Feeling cold during pregnancy is common and usually not a sign that anything is wrong with you or your baby. It happens most often in the first trimester, when many women actually prefer warmer environments compared to later in pregnancy. As pregnancy progresses, rising blood volume and a faster heart rate tend to make most women feel warmer, which is why the stereotype of the overheated pregnant woman exists. But feeling unusually chilly, especially early on, is a normal variation that has several straightforward explanations.
Why the First Trimester Feels Different
Your body undergoes enormous cardiovascular changes during pregnancy, but they don’t all kick in at once. Cardiac output starts to surge around week ten and doesn’t peak until about week 28, when it’s roughly 50% higher than before pregnancy. Blood volume increases by 25% to 52%, peaking around week 32. Heart rate climbs 20% to 25% above your baseline by the third trimester. In the early weeks, before these changes ramp up, your body is burning more energy to support the pregnancy but hasn’t yet developed the increased circulation that generates extra warmth.
Research on pregnant women’s temperature preferences confirms this pattern. A study tracking thermal comfort across all three trimesters found a clear shift: women in the first trimester preferred warmer surroundings, while women in the third trimester preferred cooler ones. The comfortable room temperature for first-trimester women was about 20.3°C (68.5°F), compared to 19°C (66.2°F) for those in the third trimester. So if you’re reaching for an extra blanket early in pregnancy while everyone else seems fine, your experience lines up with what researchers have documented.
Anemia and Iron Deficiency
One of the most common medical reasons for feeling cold during pregnancy is anemia, specifically iron-deficiency anemia. Your body needs significantly more iron during pregnancy to support the expanding blood supply and the growing baby. When iron levels drop too low, your red blood cell count falls, and those cells are responsible for carrying oxygen throughout your body. Less oxygen delivery means less heat production in your tissues.
Anemia during pregnancy often starts subtly. Mild cases may cause no noticeable symptoms at all. As it progresses, the classic signs are fatigue, feeling cold, shortness of breath, and dizziness. These symptoms overlap with normal pregnancy discomforts, which is why anemia frequently goes unnoticed until a routine blood test catches it. Your provider will check your blood counts at prenatal visits, and iron-deficiency anemia is highly treatable with supplements.
Thyroid Changes During Pregnancy
Your thyroid gland, which controls your metabolism and body temperature, works harder during pregnancy. Sometimes it can’t keep up, leading to an underactive thyroid (hypothyroidism). Cold intolerance is one of the hallmark symptoms. Other signs include extreme tiredness, constipation, muscle cramps, and difficulty concentrating.
Hypothyroidism during pregnancy matters beyond just comfort. It can affect both your health and your baby’s development, so it’s worth mentioning to your provider if you’re persistently cold alongside other symptoms like unusual fatigue or brain fog. A simple blood test can check your thyroid hormone levels, and treatment is straightforward if levels are off. The study on thermal preferences also found that women with hypothyroidism consistently preferred warmer environments, while women with an overactive thyroid leaned toward cooler ones, reinforcing the connection between thyroid function and how warm or cold you feel.
Blood Sugar Drops
Pregnancy changes how your body processes glucose, and blood sugar can dip more easily than it did before, especially between meals or after a stretch without eating. When blood sugar drops, your body releases adrenaline as part of a stress response. That adrenaline surge can cause sweating, chills, clamminess, a pounding heart, and anxiety. If your cold spells come with shakiness or happen when you haven’t eaten in a while, low blood sugar could be the trigger. Eating smaller, more frequent meals with a mix of protein, fat, and complex carbohydrates helps keep levels stable.
When Cold Feelings Signal Something Else
In most cases, feeling chilly is harmless. But certain patterns deserve attention. Shaking chills, the kind where your body shivers intensely and you can’t stop it, are different from simply feeling cold. Combined with fever (a temperature of 38°C or 100.4°F or higher), they can signal an infection. Notably, fever can sometimes make you feel cold or shivery rather than hot, so don’t assume the absence of feeling warm means you don’t have a temperature.
Kidney infections are one concern during pregnancy and can cause chills along with flank pain (just below the ribs on one or both sides), burning during urination, frequent urges to urinate, or belly pain. Urinary tract infections are more common in pregnancy and can progress to kidney infections if untreated. If your chills come with any of these symptoms, contact your provider promptly rather than waiting for your next scheduled visit.
A persistently low body temperature on its own, without other symptoms, is generally not a concern. But if feeling cold is paired with extreme fatigue, dizziness, pale skin, or shortness of breath, it’s worth getting your iron levels and thyroid checked sooner rather than later.
Practical Ways to Stay Comfortable
Layering clothes gives you flexibility as your temperature fluctuates throughout the day. Many pregnant women find their internal thermostat swings between cold and warm unpredictably, so being able to add or remove a layer quickly helps. Keep a light blanket nearby at work or on the couch.
Staying well hydrated supports healthy blood volume, which affects circulation and warmth. Warm drinks can provide immediate comfort without any downside. Light physical activity, even a short walk, boosts circulation and generates body heat. The thermal preference research found that women who exercised regularly during pregnancy were more comfortable in cooler environments, suggesting that consistent movement helps regulate temperature perception over time.
If you’re taking a prenatal vitamin with iron and eating iron-rich foods like red meat, beans, spinach, and fortified cereals, you’re already supporting the blood production your body needs. Pairing iron-rich foods with vitamin C (citrus, bell peppers, tomatoes) improves absorption.