Factors associated with spontaneous miscarriage risk in IUI treatment: A retrospectively cohort of 31,933 cycles

Early Pregnancy Loss Rate in In Vitro Fertilization Versus Non-IVF Pregnancies

OBJECTIVES

Compare early pregnancy loss (EPL) rates in in vitro fertilization (IVF) versus non-IVF pregnancies to determine whether IVF has an independent effect on first trimester outcome.

METHODS

Our study set consisted of all obstetrical ultrasounds at our institution over a 30-year period demonstrating a singleton intrauterine pregnancy (confirmed by either yolk sac but no embryo, or embryo <10 mm with cardiac activity), with known first trimester outcome. We assessed EPL rates based on mode of conception, maternal age, vaginal bleeding, and initial ultrasound finding (yolk sac only or embryo). We compared IVF versus non-IVF pregnancies with respect to EPL rate, maternal age, and vaginal bleeding. Most importantly, we used logistic regression analysis to determine whether IVF has an independent effect on loss rate, after controlling for age and bleeding.

RESULTS

Our study set consisted of 16,458 pregnancies, 1394 (8.5%) resulting from IVF and 15,064 (91.5%) non-IVF. Overall EPL rate was 3348/16,458 (20.3%) and was higher in IVF pregnancies, in women aged ≥35 years, and with vaginal bleeding (P < .001, all comparisons). IVF pregnancies had higher maternal ages and were less likely to have vaginal bleeding as an indication for sonography. Logistic regression of mode of conception, maternal age, and bleeding as predictors of outcome demonstrated that mode of conception had no independent effect on outcome (P = .33 for cases with yolk sac only, P = .30 for cases with embryo).

CONCLUSIONS

IVF has no impact on first trimester outcome. A woman pregnant via IVF has the same likelihood of miscarriage as a comparable woman with a non-IVF pregnancy.

The impact of estradiol supplementation on endometrial thickness and intrauterine insemination outcomes

The impact of estrogen supplementation during the follicular/proliferative phase on the endometrial lining thickness (EMT) prior to intrauterine insemination (IUI) remains largely unstudied. Our study examined changes in EMT and rates of clinical pregnancy, miscarriage, and live birth for all patients who completed an IUI cycle at Stanford Fertility Center from 2017-2023 (n = 2281 cycles). Cycles with estradiol supplementation (n = 309) were compared to reference cycles without supplementation (n = 1972), with the reference cohort further categorized into cycles with a pre-ovulatory EMT of < 7 mm ("thin-lining", n = 536) and ≥ 7 mm ("normal-lining", n = 1436). The estradiol group had a statistically significant greater change in EMT from baseline to ovulation compared to the thin-lining reference groups (2.4 mm vs 1.9 mm, p < =0.0001). Similar rates of clinical pregnancy and live birth were observed. After adjusting for age, BMI, race/ethnicity, infertility diagnosis, and EMT at trigger, the estradiol cohort had a significantly increased odds of miscarriage versus the entire reference cohort (2.46, 95 % confidence interval [1.18, 5.14], p = 0.02). Thus, although estradiol supplementation had a statistically significant increase in EMT compared to IUI cycles with thin pre-ovulatory EMT (<7 mm), this change did not translate into improved IUI outcomes such as increased rates of clinical pregnancy and live birth or decreased rate of miscarriage. Our study suggests that supplemental estradiol does not appear to improve IUI outcomes.

Sperm morphology by strict criteria does not predict clinical pregnancy rate following intra-uterine insemination

Objective

To determine the impact of abnormal sperm morphology of the pre-washed semen sample on the day of intrauterine insemination (IUI) on clinical pregnancy rates (CPR).

Design

Cross sectional retrospective chart review.

Setting

Academic fertility center.

Patients

Couples undergoing (IUI) from May 2014 to March 2022.

Interventions

Sperm morphology, by strict criteria, on the pre-washed IUI sample.

Main outcomes Measures

To determine the association of sperm morphology with CPR.

Results

Semen analysis reports, including Kruger strict criteria for morphology from the pre-washed IUI sample, were reviewed for 1,059 cycles, comprising 825 total treated couples.Of the total 1,059 cycles,15.1% resulted in clinical pregnancy. When categorized by strict morphology ≥4% (normal morphology), (3%-2%) [mild-moderate teratozoospermia (TZS)], and ≤1% (severe TZS), the CPR was 16%, 13%, and 10%, respectively (p value 0.30). Early spontaneous miscarriage rate was 4% and when stratified by morphology ≥4% (3%-2%), and ≤1%, was 3%, 1%, and 0%, respectively (p value 0.20).In couples with isolated TZS, the pregnancy rate was 16% in the normal morphology group, 14% in the mild-moderate group, and 8% in the severe group. (p value 0.30).In the multivariate logistic regression, sperm morphology, mild/moderate TZS vs normal forms (OR = 0.99, 95% CI [0.94-1.1]), severe TZS vs normal forms (OR = 0.98, 95% CI [0.0.83-1.1]), was not a predictor of CPR. The Pre-wash TMSC (OR = 1.0, 95% CI [0.996-1.00]) was also not predictive of CPR.The only predictive factor of CPR in IUI was the PWTMSC (OR = 1.03, 95%CI [1.00-1.06).

Conclusions

The morphology of the pre-washed sample on the day of IUI did not find a difference in CPR, neither in miscarriage rate following IUI, in couples with normal or abnormal sperm morphology, including severe TZS.Mild, moderate, or severe TZS in the semen sample should not exclude couples to attempt an IUI procedure.