title: First trimester fetal heart rate measurements by transvaginal ultrasound combined with pulsed Doppler: an evaluation of 1331 cases.
abstract: The aim of this study is to present the cardiac activity measurements obtained from 1331 embryos and first trimester fetuses in whom the crown-rump length (CRL) measurements were between 2 and 60 mm, and to correlate the pattern of changes according to growth in body length, with an objective and reliable technique; transvaginal ultrasound combined with pulsed Doppler. Sonographic examinations were performed using a Combison 320-Kretz scanner with a 5-7.5 MHz vaginal probe with 240 degrees scanning angle, combined with a 4.5 MHz pulsed Doppler. As the embryo grows, the mean heart rate increases sharply, from 106.8 +/- 6.4 at a CRL of 2 mm to 178.3 +/- 7.0 at a CRL of 23 mm; followed by a plateau and a slight decline thereafter. Statistical analysis of the body length and corresponding heart rate revealed a relationship with a correlation coefficient of 0.61 (P < 0.01), whereas relationship between CRL < or = 23 and corresponding heart rate was striking with a correlation coefficient of .87 (P < 0.01).
authors.affiliation: Department of Obstetrics and Gynecology, Doctor Zekai Tahir Burak Women's Hospital, Ankara, Turkey.
authors.forename: E G
authors.initials: EG
authors.lastname: Yapar
authors.forename: E
authors.initials: E
authors.lastname: Ekici
authors.forename: O
authors.initials: O
authors.lastname: Gökmen
mesh_terms: D018568:Crown-Rump Length; D005260:Female; D005865:Gestational Age; D006340:Heart Rate, Fetal; D006801:Humans; D011247:Pregnancy; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal