Is there more to the story than aneuploidy: uncovering factors associated with early pregnancy loss following euploid embryo transfer

In commercial equine embryo transfer programs, the cost of recipient mares represents one of the major economical items that increases the final cost of the pregnancies (Douglas 1985; Losinno and Alvarenga 2006). Due to the risks to newborn foal, it is uncommon to use foaling recipients in the large equine embryo transfer programs in Argentina. The objective of this study was to evaluate pregnancy and early embryonic loss rates between foaling and non-foaling recipients in a commercial embryo transfer program. A total of 173 embryos were collected from Arabian donor mares during 3 consecutive breeding seasons, 2006-2009. Donor mare’s ages ranged from 2 to 22 years, and donors were inseminated with either fresh or frozen semen from 8 stallions 2-17 years old and of proved fertility. Uterine flushing was performed on Day 8 to 9 post-ovulation by standard techniques (Douglas 1985) and recovered embryos were transferred nonsurgically. Recipient mares 3-12 years old were selected clinically by rectal palpation and ultrasound. All embryos were transferred to synchronized recipient mares (-1 to +1 according to donor’s ovulation day) and randomly assigned to non-foaling (n = 84) or foaling (n = 89) recipient groups. For the analysis, we first considered pregnancy and early pregnancy loss rates in both groups, and second, the foaling mares were divided in 3 groups according to the days between foaling and transfer: 1) before 30 days postpartum (n = 10), 2) between 31 and 60 days postpartum (n = 30), and 3) after 61 days postpartum (n = 49). Pregnancy diagnosis was performed by ultrasonography on Days 14, 30, and 60 post-ovulation of the donor. Results were evaluated by chi-square test. No statistical differences (P > 0.05) were observed in pregnancy rates between non-foaling and foaling recipients (76.2% and 80.9%, respectively) and in post-foaling groups (80% for recipients transferred before 30 days postpartum, 73.3% for recipients transferred between 31 to 60 days postpartum, and 85.7% for recipients transferred after 61 days postpartum). No statistical differences (P > 0.05) were found in pregnancy loss rates between recipients transferred before 30 and after 61 days postpartum (25% v. 4.8%, respectively) and between recipients transferred before 30 days postpartum and the non-foaling group (25% v. 10.9%, respectively). Pregnancy loss rates for recipients transferred after 31 and 61 days postpartum (9.1% and 4.8%, respectively) were not significantly different with the non-foaling group, and both are within previously reported values. Our results show that postpartum recipients can be used 30 days after normal foaling in a commercial embryo transfer program with similar pregnancy and early pregnancy loss rates and can be a valuable tool maximizing the use of the recipient mares during consecutive breeding seasons.

Download Full-text

Early Pregnancy Loss in Sheep at Ambient Temperatures of 70° and 90° F. as Determined by Embryo Transfer

Journal of Animal Science ◽

10.2527/jas1961.203608x ◽

1961 ◽

Vol 20 (3) ◽

pp. 608-613 ◽

Cited By ~ 44

Author(s):

C. W. Alliston ◽

L. C. Ulberg

Keyword(s):

Embryo Transfer ◽

Early Pregnancy ◽

Pregnancy Loss ◽

Early Pregnancy Loss ◽

Ambient Temperatures

Download Full-text

Correlation analysis between ultrasound findings and abnormal karyotypes in the embryos from early pregnancy loss after in vitro fertilization-embryo transfer

Journal of Assisted Reproduction and Genetics ◽

10.1007/s10815-016-0821-2 ◽

2016 ◽

Vol 34 (1) ◽

pp. 43-50 ◽

Cited By ~ 6

Author(s):

Xihong Li ◽

Yan Ouyang ◽

Yan Yi ◽

Yueqiu Tan ◽

Guangxiu Lu

Keyword(s):

In Vitro Fertilization ◽

Correlation Analysis ◽

Embryo Transfer ◽

Early Pregnancy ◽

Pregnancy Loss ◽

Early Pregnancy Loss ◽

Vitro Fertilization ◽

Ultrasound Findings

Download Full-text

Early pregnancy loss in patients with polycystic ovary syndrome after IVM versus standard ovarian stimulation for IVF/ICSI

Human Reproduction ◽

10.1093/humrep/deaa200 ◽

2020 ◽

Vol 35 (12) ◽

pp. 2763-2773

Author(s):

S Mackens ◽

L Mostinckx ◽

P Drakopoulos ◽

I Segers ◽

S Santos-Ribeiro ◽

...

Keyword(s):

Polycystic Ovary Syndrome ◽

Embryo Transfer ◽

Early Pregnancy ◽

Pregnancy Loss ◽

Polycystic Ovary ◽

Early Pregnancy Loss ◽

Fresh Embryo Transfer ◽

Ovary Syndrome ◽

Pregnancy Test ◽

Positive Pregnancy Test

Abstract STUDY QUESTION Is the incidence of early pregnancy loss (EPL) in patients with polycystic ovary syndrome (PCOS) higher after IVM of oocytes than after ovarian stimulation (OS) for IVF/ICSI? SUMMARY ANSWER Women with PCOS who are pregnant after fresh embryo transfer have a higher probability of EPL following IVM, but after frozen embryo transfer (FET), no significant difference in the incidence of EPL was observed following IVM compared to OS. WHAT IS KNOWN ALREADY There is conflicting evidence in the current literature with regard to the risk of EPL after IVM of oocytes when compared with OS. Because of the limited sample size in previous studies, the use of different IVM systems and the possible bias introduced by patient characteristics and treatment type, firm conclusions cannot be drawn. STUDY DESIGN, SIZE, DURATION This was a retrospective cohort study evaluating 800 women, with a diagnosis of infertility and PCOS as defined by Rotterdam criteria, who had a first positive pregnancy test after fresh or FET following IVM or OS between January 2010 and December 2017 in a tertiary care academic medical centre. PARTICIPANTS/MATERIALS, SETTING, METHODS Pregnancies after non-hCG triggered IVM following a short course of highly purified human menopausal gonadotropin were compared with those after conventional OS. The primary outcome was EPL, defined as a spontaneous pregnancy loss before 10 weeks of gestation. MAIN RESULTS AND THE ROLE OF CHANCE In total, 329 patients with a positive pregnancy test after IVM and 471 patients with a positive pregnancy test after OS were included. Women who were pregnant after IVM were younger (28.6 ± 3.4 years vs 29.3 ± 3.6 years, P = 0.005) and had higher serum anti-Mullerian hormone levels (11.5 ± 8.1 ng/ml vs 7.2 ± 4.1 ng/ml, P < 0.001) compared to those who were pregnant after OS. The distribution of PCOS phenotypes was significantly different among women in the IVM group compared to those in the OS group and women who were pregnant after OS had previously suffered EPL more often (28% vs 17.6%, P = 0.003). EPL was significantly higher after fresh embryo transfer following IVM compared to OS (57/122 (46.7%) vs 53/305 (17.4%), P < 0.001), while the results were comparable after FET (63/207 (30.4%) vs 60/166 (36.1%), respectively, P = 0.24). In the multivariate logistic regression analysis evaluating fresh embryo transfer cycles, IVM was the only independent factor (adjusted odds ratio (aOR) 4.24, 95% CI 2.44–7.37, P < 0.001)) significantly associated with increased odds of EPL. On the other hand, when the same model was applied to FET cycles, the type of treatment (IVM vs OS) was not significantly associated with EPL (aOR 0.73, 95% CI 0.43–1.25, P = 0.25). LIMITATIONS, REASONS FOR CAUTION The current data are limited by the retrospective nature of the study and the potential of bias due to unmeasured confounders. WIDER IMPLICATIONS OF THE FINDINGS The increased risk of EPL after fresh embryo transfer following IVM may point towards inadequate endometrial development in IVM cycles. Adopting a freeze-all strategy after IVM seems more appropriate. Future studies are needed to ascertain the underlying cause of this observation. STUDY FUNDING/COMPETING INTEREST(S) The Clinical IVM research has been supported by research grants from Cook Medical and Besins Healthcare. All authors declared no conflict of interest. TRIAL REGISTRATION NUMBER N/A.

Download Full-text