fetal sex-specific effects on placental inflammation and angiogenesis, with possible consequences on placental vascular development.