Cervical ectopic pregnancy is rare. Cervical implantation is a serious obstetric condition that can lead to mutilation if not promptly diagnosed and treated. The clinical diagnosis consists in physical examination, ballooned cervical canal, dilated cervix, and hourglass-shaped uterus detected by internal examination. Ultrasonography confirms the diagnosis by visually detecting cervical implantation below the internal orifice. Magnetic resonance imaging and three-dimensional ultrasonography validates the diagnosis. Conservative treatment proposed: cerclage, vasopressin, Foley catheter with hemostatic cervical ligation, cervical canal balloon, embolization of uterine artery, hysteroscopy, laparoscopic ligation of the uterine artery, and curettage by suction catheter. Shortcomings of conservative management are high, and a number of cases result in hysterectomy. Drug management is a therapeutic option to avoid mutilating surgery, and the most commonly used is systemic methotrexate (MTX). Local treatment with MTX and potassium chloride injection guided by transvaginal ultrasound is used when the embryo is alive.
Ectopic pregnancy (EP) is a pregnancy in which the fertilized egg attaches itself and develops outside the uterus.
Cervical ectopic pregnancy (CEP) is considered to be exceptionally rare, and it accounts for less than 1% of ectopic pregnancies (EP) [1, 2]. Its exact incidence is not yet known; some authors report from 1:978 to 1:50,000 [1, 3, 4, 5, 6, 7, 8], and other authors report 0.1% of all EP, estimating their incidence between 1:2500 and 1:98,000 pregnancies .
The implantation represents a serious obstetric event [12, 13], to an extent that in 1953, Baptiste reflected: “Most great obstetricians have never seen a case of CEP; however, a minority who had this opportunity wish they had never seen it.”
Some risk factors have been considered for cervical nidation of the egg: anatomical abnormalities, uterine leiomyomas, synechia, previous cervical interventions leading to cervical mucosal changes, cervical stenosis, in vitro fertilization with embryo transfer, and obstetric uterine curettage .
When the zygote attaches itself in the cervical canal, it is rapidly invaded by the trophoblast, reaching the conjunctival portion of the cervix, once there is no adequate decidualization. As the pregnancy develops in the cervix, bleeding could occur, initially in small amounts and later in greater volume when it reaches larger vessels. These pregnancies last, in average, 7–10 weeks .
2. Clinical diagnosis
The clinical diagnosis consists in the physical examination where a ballooned cervical canal and a dilated cervix can be detected  and hourglass-shaped uterus can be observed by internal examination  (Figure 2).
The differential clinical diagnosis between CEP and the ongoing miscarriage is that in the former, the body of the uterus tends to be larger, with dilation of the external and internal orifice of the cervix, and it is possible to detect placental tissue above the internal orifice; in the latter, the internal orifice is virtually closed .
More recently, ultrasonography has been confirming the diagnosis by visually detecting cervical implantation below the internal orifice (IO) [17, 18]. Transvaginal ultrasonography is the gold standard preliminary method for accurate diagnosis .
The ultrasound findings for the diagnosis of cervical pregnancy are empty uterine cavity, endometrial thickness due to decidual reaction, hourglass shape of the uterus, enlargement of cervical canal, gestational sac located in the cervix with or without embryo, placental tissue surrounding the gestational sac, and closed internal orifice of the cervix (Figure 3).
The classical treatment used to be total hysterectomy due to profuse bleeding. However, some authors, eager to keep their nulliparous patients’ fertility, tried the conservative treatment of uterine curettage or local suture [15, 16, 24].
Reviewing the literature CEP was only cited only in the ninth edition of Williams Obstetrics in 1945. The treatment proposed at that time was  blood transfusion, vaginal tamponade and hysterectomy .
5. Conservative surgical treatment
The conservative surgical treatment proposed in the literature are:
Laparoscopic ligation of the uterine artery 
However, the majority of the conservative surgical treatments fail and result in hysterectomy.
6. Medical treatment
The following drugs are used in the medical treatment:
Actinomycin D and cyclophosphamide 
Intramuscular methotrexate with dead embryo 
Among the drugs mentioned above, methotrexate (MTX) is the most used in the current literature for the treatment of EP. It is an antimetabolic chemotherapeutic and folic-acid antagonist which operates through the competitive inhibition of the dihydrofolate reductase enzyme, which in turn reduces the dihydrofolic acid into folinic acid , interfering the DNA synthesis and, consequently, the cell division.
Our experience advocates the therapy using a single dose of MTX as first-line treatment for CEP if the embryo does not show cardiac activity.
In cases of embryos without heart beating with high β-hcg titers greater than 5000 mui/ml and often greater than 10,000 mui/ml, a systemic treatment with multiple doses of MTX is the preferred therapeutic.
When the embryo has cardiac activity, local treatment with MTX and potassium chloride is recommended . Elito et al. published a series of eight cases of CEP where embryos are presenting cardiac activity treated with puncture of gestational sac guided by vaginal ultrasonography with MTX injection (1 mg/kg) and KCl injection .
7. Expectant management
We can rarely adopt the expectant management, monitoring throughout the development of the cervical pregnancy, as some cases can spontaneously solve itself. Patients with small-volume CEP and low and declining serum beta-hCG concentrations are candidates for this type of management. Titers of beta-hCG lower than 1500 mIU/ml and declining indicate a high possibility of spontaneous involution.
According to the historical evolution of CEP, the treatment was carried out with total abdominal hysterectomy in a heroic attempt to solve the hemorrhage after the rupture of the cervix. When the authors began to try a traditional treatment, it was usually a surgery. Early diagnosis of CEP is extremely important for choosing the appropriate treatment. Several treatment options can be used, such as surgical interventions, medical treatment, and expectant management. The treatment with MTX has a high rate of success, and it is the first choice. CEP with cardiac activity is treated with intra-aminiotic MTX and potassium chloride injection. In cases of CEP without heart beating, systemic treatment with MTX should be used in a single- or multiple-dose regimen depending on the levels of beta-hCG. When the levels of beta-hCG are low and declining, the expectant management may be chosen. The clinical treatment of CEP prevents mutilating surgeries, and the patient can preserve their original condition for an obstetric future.
Parente JT, Ou CS, Levy J, Legatt E. Cervical pregnancy analysis: A review and report of five cases. Obstetrics and Gynecology. 1983; 62:79-82
Pisarska M, Carson S. Incidence and risk factors for ectopic pregnancy. Clinical Obstetrics and Gynecology. 1999; 42(1):2-8; quiz 55-56
Dees HC. Cervical pregnancy associated with uterine leiomyomas. Southern Medical Journal. 1966; 59(8):900; passim
Shinagawa S, Nagayama M. Cervical pregnancy as a possible sequela of induced abortion. Report of 19 cases. American Journal of Obstetrics and Gynecology. 1969; 105(2):282-284
Ushakov FB, Elchalal U, Aceman PJ, Schenker JG. Cervical pregnancy: Past and future. Obstetrical & Gynecological Survey. 1997; 52(1):45-59
Bai SW, Lee JS, Park JH, Kim JY, Jung KA, Kim SK, et al. Failed methotrexate treatment of cervical pregnancy. Predictive factors. The Journal of Reproductive Medicine. 2002; 47(6):483-488
Jozwiak EA, Ulug U, Akman MA, Bahceci M. Successful resection of a heterotopic cervical pregnancy resulting from intracytoplasmic sperm injection. Fertility and Sterility. 2003; 79(2):428-430
Papaloucas CD. “Hour-glass” shape of the uterus in the diagnosis and treatment of cervical pregnancy. Clinical Anatomy. 2004; 17(8):658-661
Alanis-Fuentes J, Brindis-Rodríguez A, Martínez-Arellano M. Cervical ectopic pregnancy. Hysteroscopy treatment, case report. Ginecología y Obstetricia de México. 2015; 83(5):302-307
Dreizin DH, Schneider P. Cervical pregnancy. The American Surgeon. 1957; 93(1):27-40
Ranade V, Palermino A, Tronik B. Cervical pregnancy. Obstetrics and Gynecology. 1978; 51(4):502-503
Rubin IC. Cervical pregnancy. Surgery, Gynecology & Obstetrics. 1911; 13(s/n):625-633
Studdiford WE. Cervical pregnancy: A partial review of the literature and a report of two probable cases. American Journal of Obstetrics and Gynecology. 1945; 49(2):169-185
Musiello RB, Junior JE, Musiello RB, Camano L, Souza E, Fava JL, et al. Cervical ectopic pregnancy with live embryo: The use of methotrexate is effective? 2012:2-4
Camano L, Azevedo AR. Prenhez ectópica. In: Delascio D, editor. Síndromes Hemorrágicas da Gestação. São Paulo: Sarvier; 1977. pp. 63-78
Greenhill JP, Friedman EA. Prenhez ectopica. In: Obstetricia. Rio de Janeiro: Interamericano; 1976. pp. 351-395
Frates MC, Benson CB, Doubilet PM, Di Salvo DN, Brown DL, Laing FC, et al. Cervical ectopic pregnancy: Results of conservative treatment. Radiology. 1994; 191(3):773-775
Kligman I, Adachi TJ, Katz E, McClamrock HD, Jockle GA, Barakat B. Conserving fertility with early management of cervical pregnancy: A case report. The Journal of Reproductive Medicine. 1995; 40(10):743-746
Mangino FP, Ceccarello M, Di Lorenzo G, D’Ottavio G, Bogatti P, Ricci G. Successful rescue hysteroscopic resection of a cervical ectopic pregnancy previously treated with methotrexate with no combined safety precautions. Clinical and Experimental Obstetrics & Gynecology. 2014; 41(2):214-216
Ruano R, Reya F, Picone O, Chopin N, Pereira PP, Benach A, et al. Three-dimensional ultrasonographic diagnosis of a cervical pregnancy. Clinics (São Paulo). 2006; 61(4):355-358
Sherer DM, Gorelick C, Dalloul M, Sokolovski M, Kheyman M, Kakamanu S, et al. Three-dimensional sonographic findings of a cervical pregnancy. Journal of Ultrasound in Medicine. 2008; 27(1):155-158
Bader-Armstrong B, Shah Y, Rubens D. Use of ultrasound and magnetic resonance imaging in the diagnoses of cervical pregnancy. Journal of Clinical Ultrasound. 1989; 17(4):283-286
Rafal RB, Kosovsky PA, Markisz JA. Case report. MR appearance of cervical pregnancy. Journal of Computer Assisted Tomography. 1990; 14(3):482-484
Neme B, Pereira PP, Zugaib M. Prenhez ectópica. In: Neme B, editor. Obstetricia Básica. 3rd ed. São Paulo: Sarvier; 2006. pp. 372-394
Studdiford WE. Cervical pregnancy. American Journal of Obstetrics and Gynecology. 1945; 49:169
Stander HJ. Extra uterine pregnancy. In: Willians Obstetrics. 9th ed. New York: D. Appleton - Century Company; 1945. pp. 752-783
Bernstein D, Holzinger M, Ovadia J, Frishman B. Conservative treatment of cervical pregnancy. Obstetrics and Gynecology. 1981; 58(6):741-742
Nolan TE, Chandler PE, Hess LW, Morrison JC. Cervical pregnancy managed without hysterectomy. A case report. The Journal of Reproductive Medicine. 1989; 34(3):241-243
Thomas RL, Gingold BR, Gallagher MW. Cervical pregnancy. A report of two cases. The Journal of Reproductive Medicine. 1991; 36(6):459-462
Lobel SM, Meyerovitz MF, Benson CC, Groff B, Bengtson JM. Preoperative angiographic uterine artery embolization in the management of cervical pregnancy. Obstetrics and Gynecology. 1990; 72:938-941
Simon P, Donner C, Delcour C, Kirkpatrick C, Rodesch F. Selective uterine artery embolization in the treatment of cervical pregnancy: Two case reports. European Journal of Obstetrics, Gynecology, and Reproductive Biology. 1991; 40(2):159-161
Fylstra DL. Cervical pregnancy: 13 cases treated with suction curettage and balloon tamponade. American Journal of Obstetrics and Gynecology. 2014; 210(6):581.e1-581.e5
Takeda K, Mackay J, Watts S. Successful management of cervical ectopic pregnancy with bilateral uterine artery embolization and methotrexate. Case Reports in Emergency Medicine. 2018; 3:9593824
Tanos V, ElAkhras S, Kaya B. Hysteroscopic management of cervical pregnancy: Case series and review of the literature. Journal of Gynecology Obstetrics and Human Reproduction. 2018; 48(4):247-253
Kung FT, Lin H, Hsu TY, Chang CY, Huang HVV, Huang LY, et al. Differential diagnosis of suspected cervical pregnancy and conservative treatment with the combination of laparoscopy-assisted uterine artery ligation and hysteroscopic endocervical resection. Fertility and Sterility. 2004; 81(6):1642-1649
Wharton KR, Gore B. Cervical pregnancy managed by placement of a shirodkar cerclage before evacuation. A case report. The Journal of Reproductive Medicine. 1988; 33(2):227-229
Bakri YN, Badawi A. Cervical pregnancy successfully treated with chemotherapy. Acta Obstetricia et Gynecologica Scandinavica. 1990; 69(7):655-656
Segna RA, Mitchell DR, Misas JE. Successful treatment of cervical pregnancy with oral etoposide. Obstetrics and Gynecology. 1990; 76(5):945-947
Arowojolu AO, Ogunbode OO. Cervical ectopic pregnancy managed with methotrexate and tranexamic acid: A case report. African Journal of Medicine and Medical Sciences. 2014; 43(4):361-364
Junior JE, Musiello RB, Araújo Junior E, Souza E, Fava JL, Guerzet EA, et al. Conservative management of cervical pregnancy heart activity by ultrasound-guided local injection: An eighth case series. The Journal of Maternal-Fetal & Neonatal Medicine. 2014; 27(13):1378-1381
Zugaib M. Zugaib Obstetrícia. 3rd ed. São Paulo: Manole; 2016. 1348p
Cecchino N, Araújo Junior E, Elito Junior J. Methotrexate for ectopic pregnancy: When and how. Archives of Gynecology and Obstetrics. 2014; 2903(3):417-423