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Review
. 2017 Aug;13(2):27-33.
doi: 10.1177/1745505717709677. Epub 2017 Jun 29.

Factors to consider in pregnancy of unknown location

Shabnam Bobdiwala  1 , Maya Al-Memar  1 , Jessica Farren  1 , Tom Bourne  1   2   3
Affiliations
Review

Factors to consider in pregnancy of unknown location

Shabnam Bobdiwala et al. Womens Health (Lond). 2017 Aug.

Abstract

The management of women with a pregnancy of unknown location (PUL) can vary significantly and often lacks a clear evidence base. Intensive follow-up is usually required for women with a final outcome of an ectopic pregnancy. This, however, only accounts for a small proportion of women with a pregnancy of unknown PUL location. There remains a clear clinical need to rationalize the follow-up of PUL so women at high risk of having a final outcome of an ectopic pregnancy are followed up more intensively and those PUL at low risk of having an ectopic pregnancy have their follow-up streamlined. This review covers the main management strategies published in the current literature and aims to give clinicians an overview of the most up-to-date evidence that they can take away into their everyday clinical practice when caring for women with a PUL.

Keywords: ectopic pregnancy; human chorionic gonadotropin; pregnancy; pregnancy of unknown location; progesterone; risk prediction models.

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Conflict of interest statement

Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Figures

Figure 1.
Figure 1.
Schematic for PUL classification at the initial transvaginal ultrasound scan.
Figure 2.
Figure 2.
Schematic for PUL classification to define the final outcome.
Figure 3.
Figure 3.
hCG ratio cut-off values and the likely final outcomes with a PUL. hCG: human chorionic gonadotropin; PUL: pregnancy of unknown location; IUP: intrauterine pregnancy.
Figure 4.
Figure 4.
Flowchart of final outcome data and correct versus incorrect risk stratification by the M4 model. Source: Taken from Bobdiwala et al. hCG: human chorionic gonadotropin; FPUL: failed pregnancy of unknown location; IUP: intrauterine pregnancy; EP: ectopic pregnancy.
Figure 5.
Figure 5.
Flow diagram of the two-step approach for managing PUL. Source: Taken from Van Calster et al. hCG: human chorionic gonadotropin; UPT: urine pregnancy test; PUL: pregnancy of unknown location.
See this image and copyright information in PMC

References

    1. NICE guidelines [CG154]. Ectopic pregnancy and miscarriage: diagnosis and initial management in early pregnancy of ectopic pregnancy and miscarriage. 2012, https://www.ncbi.nlm.nih.gov/pubmed/23638497 - PubMed
    1. Abdallah Y, Daemen A, Kirk E, et al. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown-rump length measurements: a multicenter observational study. Ultrasound Obstet Gynecol 2011; 38(5): 497–502. - PubMed
    1. Condous G, Okaro E, Bourne T. The conservative management of early pregnancy complications: a review of the literature. Ultrasound Obstet Gynecol 2003; 22: 420–430. - PubMed
    1. Condous G, Okaro E, Khalid A, et al. The accuracy of transvaginal ultrasonography for the diagnosis of ectopic pregnancy prior to surgery. Hum Reprod 2005; 20: 1404–1409. - PubMed
    1. Van Calster B, Abdallah Y, Guha S, et al. Rationalizing the management of pregnancies of unknown location: temporal and external validation of a risk prediction model on 1962 pregnancies. Hum Reprod 2013; 28(3): 609–616. - PubMed

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