Analysis of the outcome of 127 pregnancies with first trimester medication (8.4% of the total number of the patients seeking genetic advice in 1997 at the Institute of Medical Genetics in Szeged) was carried out. The gestational age at the time of the medication and genetic counselling, the indications of the treatment, the drugs, the estimated fetal risk, and results of genetic ultrasound examinations and pregnancy outcome were evaluated. The majority of pregnant woman (78%) asked for genetic counselling before the 12. gestational week. The main indications the treatment were: infections, psychiatric-neurologic (depression, anxiety, epilepsy), endocrine (diabetes, hyperthyreoidism), and cardiovascular diseases and gastrointestinal problems. The main groups of the drugs were: antibiotics, antipyretic-, antidepressive-, antidiabetic- and antihypertensive drugs. When the multiple medication was conducted by simultaneous administration of two or more drugs, a complex risk calculation was performed. The fetal risk was higher than 10% in 31 cases (24%). The ultrasound examinations performed by qualified sonographer contributed to a correct evaluation and to reliable follow-up of pregnancies. No suspicious ultrasound finding was reported in the first trimester. However, a severe fatal brain malformation was found in a second trimester pregnancy, which was terminated by the couple's request in the 18th gestational week. A complete follow-up was obtained in 70.9% (90) of the cases. Out of 64 pregnancies intended to continue to term 4 fetal malformations were found. Of them three malformations (patent ductus arteriosus, Robin sequence and a ventricular septal defect) were explored at birth or in the newborn period. The actual 6.3% of fetal malformations was higher compared to the rate expected at birth, but almost equal to the rate of congenital malformation found up to the end of the first year of age in Hungary.