Endometrial regeneration is rapid, except at the placental site. Within a week or so, the free surface becomes covered by epithelium, and Sharman (1953) identified ully restored endometrium in all biopsy specimens obtained from the 16th day onward. Histological endometritis is part of the normal reparative process.
vforeover, microscopic inflammatory changes characteristic of acute salpingitis are seen in almost half of women between 5 and 15 days, however, these findings are not thought to reflect infection (Andrews, 1951).
Afterpains. Several clinical findings arise with uterine involution. In primiparas, the uterus tends to remain tonically contracted following delivery. In multiparas, it often contracts vigorously at intervals and gives rise to aterpains, which are similar to but milder than labor contractions. hese are more pronounced as parity increases and worsen when the newborn suckles, likely because of oxytocin release (Holdcroft, 2003). Usually, afterpains decrease in intensity and become mild by the third day. We have encountered unusually severe and persistent afterpains in women with postpartum uterine infections.
Lochia. Early in the puerperium, sloughing of decidual tissue results in a vaginal discharge of variable quantity. he discharge is termed lochia and contains erythrocytes, shredded decidua, epithelial cells, and bacteria. For the irst few days ater delivery, there is blood suicient to color it red-lochia rubra. Ater 3 or 4 days, lochia becomes progressively pale in color-lochia serosa. ter approximately the 10th day, because of an admixture of leukocytes and reduced fluid content, lochia assumes a white or yellow-white color-lochia alba. he average duration of lochial discharge ranges from 24 to 36 days (Fletcher, 2012). Because of this expected leukocyte component, saline preparations of lochia for microscopic evaluation in cases of suspected puerperal metritis are typically uninformative and not recommended.
Complete extrusion of the placental site takes up to 6 weeks. Immediately after delivery, the placental site is approximately palm-sized. Within hours of delivery, it normally contains many thrombosed vessels that ultimately undergo organization. By the end of the second week, it is 3 to 4 cm in diameter.
Placental site involution is an exfoliation process, which is prompted in great part by undermining of the implantation site by new endometrial proliferation (Williams, 1931). Thus, involution is not simply absorption in situ. Exfoliation consists of both extension and "downgrowth" of endometrium from the margins of the placental site, as well as development of endometrial tissue from the glands and stroma left deep in the decidua basalis after placental separation. Anderson and Davis (1968) concluded that placental site exfoliation results from sloughing of infarcted and necrotic supericial tissues followed by a remodeling process.