pregnancy, calcium is deposited on the walls of blood vessels, and proteins are deposited on the surface of the placenta, which changes the placenta. This limits the blood flow through the placenta and ultimately leads to placental insufficiency, and the baby is no longer properly nourished. Induced labor is strongly encouraged if this happens. Oligohydramnios – Low volume of amniotic fluid surrounding the fetus. It is associated with complications such as cord compression, abnormal heart rate, fetal acidosis, and meconium amniotic fluid. Meconium aspiration syndrome – Respiratory compromise secondary to meconium present in infant's lungs. Macrosomia – Excessive birth weight, estimated fetal weight of ≥ 4.5 kg. It can further increase the risk of prolonged labor and shoulder dystocia. Shoulder dystocia – Difficulty in delivering the shoulders due to increased body size. Increased forceps-assisted or vacuum-assisted birth – When postterm babies are larger than average, forceps or vacuum delivery may be used to resolve the difficulties at the delivery time, such as shoulder dystocia. Complications include lacerations, skin markings, external eye trauma, intracranial injury, facial nerve injury, skull fracture, and rarely death. Mother Increased labor induction – Induction may be needed if labor progression is abnormal. Oxytocin, a medication used in induction, may have side effects such as low blood pressure. Increased forceps assisted or vacuum assisted birth – operative vaginal deliveries increase maternal risks of genital trauma. Increased Caesarean birth – Postterm babies may be larger than an average baby, thus increasing the length of labor. The labor is increased because the baby's head is too big to pass through the mother's pelvis. This is called cephalopelvic disproportion. Caesarean sections are encouraged if this happens. Complications include bleeding, infection, abnormal wound healing, abnormal placenta in future pregnancies, and rarely death. A 2019 randomized control trial of induced labor at 42 or 43 weeks was terminated early due to statistical evidence of "significantly increased risk for women induced at the start of week 43". The study implies clinical guidelines for induction of labor no later than at 41 gestational weeks. Causes The causes of post-term births are unknown, but postmature births are more likely when the mother has experienced a previous postmature birth. Due dates are easily miscalculated when the mother is unsure of her last menstrual period. When there is a miscalculation, the baby could be delivered before or after the expected due date. Postmature births can also be