Stages of labor

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Labor, also called parturition, describes the hard work of delivering a baby!

It specifically refers to the process which starts with uterine contractions which cause cervical changes which allow the fetus to be delivered vaginally, and ends with delivery of the placenta.

Labor typically begins at some point when the fetus is considered full term—between 37 and 42 weeks’ gestation.

In the third trimester, before labor starts, a woman might have a plug of mucus and blood fall out of the opening to the cervix, sometimes called a “bloody show”.

Other times the amniotic sac might rupture, sometimes called “water breaking”.

Either of these can trigger the onset of labor and so-called true labor contractions.

These guys have to be distinguished from the milder and ineffective false labor contractions, also called Braxton Hicks contractions (or sometimes called practice contractions).

Once they start, true labor contractions progress in frequency, duration, and intensity, and they can feel like waves that build up to a peak intensity and then gradually decrease.

The contractions pull on the thick tissues of the cervix, causing it to efface or get thinner and also dilate or open up, so then the fetus can leave the uterus and enter the world.

From the moment true contractions begin to the baby’s delivery usually takes about 12 to 18 hours for a first-time pregnancy, and about half that time for subsequent pregnancies.

Although, as any mother knows, this time can vary a lot!

Even though labor is a continuous process, it can be broken down into three stages.

Additionally, this first stage is subdivided into two phases.

The first phase is the early phase or latent phase, and usually lasts up to 20 hours, or until the cervix dilates to 6 centimeters.

At first, there are irregular contractions that occur every 5 - 30 minutes and last about 30 seconds each, causing the cervix to dilate from 0 cm to about 3 cm and efface from about 0% - 30%.