Atypical course of a caesarean scar pregnancy

The 36-year old patient presented first with a caesarean scar pregnancy (vital) at 7 weeks of gestation

The 36-year old patient presented first with a caesarean scar pregnancy (vital) at 7 weeks of gestation. In her medical history, she had 2 miscarriages (10/21 and 12/21) without curettage and a caesarean section (Misgav-Ladach) in 2019. Ultrasound revealed a vital pregnancy in the caesarean scar while large parts of the trophoblast have grown into it reaching up to the serosa (β-HCGlevel: 26873U/l). Due to the risk of bleeding, a therapy with methotrexate was initiated and was administered intravenously, mifepristone was applied orally once [1]. The sonographic check-up (9th gestational week) detected a non-vital pregnancy with a chorionic cavity of 2.8 cm. Three weeks later and after application of methotrexate (2 courses) the sonographic check-up revealed the embryonic structures in regression and a decreasing perfusion by Doppler sonography. At the same time, a discrete progression of the chorionic cavity was noted (size: 3.4 × 3.2 × 2.3 cm), while the β-HCGlevel dropped to 2348U/l. Another 2 weeks later, the ultrasound check-up detected no more embryonic structures, a significantly reduced blood flow and a thinned trophoblast ring. β-HCGlevel dropped down (429U/l). Despite the serologically and sonographically visible reduction in vital tissue, the chorionic cavity increases in volume at the isthmo-cervical junction with a size of 4 × 3 × 3 cm. At 16th gestational week and after a total of three courses of methotrexate (i.v.), no further progression of the cystic structure was detected in the ultrasound check-up (β-HCG level: 116U/l) (Fig. 1a) [2]. Due to the progression of the cystic structure despite methotrexate administration, a curettage with simultaneous laparoscopic control was scheduled [3,4]. The isthmo-cervical lesion was confirmed laparoscopically (Fig. 1b) [5]. Due to the increased risk of bleeding, the lesion was removed by laparotomy ( Fig. 1c and d) followed by uterine reconstruction (blood loss: 400 ml) [6]. The histology report revealed diagnosis. The patient was discharged home a few days later with no complaints (Fig. 1).
Author contribution KS: data analysis, manuscript writing/editing and data collection or management; SK: data analysis and data collection or management; BK: data analysis, manuscript writing/editing and data collection or management; MH: data analysis and data collection or management and CB: data analysis, manuscript writing/editing and data collection or management Funding Open Access funding enabled and organized by Projekt DEAL.

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Competing interests "The authors have no relevant financial or nonfinancial interests to disclose." None of the authors has a conflict of interest to declare.

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The authors affirm that human research participants provided informed consent for publication of the images in Fig. 1a-d." Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/. Fig. 1 a Transvaginal ultrasound image of caesarean scar pregnancy with a cystic structure of 4 × 3 × 3 cm of a nonvital pregnancy at 15th week of gestation. Anatomic structures are labelled. b By laparoscopy: detection of the cystic structure sized 4 × 3 × 3 cm at the isthmocervical junction. c Situs of open surgery with demonstration of the above mentioned cystic structure at the isthmocervical junction. d Uterine reconstruction after removing the lesion