Appraisal of trimester-specific fetal heart rate and its role in gestational age prediction

P Ogenyi; H U Chiegwu; A England; U E Akanegbu; O S Ogbonna; A Abubakar; G Luntsi; D J Zira; M Dauda

doi:10.1016/j.radi.2022.06.015

Appraisal of trimester-specific fetal heart rate and its role in gestational age prediction

Radiography (Lond). 2022 Nov;28(4):926-932. doi: 10.1016/j.radi.2022.06.015. Epub 2022 Jul 9.

Authors

P Ogenyi¹, H U Chiegwu², A England³, U E Akanegbu², O S Ogbonna², A Abubakar⁴, G Luntsi⁴, D J Zira⁵, M Dauda⁶

Affiliations

¹ Radiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom. Electronic address: prince.ogenyi@uhb.nhs.uk.
² Department of Radiography, Nnamdi Azikiwe University, Awka.
³ School of Medicine, University College Cork, Ireland.
⁴ Department of Radiography, University of Maiduguri, Nigeria.
⁵ Department of Radiography, Federal University Lafia, Nigeria.
⁶ Department of Medical Physics, Nasarawa State University, Keffi, Nigeria.

PMID: 35820355
DOI: 10.1016/j.radi.2022.06.015

Abstract

Introduction: The aim of this study was to evaluate and report normal sonographic FHR values among low-risk singleton women across the three trimesters of pregnancy and determine FHR role in gestational age prediction.

Method: A prospective cross-sectional study of 2727 low-risk singleton pregnant women was undertaken. FHR measurements were obtained by a consultant radiologist and three experienced sonographers using transabdominal approach from January 2019 to December 2020. Two FHR measurements were taken for each participant. The fetal lie and presentation were also documented in the first trimester. Data were analysed using SPSS version 24 (IBM, Armonk, NY, USA).

Result: The maternal mean ± SD age was 25.8 ± 6.5 years and mean FHR for first, second and third trimesters were 151 ± 16, 145 ± 6 and 125±6 bpm respectively. The mean ± SD gestational age were 10 ± 2, 19 ± 3 and 34 ± 2 weeks for the first, second and third trimester respectively. Using ANOVA, there were statistically significant differences in FHR across the three trimesters (p ≤ 0.05). A positive correlation existed between maternal age and FHR (r = 0.57, p ≤ 0.05).

Conclusion: This study has established normal values for FHR in first, second and third trimester respectively. Referring physicians, radiologists, sonographers, obstetricians and gynaecologists may consider FHR of (135-167) bpm (139-151) bpm and (119-131) bpm as normal FHR ranges for the first, second and third trimester respectively. This study has also revealed the possibility of gestational age prediction using FHR with the equation [Gestational Age = 87.8 - (0.47) FHR].

Implications for practice: This paper provides the most up-to-date sonographic FHR recommendations for fetal management. More importantly, findings from this study also suggests that ultrasound practitioners can use FHR measurements as a reliable alternative for fetal dating.

Keywords: Cardiotocography; Fetal heart rate; Gestational age; Ultrasound.

MeSH terms

Adult
Aged, 80 and over
Cross-Sectional Studies
Female
Gestational Age
Heart Rate, Fetal* / physiology
Humans
Pregnancy
Pregnancy Trimester, Third
Prospective Studies
Young Adult