According to folklore, everything from the position of the bump to the severity of symptoms can indicate the fetus' sex.
In this article, we shed light on these myths, and look at the proven methods of identifying the sex of a fetus.
Six common myths
Scientific research does not support the following ways of guessing the sex of a fetus.
There are various myths around predicting the sex of an unborn fetus.
More than 50 percent of pregnant women feel sick during the first trimester.
Some people believe that more severe morning sickness indicates that the baby will be born female.
The reasoning is that women carrying girls have high levels of hormones, which worsens morning sickness, while women carrying boys have less nausea because hormone levels are lower.
Very little research has gone into this theory and the studies that do exist have reported conflicting findings.
For example, a study from 1999 supported the idea that women carrying female fetuses had more severe morning sickness.
However, a 2013 study of 2,450 births suggested a slightly higher rate of nausea and vomiting in women carrying boys, compared to those carrying girls.
Among the study population, 79.5 percent of women carrying male fetuses reported nausea and vomiting, while only 72.3 percent of women carrying female fetuses reported the symptoms.
Salty and savory cravings
A study from 2014 reported that 50–90 percent of pregnant women in the United States have cravings. The desired foods range widely.
One myth claims that women expecting boys crave salty and savory foods, such as potato chips, and that those carrying girls prefer sweet foods, such as ice cream and chocolate.
However, cravings are more likely to represent a woman's nutritional needs. Authors of the same study suggest a similarity between the foods a woman craved immediately before a menstrual period and those craved during pregnancy.
Healthy hair and skin
According to one old wives' tale, the female sex of a fetus causes dull skin, acne, and limp hair during pregnancy, while male sex results in no changes in appearance.
Realistically, the extensive hormonal changes that occur throughout pregnancy affect the skin and hair of most women, regardless of the sex of the fetus.
One study reported that more than 90 percent of pregnant women experienced changes in the appearance of their skin and hair.
Hormones can cause mood swings during pregnancy.
One myth suggests that pregnant women who do not experience mood swings are carrying boys, while those who experience noticeable changes in mood are carrying girls.
The truth is that most women will have mood swings during pregnancy, especially during the first and third trimesters.
Physical stresses, exhaustion, hormones, and other factors, all of which are unrelated to the fetus's sex, contribute to changes in mood.
Fetal heart rate
A fetus' heart will start to beat at approximately 6 weeks of pregnancy. A fetal heartbeat is between 140 and 170 beats per minute (bpm) by week 9, according to the American Pregnancy Association.
One myth suggests that a fetus with fewer than 140 bpm is male, while female fetuses have more rapid heartbeats.
A 2006 study found no significant difference between the heart rates of male and female fetuses in early pregnancy.
Of the 477 pregnancies studied, the average male fetal heart rate was 154.9 bpm, and the average female fetal heart rate was 151.7 bpm. On average, the male fetuses tended to have a slightly faster heart rate.
Position of the bump
Many people believe that carrying low indicates a male fetus, while carrying high indicates that the fetus is female. However, there is no truth to this belief.
A study published in the journal Birth in 1999 concluded that women who used this and other means of predicting the sex of their babies were unlikely to be right.
Factors that determine the shape and size of a pregnant woman's bump include the size of the fetus and its position. If the baby's back is parallel with the mother's, the pregnancy bump tends to be flat.
Proven ways to tell if you're having a boy
Medical testing can provide an accurate answer, and some methods can indicate the fetus' sex as early as the 10th week. Options include:
An amniocentesis test can indicate the sex of a fetus.
Doctors primarily use this test to detect issues with chromosomes.
Pregnant women can take this test at 10 weeks, and results are usually available within 7–10 days.
The test is usually reserved for pregnant women over the age of 35. A doctor may also suggest it if they suspect that there is an issue with the fetus' chromosomes.
Any pregnant woman can request the test, but some insurance plans do not cover the cost.
During this procedure, a doctor will insert a thin needle through the skin into the uterus. They will remove some amniotic fluid, which is the fluid that protects the baby during pregnancy.
Amniotic fluid contains cells and chemicals that can indicate genetic abnormalities, fetal infection, and the fetus' sex.
An amniocentesis is usually available from week 15 onward, but it should only be done if there are concerns about the presence of genetic conditions.
An amniocentesis carries various risks, including a very slight risk of pregnancy loss.
Chorionic villus sampling (CVS)
Similar to amniocentesis, CVS involves using a needle to retrieve tissue from the placenta. This test can indicate if a fetus has Down syndrome or another chromosome-related condition. It can also determine the fetus' sex.
CVS is available from week 10 of pregnancy, and it carries approximately the same risk of pregnancy loss as amniocentesis.
Women should only get CVS tests if there is an increased risk of chromosomal issues.
An ultrasound is a noninvasive way to determine the sex of the fetus.
This is only effective from weeks 18–20 onward, after the external genitalia is clearly formed.
The ultrasound technician may not always be able to tell the sex during the scan, especially if the fetus is not in an ideal position, or if the pregnancy has not yet sufficiently progressed.
While it can be exciting to guess at the fetus' sex, only medical testing can accurately identify it.
However, these tests are not always entirely accurate, and they are only an option after the 10th week of pregnancy.