Ritgen maneuver is done in:

Ritgen (Ritzen) maneuver is done for delivery of head in normal labour to allow controlled delivery of the head. When the head distends the vulva and perineum enough to open the vaginal introitus to a diameter of 5 cm of more, a towel-draped, gloved hand may be used to exert forward pressure on the chin of the fetus through the perineum just in front of the coccyx. Concurrently, the other hand exerts pressure superiorly against the occiput. This maneuver allows controlled delivery of the head. It also favors neck extension so that the head is delivered with its smallest diameters passing through the introitus and over the perineum