Effect of fetal gender on first trimester markers and on Down syndrome screening

Authors

  • Yuval Yaron,

    Corresponding author
    1. Prenatal Diagnosis Unit, Genetic Institute, Sourasky Medical Center, Tel Aviv, Israel
    2. Department of Obstetrics and Gynecology, Lis Maternity Hospital, Sourasky Medical Center, Tel Aviv, Israel
    3. Sackler Faculty of Medicine, Tel Aviv University, Israel
    • Prenatal Diagnosis Unit, Genetic Institute, Sourasky Medical Center, 6 Weizmann Street, Tel Aviv, 64239, Israel.
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  • Igal Wolman,

    1. Department of Obstetrics and Gynecology, Lis Maternity Hospital, Sourasky Medical Center, Tel Aviv, Israel
    2. Sackler Faculty of Medicine, Tel Aviv University, Israel
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  • Michael J. Kupferminc,

    1. Department of Obstetrics and Gynecology, Lis Maternity Hospital, Sourasky Medical Center, Tel Aviv, Israel
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  • Yifat Ochshorn,

    1. Department of Obstetrics and Gynecology, Lis Maternity Hospital, Sourasky Medical Center, Tel Aviv, Israel
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  • Ariel Many,

    1. Department of Obstetrics and Gynecology, Lis Maternity Hospital, Sourasky Medical Center, Tel Aviv, Israel
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  • Avi Orr-Urtreger

    1. Prenatal Diagnosis Unit, Genetic Institute, Sourasky Medical Center, Tel Aviv, Israel
    2. Sackler Faculty of Medicine, Tel Aviv University, Israel
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Abstract

Objectives

The purpose of the present study was to evaluate whether a gender-related difference exists in first trimester markers used for Down syndrome screening, namely nuchal translucency (NT), maternal serum pregnancy-associated plasma protein-A (PAPP-A), and free β-human chorionic gonadotrophin (β-hCG), and whether this has an influence on screening performance.

Methods

A total of 1325 patients with a singleton pregnancy underwent combined first trimester screening at 10–13 weeks' gestation. Maternal serum PAPP-A and free β-hCG were analyzed by fluoroimmunoassay, nuchal translucency (NT) was measured by transvaginal sonography. Only patients with normal outcomes and known fetal gender were included in the study. Data were categorized by gestational age and by fetal gender.

Results

There were no significant gender-related differences in NT and PAPP-A levels. However, free β-hCG was significantly higher (p=0.00004) in the presence of a female fetus than in the presence of a male fetus. Women with female fetuses had a higher median calculated Down syndrome risk (1:5490) compared to those having males (1:6451). This difference was not, however, statistically significant.

Conclusion

First trimester free β-hCG is significantly higher in pregnancies with a female fetus. Copyright © 2001 John Wiley & Sons, Ltd.

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