Role of Inflammaging on the Reproductive Function and Pregnancy

Precision Interventions Targeting the Maternal Metabolic Milieu for Healthy Pregnancies in Obesity

PURPOSE OF REVIEW

Entering pregnancy with obesity increases the risk of adverse health outcomes for parent and child. As such, research interventions are largely focused on limiting excess gestational weight gain during pregnancy, especially in those with obesity. Yet, while many lifestyle interventions are successful in reducing GWG, few affect pregnancy outcomes. Here we review work targeting the metabolic milieu instead of focusing solely on weight.

RECENT FINDINGS

Work done in non-pregnant populations suggests that specifically targeting glucose, triglyceride, and leptin levels or inflammatory makers improves the metabolic milieu and overall health. We posit that precision interventions that include strategies such as time restricted eating, following the 24 h movement guidelines, or reducing sedentary behavior during pregnancy can be successful approaches benefiting the maternal metabolic milieu and minimize the risk of adverse pregnancy outcomes. Personalized tools such as continuous glucose monitors or community-based approaches play an important role in pre-conception health and should be extrapolated to pregnancy interventions to directly benefit the metabolic milieu optimizing health outcomes for both parent and child.

Metformin administration during pregnancy tends to reduce the risk of gestational diabetes mellitus and improve pregnancy outcomes in previously infertile women with polycystic ovary syndrome who become pregnant

OBJECTIVE

Metformin reduces incidences of miscarriage and preterm delivery in polycystic ovary syndrome (PCOS) women, but its impact on gestational diabetes mellitus (GDM) is conflicting. Hence, this study set up selection criteria to include previously infertile women with PCOS but without pre-existing DM who became pregnant, aiming to minimize confounders and investigate the influence of metformin on GDM, miscarriage, and preterm delivery.

METHODS

This study included 195 previously infertile women with PCOS who became pregnant. They were divided into metformin (receiving metformin during pregnancy) and control (not receiving metformin) groups without intervention.

RESULTS

Metformin group tended to have a lower incidence of GDM versus control group (13.3% versus 23.3%, P = 0.070). A logistic regression model adjusted for all baseline characteristics (demographics, infertile duration, and diabetes mellitus-related features) showed that metformin was associated with a decreased probability of GDM (odds ratio (OR): 0.426, P = 0.037). Metformin group showed a similar incidence of miscarriage (6.7% versus 11.1%, P = 0.273), but decreased incidences of preterm delivery (not statistically significant) (6.7% versus 13.3%, P = 0.091) and miscarriage or preterm delivery (13.3% versus 24.4%, P = 0.046) versus control group. A logistic regression model adjusted for all the aforementioned features revealed that metformin was related to a lower risk of miscarriage or preterm delivery (OR: 0.417, P = 0.040). Fetal outcomes, including birth weight (P = 0.245) and the incidence of 5 min-Apgar score ≤ 7 (P = 0.702), were similar between groups.

CONCLUSION

Metformin administration during pregnancy may reduce GDM, miscarriage, and preterm delivery risks without adverse effects on fetal outcomes in previously infertile women with PCOS.

Placental Bioenergetics and Antioxidant Homeostasis in Maternal Obesity and Gestational Diabetes

Maternal obesity has been associated with short- and long-term risks of pregnancy-perinatal adverse events, possibly due to alterations of placental mitochondrial bioenergetics. However, several detrimental mechanisms occurring in the placentas of women with obesity still need to be clarified. Here, we analyzed placental mitochondrial features and oxidative environment of 46 pregnancies in relation to pre-pregnancy BMI. Seventeen Caucasian normal-weight (NW) and twenty-nine women who were obese (OB) were enrolled. The protein expression of mitochondrial CypD and electron transfer chain complexes (C) I-V were measured, as well as ATP production and oxygen consumption rates (OCRs). The protein levels of the pro/anti-oxidant enzymes TXNIP, SOD2, and PON2 were also analyzed. Despite no differences in CypD expression, OCRs were significantly lower in OB vs. NW women. Accordingly, ATP synthase (CV) levels and ATP content were decreased in OB women, positively correlating with placental efficiency, suggesting a link between ATP deficiency and placental dysfunction. SOD2 expression negatively correlated with maternal BMI, indicating a possible impairment of antioxidant defenses with increasing BMI. These changes were worsened in 10 OB women presenting with gestational diabetes mellitus. Overall, these results suggest alterations of placental bioenergetics in pregnancies of women with obesity, possibly leading to placental dysfunction and altered fetal development and programming.

Impact of Maternal Environment and Inflammation on Fetal Neurodevelopment

During intrauterine life, external stimuli including maternal nutrition, lifestyle, socioeconomic conditions, anxiety, stress, and air pollution can significantly impact fetal development. The human brain structures begin to form in the early weeks of gestation and continue to grow and mature throughout pregnancy. This review aims to assess, based on the latest research, the impact of environmental factors on fetal and neonatal brain development, showing that oxidative stress and inflammation are implied as a common factor for most of the stressors. Environmental insults can induce a maternal inflammatory state and modify nutrient supply to the fetus, possibly through epigenetic mechanisms, leading to significant consequences for brain morphogenesis and neurological outcomes. These risk factors are often synergic and mutually reinforcing. Fetal growth restriction and preterm birth represent paradigms of intrauterine reduced nutrient supply and inflammation, respectively. These mechanisms can lead to an increase in free radicals and, consequently, oxidative stress, with well-known adverse effects on the offspring's neurodevelopment. Therefore, a healthy intrauterine environment is a critical factor in supporting normal fetal brain development. Hence, healthcare professionals and clinicians should implement effective interventions to prevent and reduce modifiable risk factors associated with an increased inflammatory state and decreased nutrient supply during pregnancy.

A real-life prospective blinded evaluation of placental biometry and macroscopic morphology from 1008 unselected consecutive pregnancies

INTRODUCTION

The study of the macroscopic appearance of the placenta may represent a useful tool to understand the pathophysiology of adverse pregnancy outcomes. The aim of this study was to evaluate biometry and morphology of placentas in relation to maternal, neonatal and pregnancy course characteristics.

METHODS

Clinical and placental data (biometry and macroscopic features of chorionic disk and adnexa) from unselected consecutive singleton pregnancies were recorded at the same Institution. Placental efficiency was approximated as ratio between fetal and placental weight (FPR). The total population was grouped according to the presence of any maternal comorbidity or pregnancy complication (group 1), neonatal complications diagnosed only at birth (2) and absence of any comorbidity (3). Multi-adjusted general linear and logistic regression models were performed to analyze associations between groups and placental biometry and morphology.

RESULTS

The study population counted 1008 pregnancies: 576 (57.2 %) classified as group 1, 76 (7.5 %) as group 2 and 356 (35.3 %) uncomplicated controls (group 3). In multivariate models adjusted for confounding factors, no significant differences in placental biometry and macroscopic features were observed among the three groups. Maternal BMI was significantly associated with higher placental and birth weight and lower FPR; moreover FPR was significantly higher in pregnancies carrying males compared to female neonates.

DISCUSSION

Maternal comorbidity or pregnancy disease was not associated with significant changes in placental macroscopic biometry and morphology. Conversely, maternal pregestational BMI and fetal sex impact on placental biometry and efficiency, suggesting different intrauterine adaptations in obese mothers and in male and female fetuses.

What Do Higher Alanine Aminotransferase Levels Mean in Premature Ovarian Insufficiency?

The objective of this study was to investigate the relationship between alanine aminotransferase and related biochemical parameters and potential risk factors in women with premature ovarian insufficiency (POI). This is a retrospective cohort study with 126 POI patients (including subclinical POI, n= 27) and 130 healthy controls who visited our clinic between April 2021 to November 2022. Associations were investigated by multiple linear regression, Person correlation analysis, the Kruskal-Wallis test, Mann-Whitney U test, and the independent t-test. When compared to controls, analysis of POI patients showed that body mass index (BMI), uric acid (UA) and urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST), monocyte/lymphocyte ratio, monocyte count (MONO), neutrophil count (NEUT), follicle-stimulating hormone (FSH), luteinizing hormone, and neutrophil/lymphocyte ratio (NLR) were significantly higher, while estradiol (E2), the lymphocyte count and the AST/ALT ratio were lower (P < 0.05). According to linear correlation, it was clear that BMI, FSH, white blood cell count (WBC), NEUT, MONO, UA, AST, and NLR were positively associated with ALT (r = 0.215, 0.388, 0.195, 0.187, 0.184, 0.605, 0.819, and 0.189, respectively, all P < 0.05) while E2 was negatively associated with ALT (r = -0.278, P < 0.05). In addition, multiple linear regression revealed a significant, independent, and positive correlation between AST, FSH, and ALT (B =1.403 and 0.069, respectively, P < 0.05). Analysis revealed that the levels of ALT were significantly higher in POI patients. In addition, BMI, FSH, UA, AST, MONO, NLR, NEUT, and WBC were positively associated with ALT in POI patients. E2 was negatively associated with ALT. Multiple linear regression revealed an independent and positive correlation between AST, FSH, and ALT. In addition, there was also a risk of liver function damage in women with POI and subclinical POI. If patients were diagnosed with POI, early examination and corresponding intervention will be required to effectively prevent the further development of liver disease.

Associations between Maternal Nutritional Status, Hemodynamic Parameters, and Delivery Outcomes in Low-Risk Pregnancies: A Prospective Observational Study

Maternal nutritional status represents a pivotal predictor of pregnancy outcome. This prospective observational study investigates the associations between maternal characteristics and nutritional habits at term, hemodynamic parameters, and pregnancy outcomes. Healthy women with singleton uncomplicated pregnancies were enrolled at 36-41 gestational weeks. At enrollment, a nutritional score (0-10) was calculated in order to quantify maternal adherence to a healthy diet and lifestyle. Maternal hemodynamic parameters were assessed by using the Ultrasonic Cardiac Output Monitor (USCOM), including cardiac output (CO), systemic vascular resistance (SVR) and Smith-Madigan inotropy index (SMII). Pregnancy outcomes were recorded at delivery. Associations between maternal characteristics and nutritional score, hemodynamic parameters, and pregnancy outcomes were investigated by using multi-adjusted generalized linear models. In total, 143 pregnancies were enrolled. Pregestational body mass index (BMI) was positively associated with SVR, and negatively associated with CO and SMII. Additionally, a positive association was detected between the nutritional score and SMII. Finally, CO was positively associated with birth and placental weight, while RVS showed a negative association with birth and placental weight. This study shows that maternal derangements in nutritional status and habits are associated with a compromised hemodynamic profile at term, with additional impacts on intrauterine growth.

New insight into the role of macrophages in ovarian function and ovarian aging

Macrophages (MΦs) are the most abundant leukocytes in mammalian ovaries that have heterogeneity and plasticity. A body of evidence has indicated that these cells are important in maintaining ovarian homeostasis and they play critical roles in ovarian physiological events, such as folliculogenesis, ovulation, corpus luteum formation and regression. As females age, ovarian tissue microenvironment is typified by chronic inflammation with exacerbated ovarian fibrosis. In response to specific danger signals within aged ovaries, macrophages polarize into different M1 or M2 phenotypes, and specialize in unique functions to participate in the ovarian aging process. In this review, we will focus on the physiologic roles of MΦs in normal ovarian functions. Furthermore, we will discuss the roles of MΦs in the process of ovarian senescence, as well as the novel techniques applied in this field.

Impaired immune response against SARS-CoV-2 infection is the major factor indirectly altering reproductive function in COVID-19 patients: a narrative review

Coronavirus disease 2019 (COVID-19) is an infectious disease affecting multiple systems and organs, including the reproductive system. SARS-CoV-2, the virus that causes COVID-19, can damage reproductive organs through direct (angiotensin converting enzyme-2, ACE-2) and indirect mechanisms. The immune system plays an essential role in the homeostasis and function of the male and female reproductive systems. Therefore, an altered immune response related to infectious and inflammatory diseases can affect reproductive function and fertility in both males and females. This narrative review discussed the dysregulation of innate and adaptive systems induced by SARS-CoV-2 infection. We reviewed the evidence showing that this altered immune response in COVID-19 patients is the major indirect mechanism leading to adverse reproduction outcomes in these patients. We summarized studies reporting the long-term effect of SARS-CoV-2 infection on women's reproductive function and proposed the chronic inflammation and chronic autoimmunity characterizing long COVID as potential underlying mechanisms. Further studies are needed to clarify the role of autoimmunity and chronic inflammation (long COVID) in altered female reproduction function in COVID-19.

A Pilot Study on Biochemical Profile of Follicular Fluid in Breast Cancer Patients

Breast cancer (BC) is the most common type of cancer among women in almost all countries worldwide and is one of the oncological pathologies for which is indicated fertility preservation, a type of procedure used to help keep a person's ability to have children. Follicular fluid (FF) is a major component of oocyte microenvironment, which is involved in oocyte growth, follicular maturation, and in communication between germ and somatic cells; furthermore, it accumulates all metabolites during oocytes growth. To obtain information about changes on fertility due to cancer, we aimed at investigating potential biomarkers to discriminate between FF samples obtained from 16 BC patients and 10 healthy women undergoing in vitro fertilization treatments. An NMR-based metabolomics approach was performed to investigate the FF metabolic profiles; ELISA and western blotting assays were used to investigate protein markers of oxidative and inflammatory stress, which are processes closely related to cancer. Our results seem to suggest that FFs of BC women display some significant metabolic alterations in comparison to healthy controls, and these variations are also related with tumor staging.

Age-related changes in CD4+ T and NK cell compartments may contribute to the occurrence of pregnancy loss in advanced maternal age

A recent study characterized novel immune cell subsets (T, NK, and γδ T cell subsets) related to recurrent pregnancy loss (RPL). This study aims to assess whether these RPL-related immune cell subsets are affected by aging. The percentages of peripheral blood immunes cells from nulligravida women (NGW), women with a history of normal pregnancy (NP), and women with a history of pregnancy loss (PL) were detected by flow cytometry. The correlations between maternal age and cell percentages were assessed. We found a significant positive correlation between PL and maternal age. The percentages of effector memory CD4⁺ T (CD3⁺ CD4⁺ CD45RA¯ CCR7¯), terminally differentiated CD4⁺ T (CD3⁺ CD4⁺ CD45RA⁺ CCR7¯), and mature NK cells (CD3¯ CD56^+lo) significantly increased with maternal age. A significant decrease in the percentage of Naïve CD4⁺ T cells (CD3⁺ CD4⁺ CD45RA⁺ CCR7⁺) with age was observed in women from the NP group. Women aged 35 or older had significantly higher percentages of effector memory CD4⁺ T cells, terminally differentiated CD4⁺ T cells, and mature NK cells than younger women. Maternal age positively correlates with terminally differentiated CD4⁺ T, effector memory CD4⁺ T, and mature NK cell percentages. In contrast, an inverse correlation was observed between Naïve CD4⁺ T cell and age among women from the NP group. Our findings indicate that age-related CD4⁺ T and NK cell dysregulation might be involved in the pathogenesis of PL in women with advanced maternal age. The underlying mechanism needs further investigation.

Serum C-reactive protein levels are associated with clinical pregnancy rate after in vitro fertilization among normal-weight women

OBJECTIVE

To assess whether low-grade inflammation, measured by serum high-sensitivity C-reactive protein (hsCRP) levels, is associated with in vitro fertilization (IVF) outcomes.

DESIGN

A retrospective study.

SETTING

University-affiliated IVF center.

PATIENTS

In the present study, 875 women of normal weight who underwent their first fresh embryo transfer (ET) cycles for IVF treatment were divided into three groups according to serum concentrations of hsCRP.

INTERVENTIONS

Serum from women undergoing IVF was collected on days 2-4 of a spontaneous menstrual cycle prior to the commencement of ovarian stimulation.

MAIN OUTCOME MEASURES

The IVF outcomes included implantation, biochemical pregnancy, clinical pregnancy, miscarriage and live birth rates.

RESULTS

The women were divided into three groups according to the baseline serum levels of hsCRP as follows: low hsCRP (<1 mg/L; n=517), medium hsCRP (1-3 mg/L; n= 270), high hsCRP (>3 mg/L; n=88). The maternal age was similar among the three groups. The women in the high and medium hsCRP group had significantly higher BMI compared with those in the low hsCRP group. The protocol of controlled ovarian hyperstimulation, the gonadotropin dose administered, the serum estradiol levels, progesterone levels and the endometrial thickness on the day of triggering, as well as the number of retrieved oocytes, fertilized oocytes and good quality embryos, and the oocyte maturation rate were similar among the three groups. Implantation, biochemical pregnancy and clinical miscarriage rates did not differ significantly were not significantly different among three groups. The clinical pregnancy rate was significantly lower in the high hsCRP group compared with that in the low hsCRP group (50.0% versus 63.4%; P<0.0167), which contributed to a significant decrease in birth rate (39.8% versus 53.8%; P<0.0167). High serum hsCRP levels was found to be a factor affecting live birth rate.

CONCLUSIONS

Among women of normal weight undergoing their first IVF treatment, it was found that low-grade inflammation was associated with reduced clinical pregnancy and live birth rates following fresh ET cycles.

Associations between Maternal Dietary Patterns, Biomarkers and Delivery Outcomes in Healthy Singleton Pregnancies: Multicenter Italian GIFt Study

Background: Maternal nutrition represents a critical risk factor for adverse health outcomes in both mother and offspring. We aimed to investigate associations between maternal nutritional habits, biomarker status, and pregnancy outcome among Italian healthy normal-weight pregnancies. Methods: Multicenter prospective cohort study recruiting Italian healthy normal-weight women with singleton spontaneous pregnancies at 20 ± 2 weeks (T1) in Milan and Naples. All patients underwent nutritional evaluations by our collecting a 7-day weighed dietary record at 25 ± 1 weeks (T2) and a Food Frequency Questionnaire at 29 ± 2 weeks (T3). Maternal venous blood samples were collected at T3 to assess nutritional, inflammatory and oxidative biomarker concentrations (RBCs folate, vitamin D, hepcidin, total antioxidant capacity). Pregnancy outcomes were collected at delivery (T4). General linear models adjusted for confounding factors were estimated to investigate associations between maternal dietary pattern adherence, nutrient intakes, biomarker concentrations and delivery outcomes. Results: 219 healthy normal-weight pregnant women were enrolled. Vitamin D and RBCs folate concentrations, as well as micronutrient intakes, were consistently below the recommended range. In a multi-adjusted model, maternal adherence to the most prevalent ‘high meat, animal fats, grains’ dietary pattern was positively associated with hepcidin concentrations and negatively associated with gestational age at delivery in pregnancies carrying female fetuses. Hepcidin plasma levels were further negatively associated to placental weight, whereas vitamin D concentrations were positively associated to neonatal weight. Conclusions: A high adherence to an unbalanced ‘high meat, animal fats, grains’ pattern was detected among Italian normal-weight low-risk pregnancies, further associated with maternal pro-inflammatory status and gestational age at delivery. This evidence underlines the need for a dedicated nutritional counseling even among low-risk pregnancies.

Epigenetic Profiling in the Saliva of Obese Pregnant Women

Maternal obesity is associated with inflammation and oxidative stress, strongly impacting the intrauterine environment with detrimental consequences for both mother and offspring. The saliva is a non-invasive biofluid reflecting both local and systemic health status. This observational study aimed to profile the epigenetic signature in the saliva of Obese (OB) and Normal-Weight (NW) pregnant women. Sixteen NW and sixteen OB Caucasian women with singleton spontaneous pregnancies were enrolled. microRNAs were quantified by the OpenArray Platform. The promoter region methylation of Suppressor of Cytokine Signaling 3 (SOCS3) and Transforming Growth Factor Beta 1 (TGF-Beta1) was assessed by pyrosequencing. There were 754 microRNAs evaluated: 20 microRNAs resulted in being differentially expressed between OB and NW. microRNA pathway enrichment analysis showed a significant association with the TGF-Beta signaling pathway (miTALOS) and with fatty acids biosynthesis/metabolism, lysine degradation, and ECM-receptor interaction pathways (DIANA-miRPath). Both SOCS3 and TGF-Beta1 were significantly down-methylated in OB vs. NW. These results help to clarify impaired mechanisms involved in obesity and pave the way for the understanding of specific damaged pathways. The characterization of the epigenetic profile in saliva of pregnant women can represent a promising tool for the identification of obesity-related altered mechanisms and of possible biomarkers for early diagnosis and treatment of pregnancy-adverse conditions.