Embryonic heart rates

Abstract

Letter to the Editor: It continues to bewilder me why articles such as the one by Rauch et al. (1Rauch E.R. Schattman G.L. Christos P.J. Chicketano T. Rosenwaks Z. Embryonic heart rate as a predictor of first-trimester pregnancy loss in infertility patients after in vitro fertilization.Fertil Steril. 2009; 91: 2451-2454Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar) continue to stratify the embryonic heart rate (EHR) rather than performing a simple regression analysis of the EHR on the embryonic age when it has been shown that there is a linear relationship (2DuBose T.J. Cunyus J.A. Johnson L.F. Embryonic heart rate and age.J Diagnos Med Sonogr. 1990; 6: 151-157Crossref Scopus (15) Google Scholar, 3DuBose T.J. Haben-Ansert S.L. 6th ed. Obstetric measurements and gestational age. In: Hagen-Ansert-Ansert, textbook of diagnostic ultrasound. Vol. 2. Mosby-Elsevier, St. Louis, MO2006Google Scholar, 4DuBose TJ, Miller MM, Moutos DM. Embryonic heart rates compared in assisted and non-assisted pregnancies. Accessed January 2000 at http://www.obgyn.net/us/cotm/0001/ehr2000.htmGoogle Scholar, 5Wisser J. Dirschedl Embryonic heart rate in dated human embryos.Early Hum Dev. 1994; 37: 107-115Crossref PubMed Scopus (47) Google Scholar, 6Blaas H-G.K. The embryonic examination. Trondheim.Norway. Norwegian University of Science and Technology, TAPIR, 1998Google Scholar). It seems researchers continue to look for a lower threshold for the EHR, when it is obviously an age and embryonic size relationship (Fig. 1). The EHR to age relationship before 9.2 LMP weeks is described by this regression:Embryonic age in days from LMP(+/−6days)=EHR×0.3+6days Reply of the Authors: Embryonic heart ratesFertility and SterilityVol. 92Issue 4PreviewWe appreciate the comment from Mr. DuBose and the insight that he has provided in this area. We agree that the relationship between embryonic heart rate (EHR) and embryonic age is linear, and we expand on this linear relationship by providing pregnancy outcome data. We offer the following points for clarification: on page 2453 of our article, we discuss the correlation coefficients for assessing the linear relationship between increasing EHR and advancing embryonic age, stratified by the ongoing pregnancy and spontaneous abortion groups. Full-Text PDF Embryonic heart rate as a predictor of first-trimester pregnancy loss in infertility patients after in vitro fertilizationFertility and SterilityVol. 91Issue 6PreviewTo determine if embryonic heart rate (EHR) is useful to predict first-trimester pregnancy outcome after in vitro fertilization (IVF). Full-Text PDF