What is a normal fetal heart rate?

When you heard your baby’s heartbeat through ultrasound monitoring, you were probably delighted, entranced and mystified by that tiny, internal life. You might have also wondered if your baby’s fetal heart rate was normal during your pregnancy. We promise, this isn’t the first time you’ll wonder if your baby’s development is “normal” in comparison to others. While most pregnant women won’t get to hear their baby s heartbeat in the first week, or even the first trimester, this shouldn’t make you worried – you can hear it as early as the sixth week! The fetal heart rate varies during the stages of pregnancy, and with help from regular health care, monitoring and frequent ultrasound appointments, it won’t be long before the time comes to hear that first beat. Click on the bar below to hear a fetus’ heartbeat!

At about 5 weeks of gestation during pregnancy, your baby’s heart begins to beat, and you will get to hear your baby s fetal heart rate with an external method such as a Doppler ultrasound. Doppler device uses sound waves using fluid in the amniotic sac to check the flow of blood in the baby, and is also used when monitoring the baby’s heart rate.

During this trimester, the baby s heartbeat is slightly higher than that of the mother, about 100 beats per minute (bpm). From this point on during pregnancy, the baby s heart rate frequency will increase by around 3 beats per minute per day during that first month. This system is so accurate that your doctor could use the mother s heart rate to help determine your baby’s gestational age.

Fetal Heart Rate on Ultrasound
Normal fetal heart rate on ultrasound

By the beginning of the 9th week of pregnancy, the normal fetal heart rate is an average of 175 bpm (beats per minute). At this point, a rapid deceleration of the fetal heart rate begins, reaching around 110-160 beats per minute in mid-gestation. There is also a slow deceleration in fetal heart rate in the last ten weeks of pregnancy. It is important to note that variations in a baby s heart rate is normal, just as with an adult’s heart rate. Whether it will get higher or lower, rest assured your baby is fine! You will find that sleep, movement, and other related prenatal activities can contribute to these normal, healthy variations in your baby s heart rate, and your doctor has a system to test and monitor each beat. 

Fetal Heart Rate Reference Table

Gestational Age / Fetus Size NormalFetal Heart Rate
2 mm embryo75 beats per minute (bpm)
5 mm embryo100 beats per minute (bpm)
10 mm embryo110 bpm to 120 bpm
15 mm embryo130 beats per minute (bpm)
5 Weeksstarts at 80 and ends at 103 bpm
6 Weeksstarts at 103 and ends at 126 bpm
7 Weeksstarts at 126 and ends at 149 bpm
8 Weeksstarts at 149 and ends at 170 bpm
9 Weeks155-195 bpm (average 175 bpm)
12 Weeks120-180 bpm (average 150 bpm)
After 12 Weeks110-160 bpm (average 140 bpm)
Normal Fetal Heart Rate During Pregnancy

What is a False-Positive Reading?

False-positive fetal heart rate monitoring readings – which may indicate there is a problem when the baby is actually fine – are common.Your doctor has a range to classify your baby’s prenatal development and fetal heart rate readings during pregnancy. The range is reviewed according to three categories:

  • Category One: Everything is normal and no action or test is needed.
  • Category Two: Readings are unclear and may be further reviewed, or require more internal information such as an additional test, evaluation and surveillance.
  • Category Three: Readings around the heart rate are abnormal (higher or lower) and may require prompt evaluation and action.

Medical professionals can see fairly early on when a baby s heart looks normal and healthy (category 1) and know when something is wrong during gestation and we need to take immediate action (category 3). In the middle, it may get complicated, and this range is where false-positives often show up based on what your doctor can and can’t see through external ultrasound monitoring. A lot of factors go into assessing if a baby is healthy during birth – for example, the mother’s pregnancy health from the first trimester affects the baby, and must be reviewed as early as possible. This is where the use of one device can’t replace the care of a good doctor. The results are usually related to the context of what’s going on around gestation during any given week, and we know an internal fetal heart rate device can’t give us this information.

What can fetal heart rate monitoring tell us about your baby’s heartbeat during labor?

If you’re between 38-42 weeks in your pregnancy and you’ve gone into labor, your medical team will immediately set up fetal heart rate monitoring to first asses your baby’s heartbeat and health during birth. The main purpose of fetal heart rate monitoring is to provide information by observing your baby s heartbeat and alerting your doctor if your baby may not be getting enough oxygen or blood flow. We want to see your healthy baby come through pregnancy, labor and delivery as smoothly as possible. We don’t want the stress of labor to threaten a baby s heart, health or development, which is why a monitoring system as early as possible is so essential.

A baby s heart rate during labor should be between 110 and 170 bpm (beats per minute) depending on which week you’ve gone into labor, but it may fluctuate above or below this rate for a variety of reasons. Short bursts of acceleration of the baby’s heart rate are usually common and indicate that the baby is getting an adequate oxygen supply. We know that brief decelerations in the baby s heart rate are also normal and do not indicate poor fetal health. Accurate results are based on the use of a monitoring system reviewed by your health care team, regardless of how many weeks of gestation your baby is.

If these accelerations or decelerations are not occurring at the stages they should be, or if they are prolonged, it may mean a number of things, such as the umbilical cord is compressed and blood flow to the baby has been slowed. Usually, a simple method used, such as changing your labor position, may improve the situation and increase blood flow. If, when monitoring the birth, the fetal heart rate results indicate that your baby may be in danger (such as an irregular beat), your doctor may make a decision to rupture the amniotic sac to accelerate delivery, or recommend an operative vaginal delivery or a cesarean section.

Is it possible to determine my baby’s sex by the fetal heart rate?

According to an old wives’ tale, if your baby’s fetal heart rate is greater than 140 bpm, the baby is female. If the fetal heart rate is below 140 bpm, it is a boy. Of course, superstition is not used to test fetal monitoring – if it were this easy to tell the baby’s gender, obstetricians would be out of a job! Your baby’s fetal heart rate has nothing to do with his gender. A study from the 1980’s disproved this heart rate “myth” after examining more than 10,000 babies; a secondary study conducted in 2006 would help reconfirm what scientists already knew: there is no relationship between fetal heart rate and the sex of the baby. An ultrasound during pregnancy is usually the easiest and most accurate way to make sure.

One accurate predictor is the use of ultrasonography, which identifies the baby’s sex by examining fetal anatomy depending on the trimester. Find out from your doctor when you’ll be able to see your baby’s sex on ultrasound.

When You Can Find Out Baby’s Sex

The main reason for having a baby gender ultrasound is to determine the health and well-being of your baby. Having said that, it is only natural that the parents would want to learn her baby s sex as well. An amniocentesis is a medical, prenatal procedure that is used to test for risk of fetal abnormalities (birth defects) like down syndrome, cystic fibrosis or spina bifida; an amniocentesis can tell you whether your baby has a genetic disorder by analyzing fetal cells that are found in amniotic fluid, from about 15 weeks of pregnancy. You can learn more on amniocentesis and the associated risk in this article. Similarly, chorionic villus sampling (CVS) is another prenatal test that is used to detect birth defects in pregnant women, including genetic diseases.

While prenatal screening tests, including blood tests and ultrasounds, can tell parents if their baby has a riskof a disorder, wanting to know your baby s gender and when it can be identified is probably one of the most common first requests at an ultrasound appointment. In addition to ultrasounds, it is possible to know if you’re having a boy or girl through a urine test or through sexing, but for the purposes of this article, we will examine sexing through ultrasound.

Unfortunately, there isn’t one easy answer for moms-to-be. Identifying the baby s genitalia depends on a number of factors. For example, the fetal position can make it difficult, if not impossible, to see the baby’s gender. The appearance of genitalia (i.e. penis or clitoris) will also depend on your baby’s gestational age. Currently, we know that the diagnosis of sex is inaccurate until the 12th week of pregnancy — after the 13th week of pregnancy, it can reach 99 to 100% accuracy.

The gestational age tables vary from population to population, so it is preferable to use the size of the fetus (not the gestational age) to determine whether your baby is a boy or a girl. Fetuses over 72 mm that are in the right position with a clear image on the monitor will allow your technician / doctor to reveal the sex with nearly 100% accuracy.

How does the doctor know the baby’s sex?

A sonographer specializes in the use of ultrasonic (sound waves) imaging devices to produce diagnostic images, scans, videos or three-dimensional renderings of anatomy. During your pregnancy, an ultrasound technician should be able to look for and see the genital tubercle from as early as the 13th week – the structure that will develop into a penis for a boy and a clitoris for a girl. The site and positioning of the tubercle in a girl is horizontal (parallel to the spine), while in a boy it is vertical before developing into an penis (perpendicular to the spine), as shown in the image below. Medical ultrasounds are about 99 percent accurate in determination of the baby s gender.

Below is a slightly adjusted image of the genitalia to show the difference between boys and girls during pregnancy (not always easy to identify on ultrasound). Contrary to popular belief, the fetus’ heart rate does not determine the sex of your baby.

Baby gender on ultrasound
How to identify baby’s gender on ultrasound

What can impede finding out the sex of your baby?

In addition to the baby’s position during pregnancy and the size of the fetus, there is more than one medically reviewed factor that affects baby gender identification, including:

  • Sign of maternal obesity
  • Site of previous abdominal surgeries
  • Weeks of pregnancy
  • Risk of fetal abnormality
  • Uterine positioning
  • Fetal positioning
  • Quality of the medical ultrasound device used

If your doctor has said he is having difficulty determining the sex of your baby during an ultrasound, it might be too early and it’s probably best to have the test done on another day. Remember that you will get additional ultrasounds between 11 and 14 weeks to measure the nuchal translucency. When you schedule this exam, you can measure nuchal translucency at that time and have at least a good idea of your baby s gender, in addition to important information about your baby s well-being.

CAUTION: The correct time to measure nuchal translucency is when the fetus is between 45 and 84 mm in length from head to buttocks. So it’s important not to schedule your exam at the end of 14 weeks, as the fetus may have passed the appropriate measurements to determine nuchal transparency. 

When can parents find out the baby s gender?

Look at your calendar to count the gestational age. Note that not every month has 4 weeks; as the interval between 13 and 14 weeks is very short, this small difference can cause you to miss the one window that measures nuchal translucency. If you are in doubt, read this article to find our gestational age calculator. You may also like this article on converting months to weeks to make sure said calculations are accurate.

Until you find out the sex of your baby, you may decide not to get baby clothes for now. Regardless of when you determined the sex of your baby, you’ll want to wait for a second test in the list of ultrasounds (called the morphological exam), between 20 weeks and 24 weeks. After the prenatal morphological examination results, your ultrasound technician can confirm the sex of your baby with 100 percent accuracy — go ahead and find his first trousseau! 

Is there a trick to choosing the sex of the baby before becoming pregnant?

Throughout history, women have done peculiar things in the name of pre-determining the gender of their baby. Despite old wives tales, in naturally conceived pregnancies early gender selection is not possible; there is no universal sign that will ensure your baby has a penis, no food that will determine the sex of your child. Your ob gyn cannot ‘make’ you conceive a baby boy or get a ‘girl ultrasound’ with exclusively ‘female sound waves’. There is no medically reviewed, scientific sign that your lifestyle choices will affect if you’re having a boy or girl. From time to time we hear that there may be a difference in the speed of the sperm that carries the X chromosome and the sperm that carries the Y chromosome. It is said that this, in theory, may affect the gender, but is not a prediction; there is no scientific evidence used to support this claim, and no way for your ob gyn to test it (through blood tests, etc.) So having sex farther or closer to ovulation is not an accurate way to determine or learn the sex.

What are the signs of labor?

Wouldn’t it be wonderful if there was a timer that told you when labor starts? During their pregnancy, any pregnant women wonder what it will feel like, how long it will take and if they’re actually in labor, or if it’s just a false alarm (i.e. Braxton-Hicks contractions). Everyone’s pregnancy is different; similarly, everyone’s delivery experience is different. Knowing the signs of labor will help prepare you to get ready and meet your new baby.

Woman with signs of labor going to the hospital

Braxton Hicks Contractions

Since mid-pregnancy, you may have experienced some irregular labor contractions, known as Braxton-Hicks contractions. These are just “training” contractions, but as your pregnancy comes close to an end, these contractions get progressively longer and have a shorter interval; you will definitely notice the signs of active or “true” labor, a sure sign that your baby is ready to come. The early phase, known as prodromes of labor, can begin a few days or weeks before active labor.

What are the early signs of labor?

During actual labor, the contractions are quite rhythmic, occurring every 3 to 4 minutes and lasting at least 30 to 70 seconds each. If you’d like to track the progress of your labor, lie back, relax and place your hand on your abdomen, near the dome-shaped uppermost, rounded part of the uterus, called theuterine fundus. When a contraction starts, you may notice the uterus will shift forward and harden. When you feel the contraction start, use a watch to time the duration of the contraction. Contractions may or may not be associated with pain. Depending on the intensity of the contractions and the sensitivity of the mother, contractions may be experienced anywhere from mild to intense pressure and discomfort. Labor contractions are usually localized to the lower part of the belly, but can also radiate to the lower back. Time your contractions for about 10 minutes; if you count at least 3 contractions within this time frame, and they get stronger and closer together, this is probably the most important indicator that you are in labor, and it’s time for your baby to come!

It is important to note that there are situations where the uterus might be stimulated and a few contractions may come in a row and get closer together, then cease after a period of rest, without the cervix dilating. Women experience this if, for example, they walk around for a while, if there are still has a few weeks to go before the due date, or if they are very stressed about their pregnancy. In this instance, they are experiencing false labor. If a patient is ever concerned, she should go to the hospital.

How can I be sure that I’m going into labor?

To make absolutely sure that you are in labor and ready to deliver your baby, you would ideally evaluate your contractions for longer than 10 minutes. We advise that if you have 3 contractions in 10 minutes, wait another 30 minutes and then do a new evaluation. If the contractions persist at regular intervals, and are fewer minutes apart, it is time for you to go to the hospital so that you can be evaluated by your doctor.

In addition to uterine contractions, there are other early signs of labor during your pregnancy that may indicate your baby is ready. It is best to contact your doctor or midwife if you experience any of the following:

  • A few days (or even weeks) before delivery, your belly will look like it has “dropped”. This is because the uterus is shrinking in size as your baby drops and prepares to enter the world. You may experience lower back pain as well.
  • The process of your baby settling or lowering into your pelvis just before labor is called lightening. Lightening can occur a few weeks or a few hours before labor. Because the uterus rests on the bladder more after lightening, some women get the need to urinate more frequently during the last part of their pregnancy.
  • During your pregnancy, in the days before labor you may feel a sudden burst of energy and get an increased drive to clean and organize in preparation for your baby. This can even happen weeks before the time your baby is due.
  • Your cervix will dilate open when labor begins, though you will need a vaginal exam to determine this. Do not examine your own cervix! If your cervix dilates, Make sure you get the right medical advice from a doctor or midwife. They will advise if you cervix is dilated at 10 centimeters, or how much time you’ll have before that occurs.
  • When your cervix does begin to dilate, you may lose your mucus “plug”, a phlegm-like substance that seals the uterine cavity. The mucus plug may be followed by a “bloody show”, or blood-tinged vaginal discharge (there is no pain when this occurs). Mucus may present as light pink, brown or bright red.
  • You feel your water breaking. Many women feel like they’ve accidentally peed themselves, when in fact it’s amniotic fluid emptying from the amniotic sac; when your water breaks, it’s a definite sign to get ready for labor. For some women, they may not feel their water break at all, and have to rely on other signs of labor such as regular contractions that are several minutes apart.
  • When labor starts, you may feel like you have to vomit, especially while you’re having regular contractions and/or lower back pain. This may mean your baby is getting ready to come.
  • You see your baby s head. This is unusual, but some women don’t know they’re in labor, think they’re in false labor, or are unaware that they are experiencing the signs of labor. If your baby is crowning, and you’re on or near your due date, this is a key differentiator between true labor and false labor.

If you’re still unsure, if your water breaks, or even if you think you might be having false labor contractions, call your doctor or midwife, and/or get to the hospital as soon as labor starts so that an obstetrician can properly assess your pregnancy and your baby. If you are experiencing any signs of active labor such as bloody show, water breaking or another sign of labor and you are less than 37 weeks into your pregnancy, call your doctor as you may be in premature labor. In this instance, you will get an exam to assess the labor signs, as well as the risks of preterm labor, in addition to the second trimester morphological exam.

In the event of preterm labor, it is essential to arrive at the hospital as soon as possible to be medically reviewed so that the doctor can inhibit labor contractions or prescribe medication to rapidly mature the baby’s lungs. If you are in early labor you may be at risk.

How long will my labor last?

The duration of labor varies, but typically lasts between 12 to 24 hours. However, many women include the hours before labor, known as the prodromal labor phase — contractions that begin before true labor. Unlike Braxton-Hicks contractions, which help your uterus prepare for active labor, your cervix can slowly dilate or efface during prodromal labor. If we include this phase, labor can last up to a few days.

What can I do to encourage true labor?

Even in today’s age, the mechanism by which true labor begins is not fully understood. Most of the time, it is difficult to predict when the true labor will start, even if we know the due date (or the mother’s water breaks). Toward the end, when the baby is ready, she will go into labor, however there are instances that can help labor along:

  • Short walks or gentle yoga (which may feel good whether or not you’re in labor)
  • Having sex. This can cause the uterus to contract in 3 different ways: 
  • Through orgasm
  • Through the release of oxytocin (a hormone that makes the uterus contract)
  • Through semen, which can also cause contractions
  • Nipple stimulation. Small (gentle) pinches can also help release oxytocin. If you have previously breastfed a baby, you’ll remember experiencing cramps while nursing. This is due to the release of oxytocin triggered by the nipple stimulation.

If you have additional questions about the signs that labor have begun, or about whether you’re going into labor (or having false labor contractions), call your doctor or midwife to discuss your concerns.

Pregnancy Due date calculator

How do I use the Pregnancy Due Date Calculator?

Our online pregnancy due date calculator allows you to determine how many weeks old your baby is in utero (also known as your gestational age). The easiest way to use the pregnancy due date calculator is to simply enter the first day of your last period. If you don’t know when the first day of your last menstrual period was, your baby’s age can be calculated in five different ways. 

  1. Estimated Due Date (or EDD): If you know your baby’s expected delivery date, you can enter that day on the calculator and it will inform you of your baby’s current gestational age, the likely date of conception and other important information about your pregnancy. Important to note: PDD is not the day you’ve scheduled for delivery, the expected date of birth is the day your baby turns 40 weeks old.
  2. Last Menstrual Period (or LMP): The first day of your last menstruation is the most commonly used parameter to determine your baby’s gestational age. With this information, we can better understand your menstrual cycle and determine all the important milestones of your pregnancy.
  3. Date of a previous exam: Use this if you do not know when your last menstrual date was or when your probable delivery date is. In this instance, it is not possible to calculate using your menstrual cycle, so we’ll need to perform an ultrasound to be certain. Important to note: You should always use the first exam that was performed during this pregnancy for the calculation to be accurate; the earlier it is, the lower the margin of error for the ultrasound. If you choose to use this parameter for the calculation, you will need to enter the gestational age that was estimated on that exam, in addition to the date on which the exam was performed. For example, if you took an exam on the 10th of May, your baby’s estimated gestational age would be 8 weeks and 3 days. In this case, you should use the value of “10/05” in the “Date of a previous exam” field for the calculation, and in gestational age you must enter “8” weeks and “3” days.
  4. Transfer date: If you’ve gone through assisted reproductive technology cycles, you can calculate your due date more precisely using your IVF (in vitro fertilisation) transfer date.
  5. Conception date: If you happen to know precisely when you conceived, you can use this method to estimate your gestational age. Bear in mind that very few expectant moms know exactly when they conceived.

If the dates of your pregnancy are still causing you confusion, please consult your prenatal portfolio, where you will easily find all the information about your pregnancy. The due date based on your last period is calculated based on a normal menstrual cycle length. The average cycle length is 28 days, but can range anywhere from 24 to 38 days. 

Conception usually occurs around 14 days after the first day of your last period. The due date of your baby is calculated by adding 280 days to the first day of your last menstrual period. That is because the average length of human gestation is 40 weeks (or 280 days) from the first day of your last period.

I don’t know how to calculate gestational age in weeks. Can I use months instead?

No. Technically, the “correct” way to calculate gestational age is in weeks. Using months is an inaccurate way to count your pregnancy time. Months do not have the same number of days, and while there may only be a 1-day difference from one month to the next, adding that discrepancy to a 9-10 month time span would make a considerable difference. There are many reasons to count gestational age in weeks rather than months, and we have linked two posts on the subject below:

  • How is Gestational Age (Duration of Gestation) calculated?
  • Gestational Age in Months

I’m still trying to get pregnant. How do I use the calculator?

In this instance, you do not need the pregnancy due date calculator, but use the Fertile Period Calculator instead. With this calculator, it is possible to determine the probable day of your ovulation based on the characteristics of your menstrual cycle. This will allow you to determine when your chances of becoming pregnant are greatest.

Reference: Calculadora de Idade Gestacional | Fetalmed