An ectopic pregnancy occurs when a fertilized egg implants outside the uterine cavity, most commonly in the fallopian tube.
Several factors contribute to this abnormal implantation, including:
- Tubal Pathology
Damage or dysfunction of the fallopian tubes due to infections such as pelvic inflammatory disease (PID), sexually transmitted infections (e.g., chlamydia, gonorrhea), previous surgeries, adhesions, or endometriosis can impair the normal transport of the fertilized egg to the uterus, increasing the risk of ectopic implantation. - Poor Embryo Quality
While less common as a direct cause, embryos with abnormal development or poor quality may have altered implantation capabilities, sometimes leading to ectopic pregnancy, especially in assisted reproductive technologies like IVF. - Uterine Pathologies
Conditions like adenomyosis (where endometrial tissue exists within the uterine muscle) and persistently thin endometrium can create an inhospitable environment for implantation inside the uterus. This may increase the likelihood that the embryo implants outside the uterus.
Additional Risk Factors
- Previous ectopic pregnancy (increases recurrence risk)
- History of tubal surgery or ligation
- Use of intrauterine devices (IUDs)
- Assisted reproductive technology (ART) treatments like IVF
- Smoking (affects tubal motility and ciliary function)
- Advanced maternal age
- Congenital tubal anomalies
Conclusion
Ectopic pregnancy mainly results from tubal pathology that disrupts normal embryo transportation, but poor embryo quality and uterine abnormalities such as adenomyosis and a thin endometrium can also be contributing factors. Recognizing these causes helps in prevention, diagnosis, and management of this potentially life-threatening condition.