An Overview of Gender Prediction By Robin Elise Weiss, PhD | Reviewed by a board-certified physician Updated January 02, 2017 Print As soon as you announce your pregnancy, it seems everyone has their own method and set of tells to predict your baby's gender. About 80 percent of parents actually choose to find out during pregnancy whether they're having a boy or a girl. If you're not interested in finding out, that's fine too. But if your curiosity is peaked, here are ways to forecast the sex of your baby.Mid-Pregnancy UltrasoundUltrasound is probably the most common method of finding out the gender of a baby. This is generally done between 18 and 20 weeks of pregnancy. (If your practitioner schedules an ultrasound at this point on a routine basis, your insurance may or may not cover the charge.)Sometimes you may even have to schedule an ultrasound with the specific intent of finding out the baby's sex. This can run you upwards of $300 out of pocket and is generally not covered by insurance. Remember, an ultrasound can't always tell the sex of the baby, isn't always right, and sometimes the office policies are not to tell you the gender. Article When Do You Find Out the Sex of Your Baby? List Signs Ultrasound Technicians Look For to Determine a Baby's Sex Be sure to ask questions before agreeing to an ultrasound.There are also stores that provide similar services, but they are not affiliated with medical practices. They are called Keepsake ultrasounds and are not recommended by the Food and Drug Administration (FDA).Ramzi's MethodThis is a newer method of determining the sex of a baby in early pregnancy via ultrasound. It can be used at around the six-week mark in pregnancy and determines gender based on the location of the placenta. It is not commonly done, but it is something that is catching on.One thing to be aware of is that what you see on the ultrasound screen is sometimes a different orientation than what it actually is in real life. If you're having an early ultrasound in pregnancy, be sure to ask about the location of the placenta rather than guess based solely off of the screen.Genetic TestingGenetic testing is also used to determine the sex of a baby before birth. The two most common invasive methods are:Amniocentesis: Generally done after week 16 but can be done slightly earlier.Chorionic Villus Sampling (CVS): Can be a done between the tenth and the twelfth week of pregnancy.These tests are nearly 99 percent accurate in predicting a baby's sex. But due to the small chance of infection or pregnancy loss associated with these methods, they are not frequently used as sole methods of determining the sex of your baby. Rather, they take a look at genetic information. Gender information is more an added benefit.Another type of genetic testing is done using a maternal blood sample. These newer tests—called cell free DNA tests—use fetal DNA found in the mother's blood. They are used in the late first trimester.IntelligenderThis is a urine based home test. List It's a Boy: Ultrasound Images of Your Boy Developing During Pregnancy Article How to Make Sure You Have a Boy It can be used as early as the tenth week of gestation and looks for certain cells in the urine of the mother to determine whether she is carrying a boy or a girl.The test is sold online and at drugstores and can be used without the use of your doctor. It is not, however, based on science and has no research backing it up. That said, many women chose to do it for fun before they find out they baby's sex from their doctor or midwife.Belly Size & ShapeBellies are very different from one another—as you can see from the pregnant belly photos here. Most of the tales say that carrying out front and round means it's a boy. If you look pregnant all over, or are carrying side-to-side, it is supposed to be a baby girl.In truth, this is a very common old wives tale, but it's a fun one. Largely, the size and shape of your belly is determined by your body before pregnancy, the amount and speed of weight gain in pregnancy, and other factors that are mainly out of your control.Chinese Lunar CalendarsThis is another pseudo-scientific sounding way of predicting if you'll be delivering a boy or a girl. Based on the mother's age at the time of conception and the month that conception took place, you will be told the sex of your unborn (or preconceived) baby. Some people claim that the differences come from the fact that the Chinese consider a newborn baby to be one year of age.This method actually draws quite a bit of questioning, usually because you can find at least four different versions on the Internet as to what is a boy designation and what is girl designation. I wouldn't place a lot of stock in them for accuracy. They are mainly just for fun.Fetal Heart RateMany years ago people said that if you look at the fetal heart rate you can predict the sex of your baby—specifically that above 140 beats per minute meant a girl and below 140 beats per minute meant a boy.There has actually been some research done to determine if this is accurate or not, though findings appear inconclusive. Some argue that relying on fetal heart rate to predict baby gender is reliable only if you look during the first trimester, while others assert it is not a valid measure at all. Article Can You Really Change Your Odds of Having a Boy or a Girl? Article Boy or Girl: The Ultrasound Might Be Wrong Folklore & Old Wives TalesNot long ago, these were all that parents had to go by to predict the sex of their baby, including things like what you eat and how you sleep dictating gender outcome. People claim that they are fairly accurate, though they are meant more as just harmless fun. If it turns out right, then it's just an added bonus! Check out this test to get a feel for it.Preplanning Gender (Sex Selection)It's hard to talk about the sex of your baby in pregnancy without mentioning the ability for preplanning the sex of your baby. After all, why leave anything up to chance! You can now try specifically for a boy or girl. (Actually, there is a slightly better chance that everyone will have a boy. Older mothers are also more likely to have boys according to some recent studies.)Most of the sex selection methods are based on high stakes medical procedures that are risky and costly. Though there is also a fair share of sex selection theories purported by individuals without a lot of data or science behind them.A Word From VerywellThe sex of your baby is something that you will eventually find out—whether during pregnancy or at birth. Some say that finding out helps them bond with the child during pregnancy; others say that not knowing the sex of their baby helps them to motivate during that final push at the end of labor. Either way, most parents are really excited and can easily recall how they felt the moment that they heard the magical words, "It's a...".Sources:Bracero LA, Seybold DJ, Witsberger S, Rincon L, Modak A, Baxi LV. First trimester fetal heart rate as a predictor of newborn sex. J Matern Fetal Neonatal Med. 2016 Mar;29(5):803-6. doi: 10.3109/14767058.2015.1019457. Epub 2015 Mar 10.Iruretagoyena JI, Grady M, Shah D. Discrepancy in fetal sex assignment between cell free fetal DNA and ultrasound. J Perinatol. 2015 Mar;35(3):229-30. doi: 10.1038/jp.2014.231.McKenna DS, Ventolini G, Neiger R, Downing C. Gender-related differences in fetal heart rate during first trimester. Fetal Diagn Ther. 2006;21(1):144-7.Ramzi Ismail, Saad. "The Relationship Between Placental Location and Fetal Gender (Ramzi’s Method)." Web.U.S. Food & Drug Administration. Ultrasound Imaging. July 2016.Villamor E, Dekker L, Svensson T, Cnattingius S. Accuracy of the Chinese lunar calendar method to predict a baby's sex: a population-based study. Paediatr Perinat Epidemiol. 2010 Jul 1;24(4):398-400. doi: 10.1111/j.1365-3016.2010.01129.x.