A tape measure is used to measure the distance between the pubic symphysis (pubic bone) and the uterine fundus, assessed by manual palpation. The meter is stretched vertically, and the pregnant woman, whose bladder needs to be emptied, lies down so that the position of the uterus is always the same.
This examination is carried out from the 4th month of pregnancy (it is possible to start before but it is not very reliable) and until the term. The measurement is carried out once a month, or even more in the event of an anomaly. It is preferable that the same person do the examination. The way of measuring is thus identical each time and the measurement of fundal height is all the more precise.
From the 4th month of pregnancy, the uterus should measure approximately 16 cm and then take 4 cm per month until the 7th month. From 32 weeks of amenorrhea (beyond the 7th month), it evolves by 0.5 cm per week until term. We, therefore, compare the results obtained on the pregnant woman with the average uterine height:
Theoretically yes, but it depends a lot on the position of the baby – if he is in a transverse position, for example, he will reduce the height – and on the abdominal volume of the future mother. In other words, the stronger the latter, the more imprecise the measurement. If in doubt about the growth of the baby, the mother-to-be will be subject to increased monitoring.