Table of fetal weight and length according to WHO standards

This is an automatically translated article.

The article was professionally consulted by Specialist Doctor I Tran Thi Phuong Loan - Obstetrician and Gynecologist - Department of Obstetrics and Gynecology - Vinmec Phu Quoc International General Hospital
The table of standard fetal length and weight by week of age is a reference measure so that pregnant women can get an overview of their baby's development while in the womb. From there, it helps the mother to change the lifestyle and exercise regime of the pregnant mother accordingly.

1. International standard fetal weight chart

Fetal weight table is measured horizontally, for example: fetal weight at 33 weeks is 2kg and 44.1cm long, fetal weight at 34 weeks is 2.2kg and length is 45.3cm.
The standard fetal weight monitoring table is given so that the pregnant mother can closely monitor the change of the fetus week by week. These standard fetal weight indicators are given for each week of pregnancy, starting from the 8th week until the end of the 40th week of pregnancy. After examining and comparing with the fetal weight monitoring chart, the pregnant mother will know if her baby is developing well or not? Is the fetus smaller or larger than the standard fetal weight? From there, pregnant women will have a change in diet, nutrition, and exercise so that they are reasonable.

2. How to measure the length and weight of the fetus by week of age

Specific measurement according to each stage of gestational age is as follows:
From 8 to 19 weeks: baby is measured in length from head to rump. At this time, the baby's legs are bent in the fetus during the first half of pregnancy, so it is difficult to accurately measure the weight and length of the baby. This measured length is called the butthead length. From week 20 to 42, your baby's length is measured from head to toe: During this time, the size and weight of the fetus will gradually increase. From the 32nd week, the baby's weight will develop to the maximum, the final contours of the baby are completed. The development of the fetus through each specific week is:

3. Factors affecting fetal weight

There are many factors affecting fetal weight during pregnancy, including both objective and subjective factors such as:
3.1. Due to genetic factors and racial differences This means that the weight of the fetus may have similarities with the weight and physique of the parents. In each ethnic group, each country is different, there will be different fetal weight indicators.
3.2. Mother's health during pregnancy If pregnant women have diseases such as diabetes, obesity, they will tend to give birth to larger and heavier babies than other mothers. On the contrary, if the pregnant mother does not gain weight or gains too little weight, there is also a risk that the fetus will be malnourished. This is reflected in the weight index of the fetus while still in the womb.
3.3. Birth order In fact, the second child is usually larger than the first, but if the birth interval is too short, the opposite can happen, the second child weighs less than the first.
3.4. Number of fetuses Pregnant with twins or multiples, the fetal weight will also be lower than the standard fetal weight chart.

4. Notes on fetal weight standards

After examining and finding that the weight of the fetus has a big difference compared to the standard table of fetal weight, pregnant women need to be very careful. Because this can be one of the warning signs of some problems with the health and development of the fetus.
If weekly, the fetus grows more than the standard chart of fetal weight, especially in the last months of pregnancy, it is likely that the baby has grown larger than the gestational age. When the fetus is too large, it will cause difficulties during labor and delivery. If the baby's size is about 3cm larger than the standard table, the fetus will be at risk of diseases such as diabetes, obesity... right from the womb.
If the fetus has indicators much lower than the standard fetal weight chart by week, the ultrasound results compared to the fetal weight chart, the baby's length is 3cm shorter than the average length, the pregnant mother needs to quickly During the examination, the doctor will order you to perform some tests to find the cause. You may have a placental function test to see if the placenta is transporting enough nutrients to your baby, and to check for abnormalities in the umbilical cord.
At the same time, the doctor will ask you carefully to know if your diet is safe for the development of the fetus or has problems that adversely affect mental health. After determining the cause, your doctor will guide you on appropriate adjustments, such as changing your diet, resting and relaxing properly. Mothers need to make appropriate changes to improve the weight of the fetus.
If the fetus is too low weight, the baby may be malnourished from the womb, prone to lung diseases, the child's resistance at birth will be lower, and it may even affect the development of the baby. develop children's intelligence later...

5. What should be done to properly weigh the fetus by weeks of development?

Pregnant women do not eat too much but must have enough nutrients. Control your weight, don't let it happen too much or too little. During pregnancy, pregnant women should increase body weight only from 10-12kg. If you are pregnant with multiples, you can gain about 16-20 kg. In the first 3 months of pregnancy, the weight should only increase no more than 1.5-2kg. If your doctor warns you that you are underweight, you need to gain about 2kg more. If you are overweight, during the first 3 months of pregnancy, you may not need to gain weight or only gain no more than 1 kg. During pregnancy from 14 to 28 weeks, you can gain about 0.5 kg per week, but if you are overweight, you should limit your weight gain to about 0.2 - 0.3 kg / week only. There should be a proper rest and exercise regime. Do not be too stressed, because this also affects the weight of the fetus. Periodic antenatal check-up to understand the growth and weight of the fetus by week of age, if there is a big difference compared to the fetal weight table, it is necessary to change according to the doctor's advice to overcome the situation. this. The entire pregnancy monitoring process under the all-inclusive maternity care program at Vinmec International General Hospital is strictly carried out, minimizing all fetal problems, some of which can be treated. Right from the fetal stage, some have to wait until birth to be treated. At Vinmec, we have solved many difficult cases such as: comb teeth, knotted umbilical cord, pregnancy care,..
Depending on the abnormality, you will be guided and advised step by step: things to pay attention to. next step in pregnancy, make a birth plan for you, make a plan for postpartum care for your baby, plan a cesarean section if needed, guide your baby after discharge from the hospital...
In addition to the visitation process Accurate, scientific antenatal check-up, quality ultrasound system, modern equipped medical equipment will handle abnormalities during pregnancy and labor quickly so that the mother can have a pregnancy. safest period. The system of ultrasound machines and modern medical equipment at Vinmec will handle abnormalities during pregnancy so that the mother can have the safest pregnancy.
When registering for Maternity Package at Vinmec International General Hospital, mothers are comprehensively monitored from pregnancy, fetal ultrasound milestones, to childbirth and postpartum, making childbirth easier more comfortable and lighter.
Doctor Tran Thi Phuong Loan was former Head of Obstetrics and Gynecology Department, An Giang Central General Hospital; Doctor treated at Hoang Anh Gia Lai University of Medicine and Pharmacy Hospital before working as an Obstetrician and Gynecologist at Vinmec Phu Quoc International General Hospital as it is now.

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