An inherited condition characterized by episodic swelling (edema)  under the skin or mucous membranes  . Swelling may affect the face, extremities, genitals, gastrointestinal tract and upper airways . Swelling may occur spontaneously or in response to trauma. HAE is caused by low levels ( type 1)   or nonfunctional (type II) C1 esterase  inhibitor . C1 esterase inhibitor (C1-INH) is a plasma protein involved in the regulation of the complement cascade and and also inhibits several other serine proteinases including plasmin and kallikrein . Uncontrolled activation of the classical complement pathway leads to C4 consumption and low serum C4, Activated of kallikrein leads to the production of excessive levels of the vasoactive peptide bradykinin which results in angioedema. [1]

One observational study showed that women with hereditary angioedema (HAE) may have increased attack rates during pregnancy. The highest attack rates were noted for the gastrointestinal tract followed by attacks involving the extremities and  facial edema. Attacks involving the urogenital region were infrequent and laryngeal attacks were rare [2]. C1-INH concentrate may effectively control the attacks, during pregnancy and is reported  to be safe for the mother and fetus [3] . One author recommends" If the patient has suffered worsening of the condition with frequent severe episodes, then labour must be covered with C1 Inh concentrate"  Epidural is not contraindicated.[4]. One case of maternal death has been reported attributed to HAE [5]

1. Hereditary Angioedema (HAE) http://www.omim.org/entry/106100
2. Martinez-Saguer I, et.al., Characterization of acute hereditary angioedema attacks during pregnancy and breast-feeding and their treatment with C1 inhibitor concentrate. Am J Obstet Gynecol. 2010 Aug;203(2):131.e1-7. doi: 10.1016/j.ajog.2010.03.003. Epub 2010 May 14. PMID: 20471627
3. Bowen T, et al., 2010 International consensus algorithm for the diagnosis, therapy and management of hereditary angioedema. Allergy Asthma Clin Immunol. 2010 Jul 28;6(1):24. doi: 10.1186/1710-1492-6-24. PMID: 20667127
4. Bouillet L. Hereditary angioedema in women. Allergy Asthma Clin Immunol. 2010 Jul 28;6(1):17. doi: 10.1186/1710-1492-6-17. PMID: 20667120
5. Postnikoff IM, Pritzker KP. Hereditary angioneurotic edema: an unusual case of maternal mortality. J Forensic Sci. 1979 Apr;24(2):473-8. PMID: 541623