A patient was referred to our institution in the 33rd week of gestation with the preliminary diagnosis of multiple congenital anomalies. Scanning revealed:
Moderate oligohydramnios (AFI=7 cm);
Heart defect (atrioventricular canal);
Polydactyly of hands and feet;
Suspicion of horseshoe kidney with pyelectasia and abnormal origin of one of the renal arteries (the right one more anteriorly);
Abnormal position of the feet;
Camptodactyly of fingers;
Abnormal facial profile with micrognathia and thickened prenasal skinfold, markedly thickened nuchal skinfold, moderate hypertelorism;
Moderate shortening of the long bones;
Pulmonary hypoplasia was suspected.
The baby was born breech (which is rather typical of the fetuses with this disorder) and the findings were confirmed. Additionally ambiguous genitalia and dysplastic ears were identified and the normal male karyotype was ascertained. The baby"s serum steroid profile was abnormal, confirming the diagnosis of Smith-Lemli-Opitz syndrome.
Of interest is the fact, that in the case of fetal abnormalities suggestive of Smith-Lemli-Opitz syndrome, there is a non-invasive test of maternal urine readily available, allowing the diagnosis in the early second trimester by maternal urinary steroid profile.
In our case, diagnosed in the third trimester this test was not performed as it wouldn"t have influenced further obstetrical care.