Chorionic villus sampling (CVS) is a diagnostic procedure that can be performed between 100/7 and 136/7 weeks to detect genetic abnormalities; however, a majority of providers opt to perform CVS after 11 weeks. This study evaluated the feasibility of CVS performed at varying gestational ages, comparing chorionic villi (CV) yield and procedural outcomes among early, typical, and late procedures.

This multicenter retrospective study included patients with CVS categorized as early (100/7–106/7 weeks), typical (110/7–136/7 weeks), and late CVS (≥140/7 weeks). The primary outcome was median CV weight. Secondary outcomes included need for culture, time to microarray results, and a subanalysis of abnormal chromosomal microarray analysis (CMA) results, obstetric, and neonatal outcomes.

Of 719 patients, 8.1% underwent early, 83.2% typical, and 8.8% late CVS. The early cohort had a lower body mass index (BMI). Early CVS was most frequently performed transvaginally and for the indication of prior affected pregnancy, and less likely for abnormal genetic screening or ultrasound findings. Median villi weight did not differ significantly, and 89% of all procedures yielded adequate tissue, defined as ≥5 mg. The time to the microarray result was shortest in the typical group. There were no significant differences in other secondary outcomes of need for culture, number of passes, or procedure-related complication rates. There was no case of limb anomalies.

CVS performed before 11 weeks and after 14 weeks demonstrated comparable microarray outcomes and demonstrate the technical feasibility and diagnostic adequacy of CVS performed outside the typical gestational window. The results also support the availability of early CVS for cytogenetic testing in early pregnancy loss, where management may not allow for direct tissue testing. Prospective studies are warranted to validate these results and refine recommendations for optimal timing of CVS.

J.K.: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, writing–original draft, writing–review and editing. A.L.: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, validation, writing–original draft, writing–review and editing. A.R.: Data curation, investigation, methodology, writing–review and editing. L.A.A.: Conceptualization, data curation, investigation, methodology, writing–review and editing. A.L.: Conceptualization, data curation, investigation, methodology, writing–review and editing. T.D.: Data curation, investigation, methodology, writing–review and editing. A.R.: Conceptualization, methodology, supervision, writing–review and editing. J.L-R.: Conceptualization, data curation, investigation, methodology, project administration, supervision, writing–review and editing. M.P.: Conceptualization, data curation, investigation, methodology, supervision, writing–review and editing. M.C.: Conceptualization, data curation, investigation, methodology, supervision, writing–review and editing. P.R.: Conceptualization, investigation, methodology, project administration, supervision, writing–review and editing. L.P.: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, supervision, writing–review and editing.

‡ These authors share first authorship.

Received: 10 March 2026

Accepted: 18 March 2026

Accepted Manuscript online:
25 March 2026

Article published online:
07 April 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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