Assessment of Clinical Pregnancies in Up to Eight Ovarian Stimulation with Intrauterine Insemination Cycles in Those Unable to Proceed With In Vitro Fertilization

OBJECTIVE

To study the primary objective of clinical pregnancy rate per ovarian stimulation intrauterine insemination cycle in patients with repetitive cycles up to a maximum of 8 cycles.

DESIGN

Retrospective cohort.

SETTING

Large fertility clinic.

PATIENTS

A total of 37,565 consecutive ovarian stimulation intrauterine insemination cycles from 18,509 patients were included in this study.

INTERVENTIONS

Those with anovulatory diagnoses, tubal factor infertility, male factor infertility, using donor sperm, canceled cycles, and those with missing data for either baseline characteristics or outcome were excluded. Clinical pregnancy rate was analyzed by generalized estimating equations and controlled for age, stimulation protocol, and body mass index.

MAIN OUTCOMES MEASURE(S)

Clinical pregnancy was defined as intrauterine gestation with fetal heartbeat visible on ultrasound.

RESULTS

A total of 37,565 consecutive ovarian stimulation intrauterine insemination cycles from 2002 through 2019 at a private practice facility were evaluated. All cycles met inclusion criteria and were used in generalized estimating equation modeling. Patients < 35 years old comprised 47.6% of the cohort. After adjustment for confounders, the mean predicted probability of clinical pregnancy for cycles 1-8 was 15.7% per cycle. The mean predicted probability of clinical pregnancy in aggregated data from cycles 2-4 was only 1.7% lower compared to cycle 1 as the referent (16.7% vs. 15.0%, 95% CI 2^nd: 0.88 (0.82, 0.95), 3^rd: 0.86 (0.79, 0.93), 4^th: 0.88 (0.79, 0.98)). However, the 15.0% mean predicted probability of clinical pregnancy for the 2^nd through 4^th cycle was concordant with the mean for all included cycles (15.7%). The mean predicted probability of clinical pregnancy of cycles 5-8 was not significantly different when compared to the referent (16.7% vs. 16.1%, 95% CI 5^th: 0.97 (0.85, 1.11), 6^th: 0.93 (0.79, 1.10), 7^th: 1.01 (0.81, 1.26), 8^th: 1.01 (0.76, 1.34)). Modeling of consecutive cycles suggested that the adjusted cumulative predicted probability of clinical pregnancy from OS-IUI continues to increase with each of the eight successive cycles.

CONCLUSION

Clinical pregnancy rates are satisfactory in up to 8 consecutive ovarian stimulation intrauterine insemination cycles. These data are useful for counseling, especially in those patients for whom in vitro fertilization is not financially or ethically feasible.