Module 3 Unit C: Teratogens in Pregnancy

Specific Substances: Pesticides.

- Purpose is to kill, control or repel pests (insects, etc.). - Used in industry, commercial locations and homes -- 75% of homes have used pesticides, 66% within the last year - Found in the air, soil, plants, ground water sources - High risk occupations: -- Gardeners, farmers, migrant workers, exterminators, commercial flower workers, landscaping - Exposed by inhalation, percutaneous/dermal use, and ingestion. - Effects of toxicity - Avoid pesticides when possible!

Specific Substances: Lead.

- Through inhalation or ingestion. - Can cause damage to nervous system, kidney and blood formation system, higher mortality rate in 1st year of life if mother exposed in pregnancy. - High levels of exposure are associated with miscarriage, stillbirth, LBW, preterm birth, cognitive impairment, developmental delays and other minor malformations. - Found especially in older homes- up to 52% of homes may have high lead levels because of lead-based paint. Talk about if there will be any remodeling done. - Found in lead pipes, dirt, toys. - Lead levels: toxic = 20-25 mcg/dl, levels as low as 10 mcg/dl have been associated with cognitive defects in children. The CDC guidelines recommend follow-up activities and interventions beginning at blood lead levels ≥5 μcg/dL in pregnant women. - Occupations with high risk: painters, de-leaders, smelters, stained glass and ceramic workers, auto radiator repair, welders.

What is the most sensitive time to be exposed to environmental hazards?

1st trimester. When many women do not even know they are pregnant. They might find out when they are already well into organogenesis.

Specific Substances: Mercury.

3 types of exposure: organic, inorganic and elemental - Organic: fungicides and paint (accumulates in food- fish) -- Results in neurological damage (cerebral pals, microcephaly) - Inorganic: antiseptics, fungicides, skin-lightening creams - Elemental: thermometers, batteries, dental amalgam Routes of exposure - Inhalation: absorbed through alveoli and can stay in body for months. Stored mostly in kidneys and brain - Power plants: not regulated- mercury goes into the air and lands on food, rivers, and into the food chain (fish) - Broken thermometers: Pregnant women should not work in areas of high mercury exposure

A growing fetus is very sensitive to drugs and chemicals, especially in?

The first trimester.

*Principles of Teratotology*

http://www.motherisk.org/prof/elearning.jsp

What is a teratogen?

According to Blackburn (2013, p. 203): "A teratogen is any substance, organism, physical agent, or deficiency state present during gestation that is capable of inducing abnormal postnatal structure or function (biochemical, physiologic, or behavioral) by interfering with normal embryonic and fetal development."

The Occupational Health and Safety Administration (OSHA) mandates that the names and health effects of all chemicals be available to worker on site via the material Safety Data Sheet (MSDS).

Asking women to obtain the MSDS is your starting point in learning more about many workplace exposures.

Before definitive conclusions can be drawn regarding the teratogenicity of exposures, several clinical factors need to be considered. These include:

Gestational age at the time of exposure, the amount of toxin reaching the developing embryo/fetus, the duration of exposure, the impact of other factors or substances to which the mother or her fetus is simultaneously exposed, and the overall health of the mother and fetus (RMN, 2005).

Factors to consider:

Gestational age at time of exposure - Organogenesis -- Occurs during the embryonic period (from implantation to day 56-58) -- Systemic damage can occur that is out of proportion to the usual dose response. Amount of toxin reaching the embryo/fetus Duration of exposure Impact of other factors/substances for simultaneous exposure Overall health of mother/fetus

If substance exposure is identified, then further detailed history on?

Route, timing and duration of exposure is essential. Use of protective equipment such as gloves or masks should be noted.

Essential elements of an environmental risk assessment that should be done for all pregnant women. Occupational health history includes at a minimum the following 3 questions:

What is your current job/career? Are you now exposed to chemicals, pesticides, solvents, metals, fumes, gas, dust, noise, radiation, infectious diseases, body fluids, emotional stress, or other hazards?, and Have you ever had any prior illnesses or symptoms due to your work?

Pregnant women (including those who do not realize they are pregnant) are, however, at even greater risk of harm not only to themselves, but to their unborn child.

Certain occupations and exposures are linked to specific adverse pregnancy outcomes. Efforts should be made to identify, eliminate or reduce the risks associated with each pregnant employee's duties.

Magnitude of Problem:

- Approximately 3% of all developmental defects can be attributed to chemical exposures - 25% more can be attributed to a combination of environmental and genetic factors. - There is limited data about this, so we are likely underestimating the actual prevalence.

Recommendations:

- Don't use plastic containers with #7 on the bottom (may contain BPA)... Buy BPA free! - Document drinking water safety- especially if it's a private well. - Don't use pesticides during pregnancy. - Avoid oil-based paints and paint-stripping agents. - Use caution when renovating the home (and nursery!) - give lead precautions. - Use cold water for drinking, cooking and preparing formula- if hot water has been off or 6 hours or more, let it run before using it. - Don't eat fish known to be high in mercury (shark, swordfish, king mackerel, tile fish.. Limit other fish to 2 servings of 3 ounces per week. - Don't use PVC or vinyl containing plastics (#3) as food or drink containers... Opt for #1 or glass. - Don't microwave or heat plastic cling wraps - Look for phthalate and fragrance-free (not unscented) products

Possible outcomes:

- Subfecundity - Infertility - Pregnancy loss - Infant death - Preterm birth - Congenital anomalies - Low birthweight - Developmental delays - Childhood cancers

Preconception counseling:

Discuss environmental hazards - Home - Work Focus on preventable hazards - Avoid using non-latex based paint, pesticides, herbicides and other commonly-used chemical products - Discuss home renovation dangers (paint stripping, lead exposure) Refer to websites for more information www.marchofdimes.com www.endocrinedisruption.com www.nrdc.org www.ewg.org

Right to know!

Employees have the right to read the MSDS for any product to which they may be exposed. Employees have the right to work in an environment that is free from significant reproductive health risks. Work restrictions should be based upon individualized risk assessment, and not overarching policies that exclude workers for "fetal protection" (gender discrimination). Pediatric Environmental Health Specialty Units - www.aoec.org/PEHSU/index.html - Network of experts for consultation and referral for children faced with a health risk because of natural of man-made environmental hazards.

What to ask?

Employment setting - Tasks performed - Chemicals handled Potential workplace exposures - Biological agents (animal dander, bacteria, viruses, fungi, etc.) - Physical agents (temperature extremes, ionizing and non-ionizing radiation, UV radiation - Chemical agents (metals, organic solvents, pesticides/herbicides) - Physical/psychological conditions (prolonged standing/lifting, shift work, heavy lifting) Environmental history - Home (well water, age of home/remodeling, chemicals stored?) - Neighborhood (industry, hazardous waste) - Hobbies (metals, gardening, alternative healing practices)

Performing a home assessment is an integral part of an?

Environmental exposure assessment.

Vitamin A supplementation is teratogenic in pregnancy with?

Extremely high doses.

Specific Occupations:

Hair Dressers: - Evidence is conflicting but suggestions of increased risk persist. Dental Hygienists - Evidence is conflicting, but should avoid amalgams if possible (studies suggest maybe over 50/week could cause increased mercury levels) Nurses - Nurses are at increased risk of adverse pregnancy outcomes, but the strength of the association was weaker in well-designed studies. Data was limited by the number and heterogeneity of the studies. (Quansah & Jaakkola, 2010)

Although home is considered 'safe', it can contain many potentially harmful gardening and household chemicals, lead, and poor air quality due to wood stove use.

Home can be the source of lead, mercury, pesticides and other potentially toxic substances.

However, women with a history of psychiatric, seizure-related, or hematologic illnesses frequently require medication throughout pregnancy.

In these women, care must to be taken to select the safest drug from the necessary class of medication.

How we are exposed:

Inhalation. Ocular contact. Ingestion/absorption through GI tract. Percutaneous/dermal contact. Vertical transmission. Lactation.

Which heavy metals are confirmed environmental teratogens, and exposure could contribute to pregnancy loss?

Lead and mercury, organic solvents, alcohol, and ionizing radiation. All of these substances are readily found in our environment, homes, food sources, and workplaces. Caffeine, cigarette smoking, and hyperthermia are all considered teratogens.

Environmental toxins have been implicated in contributing to?

Poor reproductive outcomes.

Types of Hazards:

Toxic - Organic solvents - Metals - Pesticides - Polycholrinated biphenyl [PCB] Physical - Ionizing radiation Biological - Toxoplasma - Parvovirus B19

T/F. Women who have experienced multiple early pregnancy losses are concerned that hazardous environmental substances have contributed to their reproductive difficulty.

True.

T/F. All midwives need to be familiar with on-line toxicology data banks resources to be able to quickly and accurately inform pregnant women about potential risks, and provide appropriate counsel to reduce risk during pregnancy.

True. The midwife must be sensitive to the emotional issues raised in the inadvertent or unintentional exposure to fetotoxic substances. Keep in mind that much of the time the exposure may be brief - often reassurance is an appropriate part of your plan. However further data gathering, topic research and client education is always essential when caring for a woman with substance exposure.

T/F. Knowledge of information resources available for the latest research on potentially fetotoxic substances and workplace hazards is essential for the nurse-midwife.

True. We also must be aware of those substances that are safe so we can confidently answer women's questions and then provide the needed reassurance.

Scientific knowledge about the effects of all drugs on the developing fetus is severely limited, thus, almost all pharmaceuticals are viewed with caution during pregnancy. The best option:

Use as few medications as possible, especially during the 1st trimester.