Fetal sex discordance in a monochorionic twin pregnancy following intracytoplasmic sperm injection: A case report of chimerism and review of the literature.

A 39-year-old woman who became pregnant with twins after an intracytoplasmic sperm injection was referred at the ninth gestational week to determine chorionicity. Ultrasonographic examination showed a monochorionic diamniotic twin pregnancy. First trimester nuchal translucency measurements of the fetuses were 1.6 and 2.7 mm. A non-invasive prenatal test was performed and revealed low risk. One fetus appeared to be female and the other male at the 14th gestational week. Second trimester anatomic scanning results were otherwise normal for both fetuses. The newborns delivered at term appeared to be normal female and male babies phenotypically. At the fourth month, buccal cell analysis showed chimeric karyotypes, 46,XX[98]/46,XY[2] and 46,XY[98]/46,XX[2] in the female and male infant, respectively. The recognition of sex discordance despite monochorionicity may be a clue for the diagnosis of such rare cases of chimerism in dizygotic twins, most of which occur in pregnancies obtained by assisted reproductive technology.

Injectable tissue-engineered cartilage using commercially available fibrin glue.

OBJECTIVES/HYPOTHESIS: To achieve injectable tissue-engineered cartilage using a commercially available fibrin sealant, and to determine the most suitable fibrin glue concentration, cartilage source, and cultured chondrocyte concentration. STUDY DESIGN: Animal research. METHODS: A total of 28 immunocompetent New Zealand white rabbits were divided into four groups. The cultured chondrocytes from different anatomical sources carried in fibrin glue with and without aprotinin in different concentrations of fibrinogen and thrombin (Tisseell), were injected into forehead and interocular regions of the rabbits. The new tissue formation was harvested at 8 weeks and analyzed through gross and histological analysis. RESULTS: The new tissue formations were found in round, elliptical, and flat forms. The mean value of Tisseell and cell suspension was 0.8 cc in all of the rabbits' injection regions, but the mean volume of the samples in which immature cartilage matrix and mature cartilage was 0.1 cc. In the 20 of the 55 injection regions of rabbits (36, 36%), mature and/or immature cartilage formation were observed. We observed inflammatory reactions, abscess formation, and foreign body reactions around the new cartilage tissue of tissue-engineered cartilage. The comparison of results using different cartilage sources, chondrocyte concentrations, or different fibrin glue concentrations did not show any significant difference. CONCLUSIONS: We observed that changing the concentrations of ingredients of commercially available fibrin glue, the source of the cartilage, or the cultured chondrocyte concentration did not have significant effect on neocartilage formation.