Childbirth is a complex physiological process. While most deliveries proceed without complications, medical professionals are prepared for unforeseen situations that may arise. This preparedness ensures the safety of both the mother and the baby, allowing for effective responses when challenges occur during labor.
Medical Terminology and Definition
When a baby’s shoulder becomes lodged in the birth canal after the head has been delivered, the medical term is “Shoulder Dystocia.” This obstetric emergency occurs when the baby’s anterior shoulder gets caught behind the mother’s pubic bone, or less commonly, the posterior shoulder against the sacral promontory. It requires additional maneuvers to release the shoulders after gentle traction fails. Though rare, affecting 0.2% to 3% of vaginal births, it can lead to severe complications if not resolved quickly.
Factors Contributing to Its Occurrence
Several factors can increase the likelihood of shoulder dystocia, though it often happens unpredictably. Maternal factors include pre-existing or gestational diabetes, leading to larger babies with more upper body fat, and maternal obesity or excessive weight gain. A history of shoulder dystocia also increases recurrence risk, sometimes up to 10%.
Fetal factors primarily involve macrosomia (baby weighing over 8 pounds, 13 ounces or 4,000 grams). While most cases occur with normal birth weights, risk significantly increases for larger babies (5% to 9% for babies over 9 pounds, 14 ounces).
Labor factors include prolonged or induced labor, or assisted vaginal delivery (forceps/vacuum). Certain birthing positions, like lying flat on the back, might reduce pelvic room.
Recognizing the Situation and Medical Interventions
Healthcare providers recognize shoulder dystocia through specific signs. The most indicative is the “turtle sign,” where the baby’s head emerges but retracts against the mother’s perineum, resembling a turtle pulling its head into its shell. Other signs include difficulty delivering the fetal chin, failure of shoulders to descend, or a red, puffy baby’s face.
Once identified, the medical team takes immediate action. The first-line intervention is typically the McRoberts maneuver, hyperflexing the mother’s legs toward her abdomen to widen the pelvic outlet and dislodge the shoulder. Suprapubic pressure is often applied simultaneously, pushing on the mother’s abdomen just above the pubic bone to aid rotation. If these primary maneuvers fail, other techniques are employed, such as internal rotational maneuvers (e.g., Woods’ screw) or the Gaskin maneuver (rolling the mother onto hands and knees). Fundal pressure is avoided as it can worsen impaction, and excessive traction on the baby’s head is limited to prevent injury.
Immediate Post-Delivery Care for Mother and Baby
Following a delivery complicated by shoulder dystocia, immediate assessment and care are provided to both mother and baby. For the newborn, a thorough check is conducted for potential injuries. Common fetal complications include brachial plexus injury (BPI), affecting nerves controlling arm movement and sensation, and clavicle or humerus fractures. While BPI can cause weakness or paralysis, most cases are temporary, and fractures typically heal without long-term issues.
For the mother, potential complications include increased risk of postpartum hemorrhage (significant bleeding after birth) and vaginal lacerations or tears, particularly third or fourth-degree tears affecting the perineum and anal sphincter. Medical teams manage these issues promptly to ensure the well-being of both mother and child.