Swelling during pregnancy typically begins in the late second trimester and becomes more noticeable throughout the third trimester. Most women first notice puffiness in their feet, ankles, and lower legs somewhere around weeks 22 to 27, though it can start earlier or later depending on the individual. The swelling tends to increase as the pregnancy progresses, peaking in the final weeks before delivery.
Why Pregnancy Causes Swelling
Two major changes in your body drive pregnancy-related swelling. First, your blood volume increases dramatically. By late pregnancy, plasma volume rises by more than 50 to 60 percent, and total blood volume climbs by about 45 percent, adding roughly 1,200 to 1,600 milliliters of extra fluid to your circulation. Your body also increases its extracellular fluid (the fluid outside your cells and blood vessels) by 30 to 50 percent. All of that extra fluid has to go somewhere, and gravity pulls it toward your lower body.
Second, your growing uterus physically presses on the large vein that carries blood back from your legs to your heart. This vein runs along your lower spine, and as the uterus gets heavier, it can partially compress it, slowing the return of blood from your legs. That backed-up pressure pushes fluid out of your blood vessels and into the surrounding tissue, which is what creates the puffy, swollen feeling. This compression effect explains why swelling gets worse as the baby grows and why the third trimester is when most women notice it the most.
Where Swelling Shows Up First
The feet, ankles, and lower legs are almost always the first areas affected, simply because they’re the lowest point where fluid pools. Both legs swell equally, and the swelling is painless. As pregnancy continues, some women notice mild puffiness in their fingers too, often making rings feel tighter than usual. Swelling that stays in your lower legs and is roughly equal on both sides is considered normal.
How Swelling Changes Throughout the Day
You’ll likely notice a pattern: your feet and ankles look relatively normal in the morning and progressively puff up as the day goes on. Hours of standing or sitting with your feet down allow gravity to pull fluid into your lower legs. Hot weather and long periods without movement make this worse. By evening, your shoes may feel noticeably tight. Overnight, lying down redistributes fluid more evenly, which is why swelling tends to reset by morning.
Practical Ways to Manage It
Elevating your legs above the level of your heart is one of the simplest and most effective ways to reduce swelling. Even propping your feet up on a pillow while sitting can help. Lying on your left side takes the weight of the uterus off that major vein, improving blood flow back from your legs.
Graduated compression stockings, which are tightest at the ankle and gradually loosen toward the knee or thigh, encourage blood to flow upward rather than pooling. These are widely available at pharmacies and don’t require a prescription. Putting them on first thing in the morning, before swelling builds up, gives the best results.
Staying physically active also helps. Walking, swimming, or other gentle movement activates the calf muscles, which act like pumps to push blood back up toward your heart. Drinking plenty of water may seem counterintuitive, but staying well hydrated actually helps your body regulate fluid balance rather than holding onto excess fluid. Avoiding long stretches of standing or sitting in one position makes a difference too. If you work at a desk, taking short walking breaks every hour or so can keep swelling in check.
When Swelling Signals a Problem
Normal pregnancy swelling is gradual, painless, affects both legs equally, and gets better with rest. A few patterns should prompt a call to your provider.
- Sudden swelling in the face or hands: This can be a sign of preeclampsia, a serious blood pressure condition. Gaining more than 3 to 5 pounds in a single week from fluid retention, along with swelling in the face or hands, warrants immediate evaluation.
- Swelling in only one leg: When just one leg swells, especially if it’s also painful, warm to the touch, or the skin looks red or purple, this could indicate a blood clot. Pregnancy increases the risk of deep vein thrombosis, and these clots most often form in the calf. One-sided symptoms are the key distinction from normal pregnancy swelling.
- Swelling with headaches or vision changes: These symptoms together may point to preeclampsia and need prompt medical attention.
After Delivery
Swelling doesn’t disappear the moment you give birth. Your body still has all that extra fluid to shed, and some women actually notice swelling gets temporarily worse in the first few days postpartum, especially if you received IV fluids during labor. The extra fluid typically clears within about a week as your kidneys work to flush it out. You may notice you’re sweating more than usual or urinating frequently during this time, which is your body’s way of getting back to its pre-pregnancy fluid balance.