Question: what are the causes of post term pregnancy

title: Postterm pregnancy
text: The causes of post-term births are unknown , but post-mature births are more likely when the mother has experienced a previous post-mature 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 . Post-mature births can also be attributed to irregular menstrual cycles . When the menstrual period is irregular it is very difficult to judge when the ovaries would be available for fertilization and subsequent pregnancy . Some post-mature pregnancies are because the mother is not certain of her last period , so in reality the baby is not technically post-mature . However , in most countries where gestation is measured by ultrasound scan technology , this is less likely . 

Answer: answer: The causes of post-term births are unknown. Post-mature births can be attributed to irregular menstrual cycles or due dates are easily miscalculated when the mother is unsure of her last menstrual period.