One deletion, two American societies, opposite advice
ACMG suggests offering 22q11.2 screening to everyone. SMFM and ACOG say do not, and offer diagnostic testing instead. Both are current.
The previous stage gave you the positive predictive value for the 22q11.2 deletion in the best prospective cohort. This page is about something different: what the professional bodies tell clinicians to do with that number. They do not agree, and you deserve to know that rather than to discover it by accident.
| Body | Document and date | What it says about 22q11.2 screening |
|---|---|---|
| ACMG | Evidence-based clinical guideline, February 2023 | Suggests it be offered to all patients. Conditional recommendation, moderate certainty. |
| SMFM, endorsed by ACOG | Consult Series #74, November 2025; ACOG Practice Advisory, January 2026 | Does not recommend routine screening for any microdeletion. Those wanting this information should be offered diagnostic testing instead. |
ACMG's recommendation heading, word for word: ACMG Suggests That NIPS for 22q11.2 Deletion Syndrome Be Offered to All Patients (Conditional Recommendation, Based on Moderate Certainty of the Evidence).
SMFM's, word for word: we do not recommend routine general population screening for any microdeletion condition. Patients who choose to undergo cfDNA screening for 22q11.2 deletion specifically should do so only after appropriate pretest counseling. Pregnant people who are interested in obtaining information regarding the risk for fetal copy number variants should be offered diagnostic testing as opposed to cfDNA screening for microdeletion syndromes.
Both documents are in force. The SMFM document is nearly three years newer, it is endorsed by ACOG, and it is the one that governs US obstetric practice. It is also the more cautious one.
Two other things SMFM says about these panels that patients almost never hear.
You may be screened without asking. Some laboratories may require the ordering provider to opt out if microdeletion testing is not desired.
The default is on.
And even a correct negative result leaves a lot open. For Prader-Willi syndrome, cfDNA can only find the deletion form, which is 65% to 75% of cases. The rest, caused by other mechanisms, would not be identified by cfDNA microdeletion testing.
On the alternative SMFM recommends. If you want real information about copy number changes, the answer is a diagnostic test: chorionic villus sampling or amniocentesis. Many women decline these because they were told they are dangerous. The current best meta-analysis puts the added miscarriage risk from amniocentesis at about 0.30 percentage points, and when it compares women of genuinely similar risk the added risk falls to about 0.12 percentage points with a confidence interval that crosses zero. The authors' conclusion: The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women.
That cuts against a common argument. The reason to be careful about screening for rare deletions is not that the confirmatory test is dangerous. It is that most positive screens are not findings in the baby.
"ACMG and SMFM disagree about 22q11.2. Which do you follow, and why?"
"If I actually want to know about copy number changes, should I be having a diagnostic test instead?"