Patient's question:
I am 30 weeks pregnant and have been diagnosed with breech presentation, with the umbilical cord wrapped around the baby's neck once. Can I do the knee-chest exercise? Will it cause placental detachment or fetal asphyxia? Urgently awaiting your reply! Thank you!Doctor's answer:
Hello:Breech birth accounts for about 4% of total deliveries. Due to the largest and hardest fetal head being delivered last, it often results in difficulties, with the fetus and infant at risk of asphyxiation and death. The incidence of neonatal injuries also significantly increases in breech births.
I. Diagnosis
A rounded and hard fetal head can be palpated at the fundus of the uterus, while a softer and irregular fetal buttock can be felt in the suprapubic region. The fetal heartbeat is usually at or above the level of the umbilicus. Anorectal or vaginal examination may reveal a soft and irregular fetal buttock, sometimes with the lower limbs also palpable. Ultrasound can provide a definitive diagnosis.
II. Delivery Mechanism
The delivery of the fetus is fundamentally the same as in head-first positions, except that the order is reversed. The buttocks are delivered first, followed by the fetal head. For easier understanding, taking the left anterior sacrum as an example, the process of the buttocks, shoulders, and head being delivered is described as follows.
(1) Delivery of the Buttocks
The fetal buttocks enter the pelvic inlet via the wider intertrochanteric diameter along the longer left oblique or transverse diameter of the pelvic inlet. After descending to the pelvic floor, the anterior hip (left hip) turns downward below the pubic symphysis, aligning the intertrochanteric diameter with the longer anteroposterior diameter of the pelvic outlet. The sacrum then faces the mother’s left side, and the fetal body laterally flexes. The posterior hip (right hip) is delivered first, followed by the anterior hip, and then both lower limbs.
(2) Delivery of the Upper Limbs and Shoulders
After the buttocks are delivered, the fetal back rotates toward the mother’s left front, allowing the wider biacromial diameter to enter the pelvic inlet along the left oblique or transverse diameter. During the descent and delivery of the fetal shoulders, the fetal back rotates back toward the mother’s left side, aligning the biacromial diameter with the anteroposterior diameter of the pelvic inlet. The right upper limb and posterior shoulder are usually delivered first, followed by the left upper limb and anterior shoulder.