The course and outcome of pregnancies complicated with myasthenia gravis

Abstract

Mijastenija gravis (MG) je stečena autoimuna bolest koja nastaje kao posljedica stvaranja protutijela na acetilkolinske receptore (AChR) završne motorne ploče čime se narušava prijenos signala neuromuskularne spojnice. Usprkos nepoznavanju točnog uzroka smatra se da je bolest multifaktorijalne etiologije. Dobna raspodjela MG koja svoj vrh doseže u reproduktivnoj dobi žene zahtjeva pojačanu prekoncepcijsku, antenatalnu i postpartalnu skrb. Prema raširenosti simptoma MG razlikuju se okularni oblik s razvojem ptoze i diplopije te generalizirani oblik koji uključuje slabost ekstraokularnih mišića. Mijastenička kriza sa zatajenjem disanja predstavlja hitno neurološko stanje, a često je provocirana trudnoćom i postpartalnim razdobljem. Dijagnoza MG se postavlja na temelju anamneze, fizikalnog pregleda, serologije te dodatnih farmakoloških i elektrofizioloških ispitivanja. Liječenje uključuje inhibitore acetilkolinesteraze, imunosupresivnu terapiju, timektomiju te intravenske imunoglobuline i plazmaferezu. Prekoncepcijsko savjetovanje žena je neophodno kako bi se osigurala kontrola majčine bolesti, a istovremeno izbjegle teratogene posljedice imunosupresivne terapije na fetus. Trudnoća ima različite učinke na tijek MG, a moguće su egzacerbacije, remisije ili nepromijenjen tijek bolesti. Tijekom antenatalne skrbi provode se redoviti testovi plućne funkcije, individualna prilagodba terapije te fetalni ultrazvuk u svrhu određivanja pokreta ploda. Zbog hemodinamskih promjena prilagođava se doza lijeka, a odabir sigurne terapije u trudnoći može predstavljati izazov. Prilikom odabira načina porođaja u većini slučajeva se pristupa spontanom vaginalnom porođaju u epiduralnoj anesteziji. Dojenje se podupire uz praćenje stanja novorođenčeta i majke zbog mogućnosti postpartalne egzacerbacije u 30% slučajeva. Tranzitorna neonatalna mijastenija gravis (TNMG) nastaje kao posljedica transplacentarnog prijenosa majčinih protutijela, a prepoznaje se unutar prvih 12-48 h praćenjem kvalitete disanja novorođenčeta.Myasthenia gravis (MG) is an acquired autoimmune disease which occurs from the production of antibodies targeting the acetylcholine receptors on the motor end plate, thereby disrupting signal transmission of neuromuscular junction. Even though the exact cause is still unknown, MG is considered to have multifactorial etiology. The age distribution of MG that reaches its peak in the female's reproductive age indicates the need for enhanced preconceptional, antenatal and postpartum care. According to the distribution of symptoms, MG is classified into the ocular MG with the development of ptosis and diplopia and the generalized MG which includes extraocular muscles weakness. Myasthenic crisis with respiratory failure presents urgent neurological condition and is frequently provoked during pregnancy and postpartum period. The diagnosis is based on medical history, physical examination, serology, and additional pharmacological and electrophysiological testing. Treatment includes acetylcholinesterase inhibitors, immunosuppressive therapy, thymectomy, intravenous immunoglobulins and plasmapheresis. Preconception counseling is mandatory in an attempt to ensure disease control and to prevent teratogenic effect of immunosuppressants at the same time. Pregnancy has various effects on the course of the disease. Remission and exacerbation are possible while the severity of the disease may remain unchanged. Antenatal care includes regular pulmonary function tests, individual dose adjustment and fetal ultrasound to determine fetal movements. Due to hemodynamic changes during pregnancy, drug dose adjustment and deciding on a safe therapy in pregnancy can be very challenging. Spontaneous vaginal delivery under epidural anesthesia is usually encouraged while choosing the mode of delivery. Breastfeeding is recommended with continuous monitoring of the newborn and mother due to the possibility of postpartum exacerbation in 30% of the cases. Transient neonatal myasthenia gravis (TNMG) occurs as a result of transplacental transmission of maternal antibodies and is recognized within the first 12-48 h when it is important to monitor the quality of respiration