Molecular mechanisms involved in fetal programming and disease origin in adulthood

The Course of Minipuberty in Daughters of Women with Low Gestational Vitamin D Status

Minipuberty is a term describing temporary, sex-specific activation of the hypothalamic-pituitary-gonadal axis, which is implicated in the development of male and female genital organs. Sons of women with low vitamin D during gestation were found to be characterized by increased activity of the reproductive axis and faster postnatal growth of genital organs. The current study assesses for the first time the course of minipuberty in female descendants of women with a vitamin D deficit. The study population included three matched groups of infant girls: children born to women with vitamin D deficiency (25OHD concentration below 50 nmol/L), offspring of women with vitamin D insufficiency (25OHD concentration between 50 and 75 nmol/L), and daughters of healthy females (25OHD concentration between 75 and 150 nmol/L). Salivary concentrations of estradiol, progesterone, 17-hydroxyprogesterone and androgens, as well as urine concentrations of FSH and LH, were assayed during the first 18 months of life (once a month in the first 6 months, bimonthly between months 6 and 12, and then every three months). At each visit, beyond hormone measurements, the investigators assessed the size of reproductive organs: ovaries, uterus and breasts. In daughters of mothers with vitamin D deficiency, concentrations of FSH, LH and estradiol were higher and detectable for a longer period of time, while ovarian volume, uterine length and breast diameter were greater than in the remaining groups. Children born to women with vitamin D insufficiency were characterized by higher FSH levels than daughters of healthy females, though the detection period was the same, and both groups differed in breast diameter. These findings suggest that low vitamin D status during gestation leads to more pronounced and longer-lasting activation of the reproductive axis, and is associated with increased dimensions of sexual organs, the magnitude of which depends on the degree of vitamin D deficit.

Substance P Concentration in Gestational Diabetes and Excessive Gestational Weight Gain and Its Impact on Neonatal Anthropometry

Fetal programming is a process initiated by intrauterine conditions, leaving a lasting impact on the offspring's health, whether they manifest immediately or later in life. It is believed that children born to mothers with gestational diabetes mellitus (GDM) and excessive gestational weight gain (EGWG) may be at an increased risk of developing type 2 diabetes mellitus (T2DM) and obesity later in their adult lives. Substance P is a neurotransmitter associated with obesity development and impairment of insulin signaling. Dysregulation of substance P could lead to several pregnancy pathologies, such as preeclampsia and preterm birth. Our study aimed to compare substance P concentrations in serum and umbilical cord blood in patients with GDM, EGWG, and healthy women with a family history of gestational weight gain. Substance P levels in umbilical cord blood were significantly higher in the GDM group compared to the EGWG and control groups. Substance P levels in serum and umbilical cord blood were positively correlated in all groups and the GDM group. A very interesting direction for future research is the relationship between the concentration of substance P in newborns of diabetic mothers and the occurrence of respiratory distress syndrome as a complication of impaired surfactant synthesis. To our knowledge, it is the first study assessing substance P concentration in GDM and EGWG patients.

Current research and evidence gaps on placental development in iron deficiency anemia

Studying the effects of maternal iron deficiency anemia (IDA) is complex owing to its diverse causes, each independently impacting the placenta and fetus. Simple treatment with iron supplements does not always resolve the anemia. Therefore, delving into how IDA alters placental development at a molecular level is crucial to further optimize treatment. This review addresses the effects of IDA on placental structures and functions, including changes in oxygen levels, blood vessels, and the immune system. Profound understanding of physiological characteristics and regulatory mechanisms of placental development is key to explain the mechanisms of abnormal placental development in pregnancy-associated disorders. In turn, future strategies for the prevention and treatment of pregnancy complications involving the placenta can be devised. These studies are significant for improving human reproductive health, enhancing sociodemographic qualities, and even lifelong wellbeing, a focal point in future placental research.

Fetal hemodynamic changes and mitochondrial dysfunction in myocardium and brain tissues in response to anemia: a lesson from hemoglobin Bart's disease

OBJECTIVE

Whether or not the effects of anemia in the early phase, while the fetuses attempts to increase cardiac output to meet oxygen requirement in peripheral organs, is detrimental to the fetal developing vital organs is little-known. The objective of this is to compare prenatal cardiovascular changes and post-abortal cellular damages in the myocardium as a pumping organ and the brain as a perfused organ between anemic fetuses (using fetal Hb Bart's disease as a study model) in pre-hydropic phase and non-anemic fetuses.

METHODS

Fetuses affected by Hb Bart's disease and non-anemic fetuses at 16-22 weeks were recruited to undergo comprehensive fetal echocardiography. Cord blood analysis was used to confirm the definite diagnosis of fetal Hb Bart's disease and normal fetuses. Fetal cardiac and brain tissues were collected shortly after pregnancy termination for the determination of oxidative stress and mitochondrial function, including mitochondrial ROS production and mitochondrial membrane changes.

RESULTS

A total of 18 fetuses affected by Hb Bart's disease and 13 non-anemic fetuses were recruited. The clinical characteristics of both groups were comparable. The affected fetuses showed a significant increase in cardiac dimensions, cardiac function, cardiac output and brain circulation without deteriorating cardiac contractility and preload. However, in the affected fetuses, mitochondrial dysfunction was clearly demonstrated in brain tissues and in the myocardium, as indicated by a significant increase in the membrane potential change (p-value < 0.001), and a significant increase in ROS production in brain tissues, with a trend to increase in myocardium. The findings indicated cellular damage in spite of good clinical compensation.

CONCLUSION

The new insight is that, in response to fetal anemia, fetal heart increases in size (dilatation) and function to increase cardiac output and blood flow velocity to provide adequate tissue perfusion, especially brain circulation. However, the myocardium and brain showed a significant increase in mitochondrial dysfunction, suggesting cellular damage secondary to anemic hypoxia. The compensatory increase in circulation could not completely prevent subtle brain and heart damage.