A comprehensive review of the literature identified a long list of risk factors suggested to be included in comprehensive preconception care. The strength of evidence supporting the efficacy of the various components of preconception care varies greatly. Clinical practice guidelines (CPGs) have been developed for reducing the risk related to some of these factors. The Select Panel on Preconception care identified 14 conditions for which CPGs exist and for which there is scientific evidence demonstrating effectiveness in improving pregnancy outcomes:
Folic acid. Daily use of vitamin supplements containing folic acid has been demonstrated to reduce the occurrence of neural tube defects by at least 50%.
Rubella seronegativity. Rubella vaccination provides protective seropositivity and prevents the occurrence of congenital rubella syndrome.
Diabetes (preconception). The three-fold increase in the prevalence of birth defects among infants of women with type 1 and type 2 diabetes is substantially reduced through proper management of diabetes.
Hypothyroidism. The dosages of Levothyroxine required for treatment of hypothyroidism increases in early pregnancy. Levothyroxine dosage needs to be adjusted for proper neurologic development.
HIV/AIDS. If HIV infection is identified before conception, timely treatment can be administered and women (or couples) can be given additional information that can influence the timing of the onset of pregnancy.
Maternal phenylketonurea (PKU). Women diagnosed with PKU as infants may have infants with mental retardation. However, this adverse outcome can be prevented when mothers adhere to a low phenylalanine diet before conception and continue it throughout their pregnancy.
Oral anticoagulant. Warfarin, which is used for the control of blood clotting, has been demonstrated to be a teratogen. To avoid exposure to warfarin during early pregnancy, medications can be changed to a nonteratogenic anticoagulant before the onset of pregnancy.
Anti-epileptic drugs. Certain anti-epileptic drugs are known as teratogens. Before conception, women who are on a regimen of these drugs and who are contemplating pregnancy should be prescribed a lower dosage of these drugs.
Isotretinoins (Accutane): Use of isotretinoins in pregnancy to treat acne results in miscarriage and birth defects. Effective pregnancy prevention should be implemented to avoid unintended pregnancies among women with childbearing potential who use this medication.
Smoking. Preterm birth, low birthweight, and other adverse perinatal outcomes associated with maternal smoking in pregnancy can be prevented if women stop smoking during early pregnancy. Because only 20% of women successfully control tobacco dependence during pregnancy, cessation of smoking is recommended before pregnancy.
Alcohol or other recreational drug misuse. No time during pregnancy is safe to drink alcohol or other recreational drugs, and harm can occur early, before a woman has realized that she is or might be pregnant. Fetal alcohol syndrome and other drug-related birth defects can be prevented if women cease intake of alcohol and use of other drugs before conception.
Obesity. Adverse perinatal outcomes associated with maternal obesity include neural tube defects, preterm delivery, diabetes, cesarean section, and hypertensive and thromboembolic disease. Weight loss before pregnancy reduces these risks.
STDs. Chlamydia trachomatis and Neisseria gonorrhea have been strongly associated with ectopic pregnancy, infertility, and chronic pelvic pain. STDs during pregnancy might result in fetal death or substantial physical and developmental disabilities, including mental retardation and blindness.
Hepatitis B. Vaccination is recommended for men and women who are at risk for acquiring hepatitis B virus (HBV) infection through sexual transmission or through percutaneous or mucosal exposure to blood.. Preventing HBV infection in women of childbearing age prevents transmission of infection to infants and eliminates risk for to women of sequelae of HBV infection, including hepatic failure, liver carcinoma, cirrhosis, and death.
