Ectopic Pregnancy Outcomes in Assisted Reproductive Technologies

Ectopic pregnancy following assisted reproductive technologies remains a leading cause of early gestational morbidity and can compromise subsequent fertility. While ART offers opportunities for individuals with infertility, it also modifies factors influencing embryo transport and implantation. The overall incidence of ectopic pregnancy after in vitro fertilisation and embryo transfer ranges between 1 % and 5 %, reflecting both patient-related and procedure-related risk factors. Predisposing conditions such as tubal pathology, prior pelvic surgery or infection, and abnormal endometrial receptivity interact with technical aspects of ART—such as stage and method of embryo transfer, ovarian response and luteal support—to determine implantation site. Blastocyst transfers and frozen–thawed cycles have been explored as strategies to reduce risk, while nomograms incorporating clinical and ultrasound parameters are emerging to predict individual risk. Early diagnosis through serial β-hCG monitoring and transvaginal ultrasound permits conservative management and preserves future fertility. Recent advances have focused on refining risk stratification, improving transfer protocols and elucidating mechanisms underlying aberrant embryo transport.

Research from Nature Portfolio

A large retrospective analysis of over 27 000 ART cycles reported an ectopic pregnancy incidence of 1.8 %, similar to natural conception rates. In fresh embryo transfers, prior pelvic adhesions conferred the greatest risk, while increasing maternal age, higher basal follicle-stimulating hormone levels, procedural difficulties at transfer and use of blastocyst-stage embryos also influenced outcomes. In frozen–thawed cycles, anti-Müllerian hormone concentration emerged as the sole independent predictor. These findings underscore the persistence of patient-specific risk factors in ART and highlight the need for tailored transfer strategies according to ovarian reserve and uterine environment.

Ectopic Pregnancy Outcomes in Assisted Reproductive Technologies publication trend

The graph below shows the total number of articles in ectopic pregnancy outcomes in assisted reproductive technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Ectopic pregnancy: implantation of the embryo outside the uterine cavity, most commonly in the fallopian tube, with potential for serious maternal morbidity.

Assisted reproductive technologies (ART): medical procedures such as in vitro fertilisation and embryo transfer used to achieve pregnancy in cases of infertility.

Embryo transfer (ET): the process in ART by which one or more embryos are deposited into the uterus or fallopian tube under ultrasound guidance.

Blastocyst: an embryo at day five to six of development characterised by a fluid-filled cavity and distinct cell lineages, offering improved synchrony with endometrial receptivity.

Endometrial thickness (EMT): ultrasound measurement of the uterine lining, serving as a proxy for implantation potential during ART cycles.

References

1. Ectopic pregnancy secondary to in vitro fertilisation-embryo transfer: pathogenic mechanisms and management strategies. Reproductive Biology and Endocrinology (2015).
2. Reduced Ectopic Pregnancy Rate on Day 5 Embryo Transfer Compared with Day 3: A Meta-Analysis. PLOS ONE (2017).
3. Ectopic pregnancy risk factors in infertile patients: a 10-year single center experience. Scientific Reports (2022).
4. Body mass index impacts ectopic pregnancy during in vitro fertilization: an analysis of 42,362 clinical pregnancy cycles. Reproductive Biology and Endocrinology (2023).
5. Establishment of a prediction model for the impact of endometrial thickness on the day of embryo transfer on ectopic pregnancy in frozen-thawed embryo transfer cycle. Frontiers in Endocrinology (2023).