A transverse lie occurs when a baby is positioned horizontally across the uterus, rather than in the typical head-down or feet-down orientation. This sideways position means the baby’s long axis is at a right angle to the birthing parent’s spine. While common in early pregnancy, a transverse lie near term feels noticeably different and requires specific management.
Distinct Sensations of a Transverse Lie
An expectant parent carrying a baby in a transverse lie may experience several distinct physical sensations. Instead of feeling kicks and movements primarily in the upper or lower abdomen, these sensations are often concentrated on the sides. The baby’s extremities, like hands and feet, might be felt stretching out to the sides rather than top-to-bottom.
A sensation of emptiness or softness can be present in the lower pelvis and upper abdomen, areas that would typically feel full with a head-down or breech baby. Conversely, a firm bulge or mass might be felt stretching across the middle of the abdomen. This horizontal firmness contrasts with the vertical shape of a baby in a head-down position.
Some individuals report discomfort around their hips or ribs, which can result from the baby’s head or bottom pressing against these areas. The unusual positioning may also cause generalized abdominal discomfort or back pain. In some cases, if the baby’s head or bottom presses against the diaphragm, there might be difficulty taking deep breaths or a sensation of cramped lungs.
While these sensations offer clues, the location of kicks alone is not always a definitive indicator. A baby’s feet can kick in various directions. A stronger indication is feeling the baby’s head on one side and its bottom on the other.
Confirming a Transverse Position
When a healthcare provider suspects a transverse lie based on physical sensations or routine checks, medical confirmation becomes necessary. One common method is abdominal palpation, often performed using a systematic approach called Leopold’s maneuvers.
With a transverse lie, the top and bottom parts of the uterus may feel empty, as neither the baby’s head nor its bottom is positioned there. Instead, the healthcare provider will typically feel the baby’s head on one side of the abdomen and its bottom on the opposite side.
The definitive diagnostic tool for confirming a transverse lie is an ultrasound scan. This non-invasive imaging technique uses sound waves to create detailed images of the fetus. An ultrasound can clearly show the fetal spine and ribs in a transverse section, and the fetal heart and stomach visible in the same plane, characteristic signs of a transverse lie.
Next Steps for a Transverse Lie
Once a transverse lie is confirmed, healthcare providers typically outline a plan for monitoring and potential intervention. Babies are often in a transverse position in earlier trimesters, and many spontaneously turn to a head-down position. However, if the baby remains transverse closer to term, generally after 34 to 36 weeks, the likelihood of spontaneous turning decreases.
If the baby does not turn by itself, one potential step is an External Cephalic Version (ECV). This procedure involves a healthcare professional manually turning the baby from the outside by applying firm, gentle pressure to the birthing parent’s abdomen. ECV is usually performed in a hospital setting, often with medication to help relax the uterus, and the baby’s heart rate is closely monitored throughout the procedure. While ECV success rates can vary, they are often higher for transverse lies compared to breech positions.
If the baby remains in a transverse lie despite monitoring or if ECV is unsuccessful or not recommended, a planned Cesarean section (C-section) is typically necessary. Vaginal delivery is not possible with a transverse lie due to significant risks to both the birthing parent and the baby, such as umbilical cord prolapse or uterine rupture. Therefore, a C-section ensures a safer delivery for both.
Common Reasons for a Transverse Lie
Several factors can contribute to a baby adopting or remaining in a transverse lie. One common reason is multiparity (having had previous pregnancies). This can lead to more relaxed abdominal muscles, providing the baby with more room to move and potentially settle sideways.
The amount of amniotic fluid surrounding the baby can also play a role. Excessive amniotic fluid (polyhydramnios) gives the baby ample space to move and change positions, sometimes resulting in a transverse lie. Conversely, too little amniotic fluid (oligohydramnios) can restrict the baby’s movement, potentially trapping it in a transverse position.
Certain anatomical considerations can also increase the likelihood of a transverse lie. These include placenta previa, where the placenta covers the cervix, blocking the baby’s head from descending into the pelvis. Uterine abnormalities, such as a bicornuate uterus (a heart-shaped uterus) or uterine fibroids, can alter the shape of the uterine cavity and influence the baby’s position. Carrying multiple babies, such as twins or triplets, can also limit the available space, making a transverse lie more likely for one or more fetuses.