More than half of women of reproductive age in the most developed Western countries are overweight. Obesity reduces fertility. Adipose tissue is an active endocrine organ that aKects many metabolic processes. As a result, obesity can cause a number of complications during pregnancy, labour, and puerperium. Maternal obesity in pregnancy often results in diabetes, hypertension and preterm birth. Fetal anomalies with lower detection rates are also more frequent, and there is an increased risk of intrauterine fetal death. Such pregnancies usually end in high-risk deliveries, frequently induced due to complications, and often completed by a Caesarean section, which poses an additional risk for obese pregnant women. In addition to short-term complications during labour and early postpartum period, maternal obesity has long-term consequences, which are the result of epigenetic changes and fetal programming. Antenatal care should prevent or detect and treat potential consequences of maternal obesity in pregnancy. Moreover, it is essential that during their preconception counselling women receive adequate information about the importance of weight loss and lifestyle changes in order to start their pregnancy with normal body weight and achieve a healthy weight gain during this period.