The estimated weight of the baby can be calculated by ultrasonography in pregnancy. It is not the true weight measurement made here, it is not possible to measure the weight of the baby with an ultrasonic device or any other kind of thing in a real sense. However, ultrasound can make weight estimation by taking measurements such as head diameter (BPD), leg size (FL), abdominal circumference (AC). This estimate is made automatically by the computer program installed in the ultrasonic device. This is called Estimated Fetal Weight (EFW). Ultrasound results reports are often referred to by names such as EFW Hadlock. Ultrasonically developed methods and other methods have a certain margin of error, they do not always give exact and correct results, they are affected by various factors such as baby’s position, amount of amnion water, delivery started. In addition, since babies of each race and country have different physical characteristics, a formula that gives good results in one country can give unsuccessful results in other countries, so every country should use its successful formulas in ultrasonic devices.
Determination of the estimated weight of the baby by fundus-pubis measurement:
It is also possible to estimate the weight of the baby by making use of the size of the mother’s abdomen by clinical examination except ultrasonics. The area called the fundus is the uppermost point of the mother’s uterus. It is the upper part of the pubic bone called the pubis, the top of the pubic hair in the forehead in another description. The estimated weight of the baby can be calculated by using the value obtained after measuring the distance between these two points called fundus and pubis with a soft tape and some formulas.
An exemplary formula is:
EFW = FPM (cm) x MAC (cm)
FPM: Fundus pubis measurement in this form, MAC: The circumference of the abdomen measured around the navel of the mother, the distortion of these two gives the estimated fetal weight.
The simple calculation of the weight of the baby without the need of any device by measuring the circumference of the mother’s abdomen with the tape was found to be as successful as ultrason in some investigations. Because of the common use of ultrasonography devices, fundus-pubis ultrasound measurement is used only in the screening examinations made by midwifes. Today, it is still a valuable measurement method.
Other methods:
In addition to the above main methods, weight estimation can be done by MRI method. In addition, some hormone values in pregnancy have been tried to be used to develop formulas that can predict the weight of the baby and it is not used.
Why is the estimated weight of the baby in the mother’s womb calculated?
Estimated fetal weight calculation is a very important part of ultrasound measurement. Especially after 5th month of pregnancy, it gets more importance, since baby’s weight is very low, it does not give much idea. The main reasons for measuring baby’s weight are:
– Determine whether there is development retardation in the baby
– Predicting the birth weight of a baby at a preterm birth or a water incident and predicting that it may be necessary for the birth decision or the baby to need intensive care
– Detect macrosomic babies and give a caesarean decision to them instead of normal birth
– To evaluate the weight gain and related complications of twin babies
– Estimate the birth weight of infants at risk of premature birth, calculate that infant may need intensive care according to this measure