Due date is the estimated date of delivery calculated by two methods, using last menstrual period and other one is using conception date.
LMP Method: Using LMP method, you can calculate the due date by adding 40 weeks to first day of your last menstrual period. i.e (Due Date = LMP* + 280 days)
*LMP - Last day of first menstrual period.
Pregnancy is considered from first day of your last menstrual period (if pregnant), menstrual period is the first week of the pregnancy and lasts for approximately 40 weeks, i.e. 9 months 7 days. So, adding this length from the first days of your LMP gives your estimated date of delivery (EDD). This method is known as Dr. Nagele's rule.
Conception Date Method: If you have kept track of your ovulation for that particular month and know on which day your egg must have been fertilized, you could calculate the date based on the conception date. Here the baby due date will be 38 weeks from the conception date.Only a few expectant mothers can accurately know when they have conceived. Your calculations might go wrong as you may not conceive on the day you had intercourse during your most fertile period. The sperm could remain in the fallopian tube for some days until it meets the egg, fertilization occurs, and then you will conceive.
This is why LMP method could be more suitable than the conception date method to calculate the estimated due date. The actual delivery date may be the same or different due to many other factors related to pregnancy.
The expected date of delivery (EDD) is the date on which you are likely to give birth to your baby. It is calculated on certain assumptions and gives an approximate date, helping you to prepare for the ‘D’ day.
Around 280 days or 40 weeks is what is considered for calculation. To be exact, it is nine and one-third months or 10 lunar months.
LMP is the first day of your bleeding during the last menstrual period. You bleed as the uterus sheds the lining formed during the previous cycle. Ovulation occurs around two weeks from LMP, and that is when you become fertile. If fertilization occurs during this cycle, the uterine lining (endometrium) grows to accommodate the baby, thus making you miss your next period.
LMP is also considered for calculation because the date is easier to remember!
LMP may not be the best date for calculation as the actual ovulation and fertilization begin only after two weeks. However, it is a popular way to know your due date as most of the women cannot precisely identify when they have ovulated or conceived. There is no single method which can predict the exact date.
Ultrasound scan, clinical examination of pelvic supported by exact menstrual records in the first trimester, Doppler ultrasonography after 10 to 12 weeks, and Human Chorionic Gonadotropin Pregnancy Test are some scientific methods to calculate the EDD.
EDD is often a tentative date, to make you prepare mentally, and also, take the necessary steps to welcome the baby home. The pregnancy period is usually 266 days or 38 weeks. A healthy delivery can happen anytime from 37 to 40 weeks.
What To Expect From Momjunction’s Pregnancy Calendar:
Significant Milestones in Embryo / Fetal Development:
Use our calendar to know important milestones such as:
Disclaimer: While our tool gives you a tentative due date and other details, it cannot replace a medical consultation. Visit a physician for confirming your EDD based on your complete medical history.
Our calculations are only an indication. MomJunction is not liable for any related issues, consequences or damages.
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