First-trimester cavum veli interpositi: prevalence and natural history.

OBJECTIVE: To confirm the identity and assess the prevalence and evolution of the fluid-filled interhemispheric midline structure, thought to be the cavum veli interpositi (CVI), in fetuses at 11-14 weeks' gestation. METHODS: This was a retrospective study of first-trimester ultrasound scans performed at a single center over 3 months. Inclusion criteria were singleton pregnancies at 11-14 weeks' gestation with known neonatal outcome. Five experts reviewed the images. Mixed-effects logistic regression and generalized estimating equations (GEE) were conducted to analyze the associations between the presence of the structure and variables including ultrasound approach (transabdominal vs transvaginal), maternal body mass index (BMI), gestational age, fetal crown-rump length (CRL) and biparietal diameter (BPD). Second-trimester ultrasound scans of the fetal central nervous system at 18-24 weeks' gestation were evaluated for the persistence of the CVI in fetuses in which the structure was observed in the first trimester. RESULTS: Of the 223 cases reviewed, 104 were included, among which the CVI was observed in 25 (24%) cases. There was no statistically significant difference in CVI visualization between transabdominal and transvaginal ultrasound examinations. GEE showed significant associations between the presence of the fetal structure and CRL (odds ratio (OR) per 10-unit increase, 1.32; P < 0.0001) and BPD (OR per 10-unit increase, 1.88; P = 0.0011). Maternal BMI and gestational age showed no significant effect on the presence of the CVI. At second-trimester follow-up of the 25 fetuses in which the CVI was observed initially, 44% still showed a CVI, 32% exhibited a cavum vergae, 4% had both structures and 20% had neither. CONCLUSIONS: Based on its anatomical location and, in some fetuses, its visualization as a distinct entity from the third ventricle, the identity of the interhemispheric midline structure in the suprathalamic region of the fetal brain between 11-14 weeks' gestation was confirmed as the CVI. The CVI and/or cavum vergae persisted into the second trimester in 80% of fetuses identified initially as having a CVI. Its presence is not linked to pathology, offering reassurance to practitioners and parents. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Expression of transforming growth factor-beta (TGF beta) isoforms and TGF beta type II receptor messenger ribonucleic acid and protein, and the effect of TGF beta s on endometrial stromal cell growth and protein degradation in vitro.

Reverse transcription-polymerase chain reaction analysis of total RNA and immunocytochemical observations revealed that human endometrial glandular epithelial and stromal cells in primary culture express messenger RNAs and proteins for transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, and TGF beta 3 as well as TGF beta type II receptor. The epithelial and stromal cells synthesize and secrete into their culture-conditioned medium 2.6 +/- 0.3 and 1.4 +/- 0.2 ng TGF beta 1/10(6) cells, respectively; after transient acidification of the medium, the TGF beta 1 levels were 18.1 +/- 0.4 and 7.8 +/- 0.7 ng/10(6) cells. These cells also contain specific binding sites for [125I]TGF beta 1, indicated by light microscope autoradiography. TGF beta s at 0.01-10 ng/ml neither stimulated or inhibited subconfluent quiescent stromal cells under serum-free condition nor altered the mitogenic action of 10% fetal bovine serum. However, in the presence of 2% fetal bovine serum, which induced half-maximal stimulation of [3H]thymidine incorporation, TGF beta 1 and TGF beta 2 at 0.1-0.5 ng/ml and TGF beta 3 at 0.1-2.5 ng/ml significantly stimulated the rate of [3H]thymidine incorporation into quiescent stromal cells (P < 0.005); they were ineffective at higher concentrations. TGF beta s did not have any effect on cell proliferation, as determined by cell counting; however, at 0.1 ng/ml and higher concentrations, TGF beta s significantly reduced the metabolic activity of stromal cells, as determined by colorimetric 3-(4,5-dimethylthiazol-2-yl)2, 5-diphenyltetrazolium bromide assay (P < 0.05). The stimulatory and inhibitory actions of TGF beta s in both assays were reversible using 5-10 micrograms/ml TGF beta 1- and TGF beta 2- and 3-6 micrograms/ml TGF beta 3-specific neutralizing antibodies. TGF beta 1 at 1 ng/ml had no significant effect on long-lived protein degradation, assayed by incorporation of [14C]valine into newly synthesized protein by stromal cells, and was similar to the effect of epidermal growth factor or platelet-derived growth factor-BB (10 ng/ml). The data suggest that the TGF beta expression by various endometrial cell types in an autocrine/paracrine manner acts as a negative regulator essential for restraining endometrial growth and transition from proliferation to differentiation stages during the secretory phase after mitogenic stimulation during the proliferative phase of the menstrual cycle.