Should single embryo transfer be used in patients with any kind of infertility factor? Preliminary outcomes

Should intrauterine inseminations still be proposed in cases of unexplained infertility? Retrospective study and literature review

OBJECTIVE

Unexplained infertility is defined by the absence of identifiable causes of infertility. The results of randomized studies and meta-analysis regarding the treatment of unexplained infertility are discordant due to methodological problems.

DESIGN

The aim of this study is to compare the clinical pregnancy rate per cycle (CPR/c) in IUI and IVF/ICSI in cases of unexplained infertility, according to the woman's age group and to identify the factors which predict success.

INTERVENTIONS

We performed a retrospective study in two ART centers, comparing overall clinical pregnancy, ongoing pregnancy and live birth rates in IVF/ICSI and IUI. We also compared pregnancy and birth rates according to different female age groups.

RESULTS

855 IVF/ICSI and 804 IUI cycles were compared. We found a significant difference (p < 0.001) in the pregnancy and live birth rates per cycle between IUI and IVF/ICSI, overall and in the different female age groups, except in women aged 40 and over. The greatest chances of pregnancy with IUI are found in women with secondary unexplained infertility, during the first two cycles and with a bi-follicular response to stimulation. In IVF/ICSI, pregnancy rates are higher in women with secondary unexplained infertility, in the first two cycles, in IVF and in women receiving a transfer of two embryos regardless of the embryonic stage.

CONCLUSION

We recommend IVF/ICSI treatment rather than IUI for unexplained infertility (OR CPR/c 4.20 with 95% CI [3.72-4.68]). This is in accordance with NICE, which advises the use of IVF after 2 years.

Single-embryo transfer: a key strategy to reduce the risk for multiple pregnancy in assisted human reproduction

In the early days of assisted reproductive technology (ART), the main target was achieving gestation. Success rates were low, and multiple embryo transfers became common practice, with multiple pregnancies being 20 times higher than in natural conception. Multiple pregnancy is associated with a higher risk of complications for the mother and the baby than a singleton pregnancy. Added to healthcare costs, multiple pregnancy also involves other costs and psychosocial risks, with a high social and health costs. At present, success rates of assisted human reproduction (AHR) have improved dramatically, partially due to advances in laboratory techniques such as culture of blastocyst-stage embryos and vitrification. Additionally, there is a wide range of counseling, health and economic policies that have demonstrated being effective in increasing single-embryo transfer (SET) practices and reducing multiple pregnancies, which ensures satisfactory success rates. Therefore, single-embryo transfer emerges as the approach of choice for AHR to result in a full-term healthy newborn.

Does the sex ratio of singleton births after frozen single blastocyst transfer differ in relation to blastocyst development?

PURPOSE

To investigate the associations between blastocyst development and the sex ratio (male:female) among singleton live births resulting from single-blastocyst frozen embryo transfer (FET) cycles.

METHODS

Patients with singleton live births following the first autologous single FET of non- preimplantation genetic testing (PGT) blastocysts in a single reproductive medicine department between January 2015 and February 2019 were included in this retrospective study. The primary outcome measure was the singleton sex ratio. Multivariable logistic regression models were used to estimate the associations between blastocyst quality and singleton sex ratio after adjustment for some potential confounders.

RESULTS

There were 638 high-quality and 572 poor-quality single blastocyst FETs, and the blastocysts were conceived via 855 IVF and 355 ICSI treatments. A total of 1210 singleton live births were assessed. High-quality single blastocyst FET resulted in a significantly higher sex ratio than did poor-quality single blastocyst FET (60% vs. 49.7%, P < 0.001). The infertility cause was not associated with sex ratio among singleton live births (P = 0.537). The results of a multivariate analysis revealed that a high-quality blastocyst has a 150% higher probability of being male than a poor-quality blastocyst (adjusted odds ratio (aOR) 1.57; 95% CI 1.24-2, P < 0.001). Among the three blastocyst morphological parameters, Grade B trophectoderm was significantly associated with a higher sex ratio than Grade C (aOR 1.71; 95% CI 1.33-2.21. P < 0.001). Neither expansion degree nor inner cell mass degree were significantly associated with the singleton sex ratio.

CONCLUSIONS

A single high-quality blastocyst FET has a higher chance of resulting in a male infant than a female infant. The results demonstrate that grade B trophectoderm confers benefits in improving the implantation potential of male blastocysts.