Labour Progress (WHO)

Latent phase continues until 5 cm of cervical dilation. The active phase is strictly defined as 5 cm to 10 cm. Interventions to accelerate labor should NOT routinely be performed before 5 cm.

In 1955, Dr. Emanuel Friedman studied 500 women and created the "Friedman Curve." For 60 years, it was undisputed dogma. However, modern women are older, have higher BMIs, larger babies, and widely use epidurals, rendering the 1950s data highly dangerously inaccurate and triggering an epidemic of premature cesarean deliveries.