Fetal presentation means the
part of the fetus that is "presenting" at the cervix:
Cephalic presentation means head first. This is the normal
Breech presentation means the
fetal butt is coming out first.
Transverse lie means the fetus is
oriented from one side of the mother to the other and neither the head
nor the butt is coming out first.
Compound presentation means
that a fetal hand is coming out with the fetal head.
Shoulder presentation means
that the fetal shoulder is trying to come out first.
Fetal "presentation" is different from fetal "position." Fetal
position refers to the orientation of the fetus within the birth canal (eg,
looking toward the mother's pubic bone (OP), or look toward the mother's
coccyx (OA), etc.)
Read more about fetal
Frank breech means the buttocks are presenting and the legs are up along the fetal
chest. The fetal feet are next to the fetal face. This is the safest
arrangement for breech delivery.
Footling breech means
either one foot ("Single Footling") or both feet ("Double
Footling") is presenting. This is also known as an incomplete breech.
Complete breech means the fetal
thighs are flexed along the fetal abdomen, but the fetal shins and feet
are tucked under the legs. The buttocks is presenting first, but the
feet are very close. Sometimes during labor, a complete breech will shift to an incomplete
breech if one or both of the feet extend below the fetal buttocks.
While many breech fetuses deliver vaginally without incident, this
presentation is associated with an increased risk of:
Fetal mechanical injury (fractures, nerve damage, and soft
Fetal asphyxia due to umbilical cord prolapse and obstruction,
and fetal head entrapment.
For these reasons, many breech babies are delivered by cesarean
section, and some obstetricians feel that all breech babies should be
delivered in this way.
Read more about management of
If the fetus remains in a transverse lie, it cannot deliver deliver
vaginally as the diameter of the fetal presenting part (the whole body,
in this case) cannot descend through the birth canal.
If labor is allowed to continue for enough time with the fetus in
transverse lie, the uterus will rupture. Even before the uterus
ruptures, there is an increased risk in this presentation for prolapsed umbilical cord. For these
reasons, women found to have a transverse lie in labor will usually have
a cesarean section.
There are some exceptions to this indication for cesarean section:
If labor is occurring during the middle trimester and fetus is not
considered viable, it may be possible for this very small and fragile
fetus to compress enough to squeeze through the pelvis. In this case,
fetal survival would not be an issue.
It may be possible to perform an external version, during which
you manipulate the fetus, converting it to either breech or cephalic
presentation. This is often more difficult than it sounds,
particularly during labor, and carries some risk of injury to the
fetus, placenta, umbilical cord, or uterus.
In the case of twins, it would be acceptable to allow labor, even
though the second twin is in transverse lie, anticipating that after
delivery of the first twin, you would reach in and perform an internal
version, converting the transverse lie to cephalic or breech
presentation prior to delivery.
Some predisposing factors for a transverse lie include:
Transverse lie occurs frequently in early pregnancy, when it is of no
consequence. At 16 weeks gestation, about half of all pregnancies will
be transverse lie. This number steadily falls as pregnancy advances and
the incidence of transverse lie by the 28th week is well below 10%. It
falls steadily thereafter.
Whenever a fetal transverse lie is encountered near term or in labor,
evaluate the patient carefully with ultrasound to determine if there are
any predisposing factors, such as a placenta previa or pelvic kidney
that could modify your management of the patient. So long as a placenta
previa is not present, many obstetricians will check the patient's
cervix at frequent intervals to detect early cervical dilatation and the
consequential increased risk of cord prolapse. Sometimes, these patients
are delivered early by scheduled cesarean section to avoid that risk.
Compound presentation means that a fetal hand is coming out with the
fetal head. This is a problem because:
The amount of baby that must come through the birth canal at one
time is increased.
There is increased risk of mechanical injury to the arm and
shoulder, including fractures, nerve injuries and soft tissue injury.
A compound presentation may be resolvable if the fetus can be
encouraged to withdraw the hand, for example.
If the fetus and arm are relatively small in comparison to the
maternal pelvis, vaginal delivery may still be possible, but with some
risk of injury to the arm.
If the fetus and arm are relatively large in comparison to the
maternal pelvis, obstructed labor will occur and a cesarean will be
Shoulder presentation means that the fetal shoulder is trying to come
out first. This is a more advanced form of transverse lie and is