DIAGNOSIS OF THE MECKEL-GRUBER-SYNDROME AT 11-WEEKS TO 14-WEEKS GESTATION

OBJECTIVE: Our purpose was to examine the feasibility of diagnosing th e Meckel-Gruber syndrome at 11 to 14 weeks' gestation, both in high-ri sk pregnancies and during routine ultrasonographic screening for fetal chromosomal abnormalities. STUDY DESIGN: The high-risk population con sisted of 9 pregnancies in 7 women with previous pregnancies affected by the Meckel-Gruber syndrome. At 11 to 14 weeks' gestation, systemati c ultrasonographic examinations of the fetal skull, brain, kidneys, bl adder, hands, and feet were undertaken in each case. The low-risk popu lation 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 encephaloce le, bilateral polycystic kidneys, and postaxial polydactyly was detect ed by transabdominal ultrasonography and confirmed by transvaginal sca nning in 4 of the 9 pregnancies in the high-risk group. The parents we re counseled of the likely recurrence of the Meckel-Gruber syndrome, a nd 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 n eonatal death with the diagnosis of Meckel-Gruber syndrome. CONCLUSION : This report demonstrates that the Meckel-Gruber syndrome can be conf idently detected at the 11-to 14-week scan in both high- and low-risk populations.