Fundal height (aka McDonald's rule) is a measurement of the size of the uterus, as an indication of proper fetal growth/development and amniotic fluid development, during pregnancy. SFH is shorthand for symphysis-fundal height.

• Measured from the palpable top of the uterus (rounding, using the fifth finger of a flat palm), to the superior edge of the pubic symphysis (cartilaginous prominence, uniting the left and right pubic bones)
• The top of the uterus (i.e. the fundus) should be able to be located at:
  • Week 12, at the pubic symphysis
  • Week 20, at the umbilicus
  • Week 36, xiphoid process of sternum
  • Week 37-40, regression of fundal height back down to as low as 32cm

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• Measurement is taken in centimeters, which should roughly correspond to gestational age
  • Fundal height should correspond from 16 weeks gestation forth, but in practice, beginning around 20 weeks' gestation
• Shorter fundal height, indicates:
  • Fetus descent into the pelvis, normally seen 2-4 weeks before delivery
  • Error in estimated date of pregnancy based on the 1st day of LMP
  • Fetus is physically small, but actually healthy
  • Oligohydramnios
  • Non-longitudinal lie, as fundal height corresponds only for a vertex fetus
  • SGA or IUGR
• Longer fundal height, indicates:
  • Multiple birth (e.g. twins)
  • Error in estimated date of conception
  • Fetus is physically large, but actually healthy
  • Gestational diabetes causing a larger baby
  • Polyhydramnios
  • LGA
  • Molar pregnancy/hydatidiform mole
  • Breech birth
  • Fundal height may stop correspond after 36 weeks gestation, thereby making it less accurate towards the end of pregnancy
• Post partum, where:
  • 12 hours after delivery, the fundus is usualy 1cm above the umbilicus
  • Within 1 week, the uterus descends into the pelvis approximately 1-2cm/day, until 7 days when the fundus should be half way between the umbilicus and pubic symphysis
  • This continues until 6 weeks, when the uterus returns to its natural position

• It is generally recorded for each prenatal visit