How Hormones Affect Sleep During Pregnancy

Please note that none of this is medical advice. Consult your doctor before you use any pregnancy aides or implement any advice from Kiyo Pure.

Sleep disruptions are among the most common complaints during pregnancy, with up to 78% of expectant mothers reporting sleep problems. While physical discomfort certainly plays a role, the dramatic hormonal shifts during pregnancy are often the hidden culprits behind those restless nights. Understanding how these hormonal changes affect your sleep can help you develop strategies to improve your rest during this important time.

The Hormone Symphony of Pregnancy

Pregnancy transforms your body's hormonal landscape, creating a complex interplay that affects nearly every system—including your sleep-wake cycle. Let's examine the key hormones and how they impact your sleep:

Progesterone: The Sleepy Hormone with a Catch

Progesterone levels surge during pregnancy, increasing by up to 10 times your pre-pregnancy levels. This hormone has sedative-like properties that initially may make you feel extremely fatigued, especially during the first trimester.

How it affects sleep:

• Increased daytime sleepiness: Many women experience overwhelming fatigue early in pregnancy
• Disrupted sleep architecture: Despite making you sleepy, high progesterone can fragment your sleep cycles
• Respiratory changes: Progesterone increases your respiratory rate and can contribute to snoring and sleep apnea
• Higher body temperature: This hormone raises your core temperature, potentially making you uncomfortable at night

Estrogen: The Nasal Congestion Connection

Estrogen levels also rise significantly during pregnancy, peaking in the third trimester at levels 100 times higher than pre-pregnancy.

How it affects sleep:

• Nasal congestion: Estrogen causes swelling of the mucous membranes, leading to pregnancy rhinitis (stuffy nose)
• Increased REM sleep: Early in pregnancy, estrogen can increase REM sleep, leading to more vivid dreams
• Restless legs: Estrogen fluctuations may contribute to restless leg syndrome, a common pregnancy sleep disruptor
• Nighttime bathroom trips: Estrogen increases blood flow to the kidneys, leading to increased urination frequency

Cortisol: The Stress Hormone Shifted

Pregnancy alters your cortisol rhythm—the hormone normally peaks in the morning to help you wake up and drops at night to help you sleep.

How it affects sleep:

• Flattened daily rhythm: The difference between morning and evening cortisol levels becomes less pronounced
• Increased evening levels: Higher nighttime cortisol can make it harder to fall asleep
• Heightened stress response: Pregnancy can amplify the sleep-disrupting effects of stress

Human Chorionic Gonadotropin (hCG): First Trimester Disruptor

hCG rises rapidly in early pregnancy and is responsible for many early pregnancy symptoms.

How it affects sleep:

• Nausea and vomiting: Morning sickness (which can occur any time of day) can severely disrupt sleep
• Increased body temperature: hCG can contribute to feeling overheated at night

Relaxin and Oxytocin: The Physical Discomfort Connection

These hormones prepare your body for childbirth but can create physical challenges for sleep.

How they affect sleep:

• Joint and pelvic discomfort: Relaxin loosens joints and ligaments, which can cause positional discomfort
• Practice contractions: Oxytocin increases as pregnancy progresses, potentially causing Braxton Hicks contractions that may wake you

How Hormonal Changes Progress Throughout Pregnancy

First Trimester

• Rapidly rising progesterone and hCG lead to extreme fatigue, but paradoxically disturbed sleep
• Morning sickness peaks as hCG reaches its highest levels
• Many women experience both crushing daytime sleepiness and nighttime insomnia

Second Trimester

• Hormones stabilize relatively, often bringing improved sleep
• Physical changes are noticeable but not usually severe enough to dramatically impact sleep
• Many women experience their best sleep of pregnancy during this "golden period"

Third Trimester

• Progesterone reaches peak levels
• Physical discomfort combines with hormonal effects
• Cortisol patterns more significantly altered
• Sleep becomes increasingly fragmented as delivery approaches

Strategies to Improve Sleep Despite Hormonal Challenges

While you can't change your pregnancy hormones, you can adopt strategies to minimize their impact on your sleep:

• Create a consistent sleep schedule: Regular sleep-wake times help regulate hormonal rhythms
• Optimize your sleep environment: Keep your bedroom cool to counter progesterone's temperature-raising effects
• Use pregnancy pillows: Support your changing body to minimize discomfort from relaxin-loosened joints
• Elevate your head: Combat estrogen-induced nasal congestion with extra pillows
• Practice relaxation techniques: Meditation or deep breathing can help counteract elevated cortisol
• Time your fluids: Reduce evening liquid intake to minimize hormone-induced bathroom trips
• Discuss supplements with your doctor: If hormone-related restless legs are an issue, ask about safe iron or magnesium supplements

When to Seek Help

While some sleep disturbance is normal during pregnancy, certain symptoms warrant medical attention:

• Severe snoring or gasping for air (possible sleep apnea)
• Extreme daytime sleepiness that interferes with daily functioning
• Insomnia that persists for more than a few weeks
• Symptoms of restless legs syndrome that severely impact sleep

Remember that while hormonal changes make perfect sleep unlikely during pregnancy, severe or persistent sleep problems should be discussed with your healthcare provider. The connection between pregnancy hormones and sleep is complex, but understanding these relationships can help you develop strategies for better rest during this transformative time.