What fundal height indicates a viable fetus at the last rib and above?

A fundal height measurement is used to assess fetal growth and development during pregnancy. By 20 weeks of gestation, the top of the uterus (the fundus) typically rises to the level of the belly button, and as the pregnancy progresses, the fundal height continues to increase.

The measurement of fundal height being at the last rib and above typically correlates with a gestational age around 23 weeks. At this stage, the fetus is developing significantly, and the uterus has expanded enough to position the fundus at or above the rib cage. This height suggests that the fetus is viable and supports further maturing and development as the pregnancy continues.

As the pregnancy advances beyond this point, the fundal height will continue to rise and provide further insights into fetal growth, making 23 weeks the appropriate answer for this question.