Can the fetal heart rate tell if it's a boy or a girl?

Fetal heart rate is an important matter that requires long-term observation throughout the pregnancy. The fetal heart rate is directly related to the baby's physical health. So, can we tell whether it is a boy or a girl from the fetal heart rate?

Can the fetal heart rate tell if it's a boy or a girl?

The rumor on the Internet that "a fetal heart rate below 140 means a boy is born, and a fetal heart rate above 150 means a girl is born" is true? Here are some comments from netizens I found online:

Mother 1: The fetal heart rate has never exceeded 150, and it is a girl.

Mom 2: The fetal heart rate was always above 150, but it dropped to over 130 before delivery, and finally it was a boy.

Mom 3: The fetal heart rate was no lower than 140, so it’s a girl.

Mom 4: If the first fetal heart rate was around 150, it was a boy. If the second fetal heart rate did not exceed 140, it was a girl.

It can be seen from this that judging the gender of a baby by fetal heart rate is not accurate.

In fact, the fetal heart rate changes with the fetal age and has no direct relationship with the fetus's gender.

Around 5 weeks of pregnancy: fetal heart rate is around 80-85 beats/min;

Around 9 weeks of pregnancy: fetal heart rate gradually rises to 170-200 beats/min;

21-30 weeks of pregnancy: average fetal heart rate is 147 beats/min;

31-40 weeks of pregnancy: The average fetal heart rate is 139 beats/minute.

Therefore, the fetal heart rate is normal as long as it is between 120-160 beats/minute. However, if the fetal heart rate is lower than 120 or higher than 160 for more than 10 minutes, it indicates intrauterine hypoxia and requires timely treatment.

So, what factors affect the fetal heart rate?

1. The fetal heart rate is low when the fetus is sleeping and high when the fetus is moving.

2. The fetal heart rate will increase when the fetus suffers from intrauterine hypoxia due to umbilical cord around the neck or other factors.

Fetal heart monitoring can help us understand the condition of the fetus in the uterus. Therefore, pregnant mothers should have regular prenatal checkups and start fetal heart monitoring from the 32nd week of pregnancy (pregnant mothers with diseases such as gestational hypertension should start from the 28th week of pregnancy).

What is fetal heart rate?

Fetal heart rate is the heartbeat of the fetus, reflecting the status of the fetus in the uterus.

When fetal hypoxia is caused by various reasons, the fetal heart rate will change very sensitively. The normal fetal heart rate is 110-160 beats/minute. The normal fetal heart rate changes all the time with the different intrauterine environments. The change of fetal heart rate is a manifestation of the normal regulatory function of the central nervous system and a manifestation of the good condition of the fetus in the uterus. If the fetal heart rate is less than or >160 beats/minute and lasts for more than 10 minutes, it is called bradycardia or tachycardia.

The sex of the fetus is determined by the sex chromosomes of the mother and the father. The mother provides the X chromosome and the father provides the X/Y chromosome.

There are many factors that determine whether the father's sex chromosomes enter the uterus, X or Y, such as temperature, pH, serum conditions, etc.

It is incorrect to judge the gender by the fetal heart rate. The speed of the fetal heart rate is related to the situation of the fetus in the uterus. For example, the fetal heart rate will be slower when the fetus is in a sleeping state, and it will be faster when the fetus is active. Lack of oxygen, uterine contractions, umbilical cord compression, etc. will all affect the fetal heart rate.

The causes of fetal heart rate abnormalities are

There are many reasons for abnormal fetal heart rate clinically, the main reasons are as follows:

1. The fetus suffers from intrauterine hypoxia. The more severe the fetal heart rate abnormality is, the more severe the fetal hypoxia is. However, it does not mean that all fetal heart rate abnormalities are caused by hypoxia.

2. The pregnant mother's own physical condition affects the changes in the fetal heart rate: for example, if the pregnant mother has a fever, anemia, hyperthyroidism, or is overly anxious or nervous, the pregnant mother's own heart rate is very fast, and the fetal heart rate often exceeds 160 beats per minute.

3. Effects of taking certain drugs: For example, taking salbutamol or atropine during premature delivery may cause the heart rate of the pregnant mother and baby to increase.

4. Endometrial infection: If the fetus is infected in the uterus, fetal heart malformations and conduction abnormalities can also cause fetal heart abnormalities.