How much does a 38 week fetus weigh

Fetus size by week: Your baby's weight throughout pregnancy

Find out how big your baby is during each week of their development with our fetal growth chart. From early in pregnancy, babies grow at different rates, so your baby's actual size by week may vary substantially – but look how they grow! At 20 weeks your baby may be just over 10 inches long and weigh less than 12 ounces, but by 32 weeks they'll reach almost 17 inches and top 4 pounds. At 33 weeks they may be over 17 inches and closer to 5 pounds, and by 37 weeks they'll reach 19 inches and about 6.5 pounds.

How do you determine fetus size by week?

There are different methods for estimating how big a fetus is, which is why you'll find different numbers depending on the source.

Experts have formulas they use to come up with the estimated fetal weight (EFW) and height of a fetus, and the formulas aren't always the same. The measurements that are used in equations to estimate weight usually include biparietal (head) diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur (thigh bone) length (FL).

Height is a straightforward measurement, but the method of measuring it changes after the first trimester. For the first 13 weeks, the height measurement is taken from the top of the head to the baby's bottom. After the first 13 weeks, the measurement is taken from the top of the head to the baby's heel – explaining why, on the chart below, your baby appears to grow 3 inches from week 13 to week 14!

Hadlock, the main source we use in our fetal growth chart, provides one of the most commonly used – and most accurate – equations for estimating fetal height and weight. The American College of Obstetrics and Gynecology (ACOG) and the Society for Maternal and Fetal Medicine (SMFM) use Hadlock's figures to diagnose and manage fetal growth conditions, such as intrauterine growth restriction (IUGR).

The numbers on our chart should coincide with the numbers your healthcare provider will be checking against when they measure your baby using ultrasound. (Providers don't measure height after 13 weeks, however, so don't expect to get those numbers at your ultrasound appointments. )

Note that the data used by Hadlock was gathered from middle-class Caucasian women with no history of maternal diseases known to affect fetal growth and no evidence of congenital anomalies. Your provider may make adjustments based on your individual circumstances.

Fetal growth chart

Wondering how big your baby is during each week of pregnancy? The numbers in our chart below can give you a sense of your baby's size. Keep in mind that your baby may be much smaller or larger than these averages. That's okay – after all, healthy babies can weigh less than 5 pounds or more than 9 pounds at birth.

Boy's measurements are different than girl's measurements, even this early. For the numbers on our chart, we've taken an average of boys and girls. And remember, the height measurements up to 13 weeks are head-to-bottom estimates, while the height measurements starting at week 14 are head-to-toe estimates.

Gestational age	Length (US)	Weight (US)	Length (cm)	Mass (g)
	(head to bottom)		(head to bottom)
8 weeks	0. 62 inches	0.71 ounces	1.57 cm	20 grams
9 weeks	0.91 inches	0.95 ounces	2.30 cm	27 grams
10 weeks	1.22 inch	1.23 ounces	3.1 cm	35 grams
11 weeks	1.61 inch	1.59 ounces	4.1 cm	45 grams
12 weeks	2.13 inches	2.05 ounces	5.4 cm	58 grams
13 weeks	2.64 inches	2.58 ounces	6.7 cm	73 grams
	(head to toe)		(head to toe)
14 weeks	5.79 inches	3.28 ounces	14.7cm	93 grams
15 weeks	6.57 inches	4.13 ounces	16.7 cm	117 grams
16 weeks	7. 32 inches	5.15 ounces	18.6 cm	146 grams
17 weeks	8.03 inches	6.38 ounces	20.4 cm	181 grams
18 weeks	8.74 inches	7.87 ounces	22.2 cm	223 grams
19 weeks	9.45 inches	9.63 ounces	24.0 cm	273 grams
20 weeks	10.12 inches	11.68 ounces	25.7 cm	331 grams
21 weeks	10.79 inches	14.07 ounces	27.4 cm	399 grams
22 weeks	11.42 inches	1.05 pounds	29.0 cm	478 grams
23 weeks	12.05 inches	1.25 pounds	30.6 cm	568 grams
24 weeks	12.68 inches	1. 48 pounds	32.2 cm	670 grams
25 weeks	13.27 inches	1.73 pounds	33.7 cm	785 grams
26 weeks	13.82 inches	2.01 pounds	35.1 cm	913 grams
27 weeks	14.41 inches	2.33 pounds	36.6 cm	1055 grams
28 weeks	14.80 inches	2.67 pounds	37.6 cm	1210 grams
29 weeks	15.47 inches	3.04 pounds	39.3 cm	1379 grams
30 weeks	15.95 inches	3.44 pounds	40.5 cm	1559 grams
31 weeks	16.46 inches	3.86 pounds	41.8 cm	1751 grams
32 weeks	16.93 inches	4.30 pounds	43. 0 cm	1953 grams
33 weeks	17.36 inches	4.77 pounds	44.1 cm	2162 grams
34 weeks	17.84 inches	5.24 pounds	45.3 cm	2377 grams
35 weeks	18.23 inches	5.72 pounds	46.3 cm	2595 grams
36 weeks	18.62 inches	6.20 pounds	47.3 cm	2813 grams
37 weeks	19.02 inches	6.68 pounds	48.3 cm	3028 grams
38 weeks	19.41 inches	7.13 pounds	49.3 cm	3236 grams
39 weeks	19.72 inches	7.57 pounds	50.1 cm	3435 grams
40 weeks	20.08 inches	7.98 pounds	51.0 cm	3619 grams
41 weeks	20. 39 inches	8.35 pounds	51.8 cm	3787 grams

Thanks to Dr. Mark Curran, maternal-fetal medicine specialist, for his help preparing this chart.

Fetal weight by week: How it changes

Your baby steadily gains weight over the course of your pregnancy, but it's not always at the same rate. If you're having one baby (not twins or multiples), your baby's rate of growth accelerates until 35 weeks, then decelerates.

Here are some highlights, based on estimations:

Up until 16 weeks, a fetus grows an average of about 19 grams per week, gradually increasing from 7 grams per week at 8 weeks to 15 grams per week at 12 weeks and 29 grams per week at 16 weeks.
By 20 weeks, a fetus is gaining about 59 grams per week (just over 2 ounces).
By 30 weeks, a fetus is gaining about 175 grams each week (more than 6 ounces).
At 35 weeks, a fetus is gaining about 215 grams each week, or about 7.5 ounces. At this point their growth rate peaks.
After 35 weeks, growth slows to about 188 grams per week, or 6.6 ounces. (Twins slow earlier, at around 28 weeks, and then average about 170 grams each week.)
In the last few weeks of pregnancy, the growth rate continues to gradually slow to about 168 grams (a little less than 6 ounces) per week by week 40.

Using a tape measure stretched over your belly, your provider will use a fundal height measurement to check your baby's size at your prenatal visits. Beginning at about 24 weeks, the measurement in centimeters should roughly match the gestational age of your baby. If you're 26 weeks pregnant, for example, your fundal height should be about 26 cm, give or take a centimeter in each direction.

If your provider is concerned that your baby is too small, they'll monitor your baby's size with ultrasound, which is more accurate. Using ultrasound, your practitioner can take various measurements (head circumference and diameter, abdomen circumference, femur length) and use them to estimate your baby's size. They may also use a Doppler ultrasound to look at the blood flow to your placenta.

If your baby's estimated weight is less than the 10th percentile for their gestational age, they may be diagnosed with intrauterine growth restriction (IUGR), also called fetal growth restriction (FGR). IUGR can happen at any time during pregnancy. Some babies with IUGR just turn out to be small for their age, but sometimes there's a problem that's preventing the baby from growing properly.

At birth, a baby with IUGR is called "small for gestational age." While most SGA babies who are otherwise healthy grow just fine, some (especially those born prematurely) are at higher risk of problems such as c-section, jaundice, low blood sugar, and even long-term developmental and health problems.

Your baby's size by week

Here are some highlights of your baby's growth during pregnancy:

At 20 weeks, about the midpoint in your pregnancy, your baby is transmitting taste signals to their brain. And you may feel them hiccupping. Your baby's weight at 20 weeks is about 11.68 ounces, and they're about the length of a (10.12-inch) banana.

At 32 weeks, your baby's lungs are developing fast, and your baby's storing minerals like iron for their first 6 months of life. Your baby's weight at 32 weeks is 4.30 pounds, and their length is 16.93 inches, about the size of a jicama.

At 33 weeks, things are getting snug in there! Your baby's skin is becoming less wrinkled as they fill in – your baby's weight at 33 weeks is about 4.77 pounds. At 17.36 inches, your baby is now about the size of a pineapple.

At 37 weeks, your baby's brain and lungs are still maturing, and they're still moving a lot, despite the close quarters. Your baby's weight at 37 weeks is about 6.68 pounds, and they're about the length of a bunch of Swiss chard, 19.02 inches.

Once your baby is born, they'll be weighed and measured, and your provider will continue to monitor their growth. While the average newborn weight is a little over 7 pounds, most newborns lose about 5 to 10 percent of their weight in the first days. No worries – they gain it back by the time they're about 2 weeks old, and by 4 months they usually double their birth weight.

Learn more:

To-do lists for the first, second, and third trimesters
Pregnancy Due Date Calculator
Pregnancy Weight Gain Calculator
How to understand pregnancy weeks, months, and trimesters

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Fetal Chart from Baby My Baby

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(crown to rump measurements)

Gestational Age	Length (inches)	Weight (oz/lb)	Length (cm)	Mass (g)
8 weeks	0.63	0.04 oz	1.6	1
9 weeks	.9	0.07 oz	2.3	2
10 weeks	1.22	0.14 oz	3.1	4
11 weeks	1. 61	0.25 oz	4.1	7
12 weeks	2.13	0.49 oz	5.4	14
13 weeks	2.19	0.81 oz	7.4	23
14 weeks	3.42	1.52 oz	8.7	43
15 weeks	3.98	2.47 oz	10.1	70
16 weeks	4.57	3.53 oz	11.6	100
17 weeks	5.12	4.94 oz	13	140
18 weeks	5.59	6.70 oz	14.2	190
19 weeks	6.02	8.47 oz	15.3	240
20 weeks	6.46	10.58 oz	16.4	300
21 weeks	10.51	12.70 oz	26.7	360
22 weeks	10.94	15.17 oz	27.8	430
23 weeks	11. 38	1.10 lb	28.9	501
24 weeks	11.81	1.32 lb	30	600
25 weeks	13.62	1.46 lb	34.6	660
26 weeks	14.02	1.68 lb	35.6	760
27 weeks	14.41	1.93 lb	36.6	875
28 weeks	14.80	2.22 lb	37.6	1005
29 weeks	15.2	2.54 lb	38.6	1153
30 weeks	15.71	2.91 lb	39.9	1319
31 weeks	16.18	3.31 lb	41.1	1502
32 weeks	16.19	3.75 lb	42.4	1702
33 weeks	17.20	4.23 lb	43.7	1918
34 weeks	17.72	4.73 lb	45	2146
35 weeks	18. 19	5.25 lb	46.2	2383
36 weeks	18.66	5.78 lb	47.4	2622
37 weeks	19.13	6.30 lb	48.6	2859
38 weeks	19.61	6.80 lb	49.8	3083
39 weeks	19.96	7.25 lb	50.7	3288
40 weeks	20.16	7.63 lb	51.2	3462
41 weeks	20.35	7.93 lb	51.7	3597
42 weeks	20.28	8.12 lb	51.5	3685
43 weeks	20.20	8.19 lb	51.3	3717

English

Pregnancy calendar 38 weeks - Miracle Doctor multidisciplinary clinic in Moscow

By adding an average of 30-35 grams per day, your baby continues to prepare for life outside the mother's body. His weight reached 3100-3150 grams, growth is approaching 49 centimeters. The amount of original lubrication on the body has decreased, lanugo (vellus hair covering the body of the fetus) has disappeared almost completely. The baby's nails have grown so much that they reach the tips of the fingers. Sometimes a child may involuntarily scratch his own body with sharp nails, so do not be surprised if you see small scratches on the face or tummy of a newborn. In boys, the testicles have already descended into the scrotum. nine0003

A lot of waste products have accumulated in the lower intestines of the child. During fetal development, the baby many times swallowed amniotic fluid containing dead skin cells, fragments of vellus hair and particles of old intestinal tissues. The components processed in the stomach enter the intestines and remain there in the form of meconium until the very birth. Sometimes the original feces pass out of the body of the fetus before birth. In this case, the baby is born covered with greenish-black mucus. nine0003

A baby born at 38 weeks of gestation is already considered full-term. Girls, being fidgets, are more often in a hurry to be born and delight with their appearance already at 38 weeks. Boys are usually born on time or even linger in the mother's stomach for a week. But no matter who you expect, things in the hospital should be collected, and the card should always be with the woman.

While the weight of the fetus continues to increase, the weight of the expectant mother has stopped growing and even decreased slightly. Weight loss is one of the harbingers of the upcoming birth. It is associated with a decrease in external and internal edema, which occurs when excess fluid is removed from the body. Violation of diuresis, which caused a delay in the body of a woman of water, was due to progesterone, a hormone that for a long time supported the processes of pregnancy in the body. Shortly before childbirth, progesterone levels decrease and estrogen levels increase. Under the influence of estrogens, excess fluid is removed from the body of a pregnant woman. First of all, a woman will notice a decrease in edema on her wrists and feet. The expectant mother can again wear jewelry and shoes that she could not wear the entire last trimester of pregnancy. Depending on the degree of edema, prenatal weight loss can range from 0.5 to 2.5 kilograms. nine0003

Loosening of the stool is another characteristic harbinger of childbirth. Defecation can occur 2-3 times a day, a woman notes a decrease in the density of stool. This phenomenon is also due to an increase in the amount of estrogen and the removal of excess water from the body. The increase in physiological functions before childbirth must be distinguished from the symptoms of food poisoning. If frequent defecation is accompanied by a sharp change in the consistency, color and smell of feces, vomiting and nausea, then you should consult a doctor to rule out poisoning. nine0003

Shortly before the onset of the birth process, the uterine fundus descends. The fetus is grouped and presses the presenting part (usually the head) on the lower part of the uterus, pulling it down. As a result of this process, the pressure on the stomach, liver and lungs decreases, the woman is able to breathe freely, heartburn and a feeling of heaviness in the stomach disappear. The diaphragm and organs of the upper gastrointestinal tract regain their physiological position. At the same time, pressure on the bladder and rectum increases. The drooping of the abdomen is another cause that causes increased urge to defecate and urinate. nine0003

At 38 weeks pregnant, many women feel like a charge of electric current is running down their legs. In this way, the nerve trunks are signaled, which the fetus touches when moving deep into the pelvis.

Shortly before childbirth, most pregnant women feel discomfort in the sacrum. Describing her feelings, the woman notes a slight languor in the lower abdomen. This condition is caused by stretching of the ligaments of the pelvis and increased blood flow to the organs located in it. For women who have gone through childbirth before, the pulling sensations resemble the slightest attempts. Nulliparous women characterize the condition as premenstrual heaviness in the lower abdomen. nine0003

harbingers of childbirth in multiparous and primiparas, what happens, fetal movement, baby's weight, ultrasound

What happens to the baby at this time?

Now the child's weight is 3000-3200 g. Sometimes a mother can feel in the abdomen not only the fetus moving, but also rhythmic tremors - this is the child hiccups, swallowing amniotic fluid. It is believed that hiccups are a kind of training before the start of spontaneous breathing. By this time, the baby has already taken its final position in the uterine cavity - head down, towards the exit from the uterus. The obstetrician determines the presentation of the fetus by probing the abdomen of the expectant mother. But sometimes doctors detect breech presentation, in this case, an examination is performed, ultrasound is performed and the tactics of childbirth are determined. nine0003

Index

Norm

Weight gain of the mother

From 8.6 (with initial excess weight) to 14.5 kg (with initial weight deficit), average gain 10-12 kg

Fundal height03

35-38 cm

Fetal weight

3000-3200 g

Fetal height

48-52 cm

Important!

During the 38th week of pregnancy, the body of the expectant mother is actively preparing for the upcoming birth. It is important to know in advance, read the necessary information about this process (if you have not already done so) in order to clarify how to behave with the onset of contractions. nine0003

The first harbingers of childbirth appear in multiparous and primiparas. These are body changes, certain processes that set up the body and reproductive system for the birth of a child. The signs differ slightly depending on whether the mother is expecting her first baby or if this is her second and subsequent pregnancies.

Many mothers are afraid to miss or not recognize these important "calls". Don't worry about that - we've put together a handy labor checklist to help you figure out when it's time to go to the hospital. nine0003

During this period, drops of a yellowish-whitish liquid - colostrum - can periodically be released from the nipples of the breast. So the mammary glands prepare for childbirth and subsequent feeding of the baby. In order not to stain the linen, you can use special absorbent pads for the chest. They are sold in pharmacies and children's stores, they are a small circle of absorbent materials that is inserted into a bra. If colostrum is absent, this is not a sign of pathology. In some women, the work of the mammary glands starts only after the birth of the crumbs. nine0003

Harbingers of childbirth in women expecting their first child

One of the first signs that labor is coming is easier breathing due to the fact that the stomach has drooped. This feeling is not always so vivid that the pregnant woman herself notices it, sometimes others focus on it. Although the child is also actively moving, the mother's shortness of breath decreases, breathing becomes easier, heartburn and mild nausea after eating less often occur or completely disappear. But due to the fact that the fetal head sank lower into the small pelvis, the uterus is increasingly in good shape, urination becomes more frequent due to pressure on the bladder. nine0003

Sometimes the mother-to-be suddenly notices that the child is not moving much, his movements are not so sharp and active, he seems to calm down. This is a completely natural process, since every day there is less and less space inside the uterine cavity, the walls of its temporary “house” put more and more pressure on the arms and legs, tightly cover, and the amniotic fluid becomes a little less.

If the baby began to move less, he is also preparing for childbirth, gaining strength, but if for 10-12 hours you have not felt a single push or movement, it is better to consult a doctor. He will check if everything is fine with the baby. nine0003

Important!

If the mother feels the fetal movement is too active, a doctor's consultation is necessary. This is necessary to make sure that the baby does not have oxygen starvation, and the volume of amniotic fluid is normal.

If at earlier times the fetal movements were felt as various movements, pushes, kicks and even somersaults, then by this time it is more and more often pandiculation or slight movements. The baby already has little space, sometimes his movements are very noticeable - the woman notes that she is pulling her stomach in the area where the fetal activity is felt. nine0003

Preparing the body for childbirth

The 38th week of pregnancy is a period of active restructuring of the body. Under the influence of hormones, the body prepares for hard work: there is pain in the lower back, pulling the lower abdomen, there is an ache in the area of the pubic joint (the place where the pelvic bones are closed). The lower abdomen hurts due to the descent of the fetal head and its tight fit to the pelvic bones, the occurrence of more and more frequent training uterine contractions and the gradual loosening of the ligaments. Sometimes there is a feeling that the stomach is turning to stone - this is the tone of the uterus, muscle training for subsequent contractions. If these contractions are irregular, occur occasionally, they are not intense, you just need to lie on your side, rest, and they pass. If the same time passes between contractions, they become more and more sensitive, the interval is reduced - this is the beginning of labor, it's time to go to the maternity hospital. nine0003

There is one easy way to tell if contractions are false or true. You just need to count the number of contractions and the interval between them. Use a stopwatch on your smartphone, noting how long the contraction of the uterus lasts and how long the period of relaxation, rest, will then be. If the contractions of the uterus gradually increase, intensify, and the time intervals between them gradually decrease, this is a sign of the onset of labor. Then it was time to go to the maternity hospital. nine0003

Mucous discharge from the genital tract may occur during the 38th week. By the nature of the discharge, they look like lumps of dense transparent or whitish mucus with streaks of blood without any smell. This is the discharge of the mucous plug, which closed the cervix and prevented the penetration of pathogenic bacteria to the fetal membranes. The cervix gradually softens, opens slightly and the mucus gradually leaves.

Good to know

In nulliparous women, the harbingers of imminent labor may appear approximately one to two weeks before the onset of labor. It's about 38 or 39th weeks of pregnancy.

In some cases, the mother-to-be may have loose stools at 38 weeks of gestation, although no changes in the woman's diet have occurred. This is an acceptable bowel reaction to changing hormone levels and preparing the body for childbirth. The intestines are gradually cleared of the contents. However, not always different sensations and changes in the work of digestion are explained precisely by prenatal changes. Diarrhea at this gestational age may also be the result of dietary errors, food poisoning, or other influences. nine0003

A particularly alarming situation is when nausea and even vomiting occur against the background of diarrhea. In this case, you should immediately consult a doctor.

Harbingers of childbirth when expecting a second and subsequent children

If this is not the first pregnancy and childbirth for a woman, and the family is expecting a second, third baby, then the birth may come a little earlier. The body already knows what will happen and it takes less time for the preparatory phase. Thus, the appearance of the crumbs into the world can be expected in the period from the beginning of the 38th week of pregnancy. The processes themselves, which are associated with the preparation for childbirth, may not be so pronounced, sometimes they are absent or appear just a couple of days before the baby is born. nine0003

So, with repeated pregnancy, there may not be a pronounced and significant lowering of the abdomen. Often, the baby is initially located lower than during the first pregnancy, or the cervix relaxes just before the onset of childbirth. Then the woman feels that it has become easier to breathe, the pressure on the bladder has increased.

Important!

It is worth emphasizing that in multiparous mothers, the harbingers of childbirth may be completely absent. The birth process can begin suddenly, and the contractions will be stronger, the duration of labor will be shorter. Therefore, by the time of 38 weeks, you need to collect everything you need to go to the maternity hospital, all the necessary things and documents should be in an accessible place. nine0003

Childbirth is unique, it takes place differently in women, and even in the same woman childbirth is different. If this is the third birth or the fourth, often the precursors can be barely perceptible or completely absent. And the birth act itself proceeds quite quickly and sometimes even a little earlier than the date of birth, which is determined by the doctor. But, as for the second birth, this fact is not a strict pattern, childbirth is possible almost the same day with a pre-calculated date.

In any case, by the 38th week of pregnancy, it is necessary to collect everything necessary for a trip to the maternity hospital and, at the first contractions, immediately seek medical help. nine0003

Is it worth it to speed up labor at this time?

Many women experience fatigue towards the end of their pregnancy and want to have a baby as soon as possible. Therefore, they ask one question - how to speed up the onset of childbirth, is it possible to stimulate this process in order to meet the baby faster and return home, accept congratulations and raise the baby. But you don't need to think about inducing labor before the full term of 40 weeks. Although by the 38th week the baby is already full-term, he is still gaining weight, continues to develop, and nature knows better when he needs to be born. nine0003