Human placenta, materno-fetal organ, plays a vital role in maternal-fetal physiology with numerous responsibilities. It is not merely a passive barrier between the maternal and fetal circulations but has many physiological functions like implantation, recognition of maternal pregnancy, fetal protection from immune attacks, exchange of respiratory gases, metabolites, nutrients, and waste products as well as the endocrine function and the metabolism of xenobiotics. Abnormalities in the placenta’s function can lead to dismal pregnancy outcomes. The usual human term placenta is about 22 cm in diameter and 2.0 to 2.5 cm thick. It generally weighs about 475 g. The ratio between placenta weight and birth weight of the newborn. Placentas with less than 2.5 cm thickness are associated with intrauterine growth retardation (IUGR) of the fetus. Placentas more than 4 cm thick have an association with maternal diabetes mellitus, fetal hydrops and intrauterine fetal infections. The full-term, delivered placenta is, in more than 90% of the cases, a disk-like, flat, round to oval organ. In nearly 10%, it has abnormal shapes, such as placenta bilobata, placenta duplex, placenta succenturiata, and placenta membranacea. A well-developed placenta consists of a chorionic plate, which is of embryonic descent and of a basal plate whose essential layer is the decidua, a derivative of the endometrium. Between these two plates, there is a voluminous intervillous space. placental examination is necessary to understand the causes of perinatal deaths. Documentation of findings and submission of tissue for pathologic evaluation based on abnormal appearance or various maternal clinical disease is mandatory.
Author (s) Details
Banushree Chandrasekhar Srinivasamurthy
Department of Pathology, Indira Gandhi Medical College and Research Institute, Puducherry, India.
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