• J. Obstet. Gynaecol. Res. · Oct 2000

    Reference intervals for first trimester embryonic/fetal heart rate in a Thai population.

    • Y Tannirandorn, S Manotaya, B Uerpairojkit, S Tanawattanacharoen, T Wacharaprechanont, and D Charoenvidhya.
    • Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
    • J. Obstet. Gynaecol. Res. 2000 Oct 1;26(5):367-72.

    ObjectiveTo establish reference intervals for first trimester embryonic/fetal heart rate in a Thai population.MethodsA prospective descriptive cross-sectional study was performed on normal pregnant women registered at the antenatal clinic in their first trimester. All had a good menstrual history and the calculated gestational age using crown-rump length (CRL) in the first trimester ultrasound was in agreement. Crown-rump length and embryonic/fetal heart rate measurements were obtained by a 5 MHz vaginal probe combined with a duplex color Doppler machine. All of the newborns were proved to be normal at birth. We constructed and compared embryonic/fetal heart rate expressed as beats/min relating to gestational age (GA) (days) and CRL. The data was analyzed and the best fit mathematical model was derived using the SPSS computer program.Results547 cases were enrolled into the study. The median embryonic/fetal heart rate increased from 124 beats/min at GA of 40-44 days to 177 beats/min at GA 60-64 days, thereafter, embryonic/fetal heart rate gradually decreased to 159 beats/min at GA 95-99 days. The best fit regression equation was: embryonic/fetal heart rate (beats/min) = -21.666 + 5.4796 GA (day) - 0.0383 GA (day)2, R = 0.5, p < 0.0001). In addition, embryonic/fetal heart rate also correlated with CRL. The median embryonic/fetal heart rate increased from 131 beats/min at CRL of 5-9 mm to 177 beats/min at CRL 20-34 mm, thereafter, embryonic/fetal heart rate gradually decreased to 155 beats/min at CRL 75-79 mm. The best fit regression equation was: embryonic/fetal heart rate (beats/min) = 127.361 + 3.4939 CRL (mm) - 0.0749 CRL (mm)2 + 0.0004 CRL (mm)3, R = 0.58, p < 0.0001).ConclusionReference intervals for first trimester embryonic/fetal heart rate in a Thai population were established. Our reference intervals may be useful for further studies, such as the prediction of spontaneous abortion or chromosomal disorders after ultrasound-proven viability in the first trimester.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…