When you’re planning a baby and get a positive test result, the next biggest news you’d want to hear is when your little munchkin will arrive. That’s why there are due date calculators, which might not give you the exact date but can surely give you a head start on when you can expect.
Here’s everything you need to know about the due date calculation. But how accurate are they? Let’s find out!
Estimate Date Of Delivery (EDD)
The due date, which is technically called the estimated date of delivery or EDD, is the date when labor is expected to start. This date can be calculated using a pregnancy due date calculator. But it must be noted that it is simply a guess, and only twenty percent of women give birth on their estimated due date. Labor will most likely begin between two weeks before or after your due date.
How Many Weeks Pregnant Am I?
If you want to figure out how many weeks pregnant you are, you can do so using two methods- fetal age and gestational age.
Fetal age indicates the age of the developing kid. The gestational age, on the contrary, is used to keep track of the pregnancy and determine the due date. It is used to determine how far along you are in your pregnancy in weeks.
So, how can you calculate your gestational age?
The time between conception and birth is referred to as gestation. It is calculated as the number of weeks between your last menstrual period (LMP) – the first day of your previous menstruation — and the present date.
All of this can be a little complicated. So how can you estimate your due date in an easier manner? This is where the due date calculator comes in.
How Does A Due Date Calculator Work?
To determine your due date, the pregnancy due date calculator uses four methods:
- Last menstrual period
- Ovulation or conception date
- IVF transfer date
- Ultrasound scan
Now comes the final and the most important question, are these estimated due dates accurate?
Due Date Calculation
For most expecting mothers, the average pregnancy lasts 280 days or 9 months. The due date is calculated by adding 280 days to the beginning day of your last menstruation.
This calculation is usually based on a 28-day cycle, with the menstrual period and ovulation occurring within the first two weeks of pregnancy. Because the usual duration of your menstrual cycle affects this procedure, it does not always give an accurate result.
The pregnancy due date calculator uses various methods to calculate the due date. They are:
| Calculation Method | Principle |
| Last menstrual period | Due date is calculated by adding 280 days to the beginning day of your last menstruation |
| Ovulation or conception date | Due date is calculated by adding 266 days to the date you conceived
Note: Your conception can be many days after having unprotected intercourse. |
| IVF transfer date | Ovulation: Due date is 266 days (or 38 weeks) after if you’re having intrauterine insemination.
Embryo transfer (3 days): Due date is 263 days after the day of transfer. Embryo transfer (3 days): Due date is 261 days after the day of transfer. |
| Ultrasound scan | Your OB or midwife will determine the due date based on an ultrasound scan. |
Are Due Dates Accurate?
A research was conducted by the Centers for Disease Control and Prevention in 2017. Here’s a summary of the percentage of newborns and what week they were born.
| Percentage of newborns | Born at |
| 10% | Before 37 weeks |
| 26% | Between 37 weeks to 38 weeks |
| 57% | Between 39 weeks to 40 weeks |
| 6% | Week 41 |
| Fewer than 1% | Week 42 |
According to the study, 57 out of 100 newborns were born between weeks 39 and 40. The percentage of premature births is 10%. Premature babies are born before their due date, that is before 37 weeks. It can also be seen that about 6% of newborns and less than 1% are born at 42 weeks.
Final Thoughts
Whether it’s the first time or not, the news of your pregnancy will surely get you excited. And you’d be eager to know your due date and plan for the baby. In this aspect, the pregnancy due date calculator will really help you estimate a date for the arrival of your little one.
FAQs: Are Due Dates Accurate? Let’s Find Out!
- What is EDD?
The due date, which is technically called the estimated date of delivery or EDD, is the date when labor is expected to start. This date can be calculated using a pregnancy due date calculator.
- How does a due date calculator work?
To determine your due date, the pregnancy due date calculator uses four methods:
- Last menstrual period
- Ovulation or conception date
- IVF transfer date
- Ultrasound scan
- Are due dates accurate?
According to a study conducted by the Centers for Disease Control and Prevention in 2017, 57 out of 100 newborns were born between weeks 39 and 40. The percentage of premature births is 10%. Premature babies are born before their due date, that is before 37 weeks. It can also be seen that about 6% of newborns and less than 1% are born at 42 weeks.
