Siegfried Rotmensch

THE CYCLIC nature of the female reproductive process is largely dependent upon the unique capability of the ovarian follicle to change in structure and function. A finely tuned process of differentiation occurs in all constituents of the follicle during folliculogenesis. Granulosa cells (GCs) display a high degree of structural change and play a key role in the functional maturation of the entire follicle. These changes in response to endocrine and paracrine stimuli create the unique environment for oocyte growth and ovulation by virtue of their biochemical activity and intimate anatomical relationship. Moreover, the maintenance of early pregnancy depends on transformation of GCs into highly differentiated luteal cells (for review see Refs. 1–3). Our understanding of GC maturation and luteinization has substantially improved in the last 15 yr largely due to the extensive use of the cell culture approach. In vitro induction of differentiation in serum-free media allowed for identification of the molecular factors involved (for review see Ref. 4).

OBJECTIVE: To report the prenatal diagnosis and management of 34 fetuses with various intracranial structural pathologies diagnosed following a normal second-trimester ultrasound examination. METHODS: We retrospectively reviewed the images of 203 abnormal central nervous system ultrasound examinations performed between 13 and 37 weeks of gestation at our prenatal diagnosis unit. In 34 (16.7%) of them at least one previous second-trimester ultrasound examination had been performed and considered normal. These 34 fetuses represent the study group. RESULTS: The following intracranial pathologies were diagnosed: dysgenesis of the corpus callosum, ventriculomegaly, cerebral cysts or hemorrhage, migrational disorders, vermian dysgenesis, arachnoid cysts, macrocephaly, enlarged subarachnoid space, brain calcifications and microcephaly. CONCLUSION: A normal second-trimester ultrasound scan does not rule out significant intracranial anomalies. Parents and physicians should be informed about the limitations of second-trimester sonography as far as brain diagnosis is concerned. A repeat third-trimester scan may enable more accurate diagnosis and counseling.