How can expectant mothers manage pregnancy edema? When it comes to edema, many expectant mothers are no strangers to it. But do you know how to address this common pregnancy issue? Here, we offer tips for first-time moms to help you manage pregnancy edema with ease.
Causes of Pregnancy Edema
Physiological Edema
Increased blood volume during pregnancy. Starting around week 6 of pregnancy, blood volume gradually increases, peaking at week 34 and remaining elevated until two weeks postpartum before returning to pre-pregnancy levels. Blood volume can rise by approximately 40% compared to non-pregnant states. This increase in blood volume leads to greater interstitial fluid, making edema more likely.
Reduced relative plasma albumin concentration. As blood volume increases, plasma volume expands more than blood cell components, causing relative dilution of blood constituents. This lowers plasma albumin concentration compared to non-pregnant states. Plasma albumin is the primary component maintaining plasma osmotic pressure.Plasma osmotic pressure during pregnancy is lower than in non-pregnant states. This facilitates the permeation of fluid from the bloodstream into the interstitial fluid, leading to lower limb edema. Venous return is impeded. Generally, pregnancy-related edema tends to occur after 28 weeks of gestation. By this stage, the uterus has grown large enough to potentially compress the veins, hindering venous return.Therefore, expectant mothers with poor venous return are more prone to lower limb edema during this stage. Edema typically manifests below the ankles or knees. While symptoms may not be noticeable upon waking in the morning, they often become more pronounced by evening after prolonged standing during the day and reduced activity at night.
In such cases, the expectant mother's weight gain is usually within the normal range and does not increase suddenly. Her blood pressure remains within normal limits, and urine tests during prenatal checkups show no protein. Since physiological edema generally does not adversely affect the fetus and often resolves spontaneously after childbirth, expectant mothers need not be overly concerned.
Hormonal changes during pregnancy can easily lead to water and sodium retention.During pregnancy, increased hormones secreted by the placenta and aldosterone produced by the adrenal glands cause sodium and water retention in the body. This accumulation of fluids leads to a corresponding decrease in urine output.
Pregnancy-related anemia can also cause edema. Some expectant mothers experience significant anemia, characterized by low plasma protein levels. This condition allows fluid to leak from blood vessels into surrounding tissue spaces, making edema more likely.
As pregnancy progresses, edema becomes increasingly noticeable. Throughout pregnancy, body fluid volume increases by 6–8 liters, with 4–6 liters being extracellular fluid stored in tissues, causing edema. This phenomenon is quite common during pregnancy, most frequently affecting the soles of the feet, ankles, and calves. Mild facial swelling may also occur occasionally.Swelling tends to worsen closer to the due date, and hot weather can make it more pronounced. Mild swelling is normal, but if accompanied by high blood pressure and proteinuria, the expectant mother may be at risk for gestational hypertension and must undergo regular prenatal checkups and fully cooperate with her doctor.
Pathological Edema
Often caused by underlying conditions such as preeclampsia, renal disorders during pregnancy, cardiac complications, or liver diseases. These conditions not only impact the mother's health but also pose risks to fetal well-being. Pathological edema manifests not only in the lower limbs but may also affect the hands, face, and abdomen.When gently pressing the skin, it may appear sunken, lack elasticity, or exhibit a bluish-gray discoloration.
Can Pregnancy Edema Resolve Postpartum?
Within days after delivery, excess fluid is expelled through urine and profuse sweating, with the rate of fluid loss proportional to edema severity.Some women's feet return to their original size postpartum, while others may experience slight enlargement. This occurs because relaxin, a hormone that loosens pelvic joints to facilitate delivery, also contributes to foot expansion. What should overweight expectant mothers do about swelling?
Pregnant women experiencing edema should rest in bed more often, elevate their lower limbs appropriately, and especially lie on their left side. This improves placental blood supply and reduces swelling. Simultaneously, moderately restrict salt intake. Additionally, walking is important because it allows calf muscles to adjust and alleviate some venous compression.
Ensure adequate rest and sleep in both work and daily life; avoid excessive stress and fatigue.It's best to rest for half an hour after each meal, take a two-hour nap in the afternoon, and aim for 9–10 hours of sleep each night. If lying down isn't feasible at work, elevate your legs on a chair after lunch and adopt a semi-reclining position. Avoid prolonged standing or sitting. To reduce swelling in daily life, pregnant women who sit for long periods can place a low stool under their feet.Take appropriate breaks during work to walk around and increase blood flow to the lower limbs. When resting, lie flat or on your left side. Avoid crossing your legs while sitting; instead, frequently stretch your legs, move your heels and toes, rotate your ankles, and stretch your calf muscles.
Wear comfortable shoes and socks. Avoid socks that constrict the ankles or calves too tightly, as this can impair blood return. If using compression stockings for edema prevention or treatment, choose high-waisted styles and put them on before getting out of bed in the morning. When health permits, engage in appropriate physical activity—swimming, for instance, can be beneficial for reducing swelling.
Increase protein intake. Ensure daily consumption of animal-based foods like poultry, meat, fish, shrimp, eggs, and dairy, along with legumes. These foods are rich in high-quality protein. Pregnant women with anemia should also eat animal liver 2-3 times weekly to supplement iron, as anemia and malnutrition are contributing factors to pathological edema.
Increase intake of vegetables and fruits. These foods provide essential vitamins and trace elements that enhance immunity, boost metabolism, and offer detoxifying and diuretic effects. Pregnant women should consume vegetables and fruits daily.
Limit or avoid hard-to-digest and gas-producing foods. Examples include fried glutinous rice cakes, sweet potatoes, onions, and potatoes, as these may cause abdominal bloating, impede blood return, and worsen edema.
Avoid high-salt, processed, pickled, or canned foods.
Don't avoid drinking water during pregnancy out of fear of edema. Lower-body swelling during pregnancy results from uterine pressure or excessive salt intake (sodium in salt causes water retention), not from drinking too much water. Therefore, expectant mothers should still drink water in moderation. Water promotes metabolism and helps prevent urinary tract infections, offering significant benefits.
Increase vitamin B1 intake through food sources or B-complex supplements. Foods rich in vitamin B1 include yeast, liver, brown rice, soybeans, wheat germ, and potatoes, with animal sources offering the highest bioavailability. However, plant-based sources remain the primary dietary pathway for vitamin B1 intake.
Edema has multiple causes. If it's pathological edema, seek medical examination and treatment.
(Excerpted from the September 2013 issue of the collaborative magazine "Pregnancy Essence")