<prompt> Post term labour is seen in:HydramniosPIDAnencephalyMultiple pregnancy  <response>: Causes of Post-term pregnancy:Wrong dates: due to inaccurate LMP most common.Biologic variability Hereditary may be seen in the family.Maternal factors: Primiparaelderly multiparaHo previous prolonged pregnancy, sedentary habit.Fetal factors: Congenital anomalies: Anencephaly Abnormal fetal HPA axis, adrenal hypoplasia Diminished fetal cortisol response.Placental factors: Sulphatase deficiency Low oestrogen. 