39 weeks pregnant: baby is the size of a small watermelon

Your baby this week

Your baby is considered full term, and the organs, including the lungs, are mature. Your baby has a good layer of fat, and the skin is smooth. The head is engaged in the pelvis in many pregnancies, and the movements are smaller, with plenty of stretching and wriggling.

Your baby is still gaining a little weight, and the brain keeps developing. The nails may have grown beyond the fingertips. The placenta is nearing the end of its work, and it continues to supply oxygen and nutrients.

How it happens. Each additional week before birth helps your baby's lungs, brain and feeding skills. That is why, when there is no medical reason to hurry, waiting for labour to begin on its own is generally preferred, at least until your baby reaches full term.

Your body this week

Your cervix is likely softer and shorter, and you may have more tightenings and pressure. You may feel impatient, and people may ask if the baby has come yet. It is natural to feel tired of waiting.

If your due date is near, stay near your maternity unit and keep your bag, car seat and phone ready.

Why induction is offered

Induction means starting labour with medical help instead of waiting for it to begin naturally. Common reasons include:

• A pregnancy that goes past the due date. Many places offer induction around 41 to 42 weeks, since the risks to the baby rise slowly after that.
• Waters breaking without contractions, when labour does not start within a set time.
• High blood pressure or pre-eclampsia.
• Diabetes, including gestational diabetes, that is not well controlled.
• Concerns about your baby's growth or movements.
• Other health conditions in you or your baby.

The decision is shared. Your provider should explain why they suggest it, what the alternatives are and what will happen if you wait. You can ask questions and take time to decide unless there is an urgent reason.

How induction works

An induction may use one or more steps, depending on how ready your cervix is.

• Membrane sweep. A midwife or doctor puts a finger into the cervix and sweeps around to separate the membranes from the cervix. This releases hormones that may start labour. It may be uncomfortable and cause spotting. It is often offered from about 40 weeks in a first pregnancy, and around 41 weeks in later pregnancies.
• Softening the cervix. If the cervix is closed and firm, you may be given a tablet, gel or pessary of prostaglandin, a hormone, placed near the cervix. Or a small balloon catheter may be passed through the cervix to stretch it open.
• Breaking the waters. Once the cervix is open enough, a midwife or doctor can break the membranes with a small hook. This can bring on contractions.
• An oxytocin drip. If contractions do not begin or are not strong enough, oxytocin can be given through a drip to trigger and strengthen them. You are usually monitored continuously.

Induction can take from several hours to a few days, especially with a first baby. It may be more intense than labour that begins on its own, since the contractions can come on quickly. You will usually be able to try the same pain relief options, and an epidural is more common with induction. Ask about walking, using a pool and whether you can go home for part of the process.

If induction does not lead to labour, you will discuss the next step, which may be another attempt or a cesarean.

Planned cesarean

A planned cesarean is scheduled in advance. Reasons include a baby who is breech and not turned, a low-lying placenta covering the cervix, previous cesarean births where you prefer another, certain medical conditions or your own choice after discussion.

It is usually planned at or after 39 weeks, because babies born earlier have a higher risk of breathing problems. On the day:

• You are usually asked to stop eating and drinking for several hours beforehand.
• An anesthetist gives a spinal or epidural block, so you are awake and numb from the chest down.
• Your baby is usually born within the first 10 to 15 minutes, and the rest of the surgery takes about 30 minutes.
• Your partner can usually be with you, and skin-to-skin contact is often possible.

Ask about your recovery, pain control, feeding support and how soon you can move. See week 36 for more on cesarean and vaginal birth.

Questions to ask

• Why do you recommend this, and what are the alternatives?
• What are the benefits and risks for me and my baby?
• What will happen if I wait?
• How long might it take, and can I go home in the meantime?
• What pain relief and monitoring will I have?