Outcome of early first-trimester pregnancies (< 6.1 weeks) with slow embryonic heart rate.
Academic Article
Overview
abstract
OBJECTIVE: The purpose of this article is to assess prospectively the value of concordant versus discordant gestational age (GA) calculations in predicting subsequent embryonic demise in embryos with a slow heart rate, as determined on early first-trimester ultrasound. SUBJECTS AND METHODS: Thirty-six consecutive singleton pregnancies with slow embryonic heart rate (< 100 beats/min) measured on a 5.0- to 6.1-week ultrasound were prospectively identified. Pregnancies were defined as "discordant" if there was more than 5 days' difference between GA determined by biometrics compared with GA determined by last menstrual period and were defined as "concordant" if there was less than 5 days' difference between the GA measurements. RESULTS: Of the 36 embryos with heart rate less than 100 beats/min at 5.0-6.1 weeks' GA, 16 went on to demise and 20 survived. Of the 16 that went on to demise, 14 were discordant (88%) and two were concordant (12%). Of the 20 that survived, 16 were concordant (80%) and four were discordant (20%). The proportion of discordant pregnancies that went on to demise was 14 of 18 (negative predictive value, 78%). The proportion of concordant pregnancies that went on to survival was 16 of 18 (positive predictive value, 89%). The rate of demise in the discordant group was significantly higher than that in the concordant group (p < 0.001, Fisher's exact test). CONCLUSION: Embryonic heart rate less than 100 beats/min detected at 6.1 weeks or less is not necessarily a poor prognostic indicator. The likelihood of subsequent first-trimester survival is significantly higher if there is concordance between GA as calculated by biometrics and last menstrual period than if there is discordance.
