A good pregnancy outcome is partly determined by a women's preconceptional health and healthy lifestyle. The access to prenatal care is good nowadays but the incidence of congenital malformations, preterm births, low birth weight and maternal mortality has not significantly declined over the years. Although most women of reproductive age have a gynecological examination every two years in Belgium, they are not often counseled before starting a pregnancy. The American College of Obstetricians and Gynecologists (ACOG) states that optimizing a woman's health before and between pregnancies must be an ongoing process. The most vulnerable period for fetal defects is between 4 and 10 weeks of gestation, the period of embryogenesis, meaning that counseling for a healthy life style and reducing high-risk conditions should start preferably before conception.