The impact of supraphysiologic estradiol levels on placental pathology among in vitro fertilization-conceived singleton livebirths after fresh embryo transfer.

OBJECTIVE

To investigate the effect of supraphysiologic estradiol levels during ovarian stimulation on placental pathology among singleton livebirths conceived with in vitro fertilization (IVF) and fresh embryo transfer.

DESIGN

Retrospective cohort study.

SUBJECTS: Six hundred twenty six IVF-conceived singleton livebirths with associated placental pathology.

EXPOSURE: Two separate analyses were performed, using the ≥75th (2588.75pg/mL), and ≥ 90th (3120.5 pg/mL) estradiol percentile as cut-offs. Livebirths were categorized as below or above the estradiol cut-off at time of trigger, and placental abnormalities were compared between groups.

MAIN OUTCOME MEASURES: Placental pathology (abnormalities classified as: anatomic, vascular, infectious, and inflammatory).

RESULTS

Mean (SD) age and body mass index were 35.2 (4.0) years and 24.8 (4.5) kg/m2. Most patients were identified as White (n = 482, 77.0%), and the most common infertility diagnosis was male factor (n = 178, 28.9%). Using the 75th percentile as estradiol cut-off, unadjusted rates of placental abnormalities did not differ between the two groups (anatomic: 63.7% vs. 65.9%; vascular: 72.0% vs. 66.1%; infectious:33.1% vs. 32%; and inflammatory: 14.6% vs. 20%, for ≥75th vs. <75th percentile, respectively). Adjusted risk ratio (adjRR) (95% confidence interval [CI]) was calculated to account for possible confounding factors (maternal age, body mass index, infertility diagnosis, stimulation protocol, gestational age at delivery, and infant sex). AdjRR (95% CI) did not show significant differences between groups in risk of anatomic or infectious abnormalities. In patients with estradiol levels ≥75th percentile, the risk of vascular abnormalities was higher vs. patients in the <75th percentile group (adjRR [95% CI] 1.14 [1.00-1.29]). Among patients with estradiol levels ≥75th percentile, the risk of inflammatory abnormalities was lower vs. patients in the <75th percentile group (adjRR [95% CI] 0.62 [0.38-0.99]). When using the 90th percentile as the cut-off, no significant differences were noted between groups in rates of anatomic, vascular, infectious, or inflammatory abnormalities (65.1% vs. 65.4%; 76.2% vs. 66.6%; 34.9% vs. 32%; and 15.9% vs. 19%, for ≥90th vs. <90th percentile, respectively). AdjRR (95% CI) did not show significant differences between groups in risk of anatomic, infectious, or inflammatory abnormalities. However, risk for vascular abnormalities was higher among patients with estradiol ≥90th vs. <90th percentile (adjRR [95% CI]: 1.19 [1.01-1.39]).

CONCLUSION

Our study did not reveal clinically increased risks of placental abnormalities. Higher serum estradiol during IVF was associated with a marginally higher risk for vascular placental abnormalities.