A pregnancy that has progressed without any apparent hitch can still giveway to complications during delivery. Here are some of the most commonconcerns.

Failure to Progress (Prolonged Labor)

A small percentage of women, mostly first-time mothers, may experience alabor that lasts too long. In this situation, both the mother and the baby areat risk for several complications including infections.

Abnormal Presentation

Presentation refers to the position the fetus takes as your body preparesfor delivery, and it could be either vertex (head down) or breech (buttocksdown). In the weeks before your due date, the fetus usually drops lower in theuterus. Ideally for labor, the baby is positioned head-down, facing themother's back, with its chin tucked to its chest and the back of the head readyto enter the pelvis. That way, the smallest possible part of the baby's headleads the way through the cervix and into the birth canal.

Because the head is the largest and least flexible part of the baby, it'sbest for it to lead the way into the birth canal. That way there's little riskthe body will make it through but the baby's head will get hung up. Incephalopelvic disproportion, the baby's head is often too large to fit throughthe mother's pelvis, either because of their relative sizes or because of poorpositioning of the fetus.

Sometimes the baby is not facing the mother's back, but instead is turnedtoward her abdomen (occiput or cephalic posterior). This increases the chanceof painful "back labor," a lengthy childbirth or tearing of the birthcanal. In malpresentation of the head, the baby's head is positioned wrong,with the forehead, top of the head or face entering the birth canal, instead ofthe back of its head.

Some fetuses present with their buttocks or feet pointed down toward thebirth canal (a frank, complete or incomplete/footling breech presentation).Breech presentations are normally seen far before the due date, but most babieswill turn to the normal vertex (head-down) presentation as they get closer tothe due date. In a frank breech, the baby's buttocks lead the way into thepelvis; the hips are flexed, the knee extended. In a complete breech, bothknees and hips are flexed and the buttocks or feet may enter the birth canalfirst. In a footling or incomplete breech, one or both feet lead the way. A fewbabies lie horizontally (called transverse lie) in the uterus, which usuallymeans the shoulder will lead the way into the birth canal rather than thehead.

Abnormal presentations increase a woman's risk for injuries to the uterus orbirth canal, and for abnormal labor. Breech babies are at risk of injury and aprolapsed umbilical cord. Transverse lie is the most serious abnormalpresentation, and it can lead to injury of the uterus (ruptured uterus) as wellas fetal injury.

Your doctor will determine the presentation and position of the fetus with aphysical examination. Sometimes a sonogram helps in determining the fetus'position. When a baby is in the breech position before the last six weeks toeight weeks of pregnancy, the odds are still good that the baby will flip.However, the bigger the baby gets and the closer you get to the due date, theless room there is to maneuver. Doctors estimate that about 90% of fetuses whoare in a breech presentation before 28 weeks will have turned by 37 weeks, andover 90% of babies who are breech after 37 weeks will most likely stay thatway.