Endometrial thickness as a biomarker for ongoing pregnancy in IUI for unexplained subfertility: a secondary analysis

Effect of blastocyst morphology on the incidence of monozygotic twinning pregnancy after single blastocyst transfer

Aims: To explore whether blastocyst morphology [blastocyst stage, inner cell mass (ICM), and trophectoderm (TE) grading] impacts the occurrence of monozygotic twinning (MZT) after single blastocyst transfer (SBT).Materials and methods: A single-center retrospective cohort study was conducted including all clinical pregnancies after single blastocyst transfer between January 2015 and September 2021 (n = 9229). Blastocyst morphology was assessed using Gardner grading system. MZT was defined as more than one gestational sac (GS), or two or more fetal heartbeats in a single GS via ultrasound at 5-6 gestational weeks.Results: The overall MZT rate was 2.46% (227 of 9229 cases), of which was the highest in blastocysts of grade A TE and lowest in those with grade C TE (grade A: B:C = 3.40%:2.67%:1.58%, p = .002). Higher risk of MZT pregnancy was associated with higher trophectoderm grading [A vs. C: aOR, 1.883, 95% CI 1.069-3.315, p = .028; B vs C: aOR, 1.559, 95% CI 1.066-2.279, p = .022], but not extended culture in vitro (day 5 vs. day 6), vitrification (fresh vs. frozen-thawed ET), assisted hatching (AH), blastocyst stage (stage 1-6) or ICM grading (A vs. B).Conclusions: We conclude that TE grade is an independent risk factor of MZT after single blastocyst transfer. Blastocysts with high-grade trophectoderm are more liable to obtain monozygotic multiple gestation.

P16 and P21 are involved in the pathogenesis of endometrial thinning: A cross-sectional study

P16 plays a role in the negative regulation of cell proliferation, regulating cell apoptosis to control the growth of tumor cells. P21 is a nuclear protein that suppresses DNA synthesis and inhibits cell division. This study aimed to examine the expression and roles of P16 and P21 in endometrial thinning. Thirty cases of endometrial biopsy diagnosed as endometrial thinning were assessed by p16 and p21 immunohistochemistry from March 2014 to August 2020 in Huazhong University of Science and Technology Union Shenzhen Hospital. Another thirty cases of normal endometrium in the same period were assessed as controls. The specimens underwent histological analysis, and P16 and P21 were assessed by immunohistochemistry. There were no statistically significant differences in age, menstrual cycle, BMI, sex hormone levels, gravidity and parity between the two groups (all P > .05). In the endometrial thinning group, P16 was expressed in the endometrial adenoid nucleus, cytolymph and interstitial cell nucleus. In the normal group, P16 was mainly expressed in the endometrial adenoid nucleus, with some P16 signals detected in the endometrial interstitial nucleus. P21 expression was mainly detected in the endometrial adenoid nucleus. P16 and P21 amounts in endometrial thinning cases were significantly lower than those of the normal endometrial group. There was no correlation between p16 and p21 amounts. This study revealed aberrant expression of P16 and P21 in the endometrium might be due to a compensatory effect of the thin endometrium to increase cell proliferation and suppress cell apoptosis. However, the pathological roles of P16 and P21 in endometrial thinning and the contribution of cell senescence deserve further investigation.

Correlations between elevated basal sperm DNA fragmentation and the clinical outcomes in women undergoing IUI

OBJECTIVE

This study aimed to explore the impact of the sperm DNA fragmentation index (DFI) on the clinical outcomes in women undergoing artificial insemination by husband intrauterine insemination (AIH-IUI).

METHODS

In this retrospective study, the value of sperm DFI was detected by sperm chromatin structure assay (SCSA) in a semen analysis collected before fertility treatment (basal DFI) in 1,500 IUI cycles at the infertility clinic of Northern Jiangsu People's Hospital Reproductive Medicine Center from Jan 2016 to April 2021. Receiver operating characteristic (ROC) curves were used to calculate the cut-off value for the clinical outcomes of IUI, including the biochemical pregnancy rate, clinical pregnancy rate, delivery rate, and live birth rate, and multivariate logistic regression was conducted to analyse the risk factors for clinical outcomes after IUI.

RESULT

In 1,500 IUI cycles, the results showed that there were no statistically significant differences between the normal DFI group and the abnormal DFI group in biochemical pregnancy rate (14.41% vs. 11.3%, P = 0.386), clinical pregnancy rate (12.9% vs. 10.5%, P = 0.433), delivery rate (11.0% vs. 8.9%, P = 0.456), live birth rate (10.9% vs. 8.9%, P = 0.484) or pregnancy loss rate (14.6% vs. 15.4%, P = 1.000).

CONCLUSION

Sperm DFI alone may have limited predictive power for IUI clinical outcomes.

The strain rate of endometrium measured by real-time sonoelastography as a predictive marker for pregnancy in gonadotropin stimulated intrauterine insemination cycles

AIM

Sonoelastography is an imaging technique that measures tissue strain quantitatively. This study aims to investigate whether the strain rate of endometrium measured by elastography can predict pregnancy after intrauterine insemination (IUI).

METHODS

This study examined 197 gonadotropin-stimulated IUI cycles of 148 women diagnosed with unexplained infertility from February 2019 to November 2020. Endometrial thickness, pattern, and strain rate were measured by transvaginal ultrasonography immediately before the insemination. The endometrium and the parametrial tissue were selected for regions of interest, and the strain rate was calculated. The measurements were analyzed concerning the IUI outcome.

RESULTS

Of the 197 IUI cycles, the pregnancy rate was 15.20% (n = 30), and ongoing pregnancy rate was 12.2% (n = 24). The mean strain rates were not different between pregnant and nonpregnant groups (2.68 ± 1.28 vs. 2.81 ± 1.32, p = 0.651). Strain rate was not predictive for pregnancy, shown by receiver operating characteristic curve analysis; the area under the curve was 0.526 (95% CI 0.413-0.639; p = 0.649). Pregnancy rates were significantly affected by the women's age and the inseminated sperm count. In multiple logistic regression analysis, the other parameters, including body mass index, anti-Müllerian hormone, endometrial thickness, endometrial strain rate, and echogenic endometrial pattern, did not significantly change the odds ratio of pregnancy.

CONCLUSION

The endometrial strain rate does not significantly affect the pregnancy rates in gonadotropin stimulated IUI cycles. It appears that strain rate does not predict IUI outcome. More research is needed to evaluate the usefulness of sonoelastography in infertility treatments.

Double trouble? Impact of frozen embryo transfer on the monozygotic twinning rate: a retrospective cohort study from 8459 cycles

PURPOSE

To compare monozygotic twinning (MZT) rates in patients undergoing fresh embryo transfer (ET) and frozen embryo transfer.

METHODS

All clinical pregnancies after single ET carried out in our IVF center between 2014 and 2018 (n = 8459) were retrospectively analyzed for the incidence of MZT. MZT rate was compared in women who underwent fresh ET (n = 3876) and frozen ET (n = 4583).

RESULTS

There was a total of 120 MZT identified in the fresh ET group (3.10%) and 103 MZT in the frozen ET group (2.25%), which was significant (p = 0.015). In the univariate analysis, the risk of MZT was decreased with frozen embryo transfer (OR 0.72; 95% CI, 0.55-0.94, p = 0.016) and increased with mild stimulation protocol in the fresh cycle (OR 1.90; 95% CI, 1.04-3.45, p = 0.036). Multivariable logistic regression revealed that frozen embryo transfer was associated with a significant decrease risk of MZT (adjusted OR 0.66; 95% CI, 0.46-0.90, p = 0.011).

CONCLUSIONS

Frozen ET is associated with a lower risk of MZT.