Progesterone and fetal-neonatal neuroprotection

Allopregnanolone in the peripartum: Correlates, concentrations, and challenges - A systematic review

BACKGROUND

Allopregnanolone (ALLO) is a metabolite of progesterone and a neuroactive steroid hormone. As a positive allosteric modulator of gamma-aminobutyric acid (GABA) receptors, ALLO seems to have antidepressant and anxiolytic effects, and was therefore approved as a specific medication for the treatment of postpartum depression in 2019. Despite the growing number of publications investigating ALLO levels, results on the biological and psychological correlates in the peripartum period remain inconsistent, possibly due to methodological challenges regarding measurement. To date, however, there is no systematic review examining the correlates, concentrations, and challenges in measuring ALLO in peripartum women.

METHOD

A systematic literature search of PubMed and PsycINFO was conducted in August 2023. Original research articles that measured ALLO concentrations in peripartum women were included. Reports were excluded if they were not original research, included non-human subjects, did not include peripartum women, did not include ALLO measurement as an outcome, included (pharmacological) interventions, constituted method validations, or used the same cohort as another study.

RESULTS

The literature search yielded 234 articles, and two articles were identified from other sources. After full-text screening, 19 articles (N = 1401) met the inclusion criteria, of which seven focused on biological correlates of ALLO and 12 on mood correlates. Of the latter, six found no association between ALLO and mood, four found a negative association, and two found a positive association. Overall, the results show an increase in ALLO levels during pregnancy and a decrease after birth, with levels then remaining low until six months postpartum. ALLO was most commonly measured in blood plasma and by gas chromatography-mass spectrometry (GC-MS). A significant matrix effect was found for blood serum and a significant method effect for radioimmunoassays (RIAs). A significant effect of time of measurement was found.

CONCLUSION

ALLO measurement shows method and matrix effects. ALLO levels are higher when measured in serum compared to in plasma, and when measured using RIA compared to other methods. Time of measurement, study design, and standardization of measurement also influence the reliability of measurement and the interpretation of results.

Prenatal progesterone treatment modulates fetal brain transcriptome and impacts adult offspring behavior in mice

Maternal exposure to elevated levels of steroid hormones during pregnancy is associated with the development of chronic conditions in offspring that manifest in adulthood. However, the effects of progesterone (P4) administration during early pregnancy on fetal development and subsequent offspring behavior remain poorly understood. In this study, we aimed to investigate the effects of P4 treatment during early pregnancy on the transcript abundance in the fetal brain and assess the behavioral consequences in the offspring during adolescence and adulthood. Using RNA-seq analysis, we examined the impact of P4 treatment on the fetal brain transcriptome in a dosage-dependent manner. Our results revealed differential regulation of genes involved in neurotransmitter transport, synaptic transmission, and transcriptional regulation. Specifically, we observed bidirectional regulation of transcription factors (TFs) by P4 at different doses, highlighting the critical role of these TFs in neurodevelopment. To assess behavioral outcomes, we conducted open field and elevated plus maze tests. Offspring treated with low-dose P4 (LP4) displayed increased exploratory behavior during both adolescence and adulthood. In contrast, the high-dose P4 (HP4) group exhibited impaired exploration and heightened anxiety-like behaviors compared to the control mice. Moreover, in a novel object recognition test, HP4-treated offspring demonstrated impaired object recognition memory during both developmental stages. Additionally, both LP4 and HP4 groups showed reduced social interaction in the three-chamber test. These results suggest that prenatal exposure to P4 exerts a notable influence on the expression of genes associated with neurodevelopment and may induce alterations in behavioral characteristics in progeny, highlighting the need to monitor progesterone levels during pregnancy for long-term impacts on fetal brain development and behavior.

Progesterone for Neurodevelopment in Fetuses With Congenital Heart Defects: A Randomized Clinical Trial

Importance

Neurodevelopmental outcomes for children with congenital heart defects (CHD) have improved minimally over the past 20 years.

Objectives

To assess the feasibility and tolerability of maternal progesterone therapy as well as the magnitude of the effect on neurodevelopment for fetuses with CHD.

Design, Setting, and Participants

This double-blinded individually randomized parallel-group clinical trial of vaginal natural progesterone therapy vs placebo in participants carrying fetuses with CHD was conducted between July 2014 and November 2021 at a quaternary care children's hospital. Participants included maternal-fetal dyads where the fetus had CHD identified before 28 weeks' gestational age and was likely to need surgery with cardiopulmonary bypass in the neonatal period. Exclusion criteria included a major genetic or extracardiac anomaly other than 22q11 deletion syndrome and known contraindication to progesterone. Statistical analysis was performed June 2022 to April 2024.

Intervention

Participants were 1:1 block-randomized to vaginal progesterone or placebo by diagnosis: hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and other CHD diagnoses. Treatment was administered twice daily between 28 and up to 39 weeks' gestational age.

Main Outcomes and Measures

The primary outcome was the motor score of the Bayley Scales of Infant and Toddler Development-III; secondary outcomes included language and cognitive scales. Exploratory prespecified subgroups included cardiac diagnosis, fetal sex, genetic profile, and maternal fetal environment.

Results

The 102 enrolled fetuses primarily had HLHS (n = 52 [50.9%]) and TGA (n = 38 [37.3%]), were more frequently male (n = 67 [65.7%]), and without genetic anomalies (n = 61 [59.8%]). The mean motor score differed by 2.5 units (90% CI, -1.9 to 6.9 units; P = .34) for progesterone compared with placebo, a value not statistically different from 0. Exploratory subgroup analyses suggested treatment heterogeneity for the motor score for cardiac diagnosis (P for interaction = .03) and fetal sex (P for interaction = .04), but not genetic profile (P for interaction = .16) or maternal-fetal environment (P for interaction = .70).

Conclusions and Relevance

In this randomized clinical trial of maternal progesterone therapy, the overall effect was not statistically different from 0. Subgroup analyses suggest heterogeneity of the response to progesterone among CHD diagnosis and fetal sex.

Trial Registration

ClinicalTrials.gov Identifier: NCT02133573.

Maternal use of hormonal contraception and risk of childhood autism spectrum disorders: A Parental Exposures and Child Health (PECH) cohort study

A recent hypothesis suggests that maternal hormonal contraception use has contributed to the increasing incidence of autism spectrum disorders (ASD). We used a nationwide population-based cohort (the PECH cohort) including 1,056,149 Danish children born in the period January 1, 1998, to December 31, 2014, to assess associations between maternal hormonal contraception use and childhood ASD (end of follow-up: December 31, 2017). Maternal hormonal contraception use was grouped as "recent use" (≤ 3 months before pregnancy start or during pregnancy), "previous use" (>3 months before pregnancy start) and "never use", except for few products. Incidence rate ratios (IRRs) were estimated using Poisson regression. During follow-up of nearly 12 million person-years, 19,996 children were diagnosed with ASD. A slightly higher IRR was observed for maternal recent use of any hormonal contraception, compared to previous use. This association was largely driven by the non-oral progestin-only products, and associations were especially seen for infantile autism and other/unspecified ASD. An increased IRR of infantile autism was also observed for recent use of the oral progestin-only products, compared to previous use. Our results suggest that maternal use of hormonal contraception may be associated with ASD risk in children, especially for the progestin-only products.

Sex difference of pre- and post-natal exposure to six developmental neurotoxicants on intellectual abilities: a systematic review and meta-analysis of human studies

BACKGROUND

Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with lowered IQ in children. In some studies, these neurotoxicants impact males and females differently. We aimed to examine the sex-specific effects of exposure to developmental neurotoxicants on intelligence (IQ) in a systematic review and meta-analysis.

METHOD

We screened abstracts published in PsychINFO and PubMed before December 31st, 2021, for empirical studies of six neurotoxicants (lead, mercury, PCBs, PBDEs, OPPs, and phthalates) that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or before age six; and (3) provided effect estimates on general, nonverbal, and/or verbal IQ by sex. We assessed each study for risk of bias and evaluated the certainty of the evidence using Navigation Guide. We performed separate random effect meta-analyses by sex and timing of exposure with subgroup analyses by neurotoxicant.

RESULTS

Fifty-one studies were included in the systematic review and 20 in the meta-analysis. Prenatal exposure to developmental neurotoxicants was associated with decreased general and nonverbal IQ in males, especially for lead. No significant effects were found for verbal IQ, or postnatal lead exposure and general IQ. Due to the limited number of studies, we were unable to analyze postnatal effects of any of the other neurotoxicants.

CONCLUSION

During fetal development, males may be more vulnerable than females to general and nonverbal intellectual deficits from neurotoxic exposures, especially from lead. More research is needed to examine the nuanced sex-specific effects found for postnatal exposure to toxic chemicals.

Consequences of oxygen deprivation on myelination and sex-dependent alterations

Oxygen deprivation is one of the main causes of morbidity and mortality in newborns, occurring with a higher prevalence in preterm infants, reaching 20 % to 50 % mortality in newborns in the perinatal period. When they survive, 25 % exhibit neuropsychological pathologies, such as learning difficulties, epilepsy, and cerebral palsy. White matter injury is one of the main features found in oxygen deprivation injury, which can lead to long-term functional impairments, including cognitive delay and motor deficits. The myelin sheath accounts for much of the white matter in the brain by surrounding axons and enabling the efficient conduction of action potentials. Mature oligodendrocytes, which synthesize and maintain myelination, also comprise a significant proportion of the brain's white matter. In recent years, oligodendrocytes and the myelination process have become potential therapeutic targets to minimize the effects of oxygen deprivation on the central nervous system. Moreover, evidence indicate that neuroinflammation and apoptotic pathways activated during oxygen deprivation may be influenced by sexual dimorphism. To summarize the most recent research about the impact of sexual dimorphism on the neuroinflammatory state and white matter injury after oxygen deprivation, this review presents an overview of the oligodendrocyte lineage development and myelination, the impact of oxygen deprivation and neuroinflammation on oligodendrocytes in neurodevelopmental disorders, and recent reports about sexual dimorphism regarding the neuroinflammation and white matter injury after neonatal oxygen deprivation.

Zebrafish as an emerging model to study estrogen receptors in neural development

Estrogens induce several regulatory signals in the nervous system that are mainly mediated through estrogen receptors (ERs). ERs are largely expressed in the nervous system, yet the importance of ERs to neural development has only been elucidated over the last decades. Accumulating evidence shows a fundamental role for estrogens in the development of the central and peripheral nervous systems, hence, the contribution of ERs to neural function is now a growing area of research. The conservation of the structure of the ERs and their response to estrogens make the zebrafish an interesting model to dissect the role of estrogens in the nervous system. In this review, we highlight major findings of ER signaling in embryonic zebrafish neural development and compare the similarities and differences to research in rodents. We also discuss how the recent generation of zebrafish ER mutants, coupled with the availability of several transgenic reporter lines, its amenability to pharmacological studies and in vivo live imaging, could help us explore ER function in embryonic neural development.

In Memory of Ivo Brosens: Reflections on the Pathophysiology of Neonatal Uterine Bleeding

BACKGROUND

The occurrence of vaginal bleeding in early neonatal life has been observed for centuries and was considered a consequence of the sudden drop in circulating hormones following birth. As such, neonatal uterine bleeding was dismissed as having no clinical significance. Interest in the phenomenon was renewed when a new theory suggested a link between neonatal uterine bleeding (NUB) and accelerated endometrial maturation. This theory was based on the observation of a higher incidence of NUB in babies born post-term or after pregnancies complicated by intrauterine growth restriction, preeclampsia, or blood group incompatibility.

OBJECTIVE

The objective of this study was to review of available evidence on the pathogenesis of NUB.

METHOD

Review of available literature using Medline search (August 2022, no limit on start date or language) to identify articles that may link NUB with features of the uterus and/or endometrium.

OUTCOME

The fetal endometrial responses differ from that of the adult. In the fetus, the endometrium features progestogenic response only in a minority of cases. The endometrium in most newborn girls does not exhibit secretory or decidual changes which indicate lack of progesterone response. Most newborn girls do not have visible bleeding. Animal studies linked exogenous progestogen exposure during the period of organogenesis to poor endometrial gland development, progesterone resistance, and to alterations of reproductive performance. Although the fetal endometrium may not exhibit a full proliferative response, it is clearly sensitive to circulating estrogens. Molecular mechanisms involved in NUB may include "ontogenetic progesterone resistance."

CONCLUSION AND OUTLOOK

Endometrial development and its response to withdrawal of hormones at birth varies and may be affected by intrauterine stressors and gestational age. Factors that affect endometrial development during fetal life and in preterm neonates can have implications on future reproductive performance.

Progesterone attenuates Th17-cell pathogenicity in autoimmune uveitis via Id2/Pim1 axis

BACKGROUND

Autoimmune uveitis (AU) is the most common ophthalmic autoimmune disease (AD) and is characterized by a complex etiology, high morbidity, and high rate of blindness. AU remission has been observed in pregnant female patients. However, the effects of progesterone (PRG), a critical hormone for reproduction, on the treatment of AU and the regulatory mechanisms remain unclear.

METHODS

To this end, we established experimental autoimmune uveitis (EAU) animal models and constructed a high-dimensional immune atlas of EAU-model mice undergoing PRG treatment to explore the underlying therapeutic mechanisms of PRG using single-cell RNA sequencing.

RESULTS

We found that PRG ameliorated retinal lesions and inflammatory infiltration in EAU-model mice. Further single-cell analysis indicated that PRG reversed the EAU-induced expression of inflammatory genes (AP-1 family, S100a family, and Cxcr4) and pathological processes related to inflammatory cell migration, activation, and differentiation. Notably, PRG was found to regulate the Th17/Treg imbalance by increasing the reduced regulatory functional mediators of Tregs and diminishing the overactivation of pathological Th17 cells. Moreover, the Id2/Pim1 axis, IL-23/Th17/GM-CSF signaling, and enhanced Th17 pathogenicity during EAU were reversed by PRG treatment, resulting in the alleviation of EAU inflammation and treatment of AD.

CONCLUSIONS

Our study provides a comprehensive single-cell map of the immunomodulatory effects of PRG therapy on EAU and elaborates on the possible therapeutic mechanisms, providing novel insights into its application for treating autoimmune diseases.

The Current Status of Neuroprotection in Congenital Heart Disease

Neurological deficits are a serious and common sequelae of congenital heart disease (CHD). While their underlying mechanisms have not been fully characterized, their manifestations are well-known and understood to persist through adulthood. Development of therapies to address or prevent these deficits are critical to attenuate future morbidity and improve quality of life. In this review, we aim to summarize the current status of neuroprotective therapy in CHD. Through an exploration of present research in the pre-operative, intra-operative, and post-operative phases of patient management, we will describe existing clinical and bench efforts as well as current endeavors underway within this research area.

Pharmacokinetics, safety and bioequivalence of two formulations of progesterone soft capsule in healthy Chinese postmenopausal females: Impacts of a high-fat meal

Progesterone is an important natural hormone regulating ovulation and menstruation. The present study aimed to investigate the pharmacokinetics and safety of two formulations of progesterone in Chinese postmenopausal females under fasting and fed conditions. The study adopted a single-dose, open-label, randomized, three-period bioequivalence design. A total of 96 subjects were enrolled and randomly assigned to the fasting cohort or fed cohort. A high-fat meal (890 kcal) was used in the fed study. The reference-scaled average bioequivalence method was used for bioequivalence evaluation. A high-fat meal led to a 22-fold higher peak concentration (C_max ) and a 7-fold higher area under the curve (AUC) while time to reach C_max and half-life was not significantly affected. The concentration-time curve displayed double peaks suggesting the existence of enterohepatic circulation. The test/reference geometric mean ratios for C_max and AUC under fasting and fed conditions are all within the range of 80% to 125%. All adverse events (AEs) that occurred during the trial were mild and did not cause drop-out, though these AEs occurred more frequently under fed state. In conclusion, the two formulations of progesterone are bioequivalent in Chinese subjects under fasting and fed conditions. Drug label modification regarding food effects needs further discussion.

Autism spectrum disorder and air pollution: A systematic review and meta-analysis

Despite the widely-known effects of air pollution, pollutants exposure surrounding pregnancy and the risk for autism spectrum disorder (ASD) in newborns remains controversial. The purpose of our study was to carry out a systematic review and meta-analyses of the risk of ASD in newborns following air pollution exposure during the perinatal period (preconception to second year of life). The PubMed, Cochrane Library, Embase and ScienceDirect databases were searched for articles, published up to July 2020, with the keywords "air pollution" and "autism". Three models were used for each meta-analysis: a global model based on all risks listed in included articles, a pessimistic model based on less favorable data only, and an optimistic model based on the most favorable data only. 28 studies corresponding to a total of 758 997 newborns were included (47190 ASD and 703980 controls). Maternal exposure to all pollutants was associated with an increased risk of ASD in newborns by 3.9% using the global model and by 12.3% using the optimistic model, while the pessimistic model found no change. Each increase of 5 μg/m³ in particulate matter <2.5 μm (PM2.5) was associated with an increased risk of ASD in newborns, regardless of the model used (global +7%, pessimistic +5%, optimistic +15%). This risk increased during preconception (global +17%), during pregnancy (global +5%, and optimistic +16%), and during the postnatal period (global +11% and optimistic +16%). Evidence levels were poor for other pollutants (PM10, NOx, O3, metals, solvents, styrene, PAHs, pesticides). PM2.5 was associated with a greater risk than PM10 (coefficient 0.20, 95CI -0.02 to 0.42), NOx (0.29, 0.08 to 0.50) or solvents (0.24, 0.04 to 0.44). All models revealed that exposure to pollutants, notably PM2.5 during pregnancy, was associated with an increased risk of ASD in newborns. Pregnancy and postnatal periods seem to be the most at-risk periods.