Parturition means childbirth. Childbirth is the culmination of pregnancy, during which a baby grows inside a woman’s uterus. Childbirth is also called labor. Pregnant humans go into labor roughly nine months after conception.
Read on to learn about the three stages of parturition and how long each stage lasts on average.
- Latent phase. The cervix is 0 to 4 centimeters (cm) dilated.
- Active phase. The cervix is 4 to 10 cm dilated.
The latent phase takes about six hours for a woman who’s giving birth for the first time. It takes around five hours for a woman who’s given birth previously. For some women, the latent phase may last 8 to 12 hours.
During the active phase, it’s expected that the cervix will dilate at a rate of about 1 cm per hour for a woman who’s giving birth for the first time. For a woman who’s previously had a vaginal delivery, the rate is typically about 2 cm per hour.
The second stage of parturition starts at full dilation and continues until birth. This stage also has two phases:
- Passive phase. The baby’s head moves down through the vagina.
- Active phase. The mother feels a need to push, or contract the abdominal muscles in time with uterine contractions.
The active phase lasts about 45 minutes for a woman who’s having her first baby. For women who’ve had a vaginal delivery, the active phase lasts about 30 minutes.
Stage 2 ends with the birth of the baby. At this point, the umbilical cord is clamped, and breastfeeding is often encouraged to help with stage 3.
The third stage of parturition starts after birth and ends with the delivery of the afterbirth (placenta and membranes).
If the doctor takes an active role — including gently pulling on the placenta — stage 3 typically takes around five minutes. If the placenta is delivered without assistance, stage 3 can last around 30 minutes.
Sometimes there are complications during each of the three parturition stages.
Some of the most common complications include:
Fetal distress typically refers to a slowdown in the baby’s heart rate. A doctor usually addresses this by using a vacuum extractor or forceps to speed up the birth. If that’s unsuccessful, a cesarean delivery might be called for. This is a surgery to deliver the baby.
This is when the umbilical cord wraps around the baby’s neck. Although a nuchal cord doesn’t mean danger for the baby, it could become a problem if the mother can’t push the baby out and a vacuum extractor or forceps are unsuccessful. A cesarean delivery might be the best treatment for this situation.
Human babies should be delivered with their head down. A breech pregnancy is when the baby is positioned feet down, bottom down, or sideways. Sometimes a doctor can reposition the baby manually. Sometimes the solution is a cesarean delivery.