The progression of rapidly growing teratomas in pregnancy may be influenced by hormonal and genetic factors. The current report is about a unique case involving a mature teratoma with rapid growth characteristics, yet it did not lead to any complications throughout pregnancy of a primigravida. The benign mature teratoma was identified via antenatal ultrasound during the first trimester. In this case, the patient experienced no adverse effects, and the size of the ovarian teratoma showed a gradual increasing trend during pregnancy without resulting in any complications. In summary, mature teratoma is a benign tumor with a good prognosis, and if fetal distress is detected, cesarean section should be recommended.

1. Peterson WF. Malignant degeneration of benign cystic teratomas of the overy; A collective review of the literature. Obstet Gynecol Surv. 1957;12(6):793-830. doi: 10.1097/00006254-195712000-00001

2. Pantoja E, Noy MA, Axtmayer RW, Colon FE, Pelegrina I. Ovarian dermoids and their complications. Comprehensive historical review. Obstet Gynecol Surv. 1975;30(1):1-20. doi: 10.1097/00006254-197501000-00001

3. Westhoff C, Pike M, Vessey M. Benign ovarian teratomas: A population-based case-control study. Br J Cancer. 1988;58(1):93-98. doi: 10.1038/bjc.1988.171

4. Joudar I, El Abbassi I, Khalloufi C, Jalal M, Lamrissi A, Bouhya S. Mature teratoma during pregnancy: A case report. J Case Rep Images Obstet Gynecol. 2023;9(1):70-74. doi: 10.5348/100150Z08IJ2023CR

5. Ueda Y, Sekiyama K, Ito M, Egawa H, Tokushige M, Takakura K. Displacement of ovarian mature cystic teratoma following rupture during pregnancy: Case report. Japanese J Gynecol Obstet Endosc. 2013;29(1):84-87.

6. Sheng Y, Yuan J, Wang J, Wang L, Li Y, Wang Y. Ovarian mature cystic teratoma is an independent risk factor for the premature rupture of membranes in pregnancy: A single-center retrospective study. Int J Womens Health. 2022;14:1477-1487. doi: 10.2147/IJWH.S381297

7. Osto M, Brooks A, Khan A. Ovarian cystic teratoma in pregnant women: Conservative management or prophylactic oophorectomy? Cureus. 2021;13(8):e17354. doi: 10.7759/cureus.17354

8. Ahmed A, Lotfollahzadeh S. Cystic teratoma. In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK564325 [Last accessed on 2023 Jun 03].

9. Bouzoubaa W, Jayi S, Alaoui FZF, Chaara H, Melhouf MA. Immature teratoma of the ovary: About a case. Pan Afr Med J. 2017;27:263. doi: 10.11604/pamj.2017.27.263.6400

10. Chenana A, Kouach J, Moussaoui D, Dehayni M. Tératome immature de l’ovaire et grossesse: A propos d’un cas/ [Immature teratoma of the ovary and pregnancy: A case report]. Int J Innov Appl Stud. 2016;15(3):503-514.

11. Tan KH, Chen KC, Wang TL, Chong CF, Chen CC. Ovarian cystic teratoma torsion in pregnancy. Emerg Med J. 2010;27:879-880. doi: 10.1136/emj.2008.063883

12. Tariel O, Huissoud C, Rudigoz RC, Dubernard G. Presumed benign ovarian tumors during pregnancy. J Gynecol Obstet Biol Reprod (Paris). 2013;42(8):842-855. doi: 10.1016/j.jgyn.2013.09.038

13. Walid MS, Boddy MG. Bilateral dermoid cysts of the ovary in a pregnant woman: Case report and review of the literature. Arch Gynecol Obstet. 2009;279:105-108. doi: 10.1007/s00404-008-0695-3

14. Haddada S, Selleret L, Fedida B, et al. Adnexal masses and pregnancy: Which diagnosis and which imaging? Imagerie Femme. 2017;27(2):104-110.

15. Srisajjakul S, Prapaisilp P, Bangchokdee S. Imaging features of unusual lesions and complications associated with ovarian mature cystic teratoma. Clin Imaging. 2019;57:115-123. doi: 10.1016/j.clinimag.2019.05.013

16. Sahin H, Abdullazade S, Sanci M. Mature cystic teratoma of the ovary: A cutting edge overview on imaging features. Insights Imaging. 2017;8(2):227-241. doi: 10.1007/s13244-016-0539-9

17. Nguyen HT, Trinh NB, Tran NH, Nguyen PN. Massive mature cystic teratoma presenting as ovarian cancer grade IIIC in a young Vietnamese woman: A case report. Oman Med J. 2025;40:1-8. doi: 10.5001/omj.2028.17

18. Cong L, Wang S, Yeung SY, Lee JH, Chung JP, Chan DY. Mature cystic teratoma: An integrated review. Int J Mol Sci. 2023;24(7):6141. doi: 10.3390/ijms24076141

19. Aggarwal P, Kehoe S. Ovarian tumours in pregnancy: A literature review. Eur J Obstet Gynecol Reprod Biol. 2011;155(2):119-124. doi: 10.1016/j.ejogrb.2010.11.023

20. Cohen-Herriou K, Semal-Michel S, Lucot JP, Poncelet E, Rubod C. Management of ovarian cysts during pregnancy: Lille’s experience and literature review. Gynecol Obstet Fertil. 2013;41(1):67-72. doi: 10.1016/j.gyobfe.2012.12.001

21. Chen LH, Chang SD, Huang HY, Wang HS, Soong YK, Wu HM. Repeated pregnancy with concomitant presence of ovarian teratoma: A case report and literature review. Taiwan J Obstet Gynecol. 2017;56(5):694-696. doi: 10.1016/j.tjog.2017.08.021

22. Schreck AM, Mikdachi HF. Benign ovarian tumors in pregnancy: A case report of metachronous ipsilateral recurrent mucinous cystadenoma in initial pregnancy and mature cystic teratoma in subsequent pregnancy. Cureus. 2019;11(1):e3818. doi: 10.7759/cureus.3818

23. Gbary-Lagaud E, Effoh D, Ehui A, Koffi S, Houphouet- Mwandji C, Adjoby R. Mature ovarian teratoma and pregnancy about a case in Abidjan Cote d’Ivoire. J Gynecol Obstet. 2020;8(4):117-121. doi: 10.11648/j.jgo.20200804.19

24. Spasimir TS. А collision tumor of the ovary during pregnancy-rare combination. J Med Clin Res Rev. 2019;3(6):1-3.