The typical image of childbirth in modern Western culture involves a person lying on their back, often with legs raised in stirrups. This position, known as supine or lithotomy, is widely practiced in hospitals today, leading many to believe it is the standard, safest, or only way to deliver a baby. However, this common practice is a relatively recent development in human history, contradicting centuries of tradition and natural physiological processes. Understanding why this specific position became so prevalent requires examining its historical origins, the role of modern medicine, and its physical effects on the birthing body.
The Historical Shift to Lying Down
For most of human history, women instinctively adopted upright positions for birth, such as sitting on a birthing stool, squatting, or kneeling. These vertical postures effectively used gravity to aid the baby’s descent and were the standard practice across many cultures until the 17th century. The shift toward the supine position began to gain traction in Europe when male physicians started replacing female midwives as the primary birth attendants.
One influential figure often cited in this shift is King Louis XIV of France, who reportedly enjoyed observing his mistresses give birth. Since the upright position on a birthing stool obscured his view, he allegedly encouraged a reclining position for better visibility, lending a certain royal endorsement to the practice. Around the same time, French physician François Mauriceau began advocating for the reclining position, finding it more convenient for the attendant to observe and intervene. The introduction of obstetric forceps in the 17th century further cemented the supine position’s dominance, as the instruments were most easily applied with the mother lying on her back.
Modern Clinical Rationale
Today, the lithotomy or supine position remains common in hospital settings, primarily because it offers practical convenience for the medical care team. This orientation provides the clinician with optimal and direct visibility of the perineum, which is the area where the baby emerges. It also gives providers the easiest access for performing procedures like an episiotomy, applying forceps or a vacuum, or managing a sudden complication.
The supine position also simplifies the use of external and internal fetal monitoring devices, as the cables and sensors are less likely to be disturbed by movement. Furthermore, the administration and management of an epidural often necessitate the birthing person to remain relatively still or in a limited range of motion. While an epidural does not inherently require a flat-on-the-back position, the supine or semi-reclined posture is frequently preferred by hospital staff for continuity of care and ease of necessary medical access.
Physiological Impact of the Supine Position
Despite its clinical convenience, lying flat on the back during labor and delivery introduces several physiological disadvantages for the birthing person. One of the most significant concerns is the potential for vena cava compression, resulting in what is known as supine hypotensive syndrome. In this position, the heavy, pregnant uterus can press against the inferior vena cava.
This compression can reduce the blood flow back to the mother’s heart, potentially causing a drop in maternal blood pressure. A reduction in maternal blood flow also means less blood and oxygen are delivered to the placenta and, consequently, to the baby. Additionally, the supine position forces the mother to push against gravity, which can prolong the second stage of labor. Lying on the sacrum, the large, triangular bone at the base of the spine, prevents it from moving and flexing outward, reducing the functional size of the pelvic outlet by up to 30%.
Exploring Upright and Lateral Birthing Positions
A growing body of evidence highlights the benefits of using upright and lateral positions during the second stage of labor. Upright positions, which include squatting, standing, sitting on a birthing stool, or kneeling, use the force of gravity to assist the baby’s descent through the pelvis. These postures also allow the sacrum to move freely, which can increase the diameter of the pelvic outlet, making the passage for the baby easier.
Upright positions are associated with a decrease in the duration of the second stage of labor and a reduced likelihood of needing instrumental deliveries forceps or vacuum extraction. The lateral, or side-lying, position is another valuable alternative that avoids the risks of vena cava compression entirely, helping conserve energy and assisting with certain fetal positioning issues. The hands-and-knees position is also beneficial, as it can help relieve back labor and encourage the baby to rotate into a more optimal position. While the supine position remains standard due to ingrained clinical practices, many birthing experts encourage mobility and the use of alternative positions that align more closely with the body’s natural mechanics.