A pregnancy that has progressed without any apparent hitch can still give
way to complications during delivery. Here are some of the most common
Failure to Progress (Prolonged Labor)
A small percentage of women, mostly first-time mothers, may experience a
labor that lasts too long. In this situation, both the mother and the baby are
at risk for several complications including infections.
Presentation refers to the position the fetus takes as your body prepares
for delivery, and it could be either vertex (head down) or breech (buttocks
down). In the weeks before your due date, the fetus usually drops lower in the
uterus. Ideally for labor, the baby is positioned head-down, facing the
mother's back, with its chin tucked to its chest and the back of the head ready
to enter the pelvis. That way, the smallest possible part of the baby's head
leads the way through the cervix and into the birth canal.
Because the head is the largest and least flexible part of the baby, it's
best for it to lead the way into the birth canal. That way there's little risk
the body will make it through but the baby's head will get hung up. In
cephalopelvic disproportion, the baby's head is often too large to fit through
the mother's pelvis, either because of their relative sizes or because of poor
positioning of the fetus.
Sometimes the baby is not facing the mother's back, but instead is turned
toward her abdomen (occiput or cephalic posterior). This increases the chance
of painful "back labor," a lengthy childbirth or tearing of the birth
canal. 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 of
the back of its head.
Some fetuses present with their buttocks or feet pointed down toward the
birth canal (a frank, complete or incomplete/footling breech presentation).
Breech presentations are normally seen far before the due date, but most babies
will turn to the normal vertex (head-down) presentation as they get closer to
the due date. In a frank breech, the baby's buttocks lead the way into the
pelvis; the hips are flexed, the knee extended. In a complete breech, both
knees and hips are flexed and the buttocks or feet may enter the birth canal
first. In a footling or incomplete breech, one or both feet lead the way. A few
babies lie horizontally (called transverse lie) in the uterus, which usually
means the shoulder will lead the way into the birth canal rather than the
Abnormal presentations increase a woman's risk for injuries to the uterus or
birth canal, and for abnormal labor. Breech babies are at risk of injury and a
prolapsed umbilical cord. Transverse lie is the most serious abnormal
presentation, and it can lead to injury of the uterus (ruptured uterus) as well
as fetal injury.
Your doctor will determine the presentation and position of the fetus with a
physical examination. Sometimes a sonogram helps in determining the fetus'
position. When a baby is in the breech position before the last six weeks to
eight 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, the
less room there is to maneuver. Doctors estimate that about 90% of fetuses who
are in a breech presentation before 28 weeks will have turned by 37 weeks, and
over 90% of babies who are breech after 37 weeks will most likely stay that