The first stage of parturition starts with the onset of labor. It continues until the cervix is fully dilated. This dilation is divided into two phases: Latent phase.

What is the first stage of parturition?

The first stage of parturition is dilation of the cervix. The normal cervix is tightly closed right up until the cervical plug is completely dissolved. In stage 1, cervical dilation begins some 4 to 24 hours before the completion of parturition.

What triggers parturition?

Parturition in most animals results from changes in circulating hormone levels in the maternal and fetal circulations at the end of pregnancy (endocrine events), whereas labour in humans results from a complex dynamic biochemical dialog that exists between the fetoplacental unit and the mother (paracrine and autocrine ...