The instinct to pull the abdomen inward, often called “sucking in,” is an attempt to temporarily flatten the midsection. This action, whether a long-standing habit or a momentary desire for comfort, persists even after becoming pregnant. For many women, the motivation stems from a desire to control physical changes or minimize back strain. This raises questions about the safety and feasibility of the action during gestation, prompting a need for clear guidance.
The Direct Answer and Safety Concerns
Forcefully “sucking in” the stomach is generally discouraged, especially after the first trimester. This action significantly increases intra-abdominal pressure (IAP) within an already pressurized environment. Pregnancy naturally leads to chronically increased IAP due to the growing fetus and amniotic fluid volume. Exerting additional force compounds this pressure, potentially leading to maternal health issues.
Increased IAP places greater downward strain on the pelvic floor muscles, contributing to dysfunction like incontinence or pelvic organ prolapse. It can also worsen diastasis recti by pushing against the thinning connective tissue between the outermost abdominal muscles. The fetus is well-protected, so the focus is on the long-term health and stability of the mother’s core and pelvic structure.
Anatomy: How Pregnancy Changes Core Muscle Function
The physical mechanics of “sucking in” become challenging or impossible as pregnancy advances due to profound anatomical changes. The uterus expands upward and outward, stretching and thinning the abdominal wall, particularly the rectus abdominis muscles. This expansion reduces the mechanical advantage needed for a voluntary inward pull.
The deepest core muscle, the Transverse Abdominis (TVA), acts like a natural corset, wrapping horizontally around the midsection. Although the TVA draws the abdominal wall inward, the expanding uterus stretches its fibers to maximum capacity. This makes a strong, effective voluntary contraction difficult to achieve or maintain.
The diaphragm, the primary muscle of respiration, is also affected by the upward pressure of the uterus. Attempting to “suck in” often restricts the downward movement of the diaphragm, leading to shallow, chest-based breathing. This restriction limits deep, effective breathing, compromising the body’s natural pressure management system. Hormonal changes, specifically the increase in relaxin, further contribute to instability by softening ligaments and connective tissue.
Safe Core Engagement Techniques
Instead of forcefully sucking in, expectant mothers should focus on gentle, functional core bracing. This approach uses controlled muscle activation to support the growing weight and stabilize the spine and pelvis, rather than attempting to flatten the abdomen. This distinguishes it from harmful breath-holding, such as the Valsalva maneuver.
A preferred method is to engage the TVA through diaphragmatic breathing, often described as giving the baby a “hug.” This involves a deep inhale that expands the rib cage, followed by a slow exhale where the abdominal wall is gently drawn inward toward the spine. The engagement should be light, around 50% effort, rather than a maximal contraction.
This gentle activation helps stabilize the core during everyday activities, such as lifting or changing positions, without causing excessive IAP. Exercises like pelvic tilts and modified planks focus on this controlled engagement, supporting the pelvic floor and maintaining a neutral spine. It is important to avoid any movements that cause the abdomen to “cone” or “tent,” which signals too much forward pressure.