E1G Levels at 11 DPO in Pregnancy
There are no established reference ranges for estriol-1-glucuronide (E1G) levels at 11 days post-ovulation that reliably distinguish pregnant from non-pregnant states, and measuring E1G at this timepoint is not clinically useful for pregnancy confirmation.
Why E1G Measurement at 11 DPO Is Not Clinically Relevant
The evidence shows that absolute estrogen levels—including estriol and its metabolites—do not predict pregnancy outcomes or viability. The American College of Obstetricians and Gynecologists notes that individual vulnerability to hormonal fluctuations, rather than absolute hormone levels or magnitude of changes, determines physiologic outcomes 1.
Key Evidence Against Using E1G for Early Pregnancy Assessment
Estriol levels in non-pregnant women are extremely low, ranging from 7.9 pg/mL in the follicular phase to 11.1 pg/mL in the luteal phase, with individual variability making single measurements unreliable 2
Pregnancy-related estriol increases occur much later than 11 DPO—the dramatic 1,000-fold increase in estriol that characterizes pregnancy develops gradually over weeks to months, not in the immediate post-implantation period 1
At 11 DPO, implantation may have just occurred or not yet occurred, making any estrogen measurement premature for pregnancy assessment 1
What Actually Matters: hCG, Not Estrogen
The only reliable biochemical marker at 11 DPO is human chorionic gonadotropin (hCG), not estrogen metabolites. Most qualitative pregnancy tests detect hCG at 20-25 mIU/mL, but testing at 11 DPO is premature 1, 3.
Appropriate Timing for Pregnancy Testing
Wait until 14 DPO (day of expected menses) for initial testing, when hCG levels are reliably detectable in viable pregnancies 3, 4
Some pregnancies require an additional 11 days past expected menses to reach detectable hCG levels with qualitative tests 1, 3
Serial hCG measurements are more informative than single values—in viable pregnancies, hCG levels >200 mIU/mL at 14 days post-embryo transfer correlate with ongoing pregnancy 4
Common Pitfalls to Avoid
Do not interpret E1G fluctuations at 11 DPO as indicating pregnancy failure or success. The American College of Obstetricians and Gynecologists emphasizes that transient hormone dips during the luteal phase are physiologically normal and do not predict outcomes 5, 3.
What Constitutes Concerning Hormonal Changes
"Dramatic withdrawal" only occurs when estrogen drops precipitously from sustained high levels (>1000% above baseline) to near-baseline within 24-48 hours, as seen postpartum—not during normal luteal phase fluctuations 5, 6
A 45% decrease in E1G (e.g., from 200 to 110) does not meet criteria for pathologic withdrawal because luteal phase levels are not sustained elevations comparable to pregnancy 5
Mood disturbances are associated with three specific patterns: sudden withdrawal after sustained elevation, rapid fluctuations, and sustained deficiencies—not moderate decreases during normal cycling 5, 6
Clinical Bottom Line
Stop measuring E1G at 11 DPO—it provides no actionable information. Instead, wait until 14 DPO minimum for hCG testing, and use serial hCG measurements to assess pregnancy viability 1, 3, 4. The evidence consistently shows that absolute estrogen levels and moderate fluctuations do not predict pregnancy outcomes in the early luteal phase 1, 5.