Maternal Exposure to Endocrine Disruptors

Introduction:

Natural and synthetic substances can imitate or interfere with the endocrine system, a complex communication network between the neurological system and essential biological activities like reproduction, the immune system, metabolism, and conduct. Endocrine-disrupting chemicals (EDCs) are found in pesticides, metals, and various daily products such as plastic bottles and food containers, cleaning products, flame-retardant chemicals, children's toys, and beauty products. Because of their widespread use in everyday life, EDCs have become the focus of extensive research by the medical-scientific community, primarily to determine their significance as potential risks and possibly pathogenic triggers. Pregnancy is the most vulnerable clinical setting because EDC behavior can harm two lives simultaneously - the mother's and the growing embryo's.

What Are Endocrine Disrupting Chemicals?

The World Health Organization (WHO) defines an endocrine disruptor as "an exogenous substance or mixture that modifies the activity or activities of the endocrine system and induces negative health consequences in an intact organism, its offspring, or (sub)populations."

EDCs primarily affect endocrine functions by simulating natural hormones such as estrogens, androgens, and thyroid hormones.

Furthermore, they may change hormone metabolism, inhibiting and antagonizing hormone interactions with specific membrane and intracellular receptors. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, phthalates, phenols, flame retardants, and metals are examples of EDCs.

BPA (bisphenol A) and phthalates are of particular importance since they have been widely studied as "obesogenic" (induces weight gain) substances that may disrupt pregnancy biology and fetal growth, making them a primary cause of reproductive abnormalities.

What Is BPA?

BPA is an industrial compound derived from phenol and acetone condensation that has been utilized to make polymers and resins since the 1960s. It is regarded as the first synthetic estrogen created, despite lacking a steroid structure due to the absence of the phenanthrene nucleus. BPA is in polycarbonate plastics extensively used in food, beverage, and other storage containers. It is found in epoxy resins covering metal objects like food cans, bottle tops, and water supply pipes.

What Is the Relation Between Phthalates and Maternal Thyroid Hormone?

Maternal thyroid dysfunction has been linked to aberrant fetal development, including growth retardation, poor central nervous system development, and premature birth.

Huang et al. were the first to show that phthalate exposure during pregnancy might decrease maternal thyroid activity. It is generally understood that fetal thyroid function is immature before 12 weeks of gestation and is entirely dependent on the mother. According to various studies, prenatal phthalate exposure lowering maternal T4 levels throughout pregnancy may be a risk to pregnancy maintenance.

How Does EDC Exposure Affect Reproductive Health?

Because BPA and phthalates may impair fertility in both sexes, male and female reproductive health and EDCs are essential for human reproduction and pregnancy success.

The ovaries are responsible for female gametogenesis and endocrine processes during reproductive life. Prenatal BPA exposure has been shown to prevent the breakdown of germ cell nests in the ovaries of F1 generation mice, decrease the number of primordial, primary, preantral, and total healthy follicles at post-natal day 21, and lower estradiol levels in female rats given a year's worth of BPA doses.

EDCs like BPA and phthalates could harm human reproduction, affecting both female and male fertility before pregnancy and producing fetal gamete defects that could be passed down to succeeding generations.

Will EDC Exposure Cause Preterm Birth?

Infant mortality is primarily attributed to preterm birth, regarded as delivery before the 37th week of gestation. Exposure to EDCs can pose a danger, even if the cause of preterm birth is uncertain.

Concern over maternal exposure to EDCs and the subsequent constrained fetal growth has grown. Pregnant fetuses are susceptible to environmental influences, and EDCs can cross the placenta and possibly harm fetal and embryonic development.

During gestation, fetuses are subjected to the cumulative maternal body burden of EDCs, including polyfluoroalkyl and organochlorine chemicals.

What Is the Relationship Between EDC Exposure and the Development of Obesity, Diabetes, and Cardiometabolic Abnormalities?

A woman's reproductive years are a crucial time in her life since any pathological disorders that arise could impact how future pregnancies turn out. Obesity, diabetes, and cardiometabolic abnormalities have all been linked to an increased risk of adverse maternal and fetal outcomes during pregnancy. These outcomes include preterm birth, gestational hypertension, diabetes, cesarean section, congenital malformations, shoulder dystocia, and perinatal death. Therefore, the optimum circumstance to protect the health of both mother and child during pregnancy is one without such comorbidities.

• Gestational Diabetes Mellitus: Recent epidemiological studies have reached conflicting conclusions about the relationship between non-persistent EDCs and GDM. Three studies found positive associations with monoethyl phthalate (MEP), monobutyl phthalate (MBP), and monocarboxyoctyl phthalate (MCOP) about GDM, impaired glucose tolerance, and higher blood glucose concentrations and negative associations with monocarboxyoctyl phthalate (MCOP), monoisobutyl phthalate (MiBP), and the sum of di-2-ethylhexyl phthalate. MEP was the only metabolite that consistently and favorably correlated with GDM, decreased glucose tolerance, and blood glucose levels in all these trials. However, according to a different study, there is no connection between phthalate metabolites and either GDM or decreased glucose tolerance.

• Preeclampsia: No epidemiological literature evidence links non-persistent EDCs to preeclampsia or pregnancy hypertension diseases. Bisphenol A (BPA) with preeclampsia. Preeclampsia is a medical condition that can emerge around the 20th week of pregnancy. High blood pressure, protein in the urine, swelling, headaches, and impaired vision are all symptoms of preeclampsia.

• Obesity: Pregnancy weight increase that is insufficient or excessive can have long-term effects on mothers and their offspring. With varying degrees of success, several research studies have looked into the relationships between phthalate metabolites and gestational weight increase. Multiple studies have demonstrated a relationship between the phthalate metabolite MEP and gestational weight increase, albeit the direction of the correlation varies.

No conclusions can be drawn about the association between being exposed to EDC when in the reproductive age range and the risk of acquiring pathological problems that could impact the success of a pregnancy. However, it is critical to undertake epidemiological research with this problem in mind, considering the impact that metabolic issues and obesity can have on both mother and child health.

What Are the Recommendations for Lower Dietary Exposure to EDCs?

Dietary exposure guidelines to lower the intake of EDCs are as follows:

• Opt for seasonal, fresh foods, including seafood, fruits, and vegetables.

• Limit canned or frozen seafood consumption to once per week.

• Purchase the legumes and tomato sauce in glass jars.

• Buy alcoholic beverages in glass or plastic bottles. If at all feasible, choose tap water; to learn more about it, visit the local municipality's website.

• Stay clear of quick soups and "heat-and-go" cups.

• Prefer freshly prepared pizza or sandwiches at the counter rather than those in boxes or wrappers.

• Choose stovetop options instead of boiling popcorn in microwave-safe packets.

• Use a ceramic drip or French press instead of a plastic coffee machine.

• Avoid using plastic tea bags and only buy tea from producers who can attest that their tea bags are free of EDCs.

• Avoid eating partially charred or burned meals by removing burned parts (such as from meat or pizza).

• Limit the consumption of smoked foods to once a month.

Conclusion:

It is essential to recognize the potential health risks of endocrine-disrupting substances, particularly when considering human pregnancy. Dietary intake can easily expose pregnant women to a significant number of EDCs. EDCs produce aberrant genetic/epigenetic regulation with sex-specific changes and pass through the placental barrier due to their biochemical characteristics. As a result, they reach the developing baby and cause pregnancy- and placenta-related diseases. Chemicals that are readily apparent, like DHEAs (dehydroepiandrosterone), can affect the hormonal state. These items impact pregnancy outcomes if they are utilized as cosmetics or for other purposes. Additional study is required to validate these findings on a larger scale and determine their influence on a wider range of pregnancy and delivery outcomes.