Induction — a process of stimulating labor to begin — is very common, with one in four births in America started with labor induced. Unless there is a problem, induction is not done before 39 weeks. Reasons for induction vary and include:
- Mother or fetus is at risk
- Pregnancy has continued too far past the due date
- Fetus is diagnosed with poor growth
- Mother has preeclampsia, eclampsia or chronic high blood pressure
There are a number of common induction techniques.
Stripping the membranes. A doctor or midwife can use a gloved finger to gently separate the amniotic sac from the wall of the uterus, releasing hormones that can trigger contractions. The procedure can cause discomfort, cramping and spotting, and women who undergo it generally return home to wait for contractions.
Hormones. At the hospital, a doctor can administer hormones called prostaglandins to open the cervix and trigger contractions. As it increases the risk of uterine rupture, doctors will not use this treatment in mothers who have had a past C-section.
Mechanical dilation. A doctor or midwife can trigger labor at the hospital with a balloon catheter. This thin tube is inserted into the cervical opening through the vagina. Water inflates the balloon at the end of the tube, causing expansion of the cervix.
Medications. An IV tube inserted in the arm can deliver the medicine Pitocin (oxytocin) to start contractions. A doctor or midwife starts with a small dose, gradually increasing it until contractions are strong and frequent enough to deliver the baby.
Timing of delivery after induction can vary widely. Some women go into labor and deliver within a few hours, others take one to two days to start labor. If induction does not lead to the start of labor, you’ll most likely need a C-section, especially if your water has broken.