Relationship between urinary estrone conjugates as measured by enzyme immunoassay and serum estradiol in women receiving gonadotropins for in vitro fertilization.

OBJECTIVE

Our purpose was to determine whether urinary estrone conjugates (E1C) as measured by enzyme immunoassay correlate with serum estradiol (E2) in women undergoing controlled ovarian hyperstimulation with human menopausal gonadotropins.

DESIGN

This was a prospective, clinical study.

SETTING

The study took place in an outpatient, university-affiliated in vitro fertilization (IVF) unit.

INTERVENTIONS

First morning urine samples were analyzed for E1C using a competitive solid-phase microtiter enzyme immunoassay and the value was corrected for urinary creatinine (E1C/Cr). The value was compared to morning serum E2 as determined by radioimmunoassay.

RESULTS

Mean E2 and E1C/Cr levels demonstrated a similar pattern on the days before hCG administration. The correlation between E1C and E2 was 0.85 (P < 0.0001). Furthermore, the correlation between the number of follicles greater than 12 mm was as high for E1C/Cr (rho = 0.71, P < 0.001) as it was for E2 (rho = 0.74, P < 0.0001).

CONCLUSIONS

Urinary E1C/Cr levels in women receiving hMG correlate with serum E2. Further studies are necessary to determine whether E1C is clinically useful to predict ovarian hyperstimulation syndrome.