In day-to-day conversation, announcing a pregnancy for a woman or couple can be met with happiness, congratulations, apprehension at times, and the simple acceptance that a baby is happily growing, awaiting a healthy arrival into the world. Difficulty conceiving, miscarriage, infertility and fertility treatments are topics that can remain unspoken for many during the time of announcing a pregnancy. For most women and men, their reproductive stories are rarely straight forward, interspersed with loss, contraception, relationship changes, careers, possibly illness and of course, absolute joy.
The journey of potential parenthood is often not straightforward. Practitioners of Complementary Medicine and those integrating this into their life are already aware just how important preconception care is for mothers and fathers to be. Preconception care should ideally take at least 6 months for both men and women, longer if specific health issues are of concern.
We already know that preconception care is essential to establish the following facets of health, ideally before conception takes place:
- To identify and correct any maternal or paternal nutritional deficiencies
- To identify and treat any unresolved illness in parents, as much as possible
- To minimise or even eliminate exposure to environmental toxins, especially those affecting spermatogenesis (sperm production), oogenesis (egg production) and embryogenesis (development of the early embryo; first 12 weeks of gestation).
- To eliminate exposure to environmental toxins known to accumulate in various human body tissue, for example, heavy metals.
- Preconception care is essential to the health of all growing families, no matter the level of health experienced by parents. Preconception care maximises the nutritional status of both parents and stabilises the genome. Both allow for the transfer and inheritance of healthy genes. Though not a cure for profound heritable genetic disorders, preconception care can help to minimise some signs/symptoms in families for whom this is a problem.
- Detoxification is a significantly important topic in preconception, prenatal and antenatal health. However, did you know just being pregnant induces a state of physiological detoxification in the mother? This topic is rarely discussed, even in complementary and orthodox medicine. This is a concern for a number of reasons:
1) Detoxification can actually be initiated very simply and effectively in the preconception phase; harsh methods are not required for its efficacy. It is an excellent form of preventive medicine. Detoxification should take place in the preconception phase, and ideally, well before conception.
2) Pregnancy (due to the action of the placenta) induces a state of physiological detoxification for the mother. Many health practitioners are unaware of the full extent of placental physiology, and the role of the placenta in maternal detoxification. A potential gap may exist in the education of practitioners with regards to this topic.
3) The health of a growing embryo and baby relies on lack of exposure to harmful environmental substances, PLUS those released from maternal tissue storage. They may inadvertently be exposed to such substances in utero, simply via healthy placental function.
The unknown process of pregnancy detoxification
The concept of pregnancy being a physiological process of detoxification remains relatively unknown. This is especially the case regarding general health information aimed at pregnant women. An internet or Google search looking for pregnancy as a form of detoxification will yield no results. The only information gleaned from such a search advises women not to undergo detoxification whilst pregnant or nursing. This advice is absolutely correct; detoxification can release substances stored in tissues that can be harmful to unborn babies, and infants or toddlers who are being breastfed. A closer examination of placental structure and function can explain the physiology behind this process.
The placenta is an exchange organ that requires sufficient and continual access to the maternal circulation. The establishment of such access is a critical process of the first trimester. Maternal erythrocytes (red blood cells, RBC’s) are present in the foetal circulation, though significant maternal RBC’s are not observed until 10-12 weeks gestation. Studies show conversions of blood vessel architecture in both the uterus and placenta toward the end of the first trimester. Additionally, glandular secretions from the uterus supply most nutrients (maternal proteins, carbohydrates and glycogen (from which glucose is derived) and lipids), plus non-nutrient growth factors of early pregnancy. This then progresses toward a more haemotrophic (blood derived) contribution as maternal arteries begin to supply nutrition. This process in essential in establishing a continual nutrient and energy supply for the growing foetus.
For a maternally derived molecule to access the foetal circulation, it must cross several layers of materno-placental tissues, which are selective and tend to regulate the passage of various substances to the foetus.
Placental anatomy and paternal genes
The formation of the placenta is truly remarkable; there is no other time in life when a human acquires a completely new organ, only to be expelled at the end of a pregnancy. The paternal genome of the baby’s father has a major influence on placental development; these genes preside over the building of the placenta. Thus, fathers are not exempt from preconception care practices. They provide half of their baby’s genetic material, and the majority of the genes required for building this vitally important organ.
Placental Physiology: metabolism, transfer and endocrine secretion
Put simply, the human placenta has three main roles during pregnancy:
1) To transfer nutrients (water, simple sugars, fatty acids, amino acids, vitamins, minerals and electrolytes) from mother to baby, via blood circulation. It is known as an exchange organ.
2) The synthesis of hormones, peptides (very small proteins) and steroids required to sustain growth. It functions as an endocrine organ.
3) Metabolism. Metabolic waste products from the baby are transferred in the same way to the mother for removal. It performs the waste removal functions of the lungs, the kidneys and the liver, all of which are immature in the developing foetus.
Pregnant women and babies in utero are exposed to a large variety of xenobiotic substances. The concept of the placenta acting as a complete physical barrier, protecting the foetus from all harm is false. It is known that most pharmaceutical drugs administered during a pregnancy cross the placenta to some extent. Specific chemical properties determine just how easily a substance can cross the placenta:
Lipid solubility: Highly lipid soluble molecules cross the placenta more easily. Some pharmaceutical drugs including aminoglycosides and some environmental toxins.
Protein binding: Non-protein bound substances cross the placenta more easily. They are biologically active and retain pharmacologic/toxic effect
Molecular weight: Low molecular weight substances cross the placenta more easily. Examples include many pharmacological agents. Any molecule < 900 daltons in size, Methylmercury, lead DDT and nicotine.
Physiological exchange from maternal to foetal circulation occurs via the following processes:
Passive diffusion: gases (O2, CO2, CO), H2O, H2O soluble vitamins cross faster than lipid soluble vitamins, glucose, small amounts of free fatty acids, electrolytes (Na+, K+, Cl-, Ca2+ and Mg2+). Diffusion occurs in both directions from mother to baby and the reverse.
Transport-protein mediated passage: solutes are transferred at a rate much greater than that of diffusion. Many amino acids are transported in this way.
Endocytosis and exocytosis: Endocytosis occurs when a maternally derived molecule is ‘trapped’ within a small pouch formed by specific placental cell membranes, forming a vesicle. The contents of these vesicles may then be released or ejected into the foetal environment via exocytosis. Antibodies, unconjugated steroid hormones and infectious agents (particularly viruses) readily cross the placenta via this transport mechanism.
Solvent drag/bulk flow: this drives water transfer, with water-soluble solutes being dragged along.
The placenta is a selective barrier and does prevent the passage of maternal hormones and other substances from crossing the placenta. Additionally, a cache of cytochrome P450 (CYP) enzymes (the same detoxification enzymes present in liver tissue) are active in placental tissue. These are more restricted than those observed in liver tissue, though several drugs and foreign substances are detoxified here.
“This combination of efflux transporters and defensive enzymes provides a degree of protection to the fetus against exposure to potentially noxious xenobiotics, although many drugs and chemicals can still cross and act as teratogens”.
– Burton, G. et al. Placental anatomy and physiology. In: Obstetrics: Normal and Problem Pregnancies, 7th ed. Elsevier.
Molecules that are without chemical charge, lipophilic (lipid-soluble), minimally protein bound and of a low molecular weight are known to cross the placenta to the foetal circulation. Some pharmaceutical drugs and environmental toxins belong to this chemical category. Many environmental toxins may have been stored in maternal adipose tissue before well before pregnancy, hence the importance of detoxification prior to conception and pregnancy. Some substances are known teratogens, harmful to growing babies and may also be linked to growth restriction. The enhanced elimination physiology of pregnancy is possibly beneficial for mothers, but undesirable for growing babies. The ideal situation is that any man and women of reproductive age where a pregnancy is possible should consider following:
1. Completely avoid nicotine and recreational drugs. Some substances are linked to foetal growth restriction and can be stored in adipose tissue long-term.
2. Assess exposure to environmental toxins via your occupation, residence, beauty/grooming practices or hobbies. Limit this exposure as best as you can.
3. Limiting environmental exposure is not practical 100% of the time. Nutritional, dietary and detoxification interventions with a professional health practitioner early in the preconception phase is an ideal way to minimise risk.
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