Preconception counseling: Make it part of the annual exam

Diet modification. Many patients considering conception ask about foods that may be unsafe during pregnancy. Like most clinicians, you may want to advise patients to avoid soft cheeses because of the risk of Listeria infection, and not to eat raw or undercooked meats because of the risk of toxoplasmosis.

Women considering conception should not eat fish high in methylmercury, which can affect the neurologic development of a fetus. These include swordfish, tilefish, king mackerel, and shark. Fish with lower levels of methylmercury are shrimp, canned light tuna, pollock, catfish, and salmon.

Women may eat 12 ounces (or 2 average meals) of these safer fish each week. Methylmercury exposure is cumulative; in women with initially high levels, it can take as long as a year after reducing consumption of fish high in methylmercury for levels to return to normal.¹⁰ An Environmental Protection Agency fact sheet for clinicians and patients is available at https://www.epa.gov/waterscience/fish/advice/factsheet.html.

Hot tubs and spas. Maternal hyperthermia (core temperature greater than 100.4°F) during the first trimester is associated with an increased risk of NTDs, so tell women who are pregnant or trying to conceive to stay out of hot tubs and heated spas.¹¹

Environmental toxins. Pregnant women should avoid solvents, paint thinners, heavy metals, pesticides, ionizing radiation (unless indicated for necessary health care), alcohol, illicit drugs, and cigarette smoke.

Smoking cessation. Smoking even less than 1 pack a day can be very harmful to the developing fetus.^12,13 Smoking increases the risks of miscarriage, stillbirth, and other pregnancy complications, and is also associated with increased neonatal mortality and sudden infant death syndrome. About 11% of pregnant women smoke.¹⁴

As a primary care physician, you should use every opportunity to help smokers considering pregnancy to quit. Proven methods of smoking cessation include counseling, medications such as bupropion, and over-the-counter smoking cessation aids, such as nicotine replacement gum and lozenges.¹⁵

One intervention shown to be particularly useful for women who smoke fewer than 20 cigarettes a day is the “5 As” method (Ask, Advise, Assess, Assist, and Arrange).¹⁶ A review of studies on the effects of smoking during pregnancy that includes cessation interventions such as the 5 As method is available in the American College of Obstetricians and Gynecologists Committee Opinion No. 316.¹⁵

Substance abuse. Fetal alcohol spectrum disorders (FASDs) are among the most preventable congenital defects and developmental disabilities. Ask patients trying to conceive about their patterns of alcohol use, and tell them there is no known safe amount of alcohol intake during pregnancy.

The US Preventive Services Task Force recommends screening pregnant patients with either the TWEAK or T-ACE instruments, because these tests can detect relatively low levels of alcohol consumption that may still harm a developing fetus.¹⁷ All women contemplating pregnancy need to know that exposure to alcohol can cause FASDs, congenital malformations, intrauterine growth restriction, and miscarriages. Problem drinkers should be referred for treatment.

Illegal drugs also pose significant risks to fetal development. Damage to the placenta caused by cocaine, for example, can lead to abruption, miscarriage, growth restriction, and prematurity. Consider screening all patients for illegal drug use and referring for counseling or methadone management, as indicated.

Caffeine. Recent studies have linked excessive caffeine intake (>200 mg/d) with miscarriages during the first trimester (adjusted hazards ratio=2.23). To reduce the risk of miscarriage, counsel pregnant women to eliminate caffeine or to cut back to less than 200 mg/d.¹⁸ Amounts of caffeine in various beverages are listed in TABLE 1 .

TABLE 1
How much caffeine is your patient drinking?^30,31

Avert trouble: Manage chronic conditions now

A number of maternal health conditions have a potential for adverse consequences to the fetus, but optimizing the mother’s condition before and during pregnancy can often avert problems. Maternal disorders to monitor include:

Diabetes mellitus. Improving glycemic control prior to conception is linked to a 3-fold decrease in the prevalence of birth defects.³ Patients entering pregnancy with hemoglobin A1C levels less than 8.5% have a fetal anomaly rate of 3.4%, whereas women with a hemoglobin A1C of more than 8.5% have an anomaly rate of 22.4%.¹⁹

According to the American Association of Clinical Endocrinologists, goals for glucose control during pregnancy include a hemoglobin A1C of less than 6% and blood glucose concentrations of between 60 mg/dL fasting and 120 mg/dL 1 hour after a meal. Achieving these levels may require tighter control than patients are accustomed to. Blood pressure for these patients should not exceed 130/80 mm Hg.