TOPICS: Dizygotic (fraternal) twins, monozygotic (identical) twins, IVF, chorionicity, amnionicity, dichorionic, diamniotic, monochorionic, monoamniotic, morula, blastocyst, C (chorion shared), S (separate), A (amnion shared), bilaminar disc, B (body shared, conjoined), trilaminar disc, amnion, placenta, fertilization, blastomere, morula, oocyte, ovary, blastocyst, implantation, uterine epithelium, trophoblast, inner cell mass, outer cell mass (trophoblast), bilaminar disc formation, epiblast, yolk sac, syncytiotrophoblast, hypoblast, cytotrophoblast, primitive streak, endoderm, ectoderm, mesoderm, amniotic sac enlargement, cardiac development, neural tube formation, embryo, umbilical cord formation, organogenesis, chorion, umbilical cord, fetus, inner layer of chorionic villi, outer layer of chorionic villi
