For many expecting parents, after finding out that they’re pregnant, the question they want answered as soon as possible is: Is it a boy or a girl?
The good news is that you don’t have to wait until delivery to find out if you don’t want to. In most cases, an ultrasound can determine your baby’s sex as early as 16 weeks, and optional first trimester testing can tell you even earlier.
But since an ultrasound isn’t 100 percent reliable, and not everyone opts for early screening tests, you might use the position of your placenta to predict what you’re having.
According to some, having an anterior placenta means you’re having a girl, whereas a posterior placenta means you’re having a boy. But is this an accurate way to predict biological sex? Let’s take a look.
There are two types of cells that make up an embryo. There are the cells that develop into the baby, and the cells that develop into the placenta. The placenta is an organ that gives your baby oxygen and nutrients, and it also removes waste.
The placenta attaches to the wall of your uterus, and its position can be anywhere — front, back, right, or left. If the placenta attaches to the back of the uterus, it’s known as a posterior placenta. If it attaches to the front of the uterus, it’s called an anterior placenta.
Both types are common. One theory is that sleep position after conception might influence the location of the placenta, but that hasn’t been verified by research.
The idea of using the placement of the placenta to identify sex isn’t new. The idea that an anterior placenta means you’re having a girl may have come out of a different theory related to left-right placement.
In 2011, a paper attributed to Dr. Saad Ramzi Ismail claimed that when the placenta attaches to the right of the uterus, women were more likely to have a boy. And when the placenta attaches to the left, they were more likely to have a girl. (The study, titled “The Relationship Between Placental Location and Fetal Gender [Ramzi’s Method],” is not available online in a credible, peer-reviewed journal.)
This became known as Ramzi’s theory. But interestingly, his research only evaluated the right and left position of the placenta. It didn’t evaluate front (anterior) and back (posterior) positions.
The precise origin of the belief that an anterior placenta means a girl baby is unknown. Yet, the question comes up numerous times on online forums and discussion boards, with many women claiming that they had an anterior placenta with their girl pregnancies.
Truthfully, there isn’t enough concrete research or evidence to back up the theory linking an anterior placenta with having a girl.
One 2014 study on the topic, though, evaluated 200 placentas — with 103 anterior and 97 posterior. According to the results, 72.8 percent of pregnancies with girls did have an anterior placenta, compared to only 27.2 percent of pregnancies with boys.
The study concluded that while the location of the placenta had “significant relation with fetal gender,” more research is needed. So having an anterior placenta doesn’t indicate with certainty that you’re having a girl.
Using the location of your placenta to predict your baby’s sex is a fun game to play. But when it comes down to truly identifying biological sex, using the location of your placenta isn’t an accurate way.
There are a few ways to determine the sex of a baby. One is to have an ultrasound and locate your baby’s genitals. Additionally, tests that look for chromosome abnormalities can detect a baby’s sex. These include noninvasive prenatal testing, amniocentesis, and chorionic villus sampling.
Even though the placenta usually attaches to the back of the uterus, it’s perfectly fine to have an anterior placenta. However, this may or may not indicate that you’re having a girl. So before making any big announcements, you may want to confirm your theory with an ultrasound or blood test.