If truth be told, a pregnancy due date is in real sense only an estimated due date. This is because you might, or might not deliver on the exact date given by a due date calculator or your doctor. Actually, your chance of delivering on your given due date is only 3-5%.
1. Reasons Why Doctors Call It Estimated Due Date – Unknown Date of Conception
There are various factors that affect the accuracy of a due date, with conception being among them. Doctors believe that a healthy pregnancy runs for 40 weeks, which is the equivalent of 280 days (Naegele’s law). Conception is believed to take place within 11-21 days after the first day of the woman’s last period (LMP). Unless a woman is 100% sure of her conception date, it is not possible to predict her due date 100% accurately, not even with our due date calculator.
2. Reasons Why Doctors Call It Estimated Due Date – Dimension of the Uterus
The exact dimension of the uterus, also known as The Fundus measurement has also been known to make a difference to pregnancy due dates. When a woman’s uterus is large enough, she is very likely to give birth sooner than her estimated due date and when her uterus is a bit smaller, she can expect to deliver later than her due date.
3. Reasons Why Doctors Call It Estimated Due Date – Expansion of the Cervix
The other reason that is likely to change a woman’s due date is her cervix. If, after, a checkup her doctor notices that her cervix has started to expand weeks before her due date, then there is a likelihood of an early birth. The cervix expands to prepare for labour pains or cramps and it usually starts expanding in the 3rd trimester of pregnancy. With this in mind, an experienced doctor or midwife can confidently say that a due date is in real sense only an estimated due date.
4. Reasons Why Doctors Call It Estimated Due Date – Baby’s Position
The baby’s position is also among the various reasons doctors call a due date an estimated due date. When the baby positions its head downwards early, there is higher chance of early delivery. If, however, the baby’s head is still not positioned correctly by the time the due date arrives, the doctor might start thinking of scheduling a C-section delivery, especially when the pregnancy proceeds to 42 weeks.
5. Reasons Why Doctors Call It Estimated Due Date – Genes/ Family history
Genes or family history also have a say when it comes to pregnancy due date, or estimated due date. If a woman has a family history of early or preterm labour, she also stands a chance of early delivery. This also applies to a woman whose family has a history of overdue pregnancies under which an overdue pregnancy might be possible. In spite of everything, there are a few women (3-5%) who actually deliver their babies exactly on their given due dates.