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When you’re getting ready for the arrival of your baby, it sometimes seems that you’re being bombarded with medical terms. Take left occiput anterior position, for instance. Say what?

Around your 34th week, you’ll start hearing terms that have to do with delivery — and this one might be among them. Left occiput anterior refers to how the baby may — quite ideally — be positioned for labor and delivery.

When your OB-GYN uses the words occiput anterior (OA) to describe your baby’s position, it means your baby is lying head down in your womb and facing your back. In other words, the back of their head (occiput) is at the front (anterior).

As your baby passes through your pelvic bones to reach your vaginal opening during labor and birth, positioning is important. OA positioning is considered the optimal position for birth.

Left occiput anterior (LOA) means the back of your baby’s head is anterior (near the pubic bone) and slightly rotated to your left. Your baby will enter your birth canal facing the area between your spine and right hip.

Although it has been suggested that LOA is the optimal position for a baby at the start of labor, a 2013 study including 1,647 women concluded that the theory was unfounded.

Conversely, right occiput anterior (ROA) means the back of your baby’s head is toward your front and slightly rotated to your right.

If your baby isn’t in LOA or ROA, it doesn’t necessarily mean that there’s a problem. It usually just means that labor and birth might be different.

Your healthcare provider will determine the position of your baby. They may perform an ultrasound to confirm their understanding. With that information, they’ll decide on the easiest and safest labor and delivery for you and your baby.

Some of the other terms regarding your baby’s position that you may hear or see on your chart include:

  • Presentation. This is the part of your baby entering your pelvis (head, feet, shoulder, bottom).
  • Vertex presentation. Your baby is head down, meaning their head is entering your pelvis first.
  • Breech presentation. Your baby’s bottom, feet, or knees are entering your pelvis first.
  • Transverse position. Also called the oblique or shoulder position, this is when your baby is sideways. Oftentimes, their back or shoulders are positioned to enter the pelvis first.
  • Occiput posterior (OP) position. Also called back-to-back position, this is when your baby is lying in your womb with their back against yours. They could be in the right occiput posterior (ROP), facing away from your spine with the back of their head on the right side of your pelvis, or they could be positioned in the left occiput posterior (LOP), facing away from your spine with the back of their head on the left side of your pelvis.

Left occiput anterior (LOA) refers to the position of your baby for labor and birth. Specifically, LOA means your baby is entering your pelvis head down, facing the area between your spine and right hip.

Having your baby positioned head down in your womb facing your back (occiput anterior) is considered the optimal position for birth.