Fetal polydactyly diagnosis during early pregnancy: clinical applications.

OBJECTIVES: This study was undertaken to assess the incidence of fetal polydactyly observed by ultrasonography and to evaluate the outcome of these fetuses.

STUDY DESIGN: Detailed ultrasonographic examinations were performed in 17,760 consecutive pregnant women. Both low- and high-risk pregnancies were included in the study. Most examinations were carried out at 14 to 16 weeks' gestation.

RESULTS: Twenty-six fetuses with polydactyly were observed. Ten fetuses had either associated anomalies or polydactyly of the feet, or both, and those pregnancies were terminated. The other 16 fetuses had isolated polydactyly and a normal karyotype. Fourteen of them had postaxial polydactyly type B. The outcomes of fetuses with isolated polydactyly were usually favorable. There was 1 intrauterine death and there were 2 terminations of pregnancy. Four infants were born with polydactyly. In utero autoamputation of extra digits occurred in 2 cases, whereas in the remaining infants only a small residual bump was noted.

CONCLUSIONS: Isolated fetal postaxial polydactyly type B is associated with a favorable outcome.