If your baby is breech, his bottom is the part of his body closest to the birth canal. No one is sure what causes a breech presentation, but it happens in 3% to 5% of single-baby deliveries. As your pregnancy nears full term, your caregiver will check your baby's position during regular prenatal visits. Common methods for assessing fetal position include vaginal exams, feeling your abdomen, and listening to the baby's heartbeat with a stethoscope or Doppler device.