title: Outcome after maternal varicella infection in the first 20 weeks of pregnancy.
abstract: BACKGROUND
  Infection with the varicella-zoster virus during pregnancy can produce an embryopathy characterized by limb hypoplasia, eye and brain damage, and skin lesions. The risk is greatest when infection occurs during the first 20 weeks of pregnancy, but the magnitude of the risk is uncertain.
  
  
  METHODS
  We studied 106 women with clinically diagnosed varicella infection in the first 20 weeks of pregnancy and compared the outcomes with those in 106 age-matched, nonexposed controls.
  
  
  RESULTS
  Among the women with varicella, there was a trend toward more elective terminations of pregnancy (14 percent, vs. 7.5 percent among the controls; P = 0.1), corresponding to a significantly higher perception of teratogenic risk (P = 0.03). The proportions of miscarriages and live births and the mean birth weights were similar in the two study groups; there were more premature births (< or = 37 weeks) among the women with varicella infection (14.3 percent vs. 5.6 percent, P = 0.05). Congenital defects occurred in four infants born to the women with varicella (varicella embryopathy, hydrocephalus, meningocele and clubfeet, and hammer toe) and two infants born to the controls (ventricular septal defect and hip dislocation). The risk of varicella embryopathy after infection in the first 20 weeks was 1.2 percent (95 percent confidence interval, 0 to 2.4 percent). When we pooled our results with those from other prospective studies, the mean risk of embryopathy after infection with varicella-zoster virus in the first trimester was 2.2 percent (95 percent confidence interval, 0 to 4.6 percent).
  
  
  CONCLUSIONS
  The absolute risk of embryopathy after maternal varicella infection in the first 20 weeks of pregnancy is about 2 percent.
authors.affiliation: Motherisk Program, Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: A L
authors.initials: AL
authors.lastname: Pastuszak
authors.forename: M
authors.initials: M
authors.lastname: Levy
authors.forename: B
authors.initials: B
authors.lastname: Schick
authors.forename: C
authors.initials: C
authors.lastname: Zuber
authors.forename: M
authors.initials: M
authors.lastname: Feldkamp
authors.forename: J
authors.initials: J
authors.lastname: Gladstone
authors.forename: F
authors.initials: F
authors.lastname: Bar-Levy
authors.forename: E
authors.initials: E
authors.lastname: Jackson
authors.forename: A
authors.initials: A
authors.lastname: Donnenfeld
authors.forename: W
authors.initials: W
authors.lastname: Meschino
mesh_terms: D002644:Chickenpox / Q000150:complications*; D016001:Confidence Intervals; D000013:Congenital Abnormalities / Q000209:etiology; D005260:Female; D014645:Herpesvirus 3, Human; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies; D012306:Risk