For any expecting parent, learning their expected date of birth (EDD) is a momentous occasion. It provides you with a timeline for significant pregnancy milestones and aids in your preparation for the birth of your child. Using the date of your last menstrual period (LMP) is one of the most popular methods for calculating the EDD. Medical professionals and midwives use this easy-to-use technique frequently.
Since your last menstrual cycle initiates the start of your pregnancy cycle, it offers a dependable starting point. You can predict when your baby will likely be born based on this date. It’s crucial to keep in mind that this computation is only an estimate, as only around 5% of babies are delivered on their due date!
By being aware of your EDD, you and your healthcare provider can plan prenatal tests, keep an eye on the baby’s growth, and get ready for labor. This post will describe how to determine your due date using your LMP and what variables may affect it. We’ll go over additional approaches to estimating the arrival date of your child as well, so you’ll be fully informed and ready for the journey ahead.
| Step | Instructions |
| 1 | Note the first day of your last menstrual period (LMP). |
| 2 | Add 7 days to the LMP date. |
| 3 | Count forward 9 months from the new date. |
| 4 | The resulting date is your estimated due date (EDD). |
- What is EDD?
- How to count?
- How to count with an irregular cycle and after IVF?
- Alternative methods of calculations
- By ovulation, conception
- By fetal movements
- Ultrasound
- Video on the topic
- HOW TO QUICKLY CALCULATE THE EXPECTED DATE OF BIRTH? #shorts #EDD #pregnancy #birth
- How to calculate the expected date of birth (EDD)?
- HOW TO DETERMINE THE EXPECTED DATE OF BIRTH (EDD)
- Calculate the expected date of birth (EDD) by the last menstrual period
- How to calculate the date of birth by the last menstrual period?
- How to calculate the date of birth? We find out the EDD by menstruation, date of conception and movement. 18+
- CALCULATE the date of BIRTH from CONCEPTION/DATE OF BIRTH/40 weeks of pregnancy
- How to calculate the date of birth (EDD) and the gestational age yourself
What is EDD?
This abbreviation is well known to all women who have been pregnant. For expectant mothers, it has an almost magical meaning. EDD is the expected date of birth. Why expected? Because no one can know the exact date of birth (the day of birth of your child) in advance. There is no such method of medical diagnostics that could say exactly when the baby will be born. The only exception to the rule is a planned cesarean section, but even in this case, the operation date is usually set shortly before delivery. The rest of the time, the woman"s chart also indicates the EDD. The expected date of birth is the last day of the 40th week of pregnancy, its completion. It is considered an approximate guideline for the expectant mother and doctors. In practice, a child can be born on any other day between 38 and 42 weeks, and it will be completely normal.
Merely 5% of babies are born on PDR, according to statistics.
Given that childbirth is a complicated physiological process involving all systems, hormonal backdrop, muscles, and tissue, it will start when both the mother and the child are ready. There isn’t a single technique in existence that can forecast the arrival of this day. However, this date—the final day of 40 weeks—was selected as the base, possibly because it represents the arithmetic mean of all the feasible on-time births (urgent birth).
How to count?
The purported day of childbirth can be found and calculated using a variety of techniques, both manually and with the help of an online calculator that is convenient. The calculation algorithm is the same in both scenarios. The last menstrual date is used as the basis for the deadlines, following the obstetric method. To complete this, all you need to do is accurately recall the beginning of your most recent menstrual cycle.
Many women become confused and mistakenly identify the last day of menstruation as the date of the first day of the last menstrual bleeding. The day that menstruation started is significant because it marked the start of the cycle that led to conception.
Why is this date important? It is simpler than it seems. In medical practice, it is customary to consider it the first day of pregnancy. This may seem absurd, but this method is considered the most accurate. The fact is that you can conceive a baby only on the day of ovulation and within 24-36 hours after it. Then the egg dies, pregnancy becomes impossible. But the date of ovulation can be difficult to establish. It depends on numerous complex hormonal processes in the woman"s body, and therefore can be both early and late. The gold standard is ovulation occurring 14 days before the end cycle. Spermatozoa can get to the egg on the day of ovulation if sex took place on this day. But also male germ cells, due to their natural survivability, can exist in the sexual routes of a woman for several days and fertilize the oocyte even after they are spent in anticipation of 3-5 days. If a woman is healthy, young, has an active sex life, has sex regularly, to establish what kind of sexual intercourse has led to conception, and when it actually took place up to the day, there is no way – too many unknown in one equation. Therefore, they take as a basis the only meaning that is not doubtful and known for sure – the day when the last menstruation began.
- (date of the last monthly + 9 calendar months) – 7 days;
- (date of recent menstruation – 3 months) + 7 days;
- Date of recent menstruation + 280.
It is up to you to figure out which of the formulas to use. Despite using different formulas, obstetricians and gynecologists typically do not perform any calculations at all. Instead, they use a specialized round obstetric calendar with shifting windows that also shows the EDD if you enter the date of your last menstruation.
The calculator available online is far more practical. It computes in precisely the same way, albeit much more quickly: a few seconds after you enter the date, month, and year of your most recent menstruation, the program displays the expected day of conception (EDD), as well as your current period’s accuracy to the week and day. It also provides helpful links to articles about your current period’s development, the baby’s growth, and the physiological changes that an expectant mother’s body goes through.
How to count with an irregular cycle and after IVF?
When determining the due date, the menstrual cycle’s duration is irrelevant. The woman’s ability to recall the exact date of her most recent menstrual cycle is what matters most. The current obstetric formulas cannot be used if she cannot recall this day.
In most cases, an ultrasound is done early on in the pregnancy in order to determine the EDD based on the size of the ovum and the CTE, or crown-rump length of the fetus, depending on the current period.
The calculators and current methods are also not applicable after IVF. Unlike natural conception, in vitro fertilization involves the fusion of germ cells in a lab setting where the precise date of conception is known by medical professionals. Additionally, embryos may be implanted into the uterus at various times and developmental stages, and cryoprotocols may employ previously frozen embryos.
Consequently, you can use calculators to determine the EDD following IVF. Two values must be entered into them: the date of the embryos’ transfer (implantation) and their embryonic age (4, 5, or 6 days) at that time. Obstetric terms are also displayed alongside the result.
By starting with the first day of your most recent menstrual cycle and counting forward 280 days, or 40 weeks, which is the average length of a pregnancy, you can determine your expected date of birth (EDD) based on the last menstrual period. Although individual pregnancies may vary slightly, this technique, also known as the Naegele’s rule, offers an estimate that aids expectant parents and medical professionals in making plans for the baby’s arrival.
Alternative methods of calculations
Auxiliary or alternative methods exist as well for determining the date of birth, but their lower accuracy makes them less common.
By ovulation, conception
The technique is predicated on the woman knowing the precise day of her ovulation. This is typically only achievable with controlled ovulation, which occurs when hormonal agents cause the dominant membrane to rupture and the follicles to mature during the treatment cycle.
In this instance, the follicles are continuously monitored by ultrasonography, and the doctor can determine the day of ovulation to within a day or two. Add 280 to this date, which represents the embryonic period that will determine the birthdate.
Some attempt to determine the birthdate by subtracting the conception date. This method is similar to the one mentioned above because, as we all know, conception can only happen during ovulation. However, a mistake of one to two days is automatically assumed.
By fetal movements
This approach was the only one available to the doctor to validate his mathematical computations and provide clarification on the EDD in the absence of ultrasound. It is thought that the first baby movements are felt by primiparous women at 20 weeks, and by multiparous women at 18 weeks. As a result, in the first case, precisely 20 weeks are added to the date of the first movement, and in the second, 22 weeks.
Since there are many uncertainties and challenges associated with identifying the first movements, particularly in first-time mothers, the method can hardly be considered accurate. The first movement’s exact date is frequently missed because it is mistaken for the fermentation of gases in the intestines.
Ultrasound
It is only in the early stages of pregnancy, up to 10–12 weeks, that ultrasound examination is most effective in determining the gestational age and EDD. Then, a significant error occurs. The truth is that all babies develop nearly equally, even though the processes of embryogenesis are still ongoing and embryos grow at roughly the same rate.
The fetal period, during which the fetus grows and gains weight, starts after all organs and systems have formed. And he will act in accordance with his unique genetic program, which he inherited from his parents: some children are taller than others; some are heavier than others; and as a result, fetometry parameters can vary amongst children of the same gestational age.
It is also important to consider the baby’s sex, as boys typically grow a bit faster in the womb than girls. And figuring out the gestational age gets harder.
One easy and popular way to estimate when a baby might arrive is to use the last menstrual period (LMP) to calculate the expected date of birth (EDD). This method provides expectant parents with an approximate timeline to help them prepare for the new member of their family. It’s crucial to keep in mind that every pregnancy is different and that babies frequently have their own schedules, so this date is merely an estimate.
Although the EDD provides a helpful starting point, it’s typical for the actual delivery to take place a few weeks prior to or following this date. To track the development and health of the unborn child throughout the pregnancy, routine check-ups with a healthcare professional are imperative. These check-ups can guarantee the health of mother and child and help detect any changes that might impact the projected delivery date.
You can make better preparations for the arrival of your child if you are aware of your EDD. Remember that there will be many surprises along the way, so the most crucial thing is to remain open-minded, composed, and prepared for anything that may arise. Savor this unique moment and concentrate on getting ready for a happy and healthy birth.
