Transverse Lie and Shoulder Presentation
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Direct answer
Transverse lie is a fetal lie in which the long axis of the fetus lies at right angles to the uterus, so the shoulder presents at the pelvic brim. It is uncommon at term and is linked with grand multiparity, placenta praevia and polyhydramnios. The central danger is cord prolapse once labour begins, so a live fetus is delivered by caesarean section.
What you must remember
- Definition: in a transverse lie the back faces the anterior or posterior abdominal wall, and the head and breech lie on opposite flanks.
- Causes: a lax uterus and abdominal wall in multiparity, placenta praevia, polyhydramnios, multiple pregnancy, prematurity, fibroids and uterine anomalies.
- Diagnosis: abdominal palpation finds the head in one flank and the breech in the other, with an unusually low fundus. Vaginal examination finds no presenting part, or a shoulder with ribs and axilla, and ultrasound confirms the lie.
- Cord prolapse: the most dangerous complication, especially after rupture of membranes, because the shoulder does not seal the pelvic inlet.
- Neglected shoulder: an impacted shoulder in obstructed labour, which leads to uterine rupture, fetal death and maternal sepsis if not treated in time.
- Before labour: external cephalic version from about 36 weeks, with elective caesarean section if the lie persists or version is contraindicated.
- In labour: caesarean section for a live fetus. Internal podalic version and breech extraction is reserved for selected cases such as the second twin, and destructive operations are used only for a dead fetus.
A stepwise approach to a transverse lie at term
A woman at term with a transverse lie on ultrasound is the typical case, and the order of decisions matters as much as any single fact. The steps below follow the sequence most textbooks expect in an examination answer.
- Confirm the lie and placenta. Ultrasound establishes the presentation, the placental site, the liquor volume and the cord position before any manoeuvre. It also excludes placenta praevia, which rules out version.
- Check for contraindications. Ruptured membranes, antepartum haemorrhage, an abnormal trace, a uterine anomaly or severe pre-eclampsia makes version unsafe.
- Offer external cephalic version. At term, with tocolysis and fetal monitoring, a suitable woman is offered an attempt to turn the fetus to a cephalic presentation.
- Plan caesarean if version fails. A persistent transverse lie is booked for elective caesarean section near term, rather than a trial of labour.
- Manage spontaneous labour. Labour with a transverse lie needs senior review, a check for cord prolapse and urgent caesarean section for a live fetus.
- Manage the neglected shoulder. Obstructed labour with a dead fetus is the setting for destructive operations, while a live fetus needs urgent delivery by caesarean.
Where the exam tries to catch you
Examiners test whether the candidate protects the cord and chooses the right operation for a living or dead fetus.
- Trap: choosing vaginal delivery because the cervix is dilated and the fetus seems small Correct: a live fetus in a transverse lie cannot be delivered vaginally without a major risk of cord prolapse, so caesarean section is the standard answer.
- Trap: attempting version in a woman with placenta praevia or ruptured membranes Correct: both are contraindications, because manipulation risks haemorrhage and cord complications.
- Trap: routinely doing internal podalic version for a shoulder in labour Correct: podalic version is reserved for selected cases such as the second twin, and caesarean section is preferred for a live fetus.
Frequently asked questions
Which is the most dangerous complication of transverse lie in labour?
Cord prolapse is the most dangerous complication of transverse lie in labour, especially after rupture of membranes. The shoulder does not seal the pelvic inlet, so the cord can descend ahead of the fetus. Immediate caesarean section is the standard response for a live fetus.
What is a neglected shoulder?
A neglected shoulder is an impacted shoulder in obstructed labour that has not been treated in time. It can lead to uterine rupture, fetal death and maternal sepsis. Prolonged obstruction in a transverse lie is the classic setting for destructive operations on a dead fetus.
When is external cephalic version attempted for a transverse lie?
External cephalic version for a transverse lie is usually attempted at term, from about 36 weeks, once ultrasound confirms there are no contraindications. Tocolysis and fetal monitoring are used during the procedure. Success is more likely in multiparous women with a mobile fetus.
Can a transverse lie be delivered vaginally in a live baby?
A live fetus in a transverse lie is not delivered vaginally in standard practice, and caesarean section is the default. Internal podalic version followed by breech extraction is reserved for selected cases such as the second twin. Destructive operations are used only when the fetus is dead.
Why is multiparity linked with transverse lie?
Multiparity is linked with transverse lie because a lax uterus and abdominal wall give the fetus room to lie across the uterus. Placenta praevia and polyhydramnios are other classic causes.