Diagnosis of the Meckel-Gruber syndrome at eleven to fourteen weeks' gestation.

OBJECTIVE

Our purpose was to examine the feasibility of diagnosing the Meckel-Gruber syndrome at 11 to 14 weeks' gestation, both in high-risk pregnancies and during routine ultrasonographic screening for fetal chromosomal abnormalities.

STUDY DESIGN

The high-risk population consisted of 9 pregnancies in 7 women with previous pregnancies affected by the Meckel-Gruber syndrome. At 11 to 14 weeks' gestation, systematic ultrasonographic examinations of the fetal skull, brain, kidneys, bladder, hands, and feet were undertaken in each case. The low-risk population consisted of 21,477 self-referred pregnancies undergoing first-trimester ultrasonographic screening for chromosomal defects at 11 to 14 weeks' gestation.

RESULTS

The triad of fetal occipital encephalocele, bilateral polycystic kidneys, and postaxial polydactyly was detected by transabdominal ultrasonography and confirmed by transvaginal scanning in 4 of the 9 pregnancies in the high-risk group. The parents were counseled of the likely recurrence of the Meckel-Gruber syndrome, and all elected to terminate the pregnancy by transcervical evacuation at 12 to 13 weeks. In the low-risk population the only case of Meckel-Gruber syndrome was identified at 13 weeks; in the remaining screened pregnancies there were no other cases of termination of pregnancy or neonatal death with the diagnosis of Meckel-Gruber syndrome.

CONCLUSION

This report demonstrates that the Meckel-Gruber syndrome can be confidently detected at the 11- to 14-week scan in both high- and low-risk populations.