Abstract
Purpose
The hypothesis was fetal sex determination by ultrasound at 11–14 weeks’ gestation has sufficient accuracy to be clinically relevant.
Methods
Fetal sex assessment by transabdominal ultrasound was performed in 567 fetuses at 11–14 weeks’ gestation (CRL: 45–84 mm). A mid-sagittal view of the genital region was obtained. The angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was measured. The fetus was assigned male sex if the angle was > 30°, and female sex if the genital tubercle was parallel or convergent (< 10°). At an intermediate angle of 10–30°, the sex was not assigned. The results were divided into three categories based on gestational age: 11 + 2 to 12 + 1, 12 + 2 to 13 + 1, and 13 + 2 to 14 + 1 weeks’ gestation. To establish its accuracy, the first trimester fetal sex determination was compared to fetal sex determined on a mid-second trimester ultrasound.
Results
Sex assignment was successful in 534/683 (78%) of the cases. The overall accuracy of fetal sex assignment across all gestational ages studied was 94.4%. It was 88.3%, 94.7%, and 98.6% at 11 + 2 to 12 + 1, 12 + 2 to 13 + 1, and 13 + 2 to 14 + 1 weeks’ gestation, respectively.
Conclusion
Prenatal sex assignment at the time of first trimester ultrasound screening has a high accuracy rate. The accuracy improved with increasing gestational age, which suggests that if clinically important decisions, such as chorionic villus sampling, are to be made based on fetal sex, they should be delayed until the latter part of the first trimester.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Data availability
The data that support the findings of this study are not openly available due to reasons of sensitivity and are available from the corresponding author upon reasonable request. Data are located in controlled access data storage at Miami Valley Hospital Department of Maternal-Fetal Medicine Ultrasound and Genetics.
References
Kearin M, Pollard K, Garbett I (2014) Accuracy of sonographic fetal gender determination: predictions made by sonographers during routine obstetric ultrasound scans. Australas J Ultrasound Med 17:125–130. https://doi.org/10.1002/j.2205-0140.2014.tb00028.x
Efrat Z, Akinfenwa OO, Nicolaides KH (1999) First-trimester determination of fetal gender by ultrasound. Ultrasound Obstet Gynecol 13(5):305–307. https://doi.org/10.1046/j.1469-0705.1999.13050305.x
Efrat Z, Perri T, Ramati E, Tugendreich D, Meizner I (2006) Fetal gender assignment by first-trimester ultrasound. Ultrasound Obstet Gynecol 27(6):619–621. https://doi.org/10.1002/uog.2674
Method for estimating due date. Committee Opinion No. 611. American College of Obstetricians and Gynecologist. Obstet Gynecol. 124:863-6 (2014)
Arfi A, Cohen J, Canlorbe G et al (2016) First-trimester determination of fetal gender by ultrasound: measurement of the ano-genital distance. Eur J Obstet Gynecol Reprod Biol 203:177–181. https://doi.org/10.1016/j.ejogrb.2016.06.001
Najdi N, Safi F, Hashemi-Dizaji S, Sahraian G, Jand Y (2019) First trimester determination of fetal gender by ultrasonographic measurement of anogenital distance: a cross-sectional study. Int J Reprod Biomed 17(1):51–56. https://doi.org/10.18502/ijrm.v17i1.3820
Youssef A, Arcangeli T, Radico D et al (2011) Accuracy of fetal gender determination in the first trimester using three-dimensional ultrasound. Ultrasound Obstet Gynecol 37(5):557–561. https://doi.org/10.1002/uog.8812
Bogers H, Rifouna MS, Koning AH et al (2018) Accuracy of fetal sex determination in the first trimester of pregnancy using 3D virtual reality ultrasound. J Clin Ultrasound 46(4):241–246. https://doi.org/10.1002/jcu.22551
Funding
The authors declare that no funds, grants, or other support was received during the preparation of this manuscript. The authors have no relevant financial or non-financial interests to disclose.
Author information
Authors and Affiliations
Contributions
All authors contributed to the study conception and design. Data collection and analysis were performed by Emma C Schaefer. The first draft of the manuscript was written by Emma C Schaefer and all authors commented on previous versions of the manuscript. DSM: protocol/project development, manuscript editing. JDS: manuscript editing. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
This is an observational study. The Wright State University Institutional Review Board has confirmed that no ethical approval is required.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Schaefer, E.C., McKenna, D.S. & Sonek, J.D. First trimester identification of fetal sex by ultrasound. Arch Gynecol Obstet 309, 1453–1458 (2024). https://doi.org/10.1007/s00404-023-07046-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00404-023-07046-0