Fetus in fetu (or foetus in foetu) is a rare developmental abnormality in which a mass of tissue resembling a fetus forms inside the body of its twin. An early example of the phenomenon was described in 1808 by George William Young.There are two hypotheses for the origin of a "fetus in fetu". One hypothesis is that the mass begins as a normal fetus but becomes enveloped inside its twin. The other hypothesis is that the mass is a highly developed teratoma. "Fetus in fetu" is estimated to occur in 1 in 500,000 live births. Classification as life
A fetus in fetu can be considered alive, but only in the sense that its component tissues have not yet died or been eliminated. Thus, the life of a fetus in fetu is akin to that of a tumor in that its cells remain viable by way of normal metabolic activity. However, without the gestational conditions in utero with the amnion and placenta, a fetus in fetu can develop into, at best, an especially well differentiated teratoma; or, at worst, a high-grade metastatic teratocarcinoma. In terms of physical maturation, its organs have a working blood supply from the host, but all cases of fetus in fetu present critical defects, such as no functional brain, heart, lungs, gastrointestinal tract, or urinary tract. Accordingly, while a fetus in fetu can share select morphological features with a normal fetus, it has no prospect of any life outside of the host twin.
Urofollitropin is a purified form of follicle-stimulating hormone (FSH) that is manufactured by extraction from human urine and then purified to remove various proteins and other substances. FSH is important in the development of follicles (eggs) produced by the ovaries. Given by subcutaneous injection, it is used in combination with human chorionic gonadotropin (hCG) to assist in ovulation and fertility. It is also used with in vitro fertilization methods. The dosage is adjusted to each individuals response.The most common side effects are abdominal or pelvic pain, bloating, as well as redness, pain or swelling at the injection site. Follitropin is possibly associated with increased risk of endometrial carcinoma. It is not for use during pregnancy, as there is evidence for birth defects under follitropin treatment.Bravelle sold in the United States from March 2014 through October 2015 is subject to a recall and refund by its maker, Ferring Pharmaceuticals, because certain batches of the medicine had a lower strength than stated. References
External links
Bravelle, by Ferring Pharmaceuticals, Switzerland
Fostimon by Institut Biochemique SA, Switzerland