Published on March 15th, 2020 and Updated on January 4th, 2021
As your baby grows, so too will your belly. Factors that contribute to the size and shape of your tummy during pregnancy are your muscular structure, the position of your baby, and more. Whether or not gender plays a role in your pregnancy bump is a common question. Although it isn’t quite accurate like a gender prediction test, many people tend to believe the correlation of gender to belly shapes.
So, does your baby’s gender also contribute to your belly shape? Or is this another pervasive gender myth like pregnancy cravings and gender are related, simply due to a craving for sweets or salty foods, or even a glass of wine while pregnant? Or that mixing urine and baking soda will give insight as to whether you are having a boy or girl?
Discover the science (and pseudoscience) behind different pregnant belly shapes and gender below.
What They Say About Belly Shape
Let’s tackle the three most common statements about pregnancy:
- Gender determines whether you’re carrying the pregnancy weight high or low.
- Gender contributes to the sheer size of your belly.
- Gender drives overall belly shape (whether your stomach is wide or pointed).
Are these true or myths? If they’re myths, is there any kernel of truth behind them?
Claim 1: Carrying High vs. Carrying Low
One persistent claim is carrying the weight high up on the stomach signifies a girl; carrying the weight low signifies a boy.
How does this hold up in court? Bottom line is that researchers have yet to find a causal link between gender and the positioning of the baby weight in a woman’s body.
What The Science Says
Carrying high or low is more likely due to physical characteristics such as the skeletal and muscular structure of mum’s body. According to Dr. Kirtly Jones:
There is no fact to [this myth]. What is a fact [is] that the first pregnancy, before the abdominal wall is stretched out, tends to be visually higher. As the abdominal wall gets stretched out with each new pregnancy, the uterus appears to be carried lower, but it’s not the sex of the baby in the womb that determines this.
Before pregnancy, no two women’s abdomens are exactly alike. Once pregnant, every muscle and fiber, down to the strength of the individual abdominal muscles and the elasticity of the abdominal wall, plays a role in the shape of the baby belly.
Similarly, your abdomen won’t be alike from pregnancy one to pregnancy two (should you have more than one), and thus, the shape won’t be the same from pregnancy one to two to three.
Where this myth came from is hard to say. Though it’s a common talking point amongst pregnancy circles, the origin is omitted.
Claim 2: Size of The Pregnancy Belly
This claim says that if you have a boy, your bump will be larger; if you have a girl, your bump will be smaller. Basically, if you compared two pregnant women of the same height and weight, the size of their baby bump would correspond with the gender of their baby.
This has not held up in any scientific research.
What The Science Says
If the baby’s gender could be seen by the naked eye, then gender should play a significant role in birth weight. However, according to WHO growth charts published by the CDC:
- Females in the 50th percentile weigh 7 lb 2oz and are roughly 49.1cm in length
- Males in the 50th percentile weigh 7 lb 6oz and are roughly 49.9cm in length
With boy and girl babies only differing by 4 ounces and 0.8 cm, this doesn’t account for the visibly different tummy sizes of pregnant women.
Claim 3: Pointed vs. Wide Pregnancy Belly Shape
This one claims that the physical shape of a pregnant belly can be used to determine the gender of the baby. If the pregnancy bump is wide, it’s a girl; if the belly is narrow and pointed, it’s a boy. Unfortunately, again, no matter how it’s phrased—the answer to “does belly shape determine gender?” is going to be no.
What The Science Says
So, why do some women have wide pregnant bellies, and others have pointed and narrow bellies? While science doesn’t support gender theory, it does have an explanation. Two explanations, actually:
- Recti Diastasis – As the uterus and the uterine wall expand outward, the baby bump comes into the picture. The pressure of the growing baby pushing outward can be enough to push the ab muscles aside, creating a pocket for the baby bump to push out narrowly. In moderate cases, this can also cause back pain, constipation, and urine leakage. And after giving birth, the muscles may return to normal. If not, physical therapy and surgery have been known to help muscle tone. From WebMD:
Pregnancy puts so much pressure on women’s bodies that sometimes the muscles in front can’t keep their shape. “Diastasis” means separation. “Recti” refers to your ab muscles called the “rectus abdominis.” When the ab muscles move aside like this, the uterus, bowels, and other organs have only a thin band of connective tissue in front to hold them in place as the baby grows
- If recti diastasis occurs, the pregnancy belly shape becomes narrow and pointed; still this has nothing to do with gender.
Positioning of the baby – The baby can grow upside down, right side up, feet up or feet down, spine facing mama’s spine, or spine facing the stomach. Because of this, there are many different baby belly shapes that occur with women. For example, if the baby’s spine is facing out toward the stomach, this is known to cause the belly to protrude further. In contrast, if the baby’s spine is parallel to mama’s spine, then there will be less pressure pushing the baby bump outward.
The Real Cause of Pregnant Belly Shapes
Despite all the good-intentioned loved ones examining your belly, the final conclusion is different pregnant belly shapes don’t correlate with the gender of the fetus. The real factors behind your belly shape are:
- Your muscular structure—including the elasticity of your abdominal wall
- Whether or not recti diastasis occurs
- The fetal position of the growing baby
How to Determine The Gender of Your Baby
There are numerous gender pregnancy myths out there that you can try if you want an afternoon of entertainment. However, scientifically speaking, there are only a few true methods for women to discover their baby’s gender. Moving from latest to earliest:
- Ultrasound at 18-22 weeks
- Non-Invasive Prenatal Testing (NIPT) ordered by a physician at 12 weeks
- Early Gender DNA Test at 8 weeks
Redefining The Gender Discovery Norm
With the advent of new technologies reshaping our world in many ways, discovering the gender of your baby has never been as accessible as it is today. The SneakPeek Early Gender DNA Test relies on a small sample of mom’s blood to access this information. What the test is looking for specifically is the presence of Y chromosomes. Considering that females have X-X chromosomes and males have X-Y chromosomes, the only reason Y chromosomes would appear in the gender blood test is if mom is carrying a baby boy.
Because the sample size needed is so minute, the test can be carried out from the comfort of your home. And to make things easier, you can receive the results in 72 hours.
While your belly shape may not help determine the gender of your baby, this simple at-home test can be taken as early as 8 weeks pregnant—with 99.1% accuracy, too.
Health University of Utah. Which Pregnancy Myths Are Actually True? https://healthcare.utah.edu/the-scope/shows.php?shows=0_qtd1io6q
Huffington Post. Carrying High Or Carrying Low: Crazy Pregnancy Myths. https://www.huffingtonpost.com.au/2016/04/02/baby-pregnancy-gender_n_9588058.html
CDC. Data Table for Girls Length-for-age and Weight-for-age Charts. https://www.cdc.gov/growthcharts/who/girls_length_weight.htm
CDC. Data Table for Boys Length-for-age and Weight-for-age Charts. https://www.cdc.gov/growthcharts/who/boys_length_weight.htm
NIH. The Y chromosome: beyond gender determination. https://www.genome.gov/27557513/the-y-chromosome-beyond-gender-determination
WebMD. Abdominal Separation (Diastasis Recti). https://www.webmd.com/baby/guide/abdominal-separation-diastasis-recti#1