During pregnancy and the successive ultrasounds that we do, one of the memories that remain in our memory are the measurements of the fetus, the weight and some other information. However, the length of the future baby is one of the most difficult knowledge data.
We know that through ultrasound during pregnancy the approximate weight of the baby is estimated based on the measurements of three parameters: the abdominal circumference, the perimeter of the head and the length of the femur.
In addition, there are formulas to calculate the fetal weight according to the week of gestation and calendars to know weight and measures during pregnancy (together with the mother's weight gain), although they are based on averages.
Thanks to these estimates and measurements after ultrasound we can know if the fetus develops according to its gestational age, if it will be more or less large (although there may also be many changes in a matter of weeks), but what is harder to know is the height of the fetus.
Neither in the past nor with the means present is it possible to measure the length of the baby. Current devices allow you to measure the head, bones, limbs, blood vessels, kidneys ... but you cannot measure the length (unlike the embryo) because the fetus is shrunk in the womb and it will only stretch at all once born.
In the embryo it is enough to make a straight line from one to the other ends of the "habichuelita" to see its measurement, up to pinpoint accuracy. But when it develops and as the fetus grows, it will shrink more to engage in the small space provided by the maternal interior.
Even the total "disengagement" can come a few hours after being born, and as proof are some measures of babies at birth and after a couple of days of births, which do not match, with such a considerable difference in increase that makes To think that it is impossible for me to have grown so much in two days.
So do not be surprised if we are told in the last weeks of pregnancy that the baby is so many centimeters and that measure does not match the "real baby" that is born. How tall the fetus is an estimate a calculation made thanks to the combination of various parameters, and, for the moment, cannot be done more accurately.
