This is the easiest and most common method, but by far the least accurate, as it only measures one quantity (weight) and often does not take into account many factors such as height, body type, and relative amount of muscle mass.Skinfold calipers or "pinch test"The skin at several specific points on the body is pinched and the thickness of the resulting fold is measured. This measures the thickness of the layers of fat located under the skin, from which a general measurement of total amount of fat in the body is calculated. This method can be reasonably accurate for many people, but it assumes particular fat distribution patterns over the body—which may not apply to all individuals, and does not account for fat deposits not directly under the skin. Also, as the measurement and analysis generally involves a high degree of practice and interpretation, an accurate result requires that a professional perform it. It cannot generally be done by patients themselves.Bioelectrical impedance analysisA small electric current is passed through the body to measure its electrical resistance. As fat and muscle conduct electricity differently, this method can provide a direct measurement of the body fat percentage, in relation to muscle mass. In the past, this technique could only be performed reliably by trained professionals with specialized equipment, but it is now possible to buy home testing kits that let people do this themselves with a minimum of training.
A blighted ovum is a pregnancy in which the embryo never develops or develops and is reabsorbed. In a normal pregnancy, an embryo would be visible on an ultrasound by six weeks after the womans last menstrual period. Anembryonic gestation is one of the causes of miscarriage of a pregnancy.A blighted ovum or anembryonic gestation is characterized by a normal-appearing gestational sac, but the absence of an embryo. It likely occurs as a result of early embryonic death with continued development of the trophoblast. When small, the sac cannot be distinguished from the early normal pregnancy, as there may be a yolk sac, though a fetal pole is not seen. For diagnosis, the sac must be of sufficient size that the absence of normal embryonic elements is established. The criteria depends on the type of ultrasound exam performed. A pregnancy is anembryonic if a transvaginal ultrasound reveals a sac with a mean gestational sac diameter (MGD) greater than 25 mm and no yolk sac, or an MGD >25 mm with no embryo. Transabdominal imaging without transvaginal scanning may be sufficient for diagnosing early pregnancy failure when
an embryo whose crown–rump length is 15 mm or more has no visible cardiac activity. See also
Ovum
Products of conception

References
External links

Blighted Ovum on WebMD
Anembryonic pregnancy on Radiopaedia.org
Johnson, MR; Riddle, AF; Sharma, V; Collins, WP; Nicolaides, KH; Grudzinskas, JG (January 1993). "Placental and ovarian hormones in anembryonic pregnancy". Human Reproduction (Oxford, England). 8 (1): 112–5. doi:10.1093/oxfordjournals.humrep.a137857. PMID 8458911.