Elevated glucocorticoid metabolism in placental tissue from first trimester pregnancies at increased risk of pre-eclampsia

Obesity in pregnancy-Long-term effects on offspring hypothalamic-pituitary-adrenal axis and associations with placental cortisol metabolism: A systematic review

Obesity, affecting one in three pregnant women worldwide, is not only a major obstetric risk factor. The resulting low-grade inflammation may have a long-term impact on the offspring's HPA axis through dysregulation of maternal, placental and fetal corticosteroid metabolism, and children born of obese mothers have increased risk of diabetes and cardiovascular disease. The long-term effects of maternal obesity on offspring neurodevelopment are, however, undetermined and could depend on the specific effects on placental and fetal cortisol metabolism. This systematic review evaluates how maternal obesity affects placental cortisol metabolism and the offspring's HPA axis. Pubmed, Embase and Scopus were searched for original studies on maternal BMI, obesity, and cortisol metabolism and transfer. Fifteen studies were included after the screening of 4556 identified records. Studies were small with heterogeneous exposures and outcomes. Two studies found that maternal obesity reduced placental HSD11β2 activity. In one study, umbilical cord blood cortisol levels were affected by maternal BMI. In three studies, an altered cortisol response was consistently seen among offspring in childhood (n = 2) or adulthood (n = 1). Maternal BMI was not associated with placental HSD11β1 or HSD11β2 mRNA expression, or placental HSD11β2 methylation. In conclusion, high maternal BMI is associated with reduced placental HSD11β2 activity and a dampened cortisol level among offspring, but the data is sparse. Further investigations are needed to clarify whether the HPA axis is affected by prenatal factors including maternal obesity and investigate if adverse effects can be ameliorated by optimising the intrauterine environment.

Psychosocial status modifies the effect of maternal blood metal and metalloid concentrations on birth outcomes

BACKGROUND

Metal exposure and psychosocial stress in pregnancy have each been associated with adverse birth outcomes, including preterm birth and low birth weight, but no study has examined the potential interaction between them.

OBJECTIVES

We examined the modifying effect of psychosocial stress on the association between metals and birth outcomes among pregnant women in Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) birth cohort study.

METHODS

In our analysis of 682 women from the PROTECT study, we measured 16 essential and non-essential metals in blood samples at two time points. We administered questionnaires to collect information on depression, perceived stress, social support, and life experience during pregnancy. Using K-means clustering, we categorized pregnant women into one of two groups: "good" and "poor" psychosocial status. We then evaluated whether the effect of blood metals (geometric average) on adverse birth outcomes (gestational age, preterm birth [overall and spontaneous], birth weight z-score, small for gestation [SGA], large for gestation [LGA]) vary between two clusters of women, adjusting for maternal age, maternal education, pre-pregnancy body mass index (BMI), and second-hand smoke exposure.

RESULTS

Blood manganese (Mn) was associated with an increased odds ratio (OR) of overall preterm birth (OR/interquartile range [IQR] = 2.76, 95% confidence interval [CI] = 1.25, 6.12) and spontaneous preterm birth (OR/IQR: 3.68, 95% CI: 1.20, 6.57) only among women with "poor" psychosocial status. The association between copper (Cu) and SGA was also statistically significant only among women having "poor" psychosocial status (OR/IQR: 2.81, 95% CI: 1.20, 6.57). We also observed associations between nickel (Ni) and preterm birth and SGA that were modified by psychosocial status during pregnancy.

CONCLUSIONS

Presence of "poor" psychosocial status intensified the adverse associations between Mn and preterm birth, Cu and SGA, and protective effects of Ni on preterm. This provides evidence that prenatal psychosocial stress may modify vulnerability to metal exposure.

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

Background

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

Aim

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

Method

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

Results

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

Conclusion

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

Variants of HSD11B2 gene in hypertensive disorders of pregnancy

INTRODUCTION

One of the hypotheses concerning the etiology of gestational hypertension (GH) and pre-eclampsia (PE) assumes that they develop as a result of placenta malfunctioning at the early stage of pregnancy. Placental dysfunction is also associated with the decreased activity of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), which in normal pregnancy protects the fetus from the excess of maternal cortisol.

OBJECTIVE

The aim of the study was to analyze the sequence of HSD11B2, a gene that encodes 11β-HSD2, searching for mutations and haplotypes associated with the increased risk of GH or PE. Those may serve as potential genetic markers of GH and PE.

METHODS

The study was performed in case-control structure and included pregnant women (in third trimester) diagnosed with: GH, PE or being normotensive (control group). The research comprised DNA sequencing of HSD11B2, followed by restriction analysis (PCR-RFLP). The linkage disequilibrium analysis and haplotype-based case-control analysis were performed.

RESULTS

Six sequence variations were observed. Four mutations were indicated in the coding region of HSD11B2 and the other two in 3'-UTR. Two SNPs: c.468C > A and c.534G > A were found to be in total disequilibrium.

CONCLUSIONS

High variability in HSD11B2 sequence was indicated in the study population, but the relevance of observed SNPs to GH or PE development was not confirmed.

11β-Hydroxysteroid Dehydrogenase 2 in Preeclampsia

Preeclampsia is a serious medical problem affecting the mother and her child and influences their health not only during the pregnancy, but also many years after. Although preeclampsia is a subject of many research projects, the etiology of the condition remains unclear. One of the hypotheses related to the etiology of preeclampsia is the deficiency in placental 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), the enzyme which in normal pregnancy protects the fetus from the excess of maternal cortisol. The reduced activity of the enzyme was observed in placentas from pregnancies complicated with preeclampsia. That suggests the overexposure of the developing child to maternal cortisol, which in high levels exerts proapoptotic effects and reduces fetal growth. The fetal growth restriction due to the diminished placental 11β-HSD2 function may be supported by the fact that preeclampsia is often accompanied with fetal hypotrophy. The causes of the reduced function of 11β-HSD2 in placental tissue are still discussed. This paper summarizes the phenomena that may affect the activity of the enzyme at various steps on the way from the gene to the protein.

Uterine artery Doppler, birth weight and timing of onset of pre-eclampsia: providing insights into the dual etiology of late-onset pre-eclampsia

OBJECTIVE

To investigate the relationship between uterine artery Doppler ultrasound indices and birth weight in women with early-, intermediate- and late-onset pre-eclampsia as compared with women with uneventful pregnancy outcome.

METHODS

In a retrospective, observational cohort study, uterine artery Doppler assessment was carried out at 18+0 to 23+6 weeks' gestation in 26,893 women attending for routine antenatal care in a tertiary care center. The mean resistance index (RI) and its relationship to the outcome of pregnancy and birth-weight centiles were evaluated.

RESULTS

Uterine artery RI showed a significant, negative correlation with birth weight (r= -0.20, P<0.0001). Patients with early-onset pre-eclampsia had an increased prevalence of high uterine artery mean RI, above the 90(th) centile, corresponding to an increased proportion of small-for-gestational age (SGA) neonates with a birth weight below the 10(th) centile. In late-onset pre-eclampsia, however, there was an unexpectedly higher proportion of large-for-gestational-age (LGA) neonates with a birth weight above the 90(th) centile without a concurrent increase in the prevalence of low uterine artery mean RI below the 10(th) centile.

CONCLUSIONS

The finding of a bimodal skewed distribution of birth weight, with neonates exhibiting a higher prevalence of both LGA and SGA with late-onset pre-eclampsia, indicates that there are two types of late-onset pre-eclampsia. These findings explain the poor performance of mid-trimester uterine artery Doppler in predicting pre-eclampsia at term and provide insights into the placental origins of the early and late forms of pre-eclampsia.

Glucocorticoid synthesis-related genes: HSD11B1 and HSD11B2 in hypertensive disorders in pregnancy

OBJECTIVE

To determine whether polymorphisms of the maternal glucocorticoid-related genes (HSD11B1 and HSD11B2) are associated with pregnancy-induced hypertension (PIH) in a haplotype-based case-control study.

METHODS

A total of 166 PIH patients and 222 age-matched controls were genotyped, with two single-nucleotide polymorphisms (SNPs) for the HSD11B1 gene (rs2235543 and rs846910) and three SNPs for the HSD11B2 gene (rs12920590, rs45483293 and rs3743729) used as genetic markers. After separation into preeclampsia (PE) and gestational hypertension (GH) subgroups, PIH patients were assessed.

RESULTS

Significant differences were noted between PE and control groups (p = 0.022, p = 0.034, respectively) for the frequency of genotypes and alleles for rs846910 of HSD11B1. The frequency of the AA genotype of rs846910 was significantly higher in PIH and PE groups compared to controls. Logistic regression analyses showed that this genotype was a risk factor for PIH and PE (adjusted OR 2.9, 95% CI 1.3-6.5 and adjusted OR 3.2, 95% CI 1.4-7.4, respectively). The frequency of the T-A haplotype established by rs2235543-rs846910 was also significantly higher in PIH and PE groups (p = 0.045, p = 0.042, respectively).

CONCLUSION

rs846910 in the HSD11B1 gene could be a marker for hypertensive disorders during pregnancy. The T-A haplotype constructed by rs2235543-rs846910 was also a useful susceptibility marker for PIH and PE.

Differential expression of placental 11β-hydroxysteroid dehydrogenases in pregnant women with diet-treated gestational diabetes mellitus

Fetal exposure to excess glucocorticoid is one of the critical factors for the fetal origins of adult diseases. However, the mechanism of the local regulation of glucocorticoid activity in the human placenta of pregnancies complicated with gestational diabetes mellitus (GDM) has not been fully understood. We investigated placental 11β-hydroxysteroid dehydrogenases (11β-HSDs) expression, and analyzed their relationship with cortisol levels in maternal and umbilical vein. Pregnant women with GDM after diet intervention (n=23) or normal glucose tolerance (NGT, n=22) were studied at the community-based hospital. We collected maternal and umbilical venous cord blood and placental tissues from both groups. Explanted placentas from NGT were cultured with palmitic acid, dexamethasone, insulin or their mixture for 24-h. We examined plasma cortisol, cortisone to cortisol ratio, insulin, the homeostasis model assessment of insulin resistance index (HOMA-IR) and the insulin secretion index. Quantitative real-time PCR, Western blot and immunohistochemical assay were applied for the measurement of 11β-HSD1 and 11β-HSD2 mRNA and protein. GDM had higher maternal cortisol levels, HOMA-IR, insulin secretion index and higher cortisone to cortisol ratio in umbilical vein. No significant change in cortisol levels in umbilical vein and newborn weight was found. GDM placental 11β-HSD1 levels decreased while 11β-HSD2 increased. Treatment of placenta explants from NGT with palmitic acid, dexamethasone, insulin or their combination resulted in a significant drop of 11β-HSD1 and increase in 11β-HSD2. Differential expression of 11β-HSDs in diet-treated GDM placenta provides a protective mechanism for the fetus throughout the adverse environment of pregnancy by limiting excessive exposure of the fetus to glucocorticoid.