Perimenopause refers to the transition period leading up to menopause, when a woman’s body begins producing less estrogen and progesterone. This natural decline in hormones causes changes in menstrual cycles and various symptoms like hot flashes, night sweats, vaginal dryness, mood changes, trouble sleeping, and more. Perimenopause usually begins in a woman’s 40s, but can start as early as the 30s. It lasts up until menopause itself, which is 12 months after a woman’s last period.
Doctors may recommend certain blood tests for women going through perimenopause to help confirm they are in the transition stage, rule out other conditions, and identify any risks for diseases like osteoporosis. Some common blood tests include:
FSH and estradiol
FSH (follicle stimulating hormone) and estradiol are two key hormones that change during perimenopause. As the ovaries age and release fewer eggs, FSH levels start to rise while estradiol levels decline. Checking FSH and estradiol levels can help confirm perimenopause and determine where a woman is in the transition stage.
Thyroid hormones
Thyroid issues can cause similar symptoms to perimenopause, like irregular periods, mood changes, and trouble sleeping. Testing levels of thyroid hormones TSH, T4, and T3 helps rule out thyroid problems.
Prolactin
Elevated prolactin levels can disrupt normal menstrual cycles and cause changes like missed periods or irregular bleeding. Checking prolactin helps identify if this hormone imbalance could be contributing to perimenopausal symptoms.
Sex hormone binding globulin (SHBG)
SHBG is a protein that binds to testosterone, estradiol, and other sex hormones, affecting their availability. SHBG levels tend to increase during perimenopause. Testing SHBG provides additional information about hormonal changes.
DHEAS
DHEAS (dehydroepiandrosterone sulfate) is a testosterone precursor produced by the adrenal glands. Levels peak in a woman’s 20s then gradually decline. DHEAS testing reveals ovarian reserve and can indicate accelerated ovarian aging if levels are exceptionally low.
CBC
A complete blood count (CBC) measures levels of white blood cells, red blood cells, hemoglobin, and platelets. CBC testing checks for anemia, infection, or other blood disorders causing abnormal bleeding.
Vitamin D
Many women are deficient in vitamin D, which is important for bone health. Lower estrogen levels during perimenopause also accelerate bone loss. Testing vitamin D levels identifies any deficiencies.
Bone density test
A bone density test determines bone mineral density and risk of osteoporosis. The decline of estrogen accelerates bone loss, so it’s important to check bone health during the perimenopausal transition.
Lipid panel
A lipid panel includes total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol, and triglycerides. Post-menopause women have an increased risk of heart disease. Checking cholesterol levels identifies any need for lifestyle changes or medication to support heart health.
Blood glucose
Blood glucose testing screens for prediabetes or diabetes. Changes in estrogen can affect blood sugar and insulin levels. Testing blood glucose determines if lifestyle interventions are needed.
When to get tested
There are no universal guidelines on when to start perimenopausal blood testing. Testing typically begins sometime in a woman’s 40s. The American College of Obstetricians and Gynecologists (ACOG) recommends:
- Age 45-50: Discuss risk factors for heart disease and osteoporosis and consider blood tests based on individual risk factors.
- No periods for 3-6 months: Get FSH, estradiol, and possibly prolactin levels tested to confirm menopause transition.
- Periods become irregular: Test FSH, thyroid hormones, prolactin, and SHBG.
- New onset of hot flashes: Test FSH and estradiol.
Women with premature ovarian insufficiency or at high risk for certain conditions may need earlier testing. Yearly well-woman visits with a doctor are recommended to discuss perimenopause symptoms and determine appropriate testing based on the individual situation.
Interpreting test results
Reference ranges help interpret whether hormone and health marker levels are normal or abnormal. Typical perimenopausal ranges include:
FSH
- Follicular phase: 3-20 mIU/mL
- Midcycle peak: 21-100 mIU/mL
- Luteal phase: 1.5-13.5 mIU/mL
- Postmenopausal: 25-250 mIU/mL
Estradiol
- Follicular phase: 25-75 pg/mL
- Midcycle peak: 150-750 pg/mL
- Luteal phase: 60-200 pg/mL
- Postmenopausal:
FSH levels rise and estradiol levels decrease as a woman transitions into perimenopause. Doctors also take into account clinical symptoms when interpreting test results.
Benefits
There are many potential benefits to getting blood tests done during perimenopause:
- Confirm perimenopause: Testing FSH, estradiol and other hormones verifies the body’s transition into menopause.
- Rule out other causes: Thyroid and prolactin testing excludes disorders causing similar symptoms.
- Assess health risks: Cholesterol, blood glucose, vitamin D and bone density testing identify risks for heart disease, diabetes, and osteoporosis.
- Guide treatment: Understanding a woman’s hormonal status helps tailor the most appropriate therapies to relieve symptoms.
- Track progression: Repeated testing over time monitors hormonal changes.
- Provide peace of mind: Testing gives women insight into what’s happening in their bodies.
Potential risks
Blood testing has some general risks including:
- Discomfort, bruising, or infection from blood draw
- Feeling lightheaded or faint
- Hematoma if bleeding under the skin occurs
- Inaccurate test results due to issues like improper sample labeling or handling
Discuss any concerns about blood testing with your doctor. Proper technique by an experienced phlebotomist minimizes risks.
Preparing for blood tests
Here are some tips to prepare for getting your blood drawn:
- Discuss all medications, vitamins, and supplements you take. Some may impact test results.
- Follow instructions to fast for 8-12 hours beforehand if needed.
- Stay well hydrated by drinking extra water the day before.
- Avoid strenuous exercise before the test.
- Wear a short sleeve shirt or one with loose sleeves.
- Tell the phlebotomist if you have small or hard to find veins.
- Relax during the blood draw, tensing or holding your breath can make it harder.
- Apply pressure to the site afterward and keep the bandage on.
Proper preparation helps ensure accurate test results and a smooth blood draw process.
Common questions
When do FSH levels rise?
FSH levels begin rising during a woman’s mid-to-late 30s as fertility declines. FSH continues climbing through perimenopause into the postmenopausal years.
Do hormones cause weight gain?
Hormonal changes alone don’t directly cause weight gain. But the hormonal fluctuations during perimenopause can increase appetite, reduce metabolism, and shift body fat storage – making it easier to gain weight.
How often should testing be done?
No standard schedule exists, but 1-2 times per year is reasonable for most women. Those with severe symptoms or health risks may need testing more often.
Do irregular periods mean perimenopause?
Irregular cycles are a hallmark of perimenopause. But other issues like pregnancy, thyroid dysfunction, and some medications can also cause menstrual irregularity.
What is postmenopausal estradiol level?
Estradiol drops to around
Conclusion
Blood testing can provide helpful insights for women navigating the transition into menopause. Tracking hormone levels, monitoring health risks, and ruling out other problems allows for optimal treatment to manage symptoms and support long-term health after menopause. Women are encouraged to discuss appropriate testing with their doctor.