www.AJOG.org

The clinical content of preconception care: environmental exposures Melissa A. McDiarmid, MD, MPH; Paula M. Gardiner, MD, MPH; Brian W. Jack, MD

inks between environmental expo- L sures and of disease or other Environmental origins of disease risk and harm to have been increasingly health harm have been increasingly ac- acknowledged for numerous outcomes, in both adult and pediatric populations. Adverse knowledged for numerous outcomes reproductive and developmental effects have also been linked to environmental expo- ranging from cancer development to sures. In addition to the current queries about a patient’s alcohol and smoking history, childhood asthma. Adverse reproductive key determinants of a future pregnancy outcome should also be elicited during the and developmental effects have also been preconception visit. These determinants include: (1) intake via fish consumption; linked to environmental exposures. The (2) nitrate exposure from well water sources; (3) exposure to chemical, physical, or Institute of Medicine (IOM) describes a biologic on the job; and (4) and other toxic exposures—possibly from patient’s environment as comprising 3 hobbies or the use of lead-glazed dinnerware in the home. Eliciting a detailed environ- sectors—the home, the community, and mental history permits tailored recommendations to optimize the woman’s health and that the workplace—wherein chemical and of her future pregnancy. physical hazards may be encountered via Key words: environment, exposure, lead, mercury, preconception various media such as contaminated soil, water, and air.1,2 Although the American College of Obstetrics and Gynecology (ACOG) Ante Partum Record already tify exposures associated with adverse re- established human neurotoxin and the includes environmental history queries productive consequences that can be min- developing fetus is most sensitive to its regarding smoking and alcohol use,3 a imized during the preconception period. adverse effects.5-7 Methylmercury bioac- broader review of the patient’s home, Although the effects on human pregnancy cumulates through the food chain so that community, and work life must be added of many of the chemicals in occupational concentrations are highest in large pred- to gain a more complete picture. Diet his- use are unknown, several classes of ele- atory fish. Exposure occurs primarily tory including fish consumption can be ments and compounds—such as heavy through consumption of seafood, fresh- considered under the “home” environ- metals and organic solvents—have been water fish, and shellfish.8-12 Thus, con- ment and drinking water source under implicated in a variety of reproductive sumption of fish high in mercury, which “community.” Specifics of work duties disorders. has been organified and concentrated and agents handled enable tailored recom- Recommendation. It is prudent to edu- through the food chain and is found in mendations to optimize the woman’s cate women for whom pregnancy is a highest concentrations in large game health and that of her future pregnancy. possibility about environmental haz- fish, is of concern during the preconcep- Routine assessment of hobbies, habits, and ards, and to provide them with the facts tion period. The 2004 United States En- home and work environments might iden- available about the teratogenic potential vironmental Protection Agency (EPA) or reproductive of any chemical and the Food and Drug Administration or environmental agent to which they (FDA) issued a joint consumer advisory From the Occupational Health Program (Dr are exposed. Strength of recommenda- regarding methylmercury in fish and McDiarmid), University of Maryland, tion: A; quality of evidence: III. shellfish, advising pregnant women, Boston, MA, and the Department of Family Mercury those likely to become pregnant, and Medicine (Drs Gardiner and Jack), Boston those breastfeeding to avoid any con- University School of Medicine/Boston National norms exist for mercury levels sumption of shark, swordfish, King Medical Center, Boston, MA in both blood and urine collected during mackerel, and tile fish.13 Other fish con- Received June 17, 2008; revised Oct. 3, 2008; the National Health and Nutrition Ex- accepted Oct. 13, 2008. amination Survey (NHANES) con- sumption (such as tuna) should also be Reprints not available from the authors. ducted by Center of Disease Control limited but is allowed in up to 2 meals of 4 Conflicts of Interest: Melissa A. McDiarmid, (CDC). Measures of mercury exposure 6 ounces each per week. Counseling MD, MPH; Paula M. Gardiner, MD, MPH; and in women of childbearing age generally about fish consumption is especially im- Brian W. Jack, MD have no conflict of interest fall below levels of concern. Several sce- portant in nonmeat eating patients and including grants, honoraria, advisory board narios, however, if elicited during his- those who supplement a meager diet membership, or share holdings. tory taking at the preconception visit, with fish that the family catches (subsis- 0002-9378/$34.00 merit follow-up and possibly interven- tence fish eaters). The National Acade- © 2008 Published by Mosby, Inc. doi: 10.1016/j.ajog.2008.10.044 tion. Exposure to methylmercury is of mies of Science’s IOM has issued a more particular concern because it is a well- recent recommendation on seafood con-

Supplement to DECEMBER 2008 American Journal of Obstetrics & Gynecology S357 Supplement www.AJOG.org sumption,14 updating the 2004 EPA/ ine fetal demise, premature delivery, in- this questionnaire has been successfully FDA advisory. Generally, the IOM agrees trauterine growth restriction, and post- adapted for use in pregnant women.23 with the EPA/FDA advisory but is a bit natal neurologic sequellae.16 About 0.5% The New York State Health Department more cautious with portion size recom- of childbearing-age women in the has used questionnaires and BLLs as part mendations for pregnant women, those United States overall may have blood of routine screening in pregnancy since who could become pregnant, and those lead levels exceeding 10 mcg/dL.17 In 1995.24 Other states have subsequently breastfeeding, stating that a “reasonable 1996, blood lead surveillance of women adopted their approach. intake” of fish with lesser mercury con- aged 18-45 years old in New York State How effective are the current treat- tent is 2 meals weekly of 3 ounces each (a found that 2% of BLLs exceeded 10 mcg/ ments? Treatment such as chelation has typical can of tuna contains 7 ounces), dL. Although there is no documented been reported in pregnancy25 but is re- but the 12-ounce total intake recom- safe threshold for BLLs, the adverse ef- served only for symptomatic women mended by the EPA/FDA advisory can fects of antepartum lead levels on the fe- with very high levels of lead in their be “safely consumed.” tus in the range typically found in the blood. Active controversy regarding dietary United States have not been established. Impact of preconception care: For sea food limitation reigns in the litera- It is also difficult to interpret BLLs in women of childbearing age who are not ture due to the documented benefit of pregnancy because of the potential for pregnant, no recommendations and lit- essential fatty acids in the maternal diet hemodilution and the frequent presence tle data exist. A risk-assessment ques- 15 18 to both mother and the fetus. A reason- of coexisting anemia. This, however, tionnaire that incorporates questions able approach here is to recommend al- does not preclude measuring the BLL in about potential lead exposure may be ternative sources of dietary fatty acids a preconception or pregnant patient who useful in identifying areas of risk reduc- such as purified fish oil. gives a history suggestive of past or cur- tion for further counseling. Recommen- Recommendation. Women of child- rent exposure. The history of present or dations for women with affirmative re- bearing age who may become pregnant remote past exposure to lead suggests the sponses should include screening of any should avoid consumption of shark, need for a BLL and for monitoring of this children in the household, education swordfish, King mackerel, and tile fish. level if found to be elevated during preg- about methods of environmental clean- Other fish consumption (such as tuna) nancy and while breastfeeding.19 This is up, removal from the exposure source, should also be limited but is allowed in due to the mobilization of lead stores and nutritional counseling—such as in- up to 2 meals of 3 ounces each per week. from bone during pregnancy and lacta- creasing the amount of iron and calcium in Many state government agencies issue tion. Lead in breast is passed to the the diet—to reduce absorption of ingested fish advisories and bans relating to mer- feeding infant, as well. If lead levels are lead. These recommendations have been cury concentration in locally caught fish. elevated, calcium dietary supplements extrapolated from pediatric data and are In addition the maternal diet may be may minimize lead mobilization mod- supplemented with essential fatty acids estly,20 and consultation with an occupa- not promoted by national organizations from nonseafood sources. Strength of tional medicine specialist is reasonable nor studied in this population. recommendation: B; quality of evidence: to assist with management. Risk factors Recommendations by other groups: No III. for lead exposure include occupational national organizations currently recom- and home renovation. Lead may mend screening pregnant women for ele- Lead also be found in some cosmetics, espe- vated BLLs. The United States Preventive Lead is a known neurotoxin, especially cially from sources outside the United Services Task Force recommends against for vulnerable populations such as States.21 The most common categories routine screening for elevated BLLs in 26 young children and the fetus. Lead is for occupational exposure include preci- asymptomatic pregnant women. most commonly found in lead-based sion production, crafts, and repairs. A Recommendation. There is insufficient paint, occupational settings, and con- study from the New York City Health evidence to recommend that all women taminated soil. Hobbies may also pro- Department reported on incident BLLs should be screened for elevated lead for vide a source of lead exposure, as may use Ͼ 20 mcg/dL between 1996 and 1999 (n the purpose of improving perinatal out- of dishes and pottery with lead glaze (see ϭ 33), and found that levels were in- comes. However, women exposed to below). Exposures, even early in preg- versely associated with maternal age and high levels of lead or with a history of nancy can pose a risk to the fetus. Lead length of time in the United States, and known high lead levels, including child- levels of 10-15 ␮g/dL may lead to central directly correlated with gestational age hood , should be coun- nervous system (CNS) damage; hydro- and pica behavior.22 seled on the risk of lead to the unborn celes; skin tags; hemangiomas, lym- How detectable is the condition? Pre- child. For women with a history of high phangiomas, and undescended testicles vention strategies for childhood lead BLLs, it is reasonable to test the BLL and, in males; miscarriage; and stillbirth. Ad- poisoning include the identification of if elevated, to initiate activities to lower verse effects of elevated maternal blood at-risk pregnant women. The CDC rec- the levels before conception. Strength of lead levels (BLLs) during pregnancy in- ommends the use of a questionnaire to recommendation: C; quality of evidence: clude spontaneous abortion, intrauter- assess children’s risk of lead exposure; II-2.

S358 American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2008 www.AJOG.org Supplement

Soil and water hazards ate) and epoxy resins used in other industrial sectors, including the Hazards encountered in the soil, water, some food and drink containers. Re- use of and in the ag- or air often originate from a current or cently the Center for the Evaluation of ricultural sector, the use of solvents and former industrial source. Polluted sites Risk to Human Reproduction (CERHR) in the manufacturing sec- that are tracked on the US EPA’s Na- of the National Program is- tor, and the use of solvents and inks in tional Priority Listed (NPL) site pro- sued a report based on an evaluation of the printing sector, also present potential gram27 generally do not result in human the state of science regarding BPA. Al- risks to underprotected workers. An ini- health effects to the wider community though based largely on animal evi- tial evaluation of a patient’s job-related but may threaten residents of a home in dence, mechanisms of toxic action of exposures can be obtained by screening close proximity by allowing for soil or BPA are shared with humans and the questions regarding employment and 19,32 drinking water contamination. Al- doses at which outcomes were observed job sectors. If there is a potential though not uniformly true, many resi- occurred at those seen in humans. The chemical, biologic, or physical agent haz- dents know when they are living near an NTP therefore issued a statement voic- ard identified, then a more detailed as- NPL or site. Documentation ing “some concern” for effects on the sessment can be made by asking about of chemical intrusion into soil or drink- brain, behavior, and prostate gland when frequency of exposure, duration, timing, ing water can be obtained from local the fetus, infants or children are exposed and exposure route (inhalation, dermal health departments. Another commu- at current human exposure levels to contact, or ingestion). This assessment nity-based environmental is the BPA. They also determined there is should include questions about the use patient’s source of drinking water. If the “minimal concern” for effects on the of additional protective apparel or the source of water is a private well, docu- mammary gland and an earlier onset of use of a respirator for some job tasks. mentation of water quality should be puberty for females exposed or fetuses, However, there are some jobs in which infants, and children at current human both governmental safety and health sought. Private wells are not regulated exposures to BPA.29 Prudent practice agencies and professional organizations for water quality by the EPA, in contrast would therefore suggest avoidance of ex- recommend alternative duty (ie, differ- to public water sources. Several reports posure. This is accomplished by avoiding ent job duties without exposure to haz- of adverse pregnancy outcomes have canned food packed in epoxy (white ards of concern) for pregnant workers or been attributed to contaminated well container liners) and bottled wa- those actively trying to conceive,33 such water.28 ter with the number 7 stamped on the as nurses who handle cancer chemother- Recommendation. During preconcep- bottom. apeutic agents34 and workers with or- tion visits, women should be asked if During the preconception visit ganic solvent exposure.35 The work of their well water has ever been tested or if women should be advised about BPA the patient’s partner should also be in- there have been questions about their avoidance in their diet. Strength of rec- quired about as secondary contamina- municipal water quality in the past. Any ommendation: B; quality of evidence: II. tion of the household or maternal expo- possible water quality problems should sure opportunity is posed during be investigated by the local health de- Workplace exposure laundering of work clothes.36 partment and, if concerns are identified, The workplace represents the principal Recommendation. During preconcep- women should use alternative sources of opportunity for exposure to environ- tion visits, women should be asked about water for drinking and cooking. (Note: mental reproductive or developmental the work environment. If potential ex- avoidance of water bottled in containers toxicants. Although some chemicals are posures are identified, consultation with containing [BPA], identi- regulated by public health agencies, the an occupational medicine specialist may fied by the number 7 on the bottom of majority of chemicals considered for assist in carrying out a more detailed in- the bottle, is prudent) (see below). De- regulation are not evaluated for repro- vestigation regarding recommendations pending on the contaminant and its con- ductive endpoints. Therefore, many for work modification. Strength of rec- centrations, alternative locations for chemicals with unambiguous reproduc- ommendation: B; quality of evidence: III. bathing may also be required. Strength of tive or developmental effects are still in recommendation: B; quality of evidence: regular commercial use and thus pose a Household exposures III. risk to women before pregnancy. Several A woman’s residential activities and Although not derived from the ambi- employment sectors with such toxicants hobbies pose potential risks for her be- ent environment, dietary exposure to in common use—including laboratory fore pregnancy. Hobbies of concern in- BPA from canned food liners or water and clinical healthcare, printing, and dry clude those involving solvents such as bottles is an emerging hazard generating cleaning—employ women in large oil-based paints; heavy metals, such as conflicting recommendations from pub- numbers.30 Healthcare especially pre- lead, which are used in stained glass lic health agencies. BPA, a high produc- sents exposure opportunities to undis- work; and paint-stripping agents that of- tion (by volume) organic chemical com- puted reproductive and developmental ten contain methylene chloride, which pound with estrogenic properties is used toxicants, including hazardous antican- metabolizes to carbon monoxide and as a building block of hard (polycarbon- cer and antiviral agents.31 Aspects of can be toxic to the fetus.37 Jewelry mak-

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