Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Second trimester two-step trisomy 18 screening using maternal serum markers.

Françoise Muller1, Corinne Sault, Catherine Lemay

  • 1Service de Biochimie, Hôpital Ambroise Paré, Boulogne, France. francoise.muller@apr.ap-hop-paris.fr

Prenatal Diagnosis
|July 19, 2002
PubMed
Summary

A new two-step screening strategy effectively detects Trisomy 18 in the second trimester using maternal serum markers alpha-fetoprotein (AFP) and free beta-human chorionic gonadotrophin (beta-hCG), significantly reducing false positives with pregnancy-associated plasma protein A (PAPP-A).

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

[Maternal serum markers profiles for Down syndrome: Review of comments and actionable recommendations].

Gynecologie, obstetrique, fertilite & senologie·2026
Same author

Impact of first-trimester preeclampsia screening on perinatal and maternal morbidity: the RANSPRE open multicenter randomized trial.

BMC pregnancy and childbirth·2026
Same author

Fetal biochemistry in CAKUT: Insights from 40 Years of reference center experience.

Journal of pediatric urology·2026
Same author

Calculation of specific risk of trisomy 13: probably still a utopia.

Journal of gynecology obstetrics and human reproduction·2025
Same author

Multiple cis-regulatory modules ensure robust tup/islet1 function in dorsal muscle identity specification.

Skeletal muscle·2025
Same author

Advocating a specific risk calculation of trisomy 18 in case of low maternal serum markers during screening for fetal Down syndrome.

Journal of gynecology obstetrics and human reproduction·2025

Area of Science:

  • Prenatal Diagnostics
  • Maternal Serum Screening
  • Genetics

Background:

  • Trisomy 18 diagnosis often relies on major morphological defects, but ultrasound can be unclear in up to 30% of cases, leading to late diagnosis.
  • While pregnancy-associated plasma protein A (PAPP-A) is a key marker for Trisomy 18, its utility is limited to the first trimester for Trisomy 21 screening.

Purpose of the Study:

  • To propose and validate a novel two-step maternal serum screening strategy for Trisomy 18 in the second trimester.
  • To improve the detection rate and reduce the false-positive rate for prenatal Trisomy 18 screening, especially for pregnancies not screened in the first trimester.

Main Methods:

  • A retrospective analysis of 45 Trisomy 18 cases was conducted.
  • The study evaluated alpha-fetoprotein (AFP), free beta-human chorionic gonadotrophin (beta-hCG), and PAPP-A levels.

Related Experiment Videos

  • A two-step approach was implemented: initial screening with AFP or free beta-hCG, followed by PAPP-A testing for positive results.

    • Main Results:

    • The initial screening step using a 0.5 MoM cut-off for AFP or free beta-hCG detected 82% (37/45) of Trisomy 18 cases with a 10% false-positive rate.
    • The second step, using PAPP-A with a 0.5 MoM cut-off on false-positive cases, identified all 37 Trisomy 18 cases with a significantly reduced false-positive rate of 0.1-0.2%.
    • Amniocentesis was only recommended for the small group of patients with positive results in the second screening step.

    Conclusions:

    • The proposed two-step second-trimester screening strategy is highly effective for Trisomy 18 detection.
    • This method offers a valuable option for patients who did not undergo first-trimester screening based on nuchal translucency and first-trimester markers.
    • The strategy significantly enhances diagnostic accuracy while minimizing unnecessary invasive procedures.