The common advice to stop crossing your legs during pregnancy stems from a combination of physiological and comfort-related factors. As the body adapts to support a growing fetus, systems like circulation and musculoskeletal alignment undergo significant changes. Crossing the legs can amplify certain common pregnancy discomforts. The recommendation is a preventive measure to support the mother’s well-being and optimize her comfort throughout physical transformation.
Circulation and Venous Return
Pregnancy introduces considerable strain on the circulatory system, with blood volume increasing by up to 50% to support the mother and the developing fetus. When sitting with one leg crossed over the other, the natural flow of blood in the veins of the lower extremities is mechanically restricted. This action places pressure on the major superficial veins, which must work against gravity to return blood toward the heart. The restriction can worsen common pregnancy issues, such as edema (swelling of the feet and ankles) and the formation of varicose veins. Hormone changes cause veins to relax, and the growing uterus can compress the inferior vena cava, making blood return from the lower body challenging. Crossing the legs potentially increases the risk of numbness or tingling in the legs.
Pelvic Alignment and Back Pain
During pregnancy, the body releases the hormone relaxin, which softens and loosens ligaments, particularly those within the pelvis. This loosening prepares the pelvis for childbirth but also makes joints, especially the sacroiliac (SI) joints and the pubic symphysis, less stable. When a person crosses their legs, the pelvis shifts into an asymmetrical position, causing an uneven distribution of weight. This uneven posture places unequal strain on the compromised ligaments and joints of the lower back and pelvis. For individuals experiencing pelvic girdle pain (PGP) or symphysis pubis dysfunction (SPD), crossing the legs can immediately aggravate symptoms. Avoiding this position helps maintain a neutral spinal and pelvic alignment, which is better supported by the relaxed ligaments. Crossing the legs can also contribute to the development of sciatica or general lower back pain.
Debunking Myths About Fetal Harm
A common concern is whether crossing one’s legs can cause direct harm to the developing fetus, but this fear is not supported by medical evidence. The fetus is well-protected within the uterus, cushioned by amniotic fluid and separated from any external pressure caused by sitting posture. Crossing the legs does not cut off the baby’s oxygen supply or cause fetal distress. The only well-documented physiological effect beyond the mother’s comfort is a temporary elevation in blood pressure. When legs are crossed at the knee, the pressure on the arteries causes the heart to work harder, leading to a slight and temporary rise in blood pressure. This minor change is why medical professionals ask patients to uncross their legs during blood pressure readings to ensure an accurate measurement.
Better Seating Positions
Several practical and more comfortable seating alternatives can replace the habit of crossing the legs. Ensure both feet remain flat on the floor, distributing body weight evenly across the hips. This stance encourages a neutral pelvic position and minimizes uneven strain on the joints and ligaments. For improved circulation, slightly elevating the feet using a small footrest or stool helps venous blood return toward the heart. When sitting, the hips and knees should ideally be positioned at a 90-degree angle. It is also helpful to stand up, walk, or stretch every 30 minutes to prevent the pooling of blood and to relieve pressure on the spine.