Risk of ectopic pregnancy following day-5 embryo transfer compared with day-3 transfer

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.

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.

The role of endometrial thickness in predicting ectopic pregnancy after in vitro fertilization and the establishment of a prediction model

OBJECTIVE

To explore the risk factors of ectopic pregnancy after in vitro fertilization.

METHODS

This retrospective cohort study was conducted at the Reproductive Medical Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to April 2020. Univariate and multivariate analysis were used to analyze the related factors affecting the occurrence of ectopic pregnancy (EP) and to construct a nomographic prediction model for the incidence of ectopic pregnancy.

RESULTS

A total of 12,766 cycles of 10109 patients were included, comprising 214 cases of EP and 12,552 cases of intrauterine pregnancy (IUP). Multivariate logistic regression analysis showed that the tubal factor was associated with a 2-fold increased risk for EP (aOR = 2.72, 95% CI: 1.69-4.39, P < 0.0001). A stratified analysis showed that women with an endometrial thickness (EMT) between 7.6 to 12.1mm (aOR = 0.57, 95%CI: 0.36-0.90, P = 0.0153) and >12.1mm (aOR = 0.42, 95%CI: 0.24-0.74, P = 0.0026) had a significant reduction of the risk of EP compared to women with an EMT of <7.6mm. Compared to cleavage stage transfer, blastocyst transfer can reduce the risk of ectopic pregnancy (aOR = 0.36, 95%CI: 0.26-0.50, P < 0.0001). The saturation model (full mode) establishes a nomographic prediction model with an AUC = 0.68 and a sensitivity and specificity of 0.67and 0.64, respectively. The nomination model was internally verified by self-sampling method (bootstrap sampling resampling times = 500). The resulting AUC = 0.68 (sensitivity: 0.65; specificity: 0.65) showed that the model was relatively stable.

CONCLUSIONS

Our findings indicate that EMT is inversely proportional to the risk of EP. Embryo stage, number of embryos transferred were also significantly associated with EP rate. A simple nomogram for the predicting the risk of EP was established in order to reduce the occurrence of EP.

Factors associated with the incidence of ectopic pregnancy in women undergoing assisted reproductive treatment

Background

Ectopic pregnancy (EP) is a common complication in women undergoing assisted reproductive treatment, but the underlying causes for this remain unclear. This study aimed to explore factors affecting the incidence of EP in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

Methods

This was a retrospective study on the incidence of EP in IVF/ICSI cycles between January 1, 2013 and December 31, 2017. Patient age, infertility diagnosis (tubal factor or not), primary or secondary infertility, type of cycle (frozen-thawed or fresh), type of embryo(s) transferred (cleavage embryo or blastocyst), number of embryos transferred (one, two, or three), previous history of EP, and endometrial combined thickness were analyzed to explore their relationships with the incidence of EP. Based on clinical typing results, the patients were divided into an EP group or a non-EP group. Categorical variables were analyzed using Chi-squared test or Fisher exact test. Logistic regression analysis was performed to explore their associations with the incidence of EP.

Results

The percentage of patients with primary infertility in EP group was significantly lower than that in non-EP group (31.3% vs. 46.7%, χ² = 26.032, P < 0.001). The percentage of patients with tubal infertility in EP group was also significantly higher than that in non-EP group (89.2% vs. 63.6%, χ² = 77.410, P < 0.001). The percentages of patients with transfer of cleavage-stage embryo or blastocyst (91.4% vs. 84.4%, χ² = 10.132, P = 0.001) and different endometrial combined thickness (ECT) (χ² = 18.373, P < 0.001) differed significantly between EP and non-EP groups. For patients who had a previous history of one to four EPs, the percentage of patients undergoing transfer of a cleavage-stage embryo was significantly higher in EP group than that in non-EP group (92.2% vs. 77.6%, χ² = 13.737, P < 0.001). In multivariate logistic regression analysis, tubal infertility was strongly associated with EP (adjusted odds ratio: 3.995, 95% confidence interval: 2.706–5.897, P < 0.001).

Conclusions

In IVF/ICSI cycles, transfer of a blastocyst-stage embryo, especially for patients with a previous history of EP, reduced the rate of EP. Tubal infertility was strongly associated with EP.

Spontaneous rupture of the uterus following salpingectomy: a case report and literature review

Laparoscopic salpingectomy (LPSC) is the main treatment for ectopic pregnancy, which leads to spontaneous uterine rupture (UR) during pregnancy. We report the characteristics of a woman who had spontaneous UR during pregnancy with a history of salpingectomy. We experienced a 31-year-old woman with a UR in pregnancy with a history of LPSC twice. The patient had a successful pregnancy. We also performed a literature review including cases with spontaneous UR after LPSC. Twenty-seven case reports of 48 women were included in our review. Thirty-five (83.33%, 35/42) women previously received LPSC and 15 (31.25%) developed interstitial pregnancies. The interval between pregnancy and the last surgery did not affect the frequency of interstitial pregnancy and gestational age. Fetal outcomes in patients with UR at the third trimester were better than those at the first and second trimesters. We suggest that close observation and timely treatment by experienced clinicians lead to good outcomes of pregnant women with suspected UR.

Frozen blastocyst transfer reduces incidence of ectopic pregnancy compared with fresh blastocyst transfer: a meta-analysis

BACKGROUND

Ectopic pregnancy (EP) is the main cause of maternal death during early pregnancy. Blastocyst transfer (BT) reduces EP rates compared with cleavage stage embryo transfer (ET), and frozen ET reduces EP rates compared with fresh ET. However, data comparing the EP rate of fresh BT and frozen BT are limited. The objective of this meta-analysis was to determine whether frozen BT decreases the EP rate compared with fresh BT.

MATERIALS AND METHODS

PUBMED, EMBASE, and Cochrane Library databases were searched for papers with no limitation on language and publication year. A systemic literature search identified 14 studies which met the inclusion criteria for further analysis. EP rate is our only outcome measure. All statistical analyses were carried out using RevMan software [version 5.3]. Random effects models were chosen to calculate the odds ratio (OR).

RESULTS

Fourteen retrospective studies (n = 251,762 cycles) were finally analyzed, including 154,214 and 97,548 cycles undergoing fresh and frozen BT, respectively. Compared with fresh BT, the frozen BT was associated with an decrease in EP rate [OR = 1.79; 95% confidence interval (CI) = 1.37-2.34, heterogeneity was 71%], the EP rate was 1.74% (2683/154,214 pregnancies) for fresh BT and 0.97% (949/97,548 pregnancies) for frozen BT. The number of embryos transferred in subgroup analysis found that the incidence of EP in frozen BT is lower than fresh BT (OR = 1.62; 95% CI = 1.38-1.91), the EP rate was 1.2% (206/16,610 pregnancies) for one fresh BT and 0.8% (153/19,569 pregnancies) for one frozen BT, also the EP rate was 1.9% (78/4043 pregnancies) for two fresh BT and 1.1% (19/1790 pregnancies) for two frozen BT.

CONCLUSIONS

Our meta-analysis found that frozen BT was associated with an decrease in EP rate compared with fresh BT in IVF/ICSI patients. We also found that a single frozen BT is the better choice as a method to reduce the incidence of EP.

MicroRNAs as Potential Serum Biomarkers for Early Detection of Ectopic Pregnancy

Diagnosis of ectopic pregnancy relies on both ultrasound findings and human chorionic gonadotropin (hCG) measurements but due to the need for serial tests, tubal rupture and death represent major maternal and fetal risks. Early detection of ectopic pregnancy is essential and thus a noninvasive diagnostic tool seems crucial for the prevention of adverse effects since studies suggest there is a specific relationship between ectopic pregnancy and increasing microRNA factors. Human fluids in women with ectopic pregnancy reveal a particular change in comparison to healthy women. In addition to certain placental microRNAs circulating through plasma that present a specific concentration and serum profile, microRNAs seem to be possible biomarkers for the detection of pregnancy complications linked to placental pathologies. The aim of this study is to review current literature considering the expression levels of several circulating microRNAs that have shown to be novel potential biomarkers for the diagnosis of tubal ectopic pregnancy.

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.

Ectopic pregnancy risk factors for ART patients undergoing the GnRH antagonist protocol: a retrospective study

BACKGROUND

In-vitro fertilization is a known risk factor for ectopic pregnancies. We sought to establish the risk factors for ectopic pregnancy in GnRH antagonist cycles examining patient and stimulation parameters with an emphasis on ovulation trigger.

METHODS

We conducted a retrospective, cohort study of 343 patients undergoing 380 assisted reproductive technology (ART) cycles with the GnRH antagonist protocol and achieving a clinical pregnancy from November 2010 through December 2015.

RESULTS

Significant risk factors for ectopic pregnancy in the univariate analysis included prior Cesarean section (CS), endometriosis, mechanical factor infertility, longer stimulation, elevated estradiol and progesterone levels, GnRH agonist trigger, higher number of oocytes aspirated, and insemination technique. Independent risk factors for ectopic pregnancy in the multivariate analysis included GnRH agonist trigger, higher number of oocytes aspirated, insemination technique, and prior Cesarean section.

CONCLUSION

Excessive ovarian response, IVF (as opposed to ICSI), prior Cesarean section and GnRH agonist trigger were found to be independent risk factors for ectopic pregnancy. Caution should be exercised before incorporating the GnRH agonist trigger for indications other than preventing OHSS. When excessive ovarian response leads to utilization of GnRH agonist trigger, strategies for preventing ectopic pregnancy, such as a freeze all policy or blastocyst transfer, should be considered. Further studies should elucidate whether adjusting the luteal support can reduce the ectopic pregnancy risk.

Risk factors for ectopic pregnancy in assisted reproductive technology: a 6-year, single-center study

OBJECTIVE

To explore factors affecting the incidence of ectopic pregnancy (EP) in assisted reproductive technology (ART).

DESIGN

A retrospective cohort study on the incidence of EPs in IVF/intracytoplasmic sperm injection (ICSI) and IUI cycles from June 2009 to August 2015. Age of patients, tubal factor infertility, type of cycle (fresh or thawed), embryo being transferred (cleavage embryo or blastocyst), and number of embryos transferred were analyzed to explore their relationship with the incidence of EP.

SETTING

Teaching hospital.

PATIENT(S)

A total of 18,432 pregnancies resulting from ART treatment were retrospectively analyzed.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Ectopic pregnancy rate.

RESULT(S)

For IVF/ICSI cycles, the incidence of EP was different between cycles transferred with cleavage embryo and blastocyst (3.45% vs. 2.47%). In multivariate logistic regression analysis, tubal infertility was associated with EP (adjusted odds ratio 1.716, 95% confidence interval 1.444-2.039). For IUI cycles, EP was significantly higher in stimulated cycles compared with natural cycles (2.62% vs. 0.99%). The EP rate in cycles with sperm from donor and husband was 1.08% and 3.54%, respectively. However, when patients were stratified according to tubal infertility, the EP rate increased with level of peak estrogen. In thawed embryo transfer cycles, the EP rate was lower in blastocyst transfer cycles and in cycles transferred with fewer embryos.

CONCLUSION(S)

Irrespective of tubal infertility, for fresh IVF/ICSI cycles the rate of EP is positively associated with ovarian stimulation; for thawed IVF/ICSI cycles, blastocyst transfer or transfer with fewer embryos reduces the EP rate. In IUI cycles, EP is associated with sperm source.

Heterotopic Pregnancy After In Vitro Fertilization and Embryo Transfer After Bilateral Total Salpingectomy/Tubal Ligation: Case Report and Literature Review

Heterotopic pregnancy is defined as the simultaneous occurrence of intrauterine and ectopic pregnancy, either of which may be single or multiple. It occurs in up to 1% of pregnancies after in vitro fertilization and embryo transfer. This article reports 2 rare cases of heterotopic pregnancy after in vitro fertilization and presents a literature review. In the first case, a 28-year-old woman had previous laparoscopic bilateral total salpingectomy for a right tubal pregnancy and a left hydrosalpinx. However, she had ovarian heterotopic pregnancy after a third in vitro fertilization cycle. Emergency laparotomy was performed. The synchronous intrauterine pregnancy continued with no further complications and ended in the delivery of a singleton term pregnancy. The second case combined interstitial and intrauterine pregnancies after bilateral tubal ligation for hydrosalpinges followed by in vitro fertilization and frozen embryo transfer. The possibility of heterotopic pregnancy after bilateral total salpingectomy/tubal ligation, although extremely rare, should also be considered by gynecologists when they treat an in vitro fertilization patient even though an intrauterine pregnancy has been confirmed.

Incidence, diagnosis and management of tubal and nontubal ectopic pregnancies: a review

BACKGROUND

Ectopic pregnancy is a potentially life-threatening condition occurring in 1-2 % of all pregnancies. The most common ectopic implantation site is the fallopian tube, though 10 % of ectopic pregnancies implant in the cervix, ovary, myometrium, interstitial portion of the fallopian tube, abdominal cavity or within a cesarean section scar.

FINDINGS

Diagnosis involves a combination of clinical symptoms, serology, and ultrasound. Medical management is a safe and effective option in most clinically stable patients. Patients who have failed medical management, are ineligible, or present with ruptured ectopic pregnancy or heterotopic pregnancy are most often managed with excision by laparoscopy or, less commonly, laparotomy. Management of nontubal ectopic pregnancies may involve medical or surgical treatment, or a combination, as dictated by ectopic pregnancy location and the patient's clinical stability. Following tubal ectopic pregnancy, the rate of subsequent intrauterine pregnancy is high and independent of treatment modality.

CONCLUSION

This review describes the incidence, risk factors, diagnosis, and management of tubal and non-tubal ectopic and heterotopic pregnancies, and reviews the existing data regarding recurrence and future fertility.

Risk of ectopic pregnancy is linked to endometrial thickness in a retrospective cohort study of 8120 assisted reproduction technology cycles

STUDY QUESTION

Is endometrial combined thickness (ECT) measured prior to embryo transfer (ET) associated with ectopic pregnancy (EP)?

SUMMARY ANSWER

Following IVF, the risk of EP is 4-fold increased in women with an ECT of <9 mm compared with women with an ECT of >12 mm.

WHAT IS KNOWN ALREADY

Known risk factors for EP include tubal damage, maternal cigarette smoking and endometriosis. EP is also more common following IVF but the underlying causes for this remain unclear.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study restricted to all IVF cycles leading to a pregnancy (βhCG > 50 IU/l) between January 2006 and December 2014. A total of 6465 patients achieved a pregnancy in 8120 cycles. Cycles using preimplantation genetic screening or donor oocytes were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This cohort consists of 6465 patients achieving a pregnancy in 6920 stimulated cycles with fresh embryo transfers (STIM ET) and 1200 hormone replacement therapy frozen embryo transfers (HRT-FET) cycles at a private IVF unit (Monash IVF, Melbourne, Australia). ECT was the primary independent variable of interest; the primary outcome was a diagnosis of EP. The dataset was analysed using binary logistic general estimating equations (SPSS v22.0) to calculate odds ratio (OR) for EP adjusted for known confounders (aOR). There was no loss to follow-up in the dataset.

MAIN RESULTS AND THE ROLE OF CHANCE

The study groups did not differ significantly prior to IVF treatment. After adjusting for confounders, ECT remained statistically significant as an independent risk factor for EP. Compared with women with an ECT of <9 mm, women with an ECT of 9-12 mm had an aOR of 0.44 (95% CI 0.29-0.69, P < 0.01) and women with an ECT > 12 mm had an aOR of 0.27 (95% CI 0.10-0.77, P = 0.01). These differences remained statistically significant after performing a sensitivity analysis excluding HRT-FET, smokers and patients with tubal infertility.

LIMITATIONS, REASONS FOR CAUTION

The study design is retrospective, and it is possible that not all confounders have been accounted for. Measurement of ECT was performed by highly trained sonographers, but some inconsistency between individuals may be present.

WIDER IMPLICATIONS OF THE FINDINGS

Our group has previously demonstrated an increased risk of placenta praevia with increased ECT. These new findings suggest that the directionality of the uterine peristalsis waves matters more than their frequency or amplitude. Combining the data from both studies we now hypothesize that increased ECT is a marker for increased fundus-to-cervix uterine peristalsis, explaining both the increased placenta praevia risk and the lower EP risk. Further prospective studies are required to confirm these observations.

Ectopic pregnancy secondary to in vitro fertilisation-embryo transfer: pathogenic mechanisms and management strategies

BACKGROUND

Ectopic pregnancy (EP) is the leading cause of maternal morbidity and mortality during the first trimester and the incidence increases dramatically with in vitro fertilisation and embryo transfer (IVF-ET). The co-existence of an EP with a viable intrauterine pregnancy (IUP) is known as heterotopic pregnancy (HP) affecting about 1% of patients during assisted conception. EP/HP can cause significant morbidity and occasional mortality and represent diagnostic and therapeutic challenges, particularly during fertility treatment. Many risk factors related to IVF-ET techniques and the cause of infertility have been documented. The combination of transvaginal ultrasound (TVS) and serum human chorionic gonadotrophin (hCG) is the most reliable diagnostic tool, with early diagnosis of EP/HP permitting conservative management. This review describes the risk factors, diagnostic modalities and treatment approaches of EP/HP during IVF-ET and also their impact on subsequent fertility treatment.

METHODS

The scientific literature was searched for studies investigating EP/HP during IVF-ET. Publications in English and within the past 6 years were mostly selected.

RESULTS

A history of tubal infertility, pelvic inflammatory disease and specific aspects of embryo transfer technique are the most significant risk factors for later EP. Early measurement of serum hCG and performance of TVS by an expert operator as early as gestational week 5 can identify cases of possible EP. These women should be closely monitored with repeated ultrasound and hCG measurement until a diagnosis is reached. Treatment must be customised to the clinical condition and future fertility requirements of the patient. In cases of HP, the viable IUP can be preserved in the majority of cases but requires early detection of HP. No apparent negative impact of the different treatment approaches for EP/HP on subsequent IVF-ET, except for risk of recurrence.

CONCLUSIONS

EP/HP are tragic events in a couple's reproductive life, and the earlier the diagnosis the better the prognosis. Due to the increase incidence following IVF-ET, there is a compelling need to develop a diagnostic biomarker/algorithm that can predict pregnancy outcome with high sensitivity and specificity before IVF-ET to prevent and/or properly manage those who are at higher risk of EP/HP.

Risk factors for ectopic pregnancy in women with planned pregnancy: a case-control study

OBJECTIVE

To explore the risk factors for ectopic pregnancy (EP) in women with planned pregnancy.

STUDY DESIGN

This case-control study was conducted in women with planned pregnancy and included 900 women diagnosed with EP (case group) and 889 women with intrauterine pregnancy (IUP) as the control group matched in terms of age and gestational week. Socio-demographic characteristics, reproductive history, gynecological and surgical history, previous contraceptive use, and history of infertility were compared between the two groups. Blood samples were collected from all the participants to detect serum chlamydia trachomatis (CT) IgG antibody. The odds ratio (OR) with its 95% confidential interval (CI) of each variable was calculated by univariable conditional logistic regression analysis. Factors significantly different between both groups, as revealed by univariable analysis, were entered into a multivariable logistic regression model by stepwise selection.

RESULTS

The risk of EP was associated with previous adnexal surgery (adjusted OR=3.99, 95% CI: 2.40-6.63), uncertainty of previous pelvic inflammatory disease (adjusted OR=6.89, 95% CI: 3.29-14.41), and positive CT IgG serology (adjusted OR=5.26, 95% CI: 3.94-7.04). A history of infertility including tubal infertility (adjusted OR=3.62, 95% CI: 1.52-8.63), non-tubal infertility (adjusted OR=3.34, 95% CI: 1.60-6.93), and in vitro fertilization (IVF) treatment (adjusted OR=5.96, 95% CI: 1.68-21.21) were correlated with the risk of EP. Women who had previously used condoms were less likely to have EP during the current cycle (adjusted OR=0.27, 95% CI: 0.21-0.36).

CONCLUSIONS

Besides well-acknowledged risk factors for EP, attention should be paid to women with planned pregnancy who have a history of infertility and/or IVF treatment, to prevent complications from EP.

MicroRNA and implantation

We provide a review of microRNA (miRNA) related to human implantation which shows the potential diagnostic role of miRNAs in impaired endometrial receptivity, altered embryo development, implantation failure after assisted reproduction technology, and in ectopic pregnancy and pregnancies of unknown location. MicroRNAs may be emerging diagnostic markers and potential therapeutic tools for understanding implantation disorders. However, further research is needed before miRNAs can be used in clinical practice for identifying and treating implantation failure.