When I was pregnant with my first child, I (like virtually every single mom-to-be on the planet) wondered what my baby would look like. Would he have my blue eyes, or his dad’s thick black hair? Would he be tall like my father, or (gasp) teeny tiny like my 4-foot-8-inch (on a good day) mother-in-law? I rubbed my belly and I wondered if there were ways to tell what my baby would look before he was even born. (But not-so-secretly, I really wanted him to have blue eyes.)
In an effort to create a biological window into the womb, I resorted to my 10th grade bio class notes (yup, I still had them) to determine how my kiddo could possibly turn out. I looked at the Punnett Square for a pre-birth glimpse at my baby boy, but I really shouldn't have bothered. "When you're expecting, you can't be sure of how the baby will come out," says Dr. George Diaz, Ph.D., Professor of Genetics and Genomic Sciences at the Icahn School of Medicine at Mount Sinai Medical Center in New York City.
"If you look at two parents, you can never completely know which traits are dominant or recessive," he adds.
But as you cradle your kiddo in utero, you can look to these signs to see if your kid will look more like mom or dad when they grow up.
1. Eye Color
There’s the saying that the eyes have it, and that’s certainly true when it comes to genetics. According to Dr. Diaz, brown-eyed parents can have blue-eyed babies depending on the combination of eye color genes a baby inherits. (Blue-eyed parents can have brown-eyed babies for the same reason.) "If a brown-eyed parent has two functional copies each of the OCA2 and HERC2 genes, then the chance of having a blue-eyed baby are very much lower than if the brown-eyed parent had a non-functional version of one or both of these genes," explains Dr. Diaz. And since my hubby is from Peru, which has a lower frequency of non-functional eye color genes, it means that my chances of having a blue-eyed babe were slim from the start. Bummer.
My sister is five-foot-seven. I am a very proud five-foot-two. I could blame my equally short mama for being vertically challenged, but that would be a mistake. A Boston Children’s Hospital study found that a person’s height is not linked to just one, but hundreds of genes that collectively only comprise a mere 20 percent probability of a person’s height. That means that you can’t necessarily blame being tall or short on one particular relative, but just genetic randomness. "There are many different contributors when it comes to height," confirms Dr. Diaz. "You can't just look at one gene; it's a combination."
3. Hair Color
Some babies are born completely bald, and others, well, kind of look like a monkey, thanks to all that lovely lanugo. But if your concern is the hair on your precious baby’s head (and not, you know, everywhere else), that’s a result of the four genes that determine hair color. Two different pigments determine hair color: eumelanin (a black pigment), and phenomelanin (which is red or yellow). The amount of pigment available and how closely its granules are, plus how much eumelanin and phenomelanin is there, is what will ultimately turn your baby into a brunette or a blondie.
You might hope your little one inherits those decadent dimples that you love so much in your dad. But what are his real chances? Turns out, better than you might think. Cute as they might be, dimples are sometimes considered a defect since they are a deformity of a facial muscle. Genetic.com reported that dimples are definitely inherited, though, and if only one parent has them, then your child has a 50-50 shot of getting dimples, too. That said, sometimes your baby might have dimples when he’s little (as a result of all that juiciness) and then lose them as he gets older.
5. Cleft Chin
A cleft chin might be charming on your cutie patootie, but the jury is still out as to whether genetics play a role. Why? There are definitive cleft chins, smooth chins, and everything in between, coming from parents who have cleft chins and those who don’t, according to a University of Delaware study. Sure, chances are strong that if parents with a cleft chin will produce a baby with a chin dimple, but there are also instances of babies being born with cleft chins without parents having one.
6. Skin Tone
Most babies are born with dark red or purple skin, according to Stanford Children's Hospital, which eventually fades over the first day. Whether your baby has creamy caramel skin or pale skin (or anything in between), it’s determined by genetics. Pigmentation plays a part in skin protection — darker skin helps with the blocking of ultraviolet light exposure while paler skin more easily absorbs vitamin D, reported Science Daily. It’s still hard to say whether your baby will have darker or lighter skin based solely on his parents. Ethnicity certainly plays a role in your baby’s skin tone, but there are also other things, such as the melanocortin 1 receptor (MC1R) gene, which is responsible for pigmentation and helps determine skin, hair, and eye color, according to the Genetics Home Reference division of the U.S. National Library of Medicine. But you really won’t know what your baby’s skin tone will be until she’s at least six months-old, as per What to Expect.
There’s nothing more delicious than a juicy baby. All those rolls and folds are just to die for. Like almost everything else with genetics, your baby’s weight really is a product of a variety of factors. Interestingly, a mother’s weight is often an indicator of what her baby's (specifically, a daughter) weight will be, too. This correlation between mommy and baby girl’s weight is stronger than any other parent/sibling connection, cited the National Institutes of Health. Of course, your baby’s weight can also be affected by other factors, such as your race, pre-pregnancy weight, and weight gain during pregnancy, as well as drinking, smoking, and other maternal health issues, such as gestational diabetes. "Genes are the toolbox that nature gave us," comments Dr. Diaz. "But there are a lot of different modulators that can affect them, such as environmental factors."
8. Facial Features
From your husband’s sweet little smirk to the way you crinkle your nose when you laugh, genetics will play a big role in your baby’s future facial features. Apparently, it’s not one or two, but 15 new genes that have been identified which determine facial features, found a Nature Genetics study. So if you're lucky, your baby won't get that big ol’ schnoz from Grandpa Joe — but he just might get that twinkle in his eye from your mom.
You might not have loved being called Freckleface in school, so you might not want to hear this: Freckles are dominant. And if you or your partner have them, chances are your child will have freckles, too. Again, it’s all thanks to that MC1R gene which is responsible for pigmentation. Interestingly enough, other genes kick in when it comes to the freckles’ size, color, and patterns on your baby’s face, according to the University of Utah.
For the most part, babies are born toothless, although the National Institutes of Health reported that an estimated 1 in every 2,000 to 3,000 babies is born with teeth. While it’s too soon to tell what your kid’s chompers will look like, toothpaste brand Colgate found that genetics will play a very important role in your child’s teeth. This applies not just to their appearance (such as having buck teeth or a gap), but also in their propensity for tooth decay and gum disease. So hopefully your child will get the better end of the genetic dental deal, so he won’t wind up spending too much time in the dentist’s chair in the future.
Even if you opt to get a 4D ultrasound, there’s no way to really know exactly what your baby is going to look like before she’s born. And that’s what makes waiting those nine long months worthwhile — when you finally see your beautiful baby and realize that no matter what she inherited from whom, she’s perfect in every single way.