Most babies enter the pelvis head first with their chin tucked against their chest and the smallest diameter of the head "presenting". However, 5% of babies enter the pelvis in a different position, and are described as "malpresentations".

Some of the factors that can cause a woman to be at a higher risk for malpresentation are an abnormally shaped uterus, limited pelvis size, fibroids, twins, placenta previa, or too much or too little amniotic fluid. Women who have had many previous children are also at risk because their abdominal muscles are often more lax and fail to keep the uterine cavity upright. Premature babies and babies with decreased muscle tone also have a higher incidence of malpresentations.

Occiput posterior presentation describes the situation where a baby has her head down with her nose and chin facing upward. Babies in this position are often referred to as "sunny side up" babies. During labor they frequently are rotated by either uterine forces during dilatation or maternal forces during pushing. Some, however, never rotate and are delivered looking upwards. Many women with occiput posterior presentations experience more back pain, slower labors, or spend more time pushing.

A Breech Presentation is when a baby's bottom or feet, instead of her head, are in position to come out first. If a baby is breech, the provider may try to adjust her position before the mom goes into labor by pressing on her abdomen with ultrasound guidance. Regional anesthesia may be offered. If adjusting the baby’s position does not work, the mom still may be able to have a vaginal delivery, or, depending on the circumstances, she may need a cesarean section.

A situation called "abnormal lie" is when a baby is laying the wrong way in her mother's womb. The correct position is when the baby's spine is up and down, or longitudinal. Occasionally, a baby will be lying across, in a "transverse" lie. In this case, the provider will try to turn the baby to a longitudinal lie, or a C-section will be required.

If a baby's head is partially extended on her neck, her brow or face will present first. This is called "Face or Brow Presentation". This is a relatively rare type of malpresentation, and usually results in a longer labor. Babies that present this way usually have swollen and bruised heads after they're born. The swelling and bruises will disappear within a few days, if not sooner.

Compound presentation is when a baby's hand or leg is presented next to the baby's head or bottom. This often isn't apparent until the mom begins to push. 75% percent of babies who present this way are delivered vaginally, while the other 25% require a cesarean.

Shoulder Dystocia is the term for when labor stops progressing because the baby’s shoulder gets stuck in the birth canal after the baby’s head has emerged. The provider may try to maneuver the baby to allow for a vaginal birth, but sometimes a cesarean section may be needed.