Vertex presentation is just medical speak for “baby’s head-down in the birth canal and rearing to go!” About 97 percent of all deliveries are headfirst, or vertex—and rare is the OB who will try to deliver any other way.
Other, less common presentations include breech (when baby’s head is near your ribs) and transverse (which means the shoulder, arm or trunk is due to come out first because baby is lying on his side). Most babies will turn by about 34 weeks, but some have “unstable lies,” meaning they’re like a politician trying to make everyone happy—that is, they frequently flip positions.
About 95 percent of all babies will be head-down and ready to go by delivery day. If your little one isn’t vertex by 36 weeks, ask your doctor about your options. She may recommend doing a version procedure, in which the doctor tries to manually turn baby by pushing on your abdomen, but it does carry some risks and is only about 60 to 70 percent successful.
Expert: Melissa M. Goist, MD, assistant professor, obstetrics and gynecology, The Ohio State University Medical Center.
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