49: Amniocentesis to diagnosis congenital cytomegalovirus infection following maternal primary cytomegalovirus infection in early pregnancy

Abstract

Cytomegalovirus (CMV) infection is the most common congenital infection in the U.S. Our objective was to evaluate amniocentesis (AMNIO) in detecting congenital CMV infection (cCMV). Secondary analysis of a multicenter RCT designed to evaluate if CMV hyperimmune globulin (HIG) reduces cCMV in the offspring of women diagnosed with primary CMV infection prior to 24 weeks’ gestation and having no evidence of fetal infection (ultrasound findings or amniocentesis with CMV infection) at randomization. Eligible subjects were randomized to monthly infusions of HIG or placebo until delivery; those who underwent elective amniocentesis following randomization are included in this analysis. The fetus/neonate was tested for the presence of CMV at delivery or death. Comparisons were made between those with or without CMV at AMNIO, using chi-square test or Fisher’s exact test for categorical variables and the Wilcoxon rank test for continuous variables. A P-value of < 0.05 was considered significant. 399 women were randomized, and 55 (14%) women had AMNIO; 53 offspring had CMV results. Twelve AMNIOs were positive (12%) - one only by culture (8%), 7 only by PCR (58%) and four by culture and PCR (33%). The prevalence of fetal/neonatal infection was 26% (14/53). All 12 AMNIO-POS had cCMV infection confirmed at delivery, as well as 2 of the 41 AMNIO-NEG women (AMNIOs performed at 18.1 and 21 wks), for a sensitivity of 86%, specificity of 100%, positive predictive value of 100% and negative predictive value of 95%. (Table 1) Compared with AMNIO-NEG women, AMNIO-POS women had a lower avidity index at diagnosis and were more likely to undergo termination (Table 2). The gestational age (GA) at time of AMNIO was similar, as was the interval between maternal diagnosis and AMNIO. AMNIO-POS pregnancies delivered at an earlier GA and had a lower birthweight. AMNIO results are an accurate predictor of cCMV infection, particularly using PCR, even when performed at an early GA. Positive results are associated with increased termination rates and poor neonatal outcomes in continuing pregnancies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)