Clinical Research

The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies

Volume: 23 Number: 2 July 11, 2026
TR EN

The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies

Abstract

Aim: The biophysical profile (BPP) is a non-invasive and reliable test used to assess fetal well-being. This study aimed to evaluate the diurnal variations in BPP parameters in term and postterm pregnancies. Materials and Methods: This prospective observational study included 75 term and 75 postterm pregnant women. Participants with systemic diseases, fetomaternal risk factors, smoking habits, or social/occupational conditions that could affect the diurnal rhythm were excluded. BPP and non-stress test (NST) evaluations were performed in the morning (08:00–10:00) and evening (20:00–22:00). The collected data were analyzed both within groups and between groups. Results: Evening assessments revealed significantly higher scores for fetal movements, breathing, NST findings, and mean BPP scores compared to morning evaluations. This pattern was observed both in the overall study population and within term and postterm groups separately. In the morning measurements, mean BPP scores were significantly lower in postterm pregnancies than in term pregnancies. Although the number of fetal breathing was lower in the postterm group, the difference was not statistically significant. In the evening measurements, the postterm group also had lower mean BPP scores. Conclusion: Diurnal rhythm has a significant impact on fetal biophysical parameters. Further large-scale studies with quantitative assessment of hormonal levels are needed to clarify the underlying biological mechanisms.

Keywords

Supporting Institution

Our study did not receive any funding.

Ethical Statement

The study was approved by the Academic Board (decision number 188295, dated 28/11/2022) and the Ethics Committee (approval number E2-22-2185, dated 20/07/2022). Written informed consent was obtained from all participants. The study was conducted in accordance with the principles of the Declaration of Helsinki.

Thanks

The authors declare that there are no acknowledgements.

References

  1. Referanslar

Details

Primary Language

English

Subjects

Obstetrics and Gynaecology

Journal Section

Clinical Research

Publication Date

July 11, 2026

Submission Date

June 28, 2025

Acceptance Date

December 25, 2025

Published in Issue

Year 2026 Volume: 23 Number: 2

APA
Alaybeyoğlu, M. A., Çınar, M., Taşkum, İ., Alaybeyoğlu, C. M., & Sınacı, S. (2026). The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies. Jinekoloji-Obstetrik Ve Neonatoloji Tıp Dergisi, 23(2), 147-153. https://doi.org/10.38136/jgon.1729609
AMA
1.Alaybeyoğlu MA, Çınar M, Taşkum İ, Alaybeyoğlu CM, Sınacı S. The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies. Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi. 2026;23(2):147-153. doi:10.38136/jgon.1729609
Chicago
Alaybeyoğlu, Muhammed Alperen, Mehmet Çınar, İbrahim Taşkum, Cennet Meltem Alaybeyoğlu, and Selcan Sınacı. 2026. “The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies”. Jinekoloji-Obstetrik Ve Neonatoloji Tıp Dergisi 23 (2): 147-53. https://doi.org/10.38136/jgon.1729609.
EndNote
Alaybeyoğlu MA, Çınar M, Taşkum İ, Alaybeyoğlu CM, Sınacı S (July 1, 2026) The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies. Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi 23 2 147–153.
IEEE
[1]M. A. Alaybeyoğlu, M. Çınar, İ. Taşkum, C. M. Alaybeyoğlu, and S. Sınacı, “The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies”, Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi, vol. 23, no. 2, pp. 147–153, July 2026, doi: 10.38136/jgon.1729609.
ISNAD
Alaybeyoğlu, Muhammed Alperen - Çınar, Mehmet - Taşkum, İbrahim - Alaybeyoğlu, Cennet Meltem - Sınacı, Selcan. “The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies”. Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi 23/2 (July 1, 2026): 147-153. https://doi.org/10.38136/jgon.1729609.
JAMA
1.Alaybeyoğlu MA, Çınar M, Taşkum İ, Alaybeyoğlu CM, Sınacı S. The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies. Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi. 2026;23:147–153.
MLA
Alaybeyoğlu, Muhammed Alperen, et al. “The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies”. Jinekoloji-Obstetrik Ve Neonatoloji Tıp Dergisi, vol. 23, no. 2, July 2026, pp. 147-53, doi:10.38136/jgon.1729609.
Vancouver
1.Muhammed Alperen Alaybeyoğlu, Mehmet Çınar, İbrahim Taşkum, Cennet Meltem Alaybeyoğlu, Selcan Sınacı. The Effect of Diurnal Rhythm on Fetal Biophysical Profile in Term and Postterm Pregnancies. Jinekoloji-Obstetrik ve Neonatoloji Tıp Dergisi. 2026 Jul. 1;23(2):147-53. doi:10.38136/jgon.1729609