Journal of Ultrasound in Medicine · 1989 · 92 citations · 3 references
MedicineCardiologyObstetricsClinical CardiologyHigh-risk PregnancyMaternal-fetal MedicineFetal CardiologyFetal DistressFetal MonitoringMaternal-fetal PhysiologyPregnancyPregnancy PhysiologyCardiovascular Complications Of PregnancyFetal BradyarrhythmiasFetal Bradycardia EvaluationFetal Cardiac PrognosisHeart RateMaternal Cardiovascular PhysiologyMiscarriage LossPregnancy-related Cardiac Complications
Normal first trimester fetal heart rates rise from an average of 100 beats per minute (bpm) at 5 to 6 weeks to 140 bpm at 8 to 9 weeks. The heart rates of 65 consecutive first trimester fetuses between 5+ and 8+ weeks were measured to determine whether unusually slow first trimester fetal heartbeats are associated with a poor outcome. All five pregnancies in which heart rates were below 85 ended in spontaneous miscarriage. This study suggests that first trimester bradycardia may be associated with a poor prognosis for the pregnancy.
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Embryonic heart rates before the seventh week of pregnancy.
Lewis Shenker, Clinton M. Astle, K L Reed et al. · PubMed · 1986 · 23 citations