An historical and clinical review of the interaction of leprosy and pregnancy: a cycle to be broken.

Since earliest history the person with leprosy has been shut out from society. Laws have prohibited marriage and allowed divorce of those with leprosy. Segregation of the sufferer from the rest of society has been followed by separation of the sexes, and of leprous parents from their children. With the advent of antileprotic drugs, first dapsone then multidrug therapy (MDT), infection can be treated, individuals made non-infectious, and the pool of infection in the community reduced. The clinical signs of leprosy are due not to the degree of infection but to the immunological status of the host. Hormonal changes at puberty and in pregnancy can cause variation of the host's immune status. Pregnancy in women with leprosy is a hazardous undertaking. First appearance of leprosy, reactivation of the disease and relapse in 'cured' patients is likely to occur particularly in the third trimester of pregnancy. Leprosy reactions caused by variation in cell mediated and humoral immunity are triggered off by pregnancy: type 1 reaction (reversal reaction, RR) occurs post partum, while type 2 reaction (erythema nodosum leprosum, ENL) peaks in late pregnancy. Both types of reaction continue long into lactation. Neuritis with loss of both sensory and motor function is associated with relapse and reaction. Relapse, reaction and nerve damage, especially 'silent neuritis', with subsequent deformity and disability, occur not only in women on apparently effective treatment but also in those who have received MDT and have been released from treatment (RFT). To prevent disability, research is urgently needed into the mechanisms of early and late reaction and neuritis. Pregnancy is not only a trigger factor for reaction but an ideal in vivo model for research. Up to 20% of children born to mothers with leprosy may develop leprosy by puberty. While early leprosy in young children is self-healing, when marriage and childbearing take place at an early age the daughters of mothers with leprosy are likely to run the risk of experiencing the adverse effects of pregnancy on leprosy. Increased awareness and health education, as well as long term surveillance of 'cured' leprosy patients, are essential to break a potentially vicious cycle of leprosy and pregnancy. Women with cured leprosy could play an important role in screening for and detection of both early leprosy in children and late, post-MDT RFT, nerve damage in their mothers.