Dear Ma Bao, how is the expected date of delivery calculated, and why is it not accurate?

The expected date of delivery itself is an estimate, and there is no absolutely accurate time. According to statistics, pregnant mothers who give birth in the expected date of delivery only account for 5% of the total number of deliveries, and the rest give birth two weeks before and after the expected date of delivery.

What do you mean due date? The expected date of delivery refers to the expected date of delivery, which is generally calculated by the time of the last menstruation. For example, your last menstrual period was February 1.

Month +9(2+9= 1 1 month)

Date+7 (1+7 = 8th)

Then the expected date of delivery is 165438+ current year1October 8. This is for pregnant mothers with normal menstrual cycles. If menstruation is irregular, the calculation can be more accurate according to the results of B-ultrasound.

At the 0/2 week of pregnancy/kloc-that is, the first filing examination, the doctor will estimate the more accurate expected date of delivery according to the development of the fetus's biparietal diameter and femur length.

Dear Ma Bao, how is the expected date of delivery calculated, and why is it not accurate? My two babies were born in the 37th week, just full-term. My sister's baby was born in the whole week of 4 1. The difference between the two sisters is one month, but they are both healthy full-term babies. Therefore, the date of the expected date of delivery is not so accurate, which is specifically affected by the following aspects.

Fifth, the menstrual cycle is different: each woman's menstrual cycle is different, generally between 28-30 days. Some women may be more than 30 days, and some are less than 28 days. For example, I do it once every 25 days, and every time it is regular, so the baby's birth date is also advanced.

When the next period comes, it is estimated that 14 days will be the ovulation day. If your menstrual cycle is longer, ovulation will be delayed and pregnancy will be later.

Fetal development is different: the development of the fetus during pregnancy is not exactly the same. Some babies develop fast, while others are relatively slow. These are related to the nutrition during pregnancy and the development speed of the fetus itself, which is also the main reason for the different expected date of delivery.

Fifth, the pregnant mother's own situation: some pregnant mothers have stable mood during pregnancy, regular work and rest, and healthier diet. The fetus can get enough nutrition and develop better.

In addition, the activities of pregnant mothers will also affect the delivery time. Some mothers often exercise, have good physical fitness, open their pelvis quickly and have children early. I am pregnant with Dabao for 9 months, and I am still at work. I often do housework at ordinary times, and my baby is also very good.

What should I do if the due date is advanced or postponed? Take myself for example, I was born in 37 weeks, in fact, more than half a month early. From a medical point of view, it is normal as long as the fetus gives birth at 37~4 1(+6 days) weeks. If the baby is delivered before 37 weeks, it is premature. However, the general survival rate of babies born after 28 weeks is 95%.

Pregnant mothers with signs of premature delivery should be hospitalized as soon as possible, and prepare supplies for labor, reduce activities and stay in bed more.

If you haven't delivered before the due date, don't worry. Some babies are slow to respond, and childbirth itself is a natural process. Pregnant mothers can continue prenatal examination, shorten the interval between each examination, and at the same time do a good job in fetal heart monitoring to understand the healthy environment in the uterus. As long as these are normal, you can continue to be pregnant.

You can also walk around more, which can help the fetus enter the basin faster and make the expected date of delivery come faster. Of course, you should also prepare the items you want to send, put them in a conspicuous position, and tell your family. If there are signs of labor (see redness, water bursting, regular contractions), be sure to stay in hospital for labor.

In short, the expected date of delivery is not the standard time. Pregnant mothers should develop good living and eating habits and have a checkup on time. The baby will meet you at a specific time. Neither early nor late, just that day.

Dear Ma Bao, how is the expected date of delivery calculated, and why is it not accurate? Why is the due date calculated by my own doctor inaccurate, while the due date of several of my friends is quite accurate? Did the doctor miscalculate? When it comes to 10 pregnancy, it is not dozens of months from the first day, so there is no way to determine the possible date of pregnancy. Medically, there is no difference in pregnancy in October, but the whole pregnancy is 40 weeks. The checklist of pregnant mothers takes "week" as the calculation cycle, such as the calculation method of pregnancy 14 weeks and 20 weeks, to remind pregnant mothers what to do or pay attention to at this time or in the next few weeks.

In order to calculate the accuracy of the results, we take 40 weeks of pregnancy as the calculation base. We should know that not all pregnant mothers will be pregnant until 40 weeks, which is very small. As long as the intrauterine baby is a full-term baby after 39-4 1 week of intrauterine development, the baby born during this period will not have any influence and discomfort, and the physical function and brain are fully developed, which is a full-term pregnancy.

40 weeks of pregnancy, as mentioned above, is not counted from the first day of pregnancy, but from the end of the last menopause. Because the last menstruation is the only correct date that the pregnant mother can determine, although we can determine the ovulation date through testing, the existing technology cannot determine the time when sperm and eggs combine, because this process will last for 2-6 days before they combine with each other, and their combination is a very complicated reaction, which is difficult to describe, so the date of last menopause is used to calculate the start date of pregnancy.

Usually 40 weeks pregnant, when the pregnancy is confirmed, it has been about 2 weeks since the pregnant mother was really pregnant, so when she finally gave birth, she was actually only 28 weeks pregnant, because the first 2 weeks were counted, even though the pregnant mother was completely unaware.

It should be noted that if the pregnant mother is a woman with irregular physiological cycle, it is not very accurate to determine the expected date of delivery by the last menstruation. Although simple calculations can be made by basic mathematical methods, the accurate determination of the expected date of delivery can still refer to the results displayed by B-ultrasound examination. This examination needs to be carried out in the sixth to ninth week of pregnancy, because at this time, the size of the embryo can be determined by B-ultrasound examination, and the size of the pregnant mother's uterus will bring an accurate data to the pregnant mother.

Tips Tadpole mother's pregnancy is a matter of two people, but it takes at least three people's efforts to ensure the baby's safe and healthy growth and development until delivery. Pregnant mothers, prospective fathers and doctors, pregnant mothers and prospective fathers have completed nearly half of the pregnancy tasks, so pregnant mothers should consult the attending doctor for professional advice and help if they have any discomfort or doubts.

How to calculate the expected date of delivery is very important, but many pregnant mothers don't know how to calculate the expected date of delivery. Today, I will tell you how to calculate the expected date of delivery.

I. Introduction to the Expected Delivery Date

The estimated delivery date is the estimated production date. First of all, understand the next pregnancy: maternal pregnancy 10 month, 28 days a month, that is, the whole pregnancy is 280 days and 40 weeks.

Second, the calculation method of the expected delivery date

According to the last menstrual period.

Estimated Month = Month of Last Menstruation +9 (or -3)

Expected date of delivery = date of last menstruation +7.

That is, month +9 or -3, day +7.

For example:

The last menstrual period is July 20 12, 12 years, so the expected date of delivery is 7-3 = 4, and the expected date of delivery is12+7 = 19, that is, the expected date of delivery is 20 13 years in April,/.

The last menstrual period is February 3rd, 20th12nd, so the expected date of delivery is 2+9 =11,and 3+7 =10, which means the expected date of delivery is 201/.

I am a senior nurse who helps mothers. I personally believe in "parenting classics" to help you solve the problems on the way with your baby ~

We should also understand from the word "advance" that the expected date of delivery and the expected date of delivery are not completely accurate, at least they should not be accurate to "days", although this is based on scientific physiological prediction. Take the weather forecast as an example, it is also based on scientific prediction, but sometimes it is really inaccurate. According to scientific statistics, the probability of a child being born at the expected date of delivery is generally only about 5%.

First of all, how is the expected date of delivery calculated? The general obstetrician's calculation method is based on the first day of the last menstruation: year+1, month -3, day +7,

Or year+1, month +9, date +7.

For example, if the date of the first day of your last menstruation is 2018./kloc-0.1,then the expected date of delivery calculated according to the above two methods is 20 19.7.8.

Of course, many pregnant women may not remember the specific time of their last menstruation. Doctors usually ask about a month, the time of early pregnancy reaction, or calculate an approximate expected date of delivery according to the results of B-ultrasound examination. Therefore, these many factors will lead to the estimated delivery date is not very accurate, generally a rough calculation. And as I said before, according to statistics, the probability of a baby born due date is only about 5%.

Let me briefly talk about the length of pregnancy and some common sense about full-term babies.

The whole pregnancy is generally about 40 weeks, about 280 days, and the expected date of delivery is 40 weeks, which means that pregnancy is in October. 37 weeks to 42 weeks can be regarded as a full-term baby. In fact, the expected date of delivery of many pregnant women can be as accurate as one week. Many mothers around me are in this situation, and some can even be accurate to the sky. However, the expected date of delivery of my two babies is a little different. When Dabao was born, the expected date of delivery had not moved for a week. Later, amniotic fluid decreased during prenatal examination. Induced labor in hospital for three days, and natural delivery failed. I finally had a caesarean section. Bauer had a caesarean section at 38 weeks. When I was in the hospital, I also met many babies who passed the expected date of delivery and were finally born through induced labor. In fact, as long as the baby is born one or two weeks before and after the expected date of delivery, it is normal and generally healthy. Our mother does not have to worry too much about the accuracy of the expected date of delivery.

The main factors affecting the inaccurate expected date of delivery are as follows: First, the last menstrual time provided by pregnant women at the time of filing in the hospital is inaccurate, which leads to the deviation of doctors' calculations. In fact, many mothers, especially those who are pregnant unexpectedly, may really forget the specific time of their last menstruation, and provide doctors with an approximate time when they file in the hospital, so it will cause some time deviation.

Second, the menstrual cycle of pregnant women is irregular and the length of the cycle is different, which leads to inaccurate calculation of the expected date of delivery. The algorithm for calculating the end of menstruation is based on the average menstrual cycle of 28 days, so if the menstrual cycle of pregnant women is irregular, it will also lead to the deviation of doctors' calculation.

Third, uncontrollable external factors such as the physical quality and mood of pregnant women will also lead to the deviation of the expected date of delivery. For example, some pregnant women may affect the fetus because of anger or some unexpected factors when they are near pregnancy, leading to the early birth of the child.

Matters that pregnant women should pay attention to and some things that need to be prepared when the expected date of delivery is approaching. First, pregnant women must follow the doctor's advice when approaching the expected date of delivery. It is especially important to check the baby's fetal heart rate and amniotic fluid, especially within half a month of the expected date of delivery. You should always pay attention to the baby's fetal movement. As long as there are abnormalities, go to the hospital for examination. When I gave birth to Dabao, I suffered a big loss because I didn't have a prenatal examination on time. A few days before the due date, I had a prenatal examination. The doctor said it was normal and asked me to check it again three days later. After three days, I felt all right. I feel that the due date is coming soon anyway, and I live next to the hospital. If anything happened, I went straight to the hospital. Then several days passed, and nothing happened until almost a week after the due date. Go to the hospital for examination. The doctor said that the amniotic fluid was low, so he should come earlier. Why are you so worried? Later, I quickly induced labor. Three days later, the baby failed to give birth naturally and had a caesarean section.

Second, now medicine advocates natural delivery, mainly natural delivery. A natural baby may be healthier, and the mother will recover quickly after delivery, so a mother who wants to have a natural baby can climb the stairs more appropriately, take a walk outdoors after dinner, and don't go to a crowded place to bask in the sun properly.

Third, the expected date of delivery is approaching. If you find redness, water breakthrough or regular pain in your lower abdomen, you need to go to the hospital quickly. These are all signs that your child may be born.

Fourth, pregnant women who are approaching the expected date of delivery should prepare their luggage with their families. Generally speaking, bags can be prepared one to two months before pregnancy and delivery. Bags usually include mother products and baby products. At that time, many of our products were found online. Let me pick some important ones. For example:

1, breast pump and disposable milk storage bag. The breast pump is really useful. It is a very painful thing for a mother to raise milk after childbirth. Breast pumps can help mothers to breastfeed. It is recommended to buy automatic ones, otherwise it will kill people. Postpartum colostrum has high nutritional value and contains many immune proteins and antibodies. Novice mothers must remember that the milk within 4-5 days after delivery is called colostrum, which is very precious. If you can't drink it, you should store it temporarily, otherwise there will be no shop after this village. Therefore, when you are in the hospital, you should prepare some milk storage bags, store the mother's colostrum a few days ago, and then slowly give it to the children.

2, care for underwear, and prevent overflow as a pad. These are really useful, especially when breastfeeding in winter, and the spilled milk is easy to get wet, so this is also necessary.

3. Straps, postpartum disposable mattresses and padded sanitary napkins. These things are also very useful in mother's postpartum recovery and postpartum care.

4, baby clothes, bottles, kegs of milk powder, quilts, diapers, etc. It's better for the baby to change his clothes into jumpsuits, which is more convenient for the child to take a shower and change clothes. Within 24 hours after the baby is born, the mother generally has no breast milk and needs milk powder transition, so it is necessary to prepare milk powder bottles.

5, washbasins, towels, soaps and other toiletries for pregnant women, as well as straws and napkins can also be prepared, but these things can generally be bought temporarily.

Dear Ma Bao, how is the due date calculated?

The calculation formula of expected date of delivery: the last menstruation, minus three months, plus seven days.

For example, the last menstrual period was 10+0.

Then the due date is:

Month = 10-3 = July;

Days = 1+7 = 8 days;

The expected date of delivery is July 8 next year. Will everyone forget?

Accuracy of estimated delivery date

Generally speaking, women's menstrual cycle is generally 28-30 days. If the menstrual cycle is regular, it is generally more accurate!

So to a certain extent: the accuracy of the expected date of delivery = the accuracy of the female holiday cycle.

Why are some due dates not allowed?

1, which may be the main reason of inaccurate menstruation, physiological cycle, disobedience and irregularity.

2. The expected date of delivery refers to the expected date of delivery of women, but the expected date of delivery is only a prediction. Not the exact delivery date. Therefore, it is normal to advance 2 weeks or postpone 2 weeks.

Therefore, Ma Bao cannot fully determine the expected date of delivery. One month before delivery, she should make preparations for delivery in advance and be ready to welcome the baby at any time! ~

Dear Ma Bao, how is the due date calculated? Why is it inaccurate?

The expected date of delivery is only a rough calculation, just reminding the pregnant mother that I am going to give birth soon, so the pregnant mother should start preparing the package that has not been given birth just one week in advance or one week later, so it is possible to avoid the baby giving birth early or a few days later, and don't be too nervous.

Why is the expected date of delivery inaccurate? How to calculate the expected date of delivery? For example:

The last menstrual period is September 22nd, 20 19, and the expected date of delivery is June 29th, so the expected date of delivery is June 29th, 2020.

2. According to color Doppler ultrasound, doctors will measure the biparietal diameter, head circumference, abdominal circumference and the length of humerus and femur of the fetus when doing color Doppler ultrasound, so as to estimate the gestational age and weight of the fetus and calculate the expected date of delivery.

Therefore, during the whole pregnancy, pregnant mothers don't have to worry too much about the expected date of delivery, as long as they have a checkup on time. If there is any discomfort during the period, they will naturally start when the baby wants to come out. Don't worry too much, just keep a good mood, exercise properly and wait quietly for the healthy birth of the fetus.

Usually, the calculation method of expected date of delivery is based on the calculation algorithm of last menstruation. The calculation algorithm of last menstruation generally requires pregnant mothers to provide accurate menstrual cycle and the time of last menstruation.

Then the last menstrual calculation algorithm is like this. The first week of a pregnant mother's last menstruation counts as one week of pregnancy. If the pregnant mother is not good at calculation, she can turn over the monthly calendar, count the week of pregnancy from the week of the last menstruation, and then count it back to the 40th week, which is the expected date of delivery.

I've encountered inaccurate due dates before.

But my menstruation may be chaotic, and each menstrual cycle is different, lasting 35-38 days. In other words, it will be delayed by about 1 week every month. I also explained my situation to the doctor, but the doctor said that it should be calculated in a 30-day cycle first.

Later, I always missed a week of B-ultrasound, and after two weeks in the second trimester, I asked the doctor why. According to my information, the doctor speculated that there might be something wrong with my expected date of delivery, because my menstruation is basically delayed by one week every month, and it is very regular. Then the doctor asked me to go to the nurse station to change the expected date of delivery.

At the end of the "royal goods", it happened to be the day when the expected date of delivery was calculated before.

I learned later, because we are not sure when we will get pregnant, and the last menstrual calculation algorithm is the most widely used method to calculate the expected date of delivery. The advantage of this method is that it has high accuracy and is suitable for most pregnant mothers. The disadvantage is that there may be some errors.

In my case, the menstrual cycle is relatively long, so it is inevitable that there will be some calculation errors. For example, pregnant mothers can't remember when their last period was, which can also lead to inaccurate calculation.

Then, why are some people accurate in the expected date of delivery, while others are not? It's not the doctor's miscalculation. Only this last menstrual calculation algorithm is conditional, it is more suitable for the regularity of menstrual cycle, and pregnant mothers can accurately provide the date of last menstruation. In this case, most expected delivery dates will be more accurate.

However, calculating the expected date of delivery is only a calculation after all. It is possible that the actual delivery date may be around the expected date of delivery 1-2 weeks. Pregnant mothers don't have to worry too much, because the baby will be full-term after 36 weeks of pregnancy.

Should be counted from the last day of the last menstrual period, 280 days is full-term, that is, 28 days per month, 10 month pregnant, 280 days is 40 weeks. The delivery is normal within one or two weeks around 40 weeks. The calculation method is: add 9 to the month or subtract 3, and add 7 to the day. For example, the last menstruation is 2065438+ 1 1.

Before giving birth to a baby, a head nurse who helped me told me a calculation method, which is: the start date of your last menstruation, plus +9 (month) and +7 (day).

For example, the last menstrual period is 1.2, and the calculation method is:

1.2+9.7 = 10.9:

The production is expected to be 65438+1October 9th.

If the number of months is greater than 12, subtract 12, and if the number of days is greater than 30, subtract 30. The remaining number is your due date.

For example:

The starting date of the last menstruation101October 25th, calculated as follows:

10 .25 + 9.7 = 19.32

19- 12 = 7 (month)

32-30 = 2 (days)

The expected delivery date is July 2.

Also, because everyone's physical condition is different, everyone's menstrual cycle is different. Some people have a cycle of about 40 days, some people have a cycle of about 30 days, and some people only have more than 20 days. Therefore, according to the individual's physical condition, it is within the normal range to give birth one week before the expected date of delivery, or to postpone it for one week.

Finally, I wish you a healthy, happy, lively and lovely baby!

There are many ways to calculate the expected date of delivery, but all of them are based on the last menstruation.

First, add 9 to the month and 7 to the date of the last menstruation. The other is to directly search for the expected date of delivery calculator in Baidu, and you can directly calculate the expected date of delivery as long as you enter the date of your last menstruation.

As for your inaccuracy, there are many factors.

1. Your normal vacation is irregular. The rule here does not mean that every time you come, it is a rule only if you come, but for example, once every 20 days or once every 30 days. This is a rule.

2. The implantation time of fertilized eggs. The time of sexual intercourse is not necessarily the time when the fertilized egg is implanted. Some fertilized eggs are implanted early, and some are implanted late, so this is also related.

3. The time when the child was born. It is normal that some children who give birth naturally will come out earlier than the expected date of delivery, while others will postpone the expected date of delivery. Not to mention caesarean section, the date is up to you.

Of course, this is if everything goes well. Others will be born prematurely, which is uncontrollable. Finally, I wish you a super-fast delivery and safe mother and child.