An average pregnancy lasts 40 weeks while the actual gestation period in humans is approximately 38 weeks. This is why a baby born any time after 38 weeks is considered a full-term born baby. The due date of delivery is usually calculated by either of the various methods such as the LMP, the ‘Neigel’s Law’ or the pregnancy cycle. All these methods help in calculating the estimated date but only 5% of women actually give birth on their due date. Let’s take a look at the due date calculation and Pregnancy Journey in depth.
What is the due date of delivery?
The date on which your baby is expected to be born is known as the due date of delivery. It usually lasts about 40 weeks from the first day of your last menstruation. But if you know the exact date of conception, then from that day onwards, your delivery time will be exactly 38 weeks.
Your doctor may change your due date during your pregnancy depending on the child’s development or other reasons. The due date helps your doctor schedule various prenatal tests, estimate fetal development, and consider whether an intervention is needed when the delivery date has passed.
Calculation of due date of delivery
Every doctor calculates the due date of delivery in his / her preferred way. You can find a variety of methods online to estimate the due date. However, the three most popular methods in use are:
- ‘Neigel’s rule’ for calculating the due date of delivery
This rule is named after the German obstetrician ‘Franz Karl Neigel’, and according to this rule, pregnancy lasts for 280 days and a menstrual period of 28 days. This means that your expected due date (EDD) can be estimated by adding 280 days (9 months and 7 days) to the first day of your last menstruation. But if your menstrual period is short, suppose it is 27 days, then you have to add one day less, ie 9 months and 6 days, etc. If your cycle is long, then you need your E.D. Additional days have to be added to 9 months and 7 days to estimate.
- The date of conception method to calculate the due date of delivery
It is also known as the LMP (last menstrual) method, and in this method estimates the expected due date of your delivery based on the date of your pregnancy. According to the principle of this method, the majority of women have a menstrual period of 28 days and in this case, ovulation occurs on the 14th day or slightly further back. In this method, 40 weeks are added to the date on which your last menstruation occurred. From this date, you reduce the time of two weeks to get the expected due date of delivery. This is for ovulation that may have occurred within the first two weeks after your last menstruation.
- pregnancy wheel
The pregnancy wheel, also known as a gestational calculator, has become an easy way to estimate your expected delivery date. It calculates the due date of your delivery based on your last menstrual date.
Generally, it also contains information about the various stages of your pregnancy. A pregnancy wheel has separate sticks to display the months of the year, the stages of prenatal development, and the beginning and end of the quarters.
Can the calculated delivery due date be incorrect?
None of the methods of calculating the expected due date of delivery are defect-free and cannot be guaranteed that your baby will be born on a particular date. Delivery is normal two weeks before or after your expected due date. Statistics indicate that only 1 in 20 women give birth on their due date. About 10 percent of women conceived for the first time give birth two weeks after the expected delivery date. In addition, about 70 percent of pregnancies that last until after the due date of delivery are usually mistaken for date calculations.
Suggestion for due date of delivery
As your due date draws closer, a lot of emotions are in you – from anxiety to joy and then relief that the long wait is almost over. At this time due to lack of space in your womb for your baby, your physical malaise will be at its peak – this is for sure. If this is your first child, you may be troubled by labor and worry about giving birth. So, here is what you can do in those last days:
Exercise – Continue to do any exercise that you have been doing during pregnancy. It can induce labor and help make you flexible for labor.
Check for things to be kept in the hospital bag – it would be better if you check the things you keep in the hospital bag. See if there is something you have forgotten that you or your baby may need in the first two days.
Sleep well – Sleep as much as you can during the day. Once your baby comes home, sleep is bound to get worse during the first few months!
frequently Asked question
- How accurate is the due date of delivery?
About 5% of all infants are born on the due date of delivery. 90% of infants are born two weeks before or after their due date. Any time between 37 weeks to 42 weeks is considered normal.
- Can the due date change?
Yes, due date may change depending on various reasons like fetal development, problems in pregnancy and overall health of the mother.
- Are there any other methods to calculate the due date?
Yes! Ultrasound can also help you know the expected due date. These are usually done between eight and twenty weeks of pregnancy. Measurements of various parts of the child’s body and organs help doctors and radiologists to find out the stage of an estimated pregnancy. The first-quarter ultrasound is considered the most accurate for the due date estimate.
- What if I do not know my last last menstrual date?
There are other ways by which your doctor can determine the due date, such as ultrasound.
- What if my menstrual cycle lasts long or is irregular?
In such cases, the pregnancy wheel can help in calculating the due date of the child.
In addition to the obvious benefit of knowing when your baby is likely to be born, knowing when your due date is can be helpful in a few other ways. It gives you an idea of the amount of time you will have to prepare a baby room and also helps you determine when to start pregnancy and maternity leave. But remember that this date is just an estimate and should not worry about it. Just take care of your health and your unborn baby’s health and well-being!