Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 May;41(S 01):e1445-e1450.
doi: 10.1055/a-2040-1458. Epub 2023 Feb 21.

The Cesarean Scar of Pregnancy: Ultrasound Findings and Expectant Management Outcomes

Catherine Y Spong  1   2 , Casey S Yule  1   2 , Elaine T Fleming  1   2 , Ashlyn K Lafferty  1 , Donald D McIntire  1 , Diane M Twickler  1   3
Affiliations

The Cesarean Scar of Pregnancy: Ultrasound Findings and Expectant Management Outcomes

Catherine Y Spong et al. Am J Perinatol. 2024 May.

Abstract

Objective: The nomenclature has evolved from low implantation to cesarean scar pregnancy (CSP) and criteria are recommended for identification and management. Management guidelines include pregnancy termination due to life-threatening complications. This article applies ultrasound (US) parameters recommended by the Society for Maternal Fetal Medicine (SMFM) in women who were expectantly managed.

Study design: Pregnancies were identified between March 1, 2013 and December 31, 2020. Inclusion criteria were women with CSP or low implantation identified on US. Studies were reviewed for niche, smallest myometrial thickness (SMT), and location of basalis blinded to clinical data. Clinical outcomes, pregnancy outcome, need for intervention, hysterectomy, transfusion, pathologic findings, and morbidities were obtained by chart review.

Results: Of 101 pregnancies with low implantation, 43 met the SMFM criteria at < 10 weeks and 28 at 10 to 14 weeks. At < 10 weeks, SMFM criteria identified 45out of 76 women; of these 13 required hysterectomy; there were 6 who required hysterectomy but did not meet the SMFM criteria. At 10 to < 14 weeks, SMFM criteria identified 28 out of 42 women; of these 15 required hysterectomy. US parameters yielded significant differences in women requiring hysterectomy, at < 10 weeks and 10 to < 14 weeks' gestational age epochs, but the sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of these US parameters have limitations in identifying invasion to determine management. Of the 101 pregnancies, 46 (46%) failed < 20 weeks, 16 (35%) required medical/surgical management including 6 hysterectomies, and 30 (65%) required no intervention. There were 55 pregnancies (55%) that progressed beyond 20 weeks. Of these, 16 required hysterectomy (29%) while 39 (71%) did not. In the overall cohort of 101, 22 (21.8%) required hysterectomy and an additional16 (15.8%) required some type of intervention, while 66.7% required no intervention.

Conclusion: SMFM US criteria for CSP have limitations for discerning clinical management due to lack of discriminatory threshold.

Key points: · The SMFM US criteria for CSP at <10 or <14 weeks have limitations for clinical management.. · The sensitivity and specificity of the ultrasound findings limit the utility for management. · The SMT of <1 mm is more discriminating than <3 mm for hysterectomy..

PubMed Disclaimer

Conflict of interest statement

None declared.

Figures

Fig. 1
Fig. 1
G4 P3 with 3 previous cesarean deliveries who underwent cesarean hysterectomy with confirmed placenta percreta. ( A ) At 7 3/7 weeks, the niche is present (yellow arrow) with the smallest myometrial thickness of < 1 mm. ( B ) At 12 4/7 weeks, a niche is no longer present, with the smallest myometrial thickness of < 1 mm (yellow arrow). Also seen are placental lacunae and (blue arrows) and bladder flap varices (white arrows).
Fig. 2
Fig. 2
Summary of findings in women with suspected cesarean scar pregnancy (CSP).
Fig. 3
Fig. 3
Prediction parameters of the Society for Maternal Fetal Medicine (SMFM) criteria at ( A ) less than 10 weeks and ( B ) 10 to 14 weeks.
See this image and copyright information in PMC

References

    1. Society for Maternal-Fetal Medicine (SMFM). Electronic address: pubs@smfm.org . Miller R, Timor-Tritsch I E, Gyamfi-Bannerman C. Society for Maternal-Fetal Medicine (SMFM) Consult Series #49: cesarean scar pregnancy. Am J Obstet Gynecol. 2020;222(05):B2–B14. - PubMed
    1. Riaz R M, Williams T R, Craig B M, Myers D T. Cesarean scar ectopic pregnancy: imaging features, current treatment options, and clinical outcomes. Abdom Imaging. 2015;40(07):2589–2599. - PubMed
    1. Rotas M A, Haberman S, Levgur M. Cesarean scar ectopic pregnancies: etiology, diagnosis, and management. Obstet Gynecol. 2006;107(06):1373–1381. - PubMed
    1. Maymon R, Halperin R, Mendlovic S et al.Ectopic pregnancies in Caesarean section scars: the 8 year experience of one medical centre. Hum Reprod. 2004;19(02):278–284. - PubMed
    1. Sadeghi H, Rutherford T, Rackow B W et al.Cesarean scar ectopic pregnancy: case series and review of the literature. Am J Perinatol. 2010;27(02):111–120. - PubMed