Varicella and pregnancy

To appreciate the risk of embryo-foetopathy in case of maternal varicella occurring before 20 weeks of gestation, as well as the maternal complication risk (notably pulmonary) in case of maternal varicella occurring the third trimester of pregnancy.

Over the period from January 1987 to February 1995, 20 patients were managed for maternal varicella confirmed during the pregnancy. From these observations, the authors, by studying the literature, attempt to better specify the real fetal and/or maternal complication risk in case of maternal varicella.

In their personal series of 20 cases, including 17 before 20 weeks of gestation, the authors have noted no embryo-foetopathy. Similarly, no maternal complication (notably pulmonary complication), has been found. Careful study of the literature allows to specify some points. In case of varicella before 20 weeks, one observes an identical frequency of spontaneous abortions, as compared to the general population and a moderated increase of the frequency of premature delivery. The risk of congenital varicella syndrome reaches about 1.3%. Finally the risk of neonatal varicella consists in a maternal infection which occurs during the perinatal period and which is source of a high perinatal morbidity. The prenatal diagnosis is based essentially and currently, on the amniocentesis with viral research by polymerase chain reaction (PCR) in the amniotic fluid, completed by a ultrasound supervision.

The occurrence of maternal varicella during the pregnancy is rare (0.7/1000) because more than 90% of women are immunized. The risk of congenital varicella syndrome is limited to the 20 first weeks and seems very weak, authorizing therapists to reassure patients presenting a varicella during their pregnancy. Nevertheless, the risk of pulmonary complications for the mother, in case of varicella during the third trimester, does exist and requires appropriated treatment.