Estriol (E3)
The estrogen that climbs late in pregnancy and reflects fetal and placental wellbeing.
Consider this test if:
- Monitoring fetal-placental function in a high-risk or complicated pregnancy
- Following up preeclampsia, fetal growth restriction, diabetes, or Rh immunization in pregnancy
- Evaluating overall estrogen status alongside estradiol and estrone
- Working up a suspected estrogen-producing tumor such as choriocarcinoma or hydatidiform mole
- HSA/FSA eligible
- Typical results in 2-4 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. When you are tracking levels over time, have the blood drawn at the same time of day each visit so values are comparable.
Video consult with your Care Team
A 1:1 call to discuss your health.
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What this test is for
Estriol (E3) is one of the three main estrogens, and the one that becomes dominant in the third trimester, when it is produced from precursors supplied by the fetus and converted by the placenta. Because that pathway depends on a healthy fetus and placenta, estriol is used to evaluate fetal-placental function in pregnancies complicated by preeclampsia, fetal growth restriction, diabetes, or Rh immunization, where low or falling levels can signal a failing pregnancy. Outside of pregnancy, estriol has limited clinical use, and estradiol or estrone are the more informative estrogens for menstrual, fertility, or menopausal questions.
This test measures total estriol in serum. The separate unconjugated estriol (uE3) test is the form used in prenatal screening, as part of the triple or quad screen for Down syndrome and neural tube defects.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in 2-4 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
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Without membership
$0
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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