Correlation between Ovarian Reserve and Incidence of Ectopic Pregnancy after In Vitro Fertilization and Embryo Transfer

Risk factors of ectopic pregnancy after in vitro fertilization-embryo transfer in Chinese population: A meta-analysis

BACKGROUND

The prevalence of ectopic pregnancy after assisted reproduction is notably high, posing a significant threat to the life safety of pregnant women. Discrepancies in published results and the lack of a comprehensive description of all risk factors have led to ongoing uncertainties concerning ectopic pregnancy after assisted reproduction.

OBJECTIVE

This study aimed to understand the risk factors for ectopic pregnancy after in vitro fertilization-embryo transfer in the Chinese population and provide a reference for targeted prevention and treatment.

METHODS

A comprehensive search of the China National Knowledge Infrastructure, Wang fang Database, China Science Technology Journal Database, Chinese Biomedical Literature Database, PubMed, Web of Science, and Embase was conducted to identify relevant literature on the risk factors for ectopic pregnancy in Chinese women after assisted reproductive technology in Chinese women. A meta-analysis of the included studies was performed using Stata17.

RESULTS

Overall, 34 articles were included in the analysis. The risk factors for ectopic pregnancy after in vitro fertilization-embryo transfer in the Chinese population included a thin endometrium on the day of HCG administration and embryo transplantation, a history of ectopic pregnancy, secondary infertility, a history of induced abortion, polycystic ovary syndrome, decreased ovarian reserve, tubal factor infertility, cleavage stage embryo transfer, fresh embryo transfer, artificial cycle protocols, elevated estradiol levels on the day of human chorionic gonadotropin administration, a history of tubal surgery, two or more number of embryo transfers, previous pregnancy history, and a history of pelvic surgery.

CONCLUSION

This study clarified the factors influencing ectopic pregnancy after in vitro fertilization and embryo transfer in the Chinese population, focusing on high-risk groups. Targeted and personalized intervention measures should be adopted to prevent and detect the disease early to reduce its incidence and harm.

TRIAL REGISTRATION

The protocol for this view was registered in PROSPERO (CRD42023414710).

Assisted reproductive technology and interactions between serum basal FSH/LH and ovarian sensitivity index

Objectives

This study aimed to investigate whether the FSH (follicle-stimulating hormone)/LH (Luteinizing hormone) ratio correlates with ovarian response in a cross-sectional retrospective study of a population with normal levels of anti-Müllerian hormone (AMH).

Methods

This was a retrospective cross-sectional study with data obtained from medical records from March 2019 to December 2019 at the reproductive center in the Affiliated Hospital of Southwest Medical University. The Spearmans correlation test evaluated correlations between Ovarian sensitivity index (OSI) and other parameters. The relationship between basal FSH/LH and ovarian response was analyzed using smoothed curve fitting to find the threshold or saturation point for the population with mean AMH level (1.1<AMH<6μg/L). The enrolled cases were divided into two groups according to AMH threshold. Cycle characteristics, cycle information and cycle outcomes were compared. The Mann-Whitney U test was used to compare different parameters between two groups separated by basal FSH/LH in the AMH normal group. Univariate logistic regression analysis and multivariate logistic regression analysis were performed to find the risk factor for OSI.

Results

A total of 428 patients were included in the study. A significant negative correlation was observed between OSI and age, FSH, basal FSH/LH, Gn total dose, and Gn total days, while a positive correlation was found with AMH, AFC, retrieved oocytes, and MII egg. In patients with AMH <1.1 ug/L, OSI values decreased as basal FSH/LH levels increased, while in patients with 1.1<AMH<6 ug/L, OSI values remained stable with increasing basal FSH/LH levels. Logistic regression analysis identified age, AMH, AFC, and basal FSH/LH as significant independent risk factors for OSI.

Conclusions

We conclude that increased basal FSH/LH in the AMH normal group reduces the ovarian response to exogenous Gn. Meanwhile, basal FSH/LH of 3.5 was found to be a useful diagnostic threshold for assessing ovarian response in people with normal AMH levels. OSI can be used as an indicator of ovarian response in ART treatment.

Ectopic pregnancy risk factors in infertile patients: a 10-year single center experience

The present retrospective study included both intrauterine insemination and in vitro assisted reproductive technologies (ART) procedures performed from January 2009 to December 2018 at a tertiary-care Fertility Centre. The purpose was to assess the incidence of ectopic pregnancy (EP) in infertile population who undergoes ART and to identify any risk factor impacting the occurrence of EP after ART. Among 27,376 cycles, 7352 pregnancies were achieved, of which 132 were EPs, the 1.80% (95% CI 1.5-2.1) of all pregnancies. In fresh embryo transfer cycles, a history of prior pelvic adhesions showed the greatest impact on the incidence of EP (aOR 2.49 95% CI 1.53-4.07 p < 0.001). Other factors associated with EP incidence were also identified, such as female age, basal FSH, the transfer of blastocyst embryos and difficulties during the embryo transfer procedure. In frozen embryo transfer cycles, the only factor influencing the incidence of EP was anti Müllerian hormone (AMH) serum concentration (aOR 0.81 95% CI 0.65-1.00, p = 0.048). To conclude, the incidence of EP observed was comparable to that reported after natural conception. On the other hand, pre-existing risk factors, traditionally more common in infertile population, appeared to influence the incidence of EP and should thus be modified if possible.

Top-quality embryo transfer is associated with lower odds of ectopic pregnancy

INTRODUCTION

The incidence of ectopic pregnancy is up to four times higher after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) than in spontaneous pregnancies, and the risk of ectopic pregnancy is increased by tubal factor infertility and the transfer of multiple embryos. However, the effect of embryo quality on the probability of ectopic pregnancy has not been investigated until now and it is not clear whether ovarian stimulation parameters affect the incidence of ectopic pregnancy.

MATERIAL AND METHODS

An historical cohort study of 15 006 clinical pregnancies (diagnosed by ultrasound at 6-8 gestational weeks) after non-donor IVF/ICSI with fresh embryo transfer (n = 8952) or frozen-thawed embryo transfer (n = 6054). Treatments were performed during 2000-2017 in Finland. A total of 9207 (61.4%) single and 5799 (38.6%) double embryo transfers of no more than one top-quality embryo were evaluated. We analyzed the effects of multiple factors on ectopic pregnancy by logistic regression, including type of cycle (fresh vs frozen embryo transfer), female age, number and quality of embryos transferred, tubal factor infertility and factors of ovarian response to gonadotropin stimulation.

RESULTS

Ectopic pregnancy was observed in 2.3% of cycles. There was no significant difference in ectopic pregnancy rate after fresh embryo transfer and frozen embryo transfer (2.2% vs 2.4%, p = 0.3). The ectopic pregnancy rate was lower in cycles with top-quality embryo transfer (1.9%) than of those where only non-top quality embryos were transferred (2.7%, p < 0.0001). Tubal factor infertility was diagnosed more often in ectopic pregnancy than in intrauterine pregnancies (21.2% vs 11.0%, p < 0.0001). Logistic regression revealed lower odds for ectopic pregnancy after a top-quality embryo transfer than after transfer of a non-top quality embryo (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.56-0.92, p = 0.007). Transfer of two vs one embryo (OR 1.35, 95% CI 1.05-1.70, p = 0.02) and tubal factor infertility (OR 2.21, 95% CI 1.68-2.91, p < 0.0001) significantly increased the risk of ectopic pregnancy.

CONCLUSIONS

Transfer of non-top quality embryos is associated with a higher rate of ectopic pregnancy. This is particularly important to keep in mind in treatments with only non-top embryos available even in the absence of tubal factor infertility. To minimize the risk of ectopic pregnancy, the number of embryos transferred should be as low as possible.

Comparison of complication rates after transvaginal ultrasound-guided oocyte pick-up procedures with respect to ovarian response

Objective

The aim of this study was to compare the complication rates of oocyte pick-up (OPU) procedures via transvaginal ultrasonography in patients with different levels of ovarian reserve.

Methods

In total, 789 patients who underwent OPU procedures for in vitro fertilization (IVF) were included in the study.

Results

Individuals with normal ovarian reserve had a 2.947-fold higher risk of complications in OPU procedures than individuals with low ovarian reserve, and individuals with high ovarian reserve had a 7.448-fold higher risk of complications than individuals with low ovarian reserve. In addition, a higher number of IVF trials was associated with an increased risk of complications.

Conclusion

The results of this study show that OPU has a higher risk of complications, particularly severe pain, in patients with high ovarian reserve. It is thought that complications can be reduced by preferring mild stimulation in patients with high ovarian reserve. Collecting fewer oocytes is also associated with a lower risk of complications from OPU. Even if a patient’s reserve is very good, fewer and higher-quality oocytes should be targeted with the use of the lowest possible dose of drugs.

Interaction networks between the Fallopian tubes and the embryo in human tubal pregnancy: Current knowledge and perspectives

AIM

More than 90% of ectopic pregnancies occur in the Fallopian tubes. As the pathogenesis of tubal pregnancy remains largely unclear, the development of strategies to prevent and treat tubal pregnancy still represents a major clinical challenge. This review thoroughly summarizes the current data, aiming to determine the genes and signaling pathways that are involved in the pathophysiology of human tubal pregnancy.

METHODS

An electronic search from databases of PubMed, Google Scholar, and Chinese databases was carried out using key words pertaining to the pathogenesis of tubal pregnancy from the perspectives of both the Fallopian tubes and the embryo. A review of the literatures including review articles, experimental, and observational studies and case reports published between 1999 and 2021 was conducted.

RESULTS

Tubal pregnancy results from the interaction networks between the Fallopian tube and the embryo rather than from simple tubal abnormality. Furthermore, the embryo-maternal communication is supposed to start from the preimplantation period to the implantation period.

CONCLUSION

A greater understanding of the interaction networks between the Fallopian tubes and the embryo is of great significance for the prevention and medical treatment of tubal pregnancy.

Ovarian stimulation increases the risk of ectopic pregnancy for fresh embryo transfers: an analysis of 68,851 clinical pregnancies from the Japanese Assisted Reproductive Technology registry

OBJECTIVE

To evaluate the risk of ectopic pregnancies (EPs) for fresh cycles according to different ovarian stimulation protocols.

DESIGN

Registry-based retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 68,851 clinical pregnancies after fresh single embryo transfer between 2007 and 2015.

INTERVENTION (S)

None MAIN OUTCOME MEASURE(S): Ectopic pregnancies. Odds ratios and 95% confidence intervals for EPs were calculated by using generalized estimating equations adjusted for potential maternal and treatment characteristics.

RESULT(S)

Among 68,851 clinical pregnancies, 1,049 (1.46%) cases of EP were reported. Compared with natural cycles, all ovarian stimulation protocols were associated with a significantly increased risk of EP. Ovarian stimulation with clomiphene (CC) demonstrated the highest odds ratios for EPs. Significant associations between ovarian stimulation protocols and EP compared with natural cycles were prominent when the number of retrieved oocytes was low (1-3) to moderate (4-7), but there were no significant associations when the number of retrieved oocytes was high (≥8).

CONCLUSION(S)

Ovarian stimulation protocols were significantly associated with an increased risk of EP. In particular, ovarian stimulation with CC had the highest risk of EP compared with other stimulation protocols. Further studies are essential to investigate possible confounding factors for different ovarian stimulation protocols, especially CC, and the risk of EP.

Suboptimal endometrial-embryonal synchronization is a risk factor for ectopic pregnancy in assisted reproduction techniques

RESEARCH QUESTION

What are the main risk factors associated with ectopic pregnancy and what is the true incidence of ectopic pregnancies in an IVF programme?

DESIGN

Retrospective single-centre study of 12,429 blastocyst transfers (8182 fresh and 4247 frozen embryo transfers) conducted between January 2010 and December 2017. IVF outcome was analysed, and ectopic pregnancy risk evaluated according to patient's characteristics and assisted reproductive technology treatment factors.

RESULTS

Of 5061 patients reporting a positive pregnancy test, 43 were diagnosed with ectopic pregnancy (0.85%). Neither female age (36.7 versus 35.8 years), body mass index, quality of transfer nor stimulation protocol affected the ectopic pregnancy rate, but history of previous ectopic pregnancy (OR 3.26; P = 0.0080), tubal surgery, or both (OR 6.20; P < 0.0001) did. The incidence of ectopic pregnancy was increased in women with uterine malformations (OR 3.85; P = 0.0052), uterine pathologies (OR 5.35; P = 0.0001), uterine surgeries (OR 2.29; P = 0.0154) or sub-optimal endometrial build-up (OR 4.46 to 5.31; P < 0.0001). Transfer of slow-developing blastocysts (expressed by expansion) significantly increased the risk of ectopic pregnancy (OR 2.59; P = 0.0102).

CONCLUSIONS

Unfavourable uterine environment, including uterine pathologies, uterine or tubal surgery and suboptimal endometrial build-up were related to ectopic pregnancy. Low expansion grade of blastocysts was identified as an additional putative risk factor for ectopic pregnancy, indicating the importance of proper embryonal-maternal synchronization. The overall ectopic pregnancy rate after blastocyst transfer was low, comparable with reported ectopic pregnancy rates in spontaneous conceptions. Proper evaluation of tubal and uterine pathologies, optimizing endometrial preparation and the transfer of expanded blastocysts in a frozen embryo transfer cycle, might be beneficial.

Effect of endometrial thickness on ectopic pregnancy in frozen embryo transfer cycles: an analysis including 17,244 pregnancy cycles

OBJECTIVE

To investigate whether endometrial thickness (EMT) influences the incidence of ectopic pregnancy (EP) in frozen embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

SETTING

Academic tertiary-care medical center.

PATIENT(S)

A total of 16,556 patients were enrolled between January 2010 and December 2017, comprising 16,701 intrauterine, 488 ectopic, and 45 heterotopic pregnancy cycles after FET.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

EP was the primary outcome. EMT was the main measured variable. Data were analyzed with the binary logistic general estimating equations model to calculate the adjusted odds ratio (aOR) for EP.

RESULT(S)

After adjusting for confounders, EMT remained statistically significant as an independent risk factor for EP. Compared with women with an EMT of ≥14 mm, the aORs for women with EMT in the ranges 7-7.9, 8-9.9, and 10-11.9 mm were 2.70 (95% confidence interval [CI], 1.65-4.40), 2.06 (95% CI, 1.33-3.20), and 1.66 (95% CI, 1.07-2.58), respectively. Hormone replacement treatment for endometrial preparation during FET increased the risk of EP after adjustment for confounding variables.

CONCLUSION(S)

EMT is inversely proportional to EP rate in FET cycles and is therefore a potential quantitative marker of endometrial receptivity and uterine contractibility in an FET cycle. The predictive validity of EMT value must be evaluated in further studies.