Pregnant Belly Size Chart And Shape: Things You Should Know

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The pregnant belly size chart helps to understand the growth of a baby bump. However, the size and shape of the pregnant belly may vary in each woman. Some may have a comparatively smaller belly for women in the same weeks of gestation. While a few may have larger sizes. Keeping a size chart may help you understand the growth rate of your belly and see if there is a gradual increase or decrease in size.

Read on to know the pregnant belly size chart and identify and manage related concerns.

Does The Belly Size In Pregnancy Really Matter?

The size of your pregnancy belly may not be something of concern. Your belly could be big, small, pointy, round, or high, but that still might not necessarily affect the pregnancy. Some people may try to guess the baby’s gender, health, and progress by looking at your belly, but you should not worry about what anyone other than your obstetric or midwife says.

Does Your Belly Size Determine The Gender And Size Of The Baby?

The belly size and shape determine neither the size nor the gender of the baby. A large belly could be due to excess body weight or amniotic fluid, while a small belly could be due to less amniotic fluid or if it is the first pregnancy. The size of the belly has nothing to do with the gender of the baby.

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Other than belly size, psychological criteria such as dreams and feelings are also used to predict a baby’s gender. However, research shows that feeling-based predictions aren’t accurate (8).

According to Stephanie Langsam, MD, FACOG, a board-certified physician specializing in obstetrics and gynecology, “There is no scientific evidence between a girl bump or a boy bump. Just as people’s bodies are different, so are their pregnant bellies.”

Can Belly Size Accurately Indicate Your Stage of Pregnancy?

The size of the belly may not be an indication of the stage of pregnancy. The belly size during different phases of pregnancy differs from one woman to another, based on her body type and size. Regardless of the belly size, ensure that you’re maintaining a healthy weight as being overweight or underweight during pregnancy might affect the growth of the baby (1).

It is best not to compare the size of your bump with that of other pregnant women, as the belly size may depend on several factors.

What Factors Determine Your Belly Size?

The following factors might determine the size and shape of the pregnant belly:

  1. First pregnancy: If it is your first pregnancy, you may tend to have a more compact bump as the abdominal muscles have not been stretched before. The muscles that hold your baby high feel tighter and more toned. Also, the bump is likely to be smaller than it would be in your second or subsequent pregnancies.
  1. Second or subsequent pregnancy: The first pregnancy could stretch your abdominal muscles and make it quite flexible. Unless you are into fitness or you are an athlete, your muscles might not regain their original shape or tone back. So, you may notice a bigger bump than before. Again, that does not mean your baby would be bigger.
  1. Amniotic fluid volume: Throughout the pregnancy, the amniotic fluid index keeps changing. The average index of the amniotic fluid in a normal pregnancy is more during the second trimester, while it is comparatively less during the third trimester. Based on the production of this fluid, but not your baby’s size, your belly may appear small or big (2).
  1. Change in the baby’s positions: From the second trimester, the baby might become active and begin to move inside the tummy. This may alter the shape and size of your belly. For instance, your baby might sometimes move from one side to the other, changing the shape of the tummy slightly (3).

And during the last stage of pregnancy, the head generally moves down into the pelvis, making the tummy look bigger at the bottom. This means that the baby’s position may affect the belly size and shape.

  1. Mother’s height: Taller women have a longer torso, which gives more space for the baby to grow. So, while the baby grows, the belly grows upwards and not outwards. On the other hand, shorter women will have less space, and their baby will push outwards and not upwards.

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Where you carry your weight also determines how your belly looks. Women who carry more weight in their midsection may have a B-shaped belly than the standard D shape (9).

Next, we give you a chart of the average belly size during pregnancy.

Pregnancy Belly Size Chart

This chart shows the changes you may notice in your belly as the baby grows. It is an approximate chart, and the measurements and changes could vary from one woman to another (4).

Month/weekBelly size/fetal development
First month (week 1-4)
  • No change in belly size
  • The fetus is just about the size of ¼ inch
Second month (week 5-8)
  • A firm belly, not a lot of difference in the belly size
  • The fetus’ size is about one inch
Third month (week 9-13)
  • A tiny bump starts to appear at the bottom
  • The fetus is about four inches
Fourth month (week 14-17)
  • The belly grows and is noticeable
  • The fetus is about six inches
Fifth month (week 18-21)
  • The belly is pronounced; it is visible, and the shape may vary. Some are high, some low, and some bulge at the middle
  • The baby may grow to about ten inches
Sixth month (week 22-26)
  • The belly grows double the size and looks similar to a basketball
  • The baby grows to about 12 inches
Seventh month (week 27-30)
  • The baby’s growth gets slower, and the belly size may be constant or increase
  • The baby is now about 14 inches
Eighth month (week 31-35)
  • The belly size is the same, but it looks bigger
  • The baby would grow up to 18 inches
Ninth month (week 36-40)
  • The belly looks curvy and bigger
  • The baby would be about 18-20 inches

In case you do not notice the above changes, do not panic or assume something is wrong. Check with the midwife or doctor if you’re worried about the shape or size of the belly.

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Fundal height measurement is the most accurate way to determine a baby’s growth. For most women, fundal height, i.e., the distance between the pubic and the top of the uterus during pregnancy, can be measured from around the 20th week (10).

Dr. Langsam adds, “At each prenatal appointment, your doctor will measure the fundal height. The fundal height is the measurement from the pubic bone to the top of the uterus. This grows about one centimeter per week, and at around 20 weeks of pregnancy, the uterus is at the level of the belly button. Each week, your fundal height should be equal to your gestational age. If the measurement is more than three centimeters off, then a growth ultrasound can help us determine if your baby is too big or too small.”

Common Concerns About The Pregnant Belly

Some of the common concerns that pregnant women might have about their bellies are mentioned here:

  1. Small belly: If you have a small belly and your doctor or midwife tells you it is normal, then you do not have to worry about it. One of the concerning reasons for a small belly could be oligohydramnios or low amniotic fluid. The condition may be diagnosed through an ultrasound, and the doctor could suggest a treatment based on factors such as its extent and your medical history (5).
  1. Large belly: If your belly is growing quickly, you may visit your doctor for a check-up. Usually, it could be normal due to your previous pregnancy or other factors. One of the concerning reasons for an unusually large belly could be polyhydramnios, or a high amount of amniotic fluid (6), which would be diagnosed by your doctor and handled appropriately.

According to the Fetal Medicine Foundation, polyhydramnios is mild in roughly 80% of the cases, moderate in 15%, and severe in 5%. Proper diagnosis and timely treatment are essential for its proper management and treatment.

  1. High belly: If you are carrying high, it usually means you have a good muscle tone and strong abdominal muscles. Also, it could be because you’re tall, and in most cases, a high pregnancy belly is considered normal unless diagnosed otherwise by your doctor or midwife. However, make sure your doctor monitors the size of the belly regularly, and performs regular ultrasonography to ensure healthy fetal growth.
  1. Low belly: With a low belly, it might seem like the baby is ready to come out any minute, but that is not normally the case. Carrying a low belly could cause discomfort, pressure on the lower back, and pelvic pain, but is not a reason for concern.
  1. Wide belly: Carrying wide usually means that the baby is in a side-to-side position, a situation termed as a transverse lie (7). It could be a problem if the baby does not turn with its head down at the time of labor. However, sometimes, an overweight pregnant woman may carry wide, which is not a reason for concern.

Your pregnancy belly lasts only as long as your pregnancy does. So, celebrate it with special activities.

Celebrating Your Pregnancy Belly

Here are some exciting ideas to make your pregnancy memorable:

1. Photoshoot:

A pregnancy photoshoot is a trend these days that lets you capture your journey through motherhood by taking pictures of your pregnancy belly every month and creating a beautiful collage at the end.

Photoshoot for pregnant belly size chart

Image: Shutterstock

2. Belly painting:

Painting something creative and beautiful on your belly is another thoughtful way to celebrate your pregnancy and the beginning of your journey in parenting. You can let your husband or child do it, or get it done professionally.

Pregnant belly painting

Image: Shutterstock

3. Pregnancy book:

You can create a maternity journal and record anything and everything about your pregnancy. Take pictures of your pregnancy belly every month and paste them in the book. Also, you could write what you are feeling at every stage. Your baby would be happy to read it when he/she grows up.

Pregnancy book for pregnant belly size chart

Image: Shutterstock

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You may record the baby moving in the belly. Once your baby is grown up, share the recordings and cherish the beautiful pregnancy moments together.

Frequently Asked Questions

1. Why is my pregnant belly small in the morning?

The size of a pregnant woman’s baby bump can change throughout the day. For instance, in the morning, after the food from the previous night has been digested, the baby bump may appear smaller. However, as the day goes on and the stomach gets filled with food, the baby bump may become more prominent.

2. What does it mean if my bump is measuring big?

You may have a big belly for several reasons, such as water retention or excess weight gain due to imbalanced eating. However, a too-large baby bump could be due to high sugar levels (gestational diabetes) during pregnancy. High maternal blood sugar levels can cause the baby to receive excessive sugar and grow larger than usual. Additionally, it can lead to an excess of amniotic fluid (polyhydramnios), which can also cause the belly to appear larger (11).

3. What week is your belly the biggest?

The size of the belly varies from woman to woman, but it is usually at its largest between the 36th to 40th weeks of pregnancy. This varies depending on factors such as the mother’s body type and the position of the baby (4).

4. Are there any risks or concerns associated with measuring pregnant belly size?

Measuring pregnant belly size is generally safe and is often performed at prenatal check-ups. However, depending exclusively on belly size can occasionally lead to apprehensions and incorrect conclusions. It is hence critical to seek the advice of a healthcare expert to address any specific concerns (10).

5. How often should I measure my belly during pregnancy?

The frequency of measuring your belly during pregnancy varies based on your pregnancy health. Usually, the belly is measured at prenatal check-ups, which generally take place at 20 weeks pregnancy and more frequently in the later stages (10) (12).

6. Are there any specific tips or exercises that can help maintain a healthy belly size during pregnancy?

You can maintain a healthy weight and belly size during pregnancy by staying active daily with mild and safe activities such as walking and light aerobic exercises, staying hydrated, and by consuming a balanced diet. It’s essential to consult a healthcare professional for personalized guidance (13).

Enjoy every week of your pregnancy, eat healthy foods, and follow the instructions of your doctor or midwife. Do not pay attention to the folklore surrounding the shape and size of a pregnant woman’s belly. Also, ensure that your doctor or midwife is carefully monitoring fetal growth and belly size.

Infographic: What Factors Determine Belly Size During Pregnancy?

The anatomy and appearance of the belly in pregnancy depend on various factors and vary among women significantly. However, a few common factors are known to impact the size and shape of a pregnancy belly. Explore more about them in the infographic that follows.

relationship loyalty quotes (infographic)

Illustration: Momjunction Design Team

Key Pointers

  • The pregnancy belly size chart is an approximate guide to the changes a woman may experience as the baby grows.
  • Every woman’s belly size and shape is unique, and they do not determine the size or gender of the baby.
  • Belly size does not indicate the health, gender, or progress of the pregnancy.
  • It is not a reliable indicator of the stage of pregnancy.
  • Factors that determine the size and shape of the pregnant belly include: first pregnancy or subsequent pregnancy, amniotic fluid volume, change in the baby’s position, mother’s height, and where the mother carries her weight.

How was your pregnancy belly? Do share your experiences and what stories you came across about your belly in the comment section below.

Pregnancy is a time of change, and your belly size is no exception. Learn how to tell if your bump is too big or too small in this informative video.

References

MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.

1. R. Horsager-Boehrer; Worried about having a big baby? Four things to know about birth weight; UT Southwestern Medical Center (2017)
2. A. Kofinas and G. Kofinas; Differences in amniotic fluid patterns and fetal biometric parameters in third trimester pregnancies with and without diabetes; The Journal of Maternal-Fetal and Neonatal Medicine (2006)
3. Pregnancy: The Second Trimester; Johns Hopkins Medicine
4. Fetal development: Stages of growth; Cleveland Clinic
5. Amniotic Fluid Problems/Hydramnios/Oligohydramnios; Children’s Hospital of Philadelphia
6. Polyhydramnios; Lee Health
7. R. E. Jackson; Transverse presentation of the fetus; University of Nebraska Medical Center
8. Michael McFadzen et al.;Maternal Intuition of Fetal Gender; NCBI (2017)
9. When Will I Start Showing in Pregnancy?; Lamaze International
10. Fundal Height; Cleveland Clinic.
11. Gestational diabetes;Mayo Clinic
12. Prenatal care checkups;March of Dimes
13. How much weight will I gain during pregnancy?;Queensland Government

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Jacky Bloemraad-de Boer is a certified professional midwife, traditional Chinese medicine practitioner, doula, nutritionist and herbalist with over 20 years of experience. In 2012 she began JJ Doula Training in Amsterdam and has trained more than 200 doulas.

Read full bio of Jacky Bloemraad-de Boer