[Fetal MRI practices in a university prenatal center]. / Pratique de l'IRM fœtale dans un centre hospitalo-universitaire de diagnostic prénatal.

OBJECTIVES: Fetal MRI is a third intention examination to prenatal diagnosis. If its diagnostic value is well known in many pathologies, its place in the management of pregnancies remains unclear. METHODS: We collected retrospectively demographical, radiological (fetal MRI indications, fetal anatomical region and diagnostic information provided by fetal MRI) and obstetrical data of pregnant patients in university prenatal center during a 5 years' period. RESULTS: Among 2439 patients of the prenatal center, 196 (8%) patients with fetal MRI were included. The main anatomical regions studied were the brain (n=132, 67%), the thorax (n=31, 16%) and the abdomen (n=25, 13%). No cardiac fetal MRI was performed. Ninety-five percent of fetal MRI was consecutively of an ultrasound sign. Fetal brain MRI was abnormal in 65% of cases, the thoracic and abdominopelvic MRI in 81.5%. The ultrasound diagnosis was unchanged in 42%, completed in 50% and redirected in 8% of cases. A termination of pregnancy was deemed admissible in 31% of patients with MRI versus 21% in patients without MRI (P=0.001). CONCLUSION: Fetal MRI requires selective indications and provides additional diagnostic information with important implications for the future of the pregnancy, particularly in case of severe and incurable pathologies. Our results could be useful as a reference basis for the comparison with others prenatal center practices.

[Sonographic cerebral sulcal pattern in normal fetuses]. / Repères échographiques de gyration cérébrale foetale normale.

PURPOSE: Define normal sulcation patterns and their chronological order of appearance on transabdominal ultrasound by comparing them with brain maturation references available in fetopathological studies and MRI findings. PATIENTS AND METHODS: By means of a prospective study, 158 normal fetal brains aged 21 to 34 gestational weeks have been analyzed with standardized data by transabdominal ultrasound in eleven different views using axial, coronal and sagittal orientation. RESULTS: The sequential development of cerebral sulci has been described according to the gestational age. This chronology was consistent with anatomo-pathologic references presenting a mean late period of one week and with MRI but without any late period. This study is available on the following website: CONCLUSION: This ultrasound study provides accurate landmarks and imaging features of normal fetal brain sulcation. The analysis and the knowledge of this sulcation provide better understanding of the brain cortex maturation and may be helpful in diagnosing brain diseases.

[Value of fetal cerebral magnetic resonance imaging for the prenatal diagnosis and prognosis of corpus callosum agenesis]. / Intérêt de l'IRM cérébrale foetale pour le diagnostic et le pronostic prénatal des agénésies du corps calleux.

OBJECTIVE: To evaluate MR contribution to prenatal diagnosis and prognosis of corpus callosum agenesis suspected by ultrasound and to ascertain how and when this examination should be included part in prenatal management of such malformation. PATIENTS AND METHODS: During a six-year period from January 1st 1994 and December 31st 2000, fifteen patients (and fifteen fetuses) were referred to our fetal medicine unit with suspicion of corpus callosum agenesis on prenatal ultrasound. Cerebral MRI was performed in all cases to confirm prenatal diagnosis. In our study, prenatal MRI examinations were retrospectively studied and compared with neuropathological examinations (n=8) or postnatal imaging (n=6). RESULTS: Corpus callosum agenesis were either complete (n=13) or partial (n=1). All were visible on prenatal MRI but only six on prenatal ultrasound. In one case, ultrasound suspicion of corpus callosum agenesis was ruled-out (false positive on prenatal ultrasound) by fetal cerebral MRI. In five cases corpus callosum agenesis was an isolated finding whereas in 12 cases associated malformations were encountered (cerebral n=7 or extra-cerebral n=5). MR depicted 7 of the 12 associated neurologic abnormalities. CONCLUSION: Prenatal MRI is a valuable complementary technique for either diagnosis of corpus callosum agenesis and depiction of associated neurologic abnormalities. Superiority of MR on prenatal sonography and its help in post-mortem examination of the brain (help in the choice of the pathologic technique and localisation of the samples) makes it essential even when pregnancy termination is considered.

Prenatal diagnosis and early in utero management of fetal dyshormonogenetic goiter.

We present a case of a fetal dyshormonogenetic goiter diagnosed by ultrasound examination at 24 weeks of gestation, in a woman with no past history of thyroid disease or goitrogen treatment and with normal thyroid tests, including absence of auto-antibodies. In this situation, fetal goiter may only be associated with fetal hypothyroidism, therefore cord blood sampling was not performed but early treatment was initiated. Amniotic fluid instillation of thyroid hormone led to a rapid decrease in amniotic fluid volume and a clear reduction in thyroid goiter. However, fetal thyroid volume did not totally normalise, and cord blood analysis at birth showed elevated fetal TSH level. As prenatal treatment of fetal hypothyroidism remains controversial in euthyroid mothers, the main objective is to prevent obstetrical complications of large goiters. Therefore, in some selected cases with no maternal history of thyroid disease and normal thyroid function tests, cordocentesis is not necessary to confirm fetal thyroid status or to adjust fetal treatment.

Fetal ovarian cysts: a report of three cases managed by intrauterine aspiration.

Small follicular or functional theca-lutein cysts are a common finding in fetal and neonatal ovaries. After delivery, decrease of hormonal stimulation may lead to spontaneous resolution of the cyst. A high rate of complication has been underlined by recent studies, the most common being ovarian torsion with subsequent loss of the ovary. Because torsion may happen with any size of cyst, however large or small, we suggest in utero decompression even in small fetal ovarian cysts (< 5 cm). We report here three cases of such cysts managed by intrauterine aspiration with good outcome and no further need for neonatal surgery. In all cases cytology of the cyst aspirate demonstrated numbers of granulosa cells and fluid biochemistry showed a high amount of estradiol, progesterone, and testosterone that confirmed the etiology as ovarian. Despite the small size of the cysts, no technical difficulties were encountered and no maternal or fetal morbidity occurred. Prenatal management of fetal ovarian cysts remains controversial, however, and our limited experience needs to be assessed on a larger number of cases.