Estimate expected fundal height in centimetres from gestational week using McDonald’s rule of thumb.
| Expected height | – |
Use this calculator for McDonald’s sketch after about 20 weeks: expected fundal height in centimetres is taken as equal to the gestational week. A tape from the pubic symphysis to the uterine fundus often tracks that line within about ±2–3 cm. Polyhydramnios, fibroids, multiple pregnancy, and high BMI break the rule. This is not a growth scan.
The expected height is shown in centimetres (cm) or inches (in).
Gestational week: Weeks from last menstrual period or from a dating scan.
Expected height: McDonald estimate of fundal height.
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