Transverse baby position is an incorrect location of the fetus in the uterus, in which its longitudinal axis intersects with the axis of the uterus at an angle of 90 °; in this case, large parts of the fetus (buttocks, head) are located above the line of the ridges of the iliac bones of the pelvis. Transverse baby position is determined by external obstetric and vaginal examination, ultrasound. Pregnancy can proceed uncomplicated, but premature birth is possible, which can endanger the life of the mother and fetus. The optimal tactic is operative delivery.
Transverse baby position occurs in 0.5-0.7% of pregnancies, and in primiparous women it is 10 times less common than in women who have become more expensive. The danger of transverse baby position lies in the likelihood of severe complications in childbirth if timely obstetric care is not provided: early outpouring of water, loss of fetal parts, rupture of the uterus, the occurrence of a neglected transverse position of the fetus, death of the fetus and mother.
The variants of the incorrect location of the fetus also include an oblique position, characterized by the intersection of the axis of the fetus and the uterus at an acute angle and the placement of one of the large parts of the fetus (head or pelvic end) below the line connecting the ridges of the iliac bones. The oblique position of the fetus is considered transitional – during childbirth it can turn into a longitudinal or transverse one.
The position in transverse baby position is determined by the head: the 1st position – when the head is located on the left, the 2nd position – the head is determined on the right. The type of position depends on the reversal of the backrest: the back facing the anterior wall of the uterus is regarded as an anterior view, to the rear – a posterior view. With transverse baby position, it is also important to take into account the ratio of the fetal back to the bottom of the uterus.
The intrauterine transverse position of the fetus can be caused by various factors. These, first of all, include conditions that ensure excessive fetal mobility: polyhydramnios, flabbiness of the abdominal wall muscles, fetal hypotrophy, etc. On the other hand, the prerequisites for the formation of transverse baby position may be associated with the restriction of intrauterine activity due to lack of water, large fetus, multiple pregnancy, increased uterine tone, the threat of spontaneous termination of pregnancy, abnormalities of the uterine structure (saddle-shaped or bicornuate uterus), uterine fibroids, etc.
Transverse baby position in some cases is a consequence of anatomical reasons that prevent the insertion of the head into the pelvis, in particular, placenta previa, tumors of the lower segment of the uterus or pelvic bones, narrow pelvis. Such fetal malformations as anencephaly and hydrocephalus can contribute to the transverse position.
The incorrect (oblique or transverse) position of the fetus is established during the obstetric examination of the pregnant woman, palpation of the abdomen and vaginal examination. With transverse baby position, the abdomen acquires a transversely stretched (obliquely stretched) irregular shape. Due to transverse stretching, the uterus has a spherical, rather than an elongated oval shape. Attention is drawn to the excess of the norm of the circumference of the abdomen in comparison with the gestation period and the insufficient height of the standing of the uterine fundus.
In the process of palpation, the underlying part of the fetus is not determined; the head can be probed to the right or left of the median axis of the pregnant woman’s body, and large parts (the head or pelvic end) – in the lateral parts of the uterus. With transverse baby position, the heartbeat is better heard in the navel area. Difficulties with determining the position and position of the fetus may arise in situations of multiple pregnancy, polyhydramnios, uterine hypertension. Obstetric ultrasound reliably confirms transverse baby position.
Gynecological examination performed during pregnancy and the initial period of labor with a preserved fetal bladder is not informative enough. Its conduct only confirms the absence of the adjacent part of the fetus at the entrance to the pelvis. After the discharge of the waters and the opening of the uterine pharynx by 4-5 cm with transverse baby position, the shoulder, shoulder blade, ribs, armpit, spinous processes of the vertebrae, sometimes the elbow or the hand of the handle can be determined. In case of loss of the fetal handle from the genital slit, there is no doubt about the presence of transverse baby position.
The presence of transverse baby position, as a rule, does not violate the general course of pregnancy. However, most often, with transverse baby position, there is a premature outpouring of amniotic fluid and the development of premature labor. If transverse baby positions is accompanied by placenta previa, massive bleeding is possible.
The rapid discharge of water often leads to a sharp restriction of fetal mobility, hammering of the shoulder into the entrance of the pelvis, falling out of parts of the fetus (handle, umbilical cord) and the development of the so-called neglected transverse position of the fetus.
When parts of the fetus fall out, ascending infection may occur with the development of chorioamnionitis, diffuse peritonitis, sepsis. A long anhydrous interval lasting 12 or more hours leads to acute hypoxia or asphyxia of the fetus. The neglected transverse position of the fetus against the background of increasing labor activity threatens to rupture the uterus.
In rare cases, with transverse baby position during childbirth, self-rotation into a head or pelvic presentation or the birth of a baby with a double trunk may occur. Such an outcome of childbirth is an exception and is possible in the case of severe contractions, deep prematurity of the fetus or with a dead fetus.
Tactics of labor management
At up to 34-35 weeks of gestation, the oblique or transverse baby position is considered unstable, since it can independently change to a longitudinal one. When diagnosing transverse baby position, a complete gynecological examination of the pregnant woman is required to identify the causes of the anomaly, the choice of tactics for further management of pregnancy and the method of delivery.
At the period of 30-34 weeks of pregnancy, corrective gymnastics may be prescribed, which contributes to the reversal of the fetus into a head presentation. Special sets of exercises are indicated in the absence of signs of a threat of termination of pregnancy, scarring on the uterus, fibroids, bloody discharge, decompensated heart defects in a pregnant woman, etc. and are carried out under the supervision of an obstetrician-gynecologist observing the woman. Also, with transverse baby position, the pregnant woman is recommended to lie on her side for more time, corresponding to the determined position.
After 35-36 weeks of gestation, the fetus assumes a stable location, therefore, while maintaining the transverse position, the pregnant woman is hospitalized in the maternity hospital to determine the tactics of delivery.
The technique of external rotation on the head – changing transverse baby position using external techniques is currently practically not used. This is due to the low efficiency of rotation, since with unresolved causes, the fetus often assumes a transverse position again. In some cases, an external turn can result in severe consequences: placental abruption, rupture of the uterus, fetal hypoxia.
The optimal method of delivery of patients with a transverse baby position is a planned cesarean section. Absolute indications for operative delivery are a postponed pregnancy, the fact of placenta previa, premature discharge of amniotic fluid, scars on the uterus, the development of fetal hypoxia. When transverse baby position is running with the loss of its handle or umbilical cord, it is unacceptable to set the dropped parts.
In the case of full disclosure of the cervix, the determined live fetus and its mobility, it is possible to rotate the fetus on the leg and its subsequent extraction. However, the prognosis for the fetus in this case is less favorable. Turning on the leg and natural childbirth are justified in case of prematurity or childbirth of twins, when one fetus occupies a transverse position.
In a situation of a long anhydrous interval, complicated by the development of an infectious process, and the viability of the fetus after cesarean section, hysterectomy (removal of the uterus) and drainage of the abdominal cavity are performed. With a dead fetus, a fruit-destroying embryotomy operation is performed.