Ovarian Pregnancy Rate Drops Over Five Decades

A retrospective study published in the Archives of Gynecology and Obstetrics reports that the rate of ovarian pregnancy per delivery decreased significantly over a five-decade period at a single tertiary care center. The research team analyzed medical records from 1971 to 2025 to examine long-term trends in this rare form of ectopic pregnancy. Despite advancements in diagnostic imaging, the study found that preoperative diagnosis remains uncommon in routine emergency settings. The findings highlight a complex interplay between rising overall ectopic pregnancy rates and a specific decline in ovarian implantation frequency.

The study conducted a retrospective review of 59 women diagnosed with primary ovarian pregnancy who were treated at the medical center between 1971 and 2025. The researchers categorized these cases into four distinct time periods to assess temporal trends: 1971–1989, 1990–2001, 2002–2013, and 2014–2025. The sample sizes for these periods were 20, 19, 7, and 13 cases, respectively. This long-term observational design allowed the investigators to track changes in clinical features and surgical outcomes across different eras of medical practice.

During the study period, the center recorded a total of 317,015 deliveries. Among these, 4,357 ectopic pregnancies were diagnosed, representing an overall rate of 1.4%. Of the ectopic pregnancies, 59 were identified as ovarian pregnancies, accounting for 1.4% of all ectopic cases. The data revealed a divergent trend: while the overall ectopic pregnancy rate increased across the study periods, the specific rate of ovarian pregnancy per delivery decreased. Poisson regression analysis confirmed a statistically significant temporal increase in the overall ectopic pregnancy rate with a p-value of less than 0.001.

Conversely, the analysis demonstrated a significant temporal decrease in the ovarian pregnancy rate per delivery, with a p-value of 0.007. This decline suggests that ovarian implantation has become less frequent relative to total deliveries, even as the broader category of ectopic pregnancies has expanded. The study also examined the use of intrauterine devices (IUDs) among the patients. IUD use showed a significant decreasing trend over the five decades, dropping from 90% in the earliest period to 15.4% in the final period, as indicated by a Cochran–Armitage test with a p-value of less than 0.001.

Diagnostic capabilities remained a challenge throughout the study period. Preoperative ultrasound diagnosis of ovarian pregnancy was uncommon, occurring in only two of the 13 cases in the final period (2014–2025), which represents a 15.4% detection rate. However, the study observed an increasing trend in preoperative ultrasound diagnosis over time, with a Cochran–Armitage test p-value of 0.024. This suggests that while absolute numbers remain low, the likelihood of detecting ovarian pregnancy before surgery has improved slightly with modern imaging techniques.

Clinical outcomes varied across the study periods, particularly regarding hemodynamic stability. Hemodynamic shock differed significantly across the four time periods, with a p-value of 0.003. However, no significant monotonic temporal trend was observed in the incidence of shock, as determined by a Cochran–Armitage test with a p-value of 0.515. This indicates that while the occurrence of shock fluctuated over the decades, it did not follow a consistent upward or downward trajectory. The variability in hemodynamic instability highlights the unpredictable nature of ovarian pregnancy complications, even as surgical techniques have evolved.

Surgical management improvements were associated with better postoperative outcomes. Over the five decades, the study noted reduced blood transfusion requirements and shorter hospitalization lengths. These improvements suggest that advances in surgical techniques and perioperative care have contributed to more efficient management of ovarian pregnancy.

Long-term fertility outcomes were also assessed using updated institutional medical records and telephone contacts where possible. Among the 37 women who attempted conception after their ovarian pregnancy, 27 (72.9%) achieved spontaneous intrauterine pregnancy. This high rate of subsequent fertility indicates that ovarian pregnancy does not necessarily preclude future successful pregnancies.

The study concludes that despite advances in imaging, preoperative diagnosis of ovarian pregnancy remains uncommon in emergency settings. Increased awareness of characteristic ultrasound findings and timely surgical management may improve clinical outcomes and reduce severe hemorrhagic complications. The five-decade experience from this single medical center provides valuable insights into the changing landscape of ovarian pregnancy, highlighting both the challenges in diagnosis and the improvements in surgical care.

Subject of Research: Five-decade trends in ovarian pregnancy incidence and outcomes

Article Title: Time trends in ovarian pregnancy: a 5-decade experience from a single medical center

Article References: Melcer, Y., Maymon, R., Levin, A., Naor-Dovev, M., Smorgick, N., & Pekar-Zlotin, M. (2026). Time trends in ovarian pregnancy: a 5-decade experience from a single medical center. Archives of Gynecology and Obstetrics, 313(1), Article 305. https://doi.org/10.1007/s00404-026-08556-3

Image Credits: AI Generated

DOI: 10.1007/s00404-026-08556-3

Keywords: ovarian pregnancy, ectopic pregnancy, retrospective study, gynecology, surgical outcomes, diagnostic trends, fertility outcomes, medical history, Time, trends, ovarian, pregnancy