Ectopic pregnancy rates after in vitro fertilization: a look at the donor egg population

Mechanism of Human Tubal Ectopic Pregnancy Caused by Cigarette Smoking

In the past few decades, the smoking rate of women of childbearing age has increased. Epidemiological data has repeatedly shown that smoking women have an increased risk of various reproductive diseases, including ectopic pregnancy (EP), decreased fertility, adverse pregnancy outcomes, and failure of assisted reproduction. The oviduct was the target of cigarette smoke in many in vivo and in vitro studies. The fallopian tube is a well-designed organ. Its function is to collect and transport the ova to the fertilized site and provide a suitable environment for fertilization and early embryonic development. Lastly, the fallopian tube transports the pre-implantation embryo to the uterus. Various biological processes can be studied in the fallopian tubes, making it an excellent model for toxicology. This paper reviews the roles of the fallopian tube in gametes and embryo transportation, and the possible mechanism tobacco smoke contributes to tubal EP. A possible signal pathway might be a model to develop intervention of EP for pregnant women exposed to smoking.

An Endometrial Thickness < 8 mm Was Associated With a Significantly Increased Risk of EP After Freeze-Thaw Transfer: An Analysis of 5,960 Pregnancy Cycles

INTRODUCTION

Endometrium characteristics that are most likely to induce ectopic pregnancy were investigated on the basis of the data of 5,960 pregnant freeze-thaw cycles.

METHODS

A total of 5,960 pregnancy cycles after freeze-thaw embryos transfer were included, with the number of intrauterine and ectopic pregnancies being 5,777 and 183, respectively. Ectopic pregnancy was the primary outcome. Endometrial thickness was the main measured variable. The risk factors of ectopic pregnancy were eventually determined based on univariate analysis and subsequent multiple-stepwise logistic regression analysis.

RESULTS

1. After adjusting for confounders, endometrial thickness could independently predict ectopic pregnancy. The adjusted odd ratios for women with endometrial thickness in the ranges of < 8 mm, 8-9.9 mm, and 10-11.9 mm were 3.270 [95% confidence interval (CI), 1.113-9.605, P = 0.031], 2.758 (95% CI, 0.987-7.707, P = 0.053), and 1.456 (95% CI, 0.502-4.225, P = 0.489), respectively, when compared with those having an endometrial thickness of 12-13.9 mm. 2. Endometrial type and preparation protocol were however not identified as risk factors for ectopic pregnancy.

DISCUSSION

1. After freeze-thaw embryo transfer, risks of ectopic pregnancy were significantly higher when the endometrial thickness was < 8 mm. 2. A thin endometrial thickness could be linked with abnormal endometrial peristaltic waves or abnormal endometrial receptivity. 3. Adequate attention should therefore be paid to patients with a thin endometrial thickness to prevent EP or to achieve early diagnosis during the peri-transplantation period.

Ectopic pregnancy in left ovary and contralateral uterine tube diagnosed one week apart in In Vitro Fertilization with donor eggs: Case report

Bilateral ectopic pregnancy is a rare clinical condition with an estimated prevalence of 1/200 000 in spontaneous pregnancies. Studies have found that In Vitro Fertilization (IVF) is related to ectopic pregnancy independently, but the incidence of tubal disease in the donor egg recipient population is thought to be significantly lower than in the standard IVF population. We report the case of a patient participating in the egg-sharing program, who was diagnosed with ovarian ectopic pregnancy, treated with surgery. After one week, she was diagnosed with tubal ectopic pregnancy in the contralateral tube. The clinician should be aware that the treatment of one ectopic pregnancy does not preclude the occurrence of a second ectopic pregnancy in the same patient and should pay attention to the intra-operatory inspection of both side fallopian tubes in any ectopic pregnancy case. Routine ultrasound after ectopic pregnancy treatment may be reasonable, especially in high risk patients.

Reduced Ectopic Pregnancy Rate on Day 5 Embryo Transfer Compared with Day 3: A Meta-Analysis

OBJECTIVE

To compare the risk of ectopic pregnancy (EP) after embryo transfer on day 3(D3-ET) and day 5(D5-ET).

DESIGN

Meta-analysis.

PATIENTS

Women with pregnancy resulting from in vitro undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

RESULT(S)

Twenty-two studies were identified through research conducted using the PubMed, Embase, and Cochrane databases and ClinicalTrials.gov. All studies were conducted prior to October 2016. Adding the reproductive data from our center, a total of 143 643 pregnancies were reviewed(D3-ET: n = 62027,D5-ET:n = 81616). A lower EP rate was found in women undergoing D5-ET than in those undergoing D3-ET [relative risk (RR), 0.67;95% confidence interval (CI), 0.54-0.85;143643 pregnancies in 23 studies; I2 = 67%]. These results were validated in subgroups of fresh embryo-transfer (Fre-ET) cycles [RR, 0.78; 95%CI, 0.69-0.88; 91 871 pregnancies in 21 studies; I2 = 29%] and frozen-thawed embryo-transfer (Fro-ET) cycles [RR, 0.43; 95%CI, 0.36-0.51; 51 772 pregnancies in 10 studies; I2 = 33%]. After separating out the randomized controlled trials (RCTs), a significant difference was found in the retrospective studies in both subgroups [both Fre-ET (RR,0.78;95% CI 0.69-0.88);91182 pregnancies in 14 studies; I2 = 45%] and Fro-ET(RR,0.43;95% CI 0.36-0.51; 51751pregnancies in 9 studies;I2 = 33%)], while the RCTs showed no statistical significance for Fre-ET cycles[RR,0.86;95% CI 0.32-2.26); 689 pregnancies in 7 studies; I2 = 0%].

CONCLUSION(S)

The present study indicates that D5-ET reduces the risk for EP in cycles that use IVF or ICSI, compared with D3-ET. It suggests that D5-ET may be a better choice for decreasing the EP rate in assisted reproductive technology. Further high-quality randomized controlled trials are anticipated.

Ectopic pregnancy following in vitro fertilization: meta-analysis and single-center experience during 6 years

BACKGROUND

Ectopic pregnancy (EP) has been reported to occur in 1.4-5.4% of all clinical pregnancies resulting from in vitro fertilization (IVF) and embryo transfer (ET). Data on factors associated with abnormal embryo implantation following assisted conception are limited.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed to determine whether there is an association between the day (cleavage-stage, D3, versus blastocyst, D5) or the type (fresh versus frozen/thawed) of ET and EP rate. Risk factors for EP were evaluated in a retrospective study of 1194 women, who achieved pregnancy at our IVF unit between 2010 and 2016.

RESULTS

Sixteen papers were considered for the meta-analysis. EP rate did not differ between D3 and D5 fresh ET groups (RR = 0.99, 95%CI: 0.76-1.30) and was higher after fresh versus frozen ET (RR = 1.56, 95%CI: 1.25-1.95). At our clinic, 21 (1.76%) pregnancies were documented as ectopic. The risk of EP was associated with tubal pathology (OR = 3.37, 95%CI: 1.39-8.2), previous appendectomy and past chlamydial infection.

CONCLUSIONS

Present meta-analysis suggests that EP rate is similar following fresh blastocyst and cleavage ETs, but is significantly reduced after frozen compared with fresh ET. Our own findings demonstrate that tubal pathology has the major impact on EP occurrence following assisted conception.

Risk of ectopic pregnancy lowest with transfer of single frozen blastocyst

STUDY QUESTION

What type of transferred embryo is associated with a lower rate of ectopic pregnancy?

SUMMARY ANSWER

The lowest risk of ectopic pregnancy was associated with the transfer of blastocyst, frozen and single embryo compared with cleavage stage, fresh and multiple embryos.

WHAT IS KNOWN ALREADY

Ectopic pregnancy is a recognized complication following assisted reproductive technology (ART) treatment. It has been estimated that the rate of ectopic pregnancy is doubled in pregnancies following ART treatment compared with spontaneous pregnancies. However, it was not clear whether the excess rate of ectopic pregnancy following ART treatment is related to the underlying demographic factors of women undergoing ART treatment, the number of embryos transferred or the developmental stage of the embryo.

STUDY DESIGN, SIZE, DURATION

A population-based cohort study of pregnancies following autologous treatment cycles between January 2009 and December 2011 were obtained from the Australian and New Zealand Assisted Reproduction Technology Database (ANZARD). The ANZARD collects ART treatment information and clinical outcomes annually from all fertility centres in Australia and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between 2009 and 2011, a total of 44 102 pregnancies were included in the analysis. The rate of ectopic pregnancy was compared by demographic and ART treatment factors. Generalized linear regression of Poisson distribution was used to estimate the likelihood of ectopic pregnancy. Odds ratios, adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall rate of ectopic pregnancy was 1.4% for women following ART treatment in Australia and New Zealand. Pregnancies following single embryo transfers had 1.2% ectopic pregnancies, significantly lower than double embryo transfers (1.8%) (P < 0.01). The highest ectopic pregnancy rate was 1.9% for pregnancies from transfers of fresh cleavage embryo, followed by transfers of frozen cleavage embryo (1.7%), transfers of fresh blastocyst (1.3%), and transfers of frozen blastocyst (0.8%). Compared with fresh blastocyst transfer, the likelihood of ectopic pregnancy was 30% higher for fresh cleavage stage embryo transfers (AOR 1.30, 95% CI 1.07-1.59) and was consistent across subfertility groups. Transfer of frozen blastocyst was associated with a significantly decreased risk of ectopic pregnancy (AOR 0.70, 95% CI 0.54-0.91) compared with transfer of fresh blastocyst.

LIMITATIONS, REASON FOR CAUTION

A limitation of this population-based study is the lack of information available on clinical- specific protocols and processes for embryo transfer (i.e. embryo quality, cryopreservation protocol, transfer techniques, etc.) and the potential impact on outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The lowest risk of ectopic pregnancy was associated with the transfer of a single frozen blastocyst. This finding adds to the increasing evidence of better perinatal outcomes following frozen embryo transfers. The approach of freezing all embryos in the initiated fresh cycle and transfer of a single frozen blastocyst in the subsequent thaw cycle may improve the overall pregnancy and birth outcomes following ART treatment, in part by reducing the ectopic pregnancy rate.

STUDY FUNDING/COMPETING INTERESTS

There is no funding for this study. Authors declared no competing interest related to this study.

Misdiagnosis and delayed diagnosis for ectopic and heterotopic pregnancies after in vitro fertilization and embryo transfer

This study examined the misdiagnosis and delayed diagnosis factors for ectopic pregnancy (EP) and heterotopic pregnancy (HP) after in vitro fertilization and embryo transfer (IVF-ET) in an attempt to reduce the diagnostic error. Clinical data of patients who underwent IVF-ET treatment and had clinical pregnancy from 12463 cycles were retrospectively analyzed. Their findings of serum β-hCG test and transvaginal ultrasonography were also obtained during follow-up. These patients were divided into two groups according to the diagnosis accuracy of EP/HP: early diagnosis and misdiagnosis/delayed diagnosis. The results showed that the incidence of EP and HP was 3.8% (125/3286) and 0.8% (27/3286) respectively for IVF/ICSI-ET cycle, and 3.8% (55/1431) and 0.7% (10/1431) respectively for frozen- thawed embryo transfer (FET) cycle. Ruptured EP occurred in 28 patients due to initial misdiagnosis or delayed diagnosis. Related factors fell in 3 categories: (1) clinician factors: misunderstanding of patients' medical history, insufficient training in ultrasonography and unawareness of EP and HP; (2) patient factors: noncompliance with medical orders and lack of communication with clinicians; (3) complicated conditions of EP: atypical symptoms, delayed elevation of serum β-hCG level, early rupture of cornual EP, asymptomatic in early gestation and pregnancy of unknown location. All the factors were interwoven, contributing to the occurrence of EP and HP. It was concluded that complicated conditions are more likely to affect the diagnosis accuracy of EP/HP after IVF-ET. Transvaginal ultrasonography should be performed at 5 weeks of gestation. Intensive follow-up including repeated ultrasonography and serial serum β-hCG tests should be performed in patients with a suspicious diagnosis at admission.

Ectopic pregnancy in frozen-thawed embryo transfer: a retrospective analysis of 4,034 cycles and related factors

We analyzed the incidence of ectopic pregnancy in frozen-thawed embryo transfer (FET) as a function of natural and hormone replacement cycles and ectopic pregnancy-related factors. In this study, there were 4,034 FET cycles performed in our center between January 2005 and December 2010, and the rates of ectopic pregnancy were compared between natural and hormone replacement cycles. The analysis of ectopic pregnancy-related factors in FET was performed with 1:4 age-matched chi-square tests. The rate of ectopic pregnancy was lower in natural FET cycles (1.46%) than in hormone replacement FET cycles (3.31%) with a statistical significance (P < 0.05). Many factors were associated with ectopic pregnancy in FET, but only treatment protocols were considered as a controllable factor. We conclude that the incidence of ectopic pregnancy is significantly lower in natural FET cycles than in hormone replacement FET cycles. The application of exogenous sex hormones in assisted reproductive cycles may be an important factor to cause ectopic pregnancy in FET. This suggests that care should be taken when selecting the treatment protocol in order to avoid ectopic pregnancy.