Pregnancy Myths

MYTH: If the fetal heart rate is below 140 beats per minute, it's a boy; if it's above 140, it's a girl.
Shawn A. Tassone, M.D. (OB/GYN)

From ten weeks until delivery, a routine doctor's visit includes listening to the fetal heart rate with a Doppler device. Many patients ask us whether or not the heart rate of the baby can determine its gender. Although we've heard it reversed occasionally, it seems to be widely accepted by most patients that a heart rate above 140 is most likely to be a girl. This myth crosses all cultures and age groups. No one seems to know where it came from. In fact, in our research, few theories even exist.

Studies, however, show no significant difference between a male and a female heart rate, at least statistically speaking. The normal heart rate for a fetus is anywhere from 120 to 160 beats per minute. The heart rate will fluctuate from beat to beat and demonstrates what is called fetal heart rate variability. The developing fetal brain is controlled by the sympathetic nervous system (the fight-or-flight response) and the parasympathetic (relaxation) system. As the brain develops, these two systems engage in a power struggle. The heart rate speeds up when stimulated by the sympathetic system and slows down when controlled by the parasympathetic response. So, depending on the arousal of the fetus, the heart rate can be 130 on one day, 110 the next, and 150 the next. We usually listen to the fetal heart rate for about ten to thirty seconds at a time. If the baby is awake and moving, the heart rate may be higher than if it is sleeping.

We can extrapolate this theory. Men and women, boys and girls do not have different heart rates based on gender. The heart rate in a healthy individual is a response to external stimuli and not necessarily caused by the gender of the individual. Shawn A. Tassone, M.D. author of "Hands Off My Belly! The Pregnant Woman's Guide to Surviving Myths, Mothers, and Moods" Other Myths:

• Pregnancy Myths: The way you "carry" the baby gives a clue as to its gender.
• Pregnancy Myths: Cramping in early pregnancy is a sign of miscarriage.

	Comment from monroezelda » Posted Jan. 6, 2013 7:05pm All my childrens hb av been 145 or above got 2 boys 1 girl an a boy on the way, my midwife says if it sounds like a train its a boy if it sounds like a horse its a girl ha ha
	Comment from a guest » Posted Mar. 18, 2012 8:05pm Yes it is accurate (for the aoumnt of info you 100% are sure about ie lmp, conception, cycle length), I use this site all the time. Somewhere in the trimester calculator it breaks it down that you could break the trimesters in gestational age, development and conception. So it is probably using one of the methods the other site isn't There are basically three ways of dividing up a pregnancy into the three trimesters; they are by:Development, Gestation, Conception. They give different dates for when the second trimester begins and for when the third trimester begins. Your health care provider might prefer to use the Development method, while another Midwife or Doctor may use the Gestation method.I am sure they do that just to confuse pregnant women.by Development:This uses actual developmental stages to divide up a pregnancy. From LMP to 12 weeks the embryo develops all the major organs and becomes a fetus. From 12 weeks to 27 weeks the fetus continues developing and reaches viabili
	Comment from flowdabeht » Posted Aug. 29, 2011 7:58pm SOO a myth, I have had 4 pregnancies and each time the heart rate has been above 140bpm and resulted in two girls and two boys