The sixth month of pregnancy, spanning approximately weeks 23 through 27, marks a dynamic phase as the second trimester concludes. This period is a significant transition point, characterized by a substantial acceleration in fetal growth and considerable physical adaptations for the mother. The focus shifts from foundational organ development to rapid maturation and weight gain, preparing the baby for life outside the womb. Expectant mothers begin to feel stronger, more defined movements, while their bodies adjust to the increasing demands of a growing uterus.
Fetal Milestones During the Sixth Month
The fetus experiences a remarkable growth spurt during the sixth month, transitioning from a lean form to one beginning to accumulate insulating fat. By the end of this period, the baby often weighs between 1.5 and 2 pounds and measures about 12 inches in length, gaining weight faster than in previous months. This weight gain helps smooth out the previously wrinkled skin as layers of fat begin to deposit beneath the surface.
A significant developmental step is the continued maturation of the respiratory system, as the lungs develop more complex branching structures in preparation for breathing air. While the lungs are structurally formed, the baby practices breathing movements by inhaling and exhaling amniotic fluid. Sensory development is also well-advanced; the inner ear structures are fully formed, allowing the fetus to recognize and respond to external sounds, including the mother’s voice. The baby develops distinct sleep and wake cycles, and the previously fused eyelids may begin to open, allowing the eyes to perceive light filtered through the maternal abdomen.
Maternal Physiological Changes and Common Discomforts
The mother’s body continues its dramatic transformation, with the enlarging uterus moving above the navel. This shifts the center of gravity and exaggerates the curve of the lower back, a condition called hyperlordosis. This change in posture is the primary cause of the common backache experienced during this time. As the breasts continue to grow, preparing for nursing, some mothers may notice the leakage of colostrum, a yellowish pre-milk fluid that is rich in antibodies.
Increased internal pressure from the expanding uterus often leads to digestive complaints, such as persistent heartburn and reflux, as well as constipation. Mild swelling, or edema, in the feet and ankles is also common due to the increased blood volume and the pressure the uterus places on pelvic veins. Many women also begin to notice Braxton Hicks contractions, which are non-painful, irregular tightening of the uterine muscles that serve as practice contractions.
Key Medical Screenings and Check-ups
Routine prenatal visits in the sixth month involve several standard clinical measurements. The healthcare provider will regularly measure the fundal height, which is the distance from the pubic bone to the top of the uterus, to assess the baby’s growth rate. Monitoring blood pressure and fetal heart rate are also standard procedures at every appointment to check for maternal hypertension and fetal well-being.
The most notable test performed during this time is the Glucose Challenge Screening, typically scheduled between weeks 24 and 28, to check for gestational diabetes. This test involves drinking a glucose solution followed by a blood draw one hour later to measure the body’s ability to process sugar. If the initial screening result is elevated, a Glucose Tolerance Test is ordered to confirm a diagnosis. Early detection is important, as gestational diabetes can be managed through diet, exercise, and sometimes medication, reducing the risk of complications for both mother and baby.
Recognizing Critical Warning Signs
While many physical changes are normal during this month, some symptoms require immediate attention from a healthcare provider. A significant and sudden decrease in the baby’s movement warrants urgent evaluation, as fetal activity is a direct indicator of well-being. Any fluid leakage from the vagina or noticeable vaginal bleeding should be reported right away, as these can be signs of preterm labor or placental issues.
Symptoms that may indicate the onset of preeclampsia, a serious blood pressure disorder, include severe or persistent headaches that do not improve with pain relief, sudden, excessive swelling of the hands or face, and changes in vision, such as blurriness or seeing spots. Signs of preterm labor, such as rhythmic lower backache, persistent abdominal cramping, or more than four to six contractions in an hour that do not subside with rest and hydration, should prompt a call to the care provider for guidance.