A cervical pregnancy is an

ectopic pregnancy Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these sympt ...

that has implanted in the uterine

endocervix The cervical canal is the spindle-shaped, flattened canal of the cervix, the neck of the uterus. Anatomy The cervical canal communicates with the uterine cavity via the internal orifice of the uterus (or internal os) and with the vagina via the ...

. Such a pregnancy typically aborts within the first

trimester Trimester or Trimestre may refer to: * Academic term, a trimester system divides the academic year into three terms * Trimester (pregnancy) in humans, where the time of pregnancy is divided into three terms of 13 weeks to refer to the fetus's deve ...

, however, if it is implanted closer to the uterine cavity – a so-called cervico-isthmic pregnancy – it may continue longer.

Placenta The placenta is a temporary embryonic and later fetal organ (anatomy), organ that begins embryonic development, developing from the blastocyst shortly after implantation (embryology), implantation. It plays critical roles in facilitating nutrien ...

l removal in a cervical pregnancy may result in major hemorrhage.

Diagnosis

The diagnosis is made in asymptomatic pregnant women either by inspection seeing a bluish discolored

cervix The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes durin ...

or, more commonly, by

obstetric ultrasonography Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a sta ...

. A typical

non-specific symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

vaginal bleeding Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproducti ...

during pregnancy. Ultrasound will show the location of the

gestational sac The gestational sac is the large cavity of fluid surrounding the embryo. During early embryogenesis it consists of the extraembryonic coelom, also called the chorionic cavity. The gestational sac is normally contained within the uterus. It is the o ...

in the cervix, while the uterine cavity is "empty". Cervical pregnancy can be confused with a

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion and pregnancy loss, is the death of an embryo or fetus before it is able to survive independently. Miscarriage before 6 weeks of gestation is defined by ESHRE as biochemical ...

when pregnancy tissue is passing through the cervix. Histologically the diagnosis has been made by Rubin's criteria on the surgical specimen: cervical glands are opposite the

trophoblast The trophoblast (from Greek : to feed; and : germinator) is the outer layer of cells of the blastocyst. Trophoblasts are present four days after fertilization in humans. They provide nutrients to the embryo and develop into a large part of the pl ...

ic tissue, the trophoblastic attachment is below the entrance of the uterine vessels to the uterus or the anterior peritoneal reflection, and fetal elements are absent from the uterine corpus. As many pregnancies today are diagnosed early and no hysterectomy is performed, Rubin's criteria can often not be applied.

Management

True cervical pregnancies tend to abort; if, however, the pregnancy is located higher in the canal and the placenta finds support in the uterine cavity, it can go past the first trimester. With the placenta being implanted abnormally, extensive vaginal bleeding can be expected at time of delivery and placental removal. While early cervical pregnancies may abort spontaneously or can be managed with excision, D&C, suturing, electrocautery, and tamponading, by medication such as

methotrexate Methotrexate (MTX), formerly known as amethopterin, is a chemotherapy agent and immune-system suppressant. It is used to treat cancer, autoimmune diseases, and ectopic pregnancies. Types of cancers it is used for include breast cancer, leuke ...

, and/or by

uterine artery embolization Uterine artery embolization is a procedure in which an interventional radiologist uses a catheter to deliver small particles that block the blood supply to the uterine body. The procedure is done for the treatment of uterine fibroids and adenom ...

, a more advanced pregnancy may require a

hysterectomy Hysterectomy is the surgical removal of the uterus. It may also involve removal of the cervix, ovaries ( oophorectomy), Fallopian tubes ( salpingectomy), and other surrounding structures. Usually performed by a gynecologist, a hysterectomy may ...

to control bleeding. The more advanced the pregnancy, the higher the risk for major bleeding necessitating a hysterectomy. On very rare occasions, a cervical pregnancy results in the birth of a live baby; typically, the pregnancy is in the upper part of the cervical canal and manages to extend into the lower part of the uterine cavity. A cervical pregnancy can develop together with a normal intrauterine pregnancy; such a heterotopic pregnancy will call for expert management as to not to endanger the intrauterine pregnancy.

Epidemiology

The incidence has been reported to be about 1:1,000 to 1:16,000 pregnancies. Pregnancies involving the isthmus – the segment of the

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

between the cervix and the fundus – are more common than true cervical pregnancies. While in many situations the cause of the abnormal implantation remains unclear, there is evidence to link the development of cervical pregnancy to uterine instrumentation, specifically repeated D&Cs (

dilatation and curettage Dilation (or dilatation) and curettage (D&C) refers to the dilation (widening/opening) of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping (curettage). It is a gynecologic ...

). Cervical pregnancies are to be distinguished from pregnancies that start from an implantation in a scar of a previous

cesarean section Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or ...

, so-called ''scar pregnancies''.

References

External links

{{DEFAULTSORT:Cervical Pregnancy Wikipedia articles with sections published in WikiJournal of Medicine Medical emergencies Ectopic pregnancy Health issues in pregnancy