Published online by Cambridge University Press: 20 November 2021
Placental adhesive spectrum disorders (PASD) are on the increase. Histologically, the placenta may be adherent to the myometrium without intervening decidua (acreta), invade the myometrium (increta) and/or extend beyond the myometrium and seen via the serosa of the uterus or invade into adjacent tissues like the bladder or parametrium (percreta). Since there are difficulties in defining each entity by ultrasound or by histology and also due to the possibility of histology showing different degrees of invasion in the same case, PASD is the term now commonly used and the previous terminology of morbidly adherent placenta is no longer used. The main contributor towards PSAD is previous caesarean section (CS). With the global increase in CS, the incidence of PASD and related morbidity and mortality is on the increase.