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Updated: Jun 24, 2026

Surgical Techniques to Optimize Ovarian Reserve during Laparoscopic Cystectomy for Ovarian Endometrioma
Published on: January 22, 2022
A retrospective analysis of ovarian endometriosis during pregnancy
Yutaka Ueda1, Takayuki Enomoto, Takashi Miyatake
1Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
Objective:
To clarify the frequency of pregnancy complicated by ovarian endometriosis and to investigate the size change and outcome of ovarian endometriosis during pregnancy.
Design:
Retrospective study.
Setting:
Departments of obstetrics and gynecology of the Osaka University and Izumiotsu Municipal Hospitals of Osaka, Japan.
Patient(S):
Women who delivered between 1996 and 2007.
Intervention(S):
None.
Main Outcome Measure(S):
The frequency of pregnancies complicated by ovarian endometriosis and the size change of the lesions during pregnancy.
Result(S):
The frequency of ovarian endometriosis-complicated pregnancy has almost quadrupled over the last 12 years, to become the most common adnexal mass detected during pregnancy; it was 0.14% (five cases among 3558 deliveries) during the 6-year period from 1996 to 2001, but has increased to 0.52% (19 cases among 3599 deliveries) during the 6-year period from 2002 to 2007, a statistically significant increase of 3.8-fold. Among 25 ovarian endometriotic lesions observed during pregnancy in 24 women (one case had two lesions), the size of the cyst decreased in 13 lesions (52%), went unchanged in 7 (28%), and increased in 5 (20%), that demonstrated decidualization, abscess and rupture.
Conclusion(S):
Ovarian endometriosis during pregnancy can be safely observed conservatively; however, further investigation is required to predict the occurrence of abscess formation or rupture of ovarian endometriosis, and to distinguish the enlargements due to malignant transformation from those related to decidualization.
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