**6. HAE in pregnancy**

The influence of pregnancy on the course of the HAE is variable. Some patients can experi‐ ence fewer attacks while others experience them more frequently [9]. There are a few case series about pregnancy and delivery in HAE, which include few patients. Therefore, the approach and management of pregnancies is debated. In a recently published study, 125 pregnancies in 61 patients were analyzed and 59.2% of the patients reported a mild increase in HAE symptoms, 14% reported no symptoms, and the symptoms of 40% of the patients were sustained in a similar severity and frequency throughout the pregnancy. A HAE diagnosis was known before gestation in 30.7% of the pregnancies. Long‐term prophylaxis was used in nine pregnancies including one with epsilon‐amino‐caproic acid, two with tranexamic acid, two with anabolic steroids (temporary usage for 8 and 12 weeks in two male‐confirmed fetuses), and four with plasma‐derived C1‐inh concentrates. None of the babies experienced side effects from these drugs. Most of the deliveries were vaginal (88%) with cesarean sections required in 15 patients. Ten patients did not receive prophylaxis and one of them experienced mild symptoms during delivery and was treated with a plasma‐derived C1‐inh concentrate. After vaginal delivery without prophylaxis, a few patients developed mild local edema [63]. Similar observations were also reported by other authors [64, 65]. In another study, none of the patients who received prophylactic treatment before cesarean sections experienced any symptoms [66].

In conclusion, the course of HAE varies from patient to patient in pregnancy. Although the frequency and severity of episodes can increase in some patients, others may not have any symptoms. Patients who have had severe or more frequent episodes during this pregnancy or a previous pregnancy or have additional risk factors are recommended to have a vaginal delivery with a prophylactic plasma‐derived C1‐inh concentrate before delivery [63]. In addi‐ tion, plasma‐derived C1‐inh should be accessible during delivery and hospitalization [63].
