Depressive disorders and anxiety are the most common mental disorders in the perinatal period, occurring in 14–23% of women. Antidepressants from the selective serotonin reuptake inhibitor (SSRI) group are considered the drugs of choice for the treatment of these disorders. Although SSRIs are the best-studied antidepressants used in pregnant women, there are still conflicting opinions about their effect on pregnancy course and outcomes of pregnancy. At the same time, the risks associated with their use in pregnant women are often exaggerated, while the risks of untreated mental disorders are underestimated. SSRI use during pregnancy has been associated with a modestly increased risk of adverse events, including postpartum haemorrhage, miscarriage, preterm birth, cesarean delivery, fetuses small for their gestational age and low birth weight, low Apgar scores, and increased rates of neonatal hospitalization to intensive care units. However, depressive and anxiety disorders in the mothers themselves also contribute to similar outcomes, so it is not always possible to distinguish the contribution of medication and illness. Comparative data on the effects of different SSRI medications on outcome for the mother and fetus during pregnancy are limited, but paroxetine and fluoxetine are reported to pose the greatest risk to the fetus/neonate. Information on the safety of citalopram and escitalopram during pregnancy and lactation is limited. Citalopram has the highest concentrations in amniotic fluid of all SSRIs. According to current data, sertraline has the most favourable safety profile during pregnancy and lactation, which is explained by its low penetration through the placenta. Sertraline concentrations in the fetus are approximately 1/3 of those in maternal plasma. Sertraline has the lowest concentrations in breast milk of all SSRIs and is associated with a low risk of adverse effects in a baby, making it the drug of choice for nursing mothers. In conclusion, sertraline is one of the best studied SSRIs and has a favourable safety profile for both the mother and the fetus/neonate.