When your obstetrician talks about the position your baby is in, he might use the medical term "cephalic" to describe it. A cephalic fetal position simply means the baby's head is in the pelvis. A cephalic presentation is the most common position for a fetus at the end of pregnancy; around 97 percent of babies are born headfirst, according to MedlinePlus. Not all babies that emerge headfirst come out in the same way, however. Talk to your obstetrician about your baby's position and what it might mean for your labor.
Ask your doctor if he thinks your baby is in an anterior position, the most common cephalic presentation. Your doctor can often tell your baby's position by palpating your abdomen. Feeling the fontanelles -- soft spots -- on the top of the baby's head during labor also helps him determine the baby's position. By palpation or from the position of the suture lines, your doctor can tell if your baby is left occiput anterior -- referred to as LOA -- the most common position, with 60 percent of babies facing this way, according to the Geneva Foundation for Medical Education and Research. The back of his head is facing the front of your pelvis, but he's turned slightly so that he's looking to the right. If he's right occiput anterior, he's looking to the left. In this position, his chin is tucked down to his chest.
Notice where you're feeling your baby move. If he's posterior -- which is the case with 15 to 20 percent of cephalic babies, obstetrician Dr. Cynthia Argani explains on UptoDate -- he's facing forward -- what your doctor might call "sunny side up." If your baby is posterior, you might notice more back pain, because the back of his head is putting pressure on your spine. You might also feel his hands moving to the front of your abdomen rather than to one side of the other. If your baby is posterior, he might rotate during labor or remain posterior throughout the delivery. Posterior babies may have longer labors because the head doesn't conform to the pelvis as well in this position.
Realize that some headfirst babies still can't deliver vaginally. A few babies come face, chin or forehead first, with the head extended back or in an upright position, rather than with the chin tucked down to the chest. Most of the time, the baby's head won't fit through the pelvis in this position, because the diameter of the head is too large. Looking at pictures of brow and chin -- also called mentum -- presentations can help you visualize why your baby probably won't be able to navigate the pelvis this way. Some babies are head down, but with the head transverse, or facing sideways.