Early obstetric ultrasound, comparing the size of an embryo or fetus to that of a reference group of pregnancies of known gestational age (such as calculated from last menstrual periods), and using the mean gestational age of other embryos or fetuses of the same size. If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy. In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days. Trimesters
Pregnancy is divided into three trimesters, each lasting for approximately three months. The exact length of each trimester can vary between sources. The first trimester begins with the start of gestational age as described above, that is, the beginning of week 1, or 0 weeks + 0 days of gestational age (GA). It ends at week 12 (11 weeks + 6 days of GA) or end of week 14 (13 weeks + 6 days of GA). The second trimester is defined as starting, between the beginning of week 13 (12 weeks +0 days of GA) and beginning of week 15 (14 weeks + 0 days of GA). It ends at the end of week 27 (26 weeks + 6 days of GA) or end of week 28 (27 weeks + 6 days of GA).
Symphysiotomy is suggested for woman in isolated areas experiencing obstructed labor where other medical intervention is unavailable.This practice was carried out in Europe before the introduction of the Caesarean section. Historically, during obstructed labor, the skull of the fetus was also, at least occasionally, crushed in order to further facilitate the delivery. Society and culture
Use in forensic anthropology
Pubic symphyses have importance in the field of forensic anthropology, as they can be used to estimate the age of adult skeletons. Throughout life, the surfaces are worn at a fairly predictable rate. By examining the wear of the pubic symphysis, it is possible to estimate the age of the person at death. Additional images
See also
References
External links
Pelvic Instability Network Support (PINS)
Anatomy photo:17:st-0206 at the SUNY Downstate Medical Center – "Major Joints of the Lower Extremity – hip and sacrum (anterior view)"
Anatomy photo:44:03-0104 at the SUNY Downstate Medical Center – "The Male Pelvis: Hemisection of the Male Pelvis"
Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna