Consultation Requirements After Fetal Gender Scan
After a routine fetal gender scan (typically performed at 18-22 weeks as part of the anatomic survey), no specific consultation is routinely required if the scan is normal and no soft markers or structural abnormalities are identified. 1
When No Consultation is Needed
The following findings require no further evaluation or specialist referral:
Normal anatomic survey with gender identification only - This is a routine component of second-trimester ultrasound screening and requires no additional follow-up beyond standard prenatal care 1
Isolated echogenic intracardiac focus - This is a normal variant with no clinical significance; no fetal echocardiography, follow-up ultrasound, or postnatal evaluation is indicated 1
Isolated choroid plexus cysts - These are normal variants requiring no further aneuploidy evaluation, follow-up imaging, or postnatal assessment 1
When Maternal-Fetal Medicine Consultation IS Required
Specific findings on the gender scan that mandate specialist referral include:
Soft Markers Requiring Aneuploidy Counseling
Thickened nuchal fold or absent/hypoplastic nasal bone - Even with negative prior screening, these findings warrant genetic counseling to discuss probability of trisomy 21 and options for cell-free DNA testing or amniocentesis 1
Multiple soft markers - The presence of two or more soft markers significantly increases aneuploidy risk and requires maternal-fetal medicine consultation regardless of prior screening results 1
Findings Requiring Specific Follow-Up
Isolated echogenic bowel - Requires evaluation for cystic fibrosis (carrier screening if not already done), fetal cytomegalovirus infection testing, and third-trimester ultrasound for growth assessment 1
Single umbilical artery - Requires third-trimester ultrasound for growth evaluation and consideration of weekly antenatal surveillance beginning at 36 weeks gestation 1
Urinary tract dilation (UTD) - UTD A1 requires ultrasound at ≥32 weeks to determine need for postnatal pediatric urology/nephrology follow-up; UTD A2-3 requires individualized follow-up ultrasound with planned postnatal specialist referral 1
Shortened humerus or femur - Requires third-trimester ultrasound for reassessment and growth evaluation 1
Structural Abnormalities
Any structural abnormality identified during the gender scan mandates immediate maternal-fetal medicine referral for detailed anatomic assessment, genetic counseling, and discussion of diagnostic testing options 1
Critical Caveats
Gender determination accuracy varies by gestational age - At 12 weeks accuracy is 92-98%, but errors can occur, particularly with male fetuses being misidentified as female in early scans 2, 3
Soft markers in isolation with negative aneuploidy screening - For pregnant individuals with negative serum or cell-free DNA screening and isolated findings like echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened long bones, no further aneuploidy evaluation is recommended 1
The gender scan is primarily an anatomic survey - The focus should be on structural assessment, not just gender identification; any abnormality detected requires appropriate specialist referral 1
Documentation of chorionicity in multiple gestations - If twins are identified during the gender scan and chorionicity was not previously determined, this must be documented and appropriate follow-up arranged, as monochorionic twins require specialized monitoring 1