The significance of prenatally identified isolated clubfoot: Is amniocentesis indicated?

Objective: Our purpose was to determine the significance of finding an isolated clubfoot on a prenatal sonogram. Study Design: All fetuses found to have an isolated congenital clubfoot over a 9-year period were retrospectively identified. Fetuses with associated anomalies were excluded. Review of medical records for obstetric and neonatal outcome and pathologic and cytogenic results were tabulated. Results: Eighty-seven fetuses were identified from our database as having isolated clubfoot on prenatal ultrasonography, with complete follow-up available for 68 fetuses. Sixty of the 68 fetuses were confirmed as having clubfoot after delivery (false-positive rate = 11.8%). The male/female ratio was 2:1. Four fetuses (5.9%) had abnormal karyotypes: 47,XXY, 47,XXX, trisomy 18, and trisomy 21. Nine fetuses had hip or other limb abnormalities noted after birth. Other anomalies not detected until delivery included a unilateral undescended testis, ventriculoseptal defects (n = 2), hypospadias (n = 2), early renal dysplasia, mild posterior urethral valves, and a two-vessel cord. Five of the 68 patients (including those with aneuploidy) had pregnancy terminations. Eleven patients were delivered preterm. Conclusion: Karyotypic evaluation is recommended when isolated clubfoot is identified on prenatal sonogram because other subtle associated malformations may not be detected ultrasonographically in the early second trimester. (Am J Obstet Gynecol 1998;178:600-2.)