Delivery presentation describes the way the baby is positioned to come down the birth canal for delivery.
Your baby must pass through your pelvic bones to reach the vaginal opening. The ease at which this passage will take place depends on how your baby is positioned during delivery. The best position for the baby to be in to pass through the pelvis is with the head down and the body facing towards the mother's back. This position is called occiput anterior (OA).
In breech position, the baby's bottom is facing down instead of the head. Your health care provider will usually detect this in an office visit before your labor begins. Most babies will be in the head-down position by about 34 weeks.
Part of your prenatal care after 34 weeks will involve making sure your baby is in the head-down position.
If your baby is breech, it is not safe to deliver vaginally. If your baby is not in a head -down position after your 36th week, your provider can explain your choices and their risks to help you decide what steps to take next.
Occiput Posterior (OP)
In occiput posterior position, your baby's head is down, but it is facing the mother's front instead of her back.
It is safe to deliver a baby facing this way. But it is harder for the baby to get through the pelvis. If a baby is in this position, sometimes it will rotate around during labor so that the head stays down and the body faces the mother's back (OA position).
The mother can walk, rock, and try different delivery positions during labor to help encourage the baby to turn. If the baby does not turn, labor can take longer. Sometimes the provider may use forceps or a vacuum device to help get the baby out.
A baby in the transverse position is sideways. Often, the shoulders or back are over the mother's cervix. This is also called the shoulder, or oblique, position.
The risk for having a baby in the transverse position increases if you:
Unless your baby can be turned into head-down position, a vaginal birth will be too risky for you and your baby. A doctor will deliver your baby by cesarean birth (C-section).
Less Common Presentations
With the brow-first position, the baby's head extends backward (like looking up), and the forehead leads the way. This position may be more common if this is not your first pregnancy.
Your provider rarely detects this position before labor. An ultrasound may be able to confirm a brow presentation.
More likely, your provider will detect this position while you are in labor during an internal exam.
With face-first position, the baby's head is extended backwards even more than with brow first position.
Most of the time, the force of contractions causes the baby to be in face-first position.
It is also detected when labor does not progress.
In some of these presentations, a vaginal birth is possible, but labor will generally take longer. After delivery, the baby's face or brow will be swollen and may appear bruised. These changes will go away over the next few days.
Lanni SM, Seeds JW. Malpresentations and shoulder dystocia In: Gabbe SG, Niebyl JR, Simpson JL, et al, eds. Obstetrics: Normal and Problem Pregnancies. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 18.
Cynthia D. White, MD, Fellow American College of Obstetricians and Gynecologists, Group Health Cooperative, Bellevue, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.