Varicella Vaccine Does Not Increase Risk of Birth Defects.

2001 JUL 26 - (NewsRx Network) -- by N.R. Saltmarsh, staff medical writer - Women who inadvertently receive the varicella vaccine during or just before pregnancy probably do not have cause for alarm, say researchers working in the United States. Accidental exposure to the vaccine does not appear to cause congenital varicella syndrome or other birth defects.

K.E. Shields and colleagues at Merck and Co. prospectively monitored a cohort of 362 women who were inadvertently exposed to the vaccine either during pregnancy or within three months prior to conception. Their findings were published in the journal Obstetrics and Gynecology.

The women's health care providers voluntarily enrolled their patients in the Pregnancy Registry for VARIVAX and completed surveys about pregnancy outcomes. Of the 92 women known to be seronegative to varicella, 58 received their first dose of vaccine in the first or second trimester reported Shields and team. None of the 56 live offspring born to these women had congenital varicella syndrome.

Among all the prospectively identified cases, only five congenital anomalies were reported and ultimately researchers were unable to identify any specific pattern in either the susceptible cohort or the larger sample population ("Varicella vaccine exposure during pregnancy: Data from the first 5 years of the pregnancy registry (1)," Obstet Gynecol, July 2001;98(1):14-19).

"No abnormal features have been reported that suggested the occurrence of congenital varicella syndrome ...