Feeling cold, or having difficulty regulating body temperature, is a common symptom that can occur at any stage of gestation. This temperature dysregulation happens because the body is undergoing profound physiological changes to support the developing fetus. Understanding the normal adjustments and the potential underlying medical issues can help determine if the sensation is a typical part of pregnancy or requires further attention.
Normal Pregnancy Shifts Affecting Body Temperature
The body’s internal thermostat is directly influenced by the dramatic surge in hormones, altering temperature perception. Progesterone, which rises substantially throughout pregnancy to maintain the uterine lining, has a thermogenic effect that typically raises the basal body temperature slightly. However, this hormone also causes the smooth muscles in blood vessel walls to relax, a process called vasodilation. This process can lead to heat loss from the skin surface, resulting in a chilling sensation, especially in the extremities.
The cardiovascular system is reprogrammed to manage the demands of the growing placenta and fetus. Plasma volume and cardiac output significantly increase throughout pregnancy. This massive increase in blood flow is prioritized toward the core organs and the uterus to ensure adequate nutrient and oxygen delivery to the baby.
This central prioritization of blood flow often comes at the expense of peripheral circulation. The body draws heat inward, leading to peripheral vasoconstriction in the hands and feet. Consequently, the extremities often feel noticeably cooler to the touch, contributing to the overall perception of being cold.
The basal metabolic rate (BMR) increases by about 15 percent by the end of pregnancy to fuel the growth of maternal tissues and the fetus. While this heightened metabolism generates more heat overall, the process is not always perfectly regulated. When the person is resting or not actively moving, this increased metabolic demand can leave them susceptible to feeling cold. The interplay between increased heat production and altered distribution often confuses the body’s normal thermoregulatory feedback loops.
Medical Causes Requiring Evaluation
While many cases of coldness are due to normal physiological shifts, the symptom can also signal an underlying medical condition common in pregnancy that needs treatment. Anemia, specifically iron deficiency anemia, is the most frequent correctable cause of cold intolerance during this time. The expansion of blood volume dilutes the red blood cell count, and insufficient iron impairs the body’s ability to produce enough hemoglobin, the protein responsible for transporting oxygen.
A reduction in oxygen-carrying capacity means the body’s tissues do not function as efficiently, leading to a generalized feeling of coldness and profound fatigue. Unlike the coldness from normal circulation changes, anemic coldness is often accompanied by pallor (pale skin) and may involve shortness of breath or an irregular heartbeat. A complete blood count is routinely performed during prenatal care to screen for this condition.
Another cause is an underactive thyroid gland, a condition known as hypothyroidism, which is marked by a decreased production of thyroid hormones. Since these hormones are the primary regulators of the body’s metabolism, a deficiency directly slows down cellular processes and reduces the body’s ability to generate heat. Cold sensitivity is a hallmark symptom of hypothyroidism.
Routine prenatal screening often includes a check of thyroid-stimulating hormone (TSH) levels because untreated hypothyroidism can pose risks to the pregnancy. Symptoms typically include cold intolerance, significant weight gain, dry skin, constipation, and muscle weakness. These symptoms, when combined with persistent coldness, warrant a conversation with a healthcare provider.
Temporary drops in blood pressure, or hypotension, can cause a sudden feeling of being chilled or clammy. The vasodilation caused by pregnancy hormones can sometimes cause blood pressure to fall, reducing the force that pushes blood to the extremities. If the coldness is accompanied by lightheadedness, dizziness, or reduced alertness, it may be due to low blood pressure and should be monitored.
Strategies for Symptom Relief and Monitoring
Symptom Relief
Managing the sensation of cold often involves simple, practical adjustments that help the body regulate temperature more effectively. Layering clothing is an effective strategy, as it allows for easy removal or addition of insulation to match the body’s fluctuating internal temperature. Wearing warm socks and gloves can counteract the peripheral vasoconstriction that makes the hands and feet feel particularly chilled.
Maintaining consistent hydration is also helpful, as water plays a significant role in temperature regulation. Incorporating moderate physical activity, such as a short walk, can temporarily increase circulation. Dietary adjustments, especially focusing on iron-rich foods or taking a prescribed iron supplement, can help prevent or correct anemia.
Monitoring and Red Flags
Monitoring the nature of the cold sensation is an important part of self-care during pregnancy. If the coldness is persistent and unrelenting, or if it is accompanied by concerning symptoms, medical evaluation becomes necessary. Persistent, extreme coldness, inability to warm up, or coldness combined with symptoms like palpitations, excessive fatigue, or a fever requires immediate contact with a healthcare provider.