Ectopic pregnany pt.1 Flashcards
What is the uterus?
Thick-walled, pear-shaped hollow sexual muscular organ
What does the uterus consist of anatomically? Provide location and significance in size
Three parts:
- The body/corpus (Superior two thirds)
- The isthmus (1cm portion connecting the body to the cervix)
- The cervix (narrower cylindric inferior one third)
Describe the shape of the body of the uterus
- The body of the uterus narrows from the fundus, the rounded superior part of the body, to the isthmus, the 1-cm-long constricted region between the body and cervix
- Constricted opening at each end The internal os (opening) of the cervix communicates with the cavity of the uterine body, and the external os communicates with the vagina
What is the shape of the cervix?
Cylindrical
What is the area within the uterus called?
Uterine cavity
What is the lumen of the cervix known as?
Cervical canal
Describe the relation of the cervical canal to the rest of the female reproductive system
- The lumen of the cervix, the cervical canal, has a constricted opening at each end
- The internal os (opening) of the cervix communicates with the cavity of the uterine body, and the external os communicates with the vagina
- In front of the upper part of the cervix lies the bladder, separated from it by cellular connective tissue known as parametrium, which also extends over the sides of the cervix
- To the rear, the supravaginal cervix is covered by peritoneum, which runs onto the back of the vaginal wall and then turns upwards and onto the rectum, forming the recto-uterine pouch.
- The cervix is more tightly connected to surrounding structures than the rest of the uterus
What can the cervix be divided into anatomically?
Two portions:
- Vaginal portion of cervix (ectocervix)
- Supravaginal portion of cervix
Describe the location of the vaginal portion of the cervix
- Lower end of the cervix which bulges through the anterior wall of the vagina projecting into the cervix between the anterior and posterior vaginal fornices
Describe the location of the supravaginal portion of the cervix
The rest of the cervix above the vagina
What is the mucosa lining the cervix known as?
The mucosa lining the cervical canal is known as the endocervix, and the mucosa covering the ectocervix is known as the exocervix
What do the walls of the uterus consist of? Describe their thickness
The walls of the body of the uterus consist of three layers:
• Perimetrium, the thin external layer
• Myometrium, the thick smooth muscle layer
• Endometrium, the thin internal layer
What is the uterine cavity?
A virtual space lined by the endometrium
Where does the uterus extend from and to? What is it connected to basically
Extends from the fundus superiorly to the vaginal portion of cervix inferiorly (external os)
What is another term for normal pregnancy?
Eutopic pregnancy
What is an ectopic pregnancy?
Refers to the implantation of
the gestational sac (blastocyte) outside the uterine cavity
Where do ectopic pregnancies occur?
- Most commonly (around 90%) in the fallopian tubes (most commonly in ampula but also common in isthmus)
- Nontubal EPs (less than 10%)
What are possible locations for nontubal EPs?
The cervix, ovary, myometrium, abdominal cavity, interstitial (i.e.intramuscular/proximal) portion of the fallopian tube, cesarean scar
What is an abdominal EP?
ECtopic pregnancy in which implantation occurs in the peritoneal cavity
What can abdominal EP be divided into?
Primary or secondary
What are primary abdominal EPs?
The original site of implantation is the peritoneal cavity.
What are secondary abdominal EPs?
The result of tubal rupture or expulsion of pregnancy through the fimbrial end of the tube and its re-implantation into the abdominal cavity.
What are the most common sites of abdominal EPs?
The most common sites for implantation are the broad ligament, pouch of Douglas,
uterovesical pouch and surface of the tubes and uterus.
How hard is it to diagnose abdominal pregnancies?
Early abdominal pregnancies are often difficult to diagnose: there is usually an empty uterine cavity and no evidence of a dilated Fallopian tube or an adnexal mass
What is a heterotopic pregnancy?
Refers to the coexistence of an intrauterine pregnancy with an EP
What is the incidence rate of heterotopic pregnancies?
- Extremely rare (Less than 0.05%) in the general population
- About 1% following IVF
What is the incidence rate of ectopic pregnancies?
- 1–2 % in the general population
- 2–5 % of pregnancies obtained by using
assisted reproductive technology (ART)
How much do ectopic pregnancies account for maternal mortality?
- Up to 6 % of all maternal deaths
- Despite advances in early diagnosis, ectopic pregnancy still accounts for 4% to 10% of pregnancy-related deaths
How do Nontubal EPs vs Tubal EPs differ when it comes to maternal morbidity and mortality?
Nontubal EPs contribute disproportionately to maternal morbidity and mortality in comparison to tubal EPs.
How much do interstitial pregnancies make up of all ectopic pregnancies?
4% of all EP
Describe the effect of interstitial pregnancies on maternal morbidity
Associated morbidity much higher, with mortality rates of 2.5 % (7 times the mortality rate associated with other EP locations, largely due to hemorrhage)
What are ultrasound diagnosis criteria for interstitial pregnancy?
Ultrasound criteria for diagnosis include a gestational sac at least 1 cm lateral to the edge of the uterine cavity, with a thin (5 mm or less) layer of overlying myometrium surrounding it.
What is a cesarean scar EP?
The implantation of a pregnancy is on the scar of a
previous cesarean section (“scar pregnancy”)
What is the incidence rate of cesarean scar EP?
Extremely rare (Less than 0.1%)
What are risk factors of tubal ectopic pregnancies?
- Risk factors include smoking, infection, toxic, immunological, and hormonal factors
- Up to 50% of cases have no identifiable risk factors
- The most important predisposing condition, present in 35% to 50% of patients, is prior pelvic inflammatory disease resulting in intraluminal fallopian tube scarring (chronic salpingitis)
- The risk of ectopic pregnancy is also increased with peritubal scarring and adhesions, which may be caused by appendicitis, endometriosis, and previous surgery. In some cases, however, the fallopian tubes are apparently normal.
- Another risk factor is use of an intrauterine contraceptive device, which is associated with a twofold increase in ectopic pregnancy.
- Age (over the age of 35 in both spontaneous pregnancies and after ART)
- Smoking (causing tubal dysfunction, dysregulation of the paracrine signals
needed for coordinated embryo transport and development) - History of EP (strong risk factor: recurrence rate of 5–25%, or up to 10 times
the risk in the general population) - Tubal surgery or tubal damage: tubal reanastomosis, salpingostomy, tuboplasty
and lysis of adhesions. Similarly, any causes of pelvic adhesions (including
endometriosis, appendicitis, or other pelvic surgeries) may distort the anatomy of
the fallopian tube - Prior pelvic infection: Chlamydia trachomatous (the risk increasing with each successive infection), Neisseria gonorrhoeae, Mycoplasma and schistosomiasis.
- Pregnancy conceived by ART (2–5 % of pregnancies from ART are ectopic): the
main risk factors are the specific type of procedure and the history of infertility.
What do risk factors of tubal ectopic pregnancy cause to increase the likelihood of the event of a tubal ectopic pregnancy occurring
- They lead to tubal dysfunction or damage
- This can lead to abnormal embryo transport and alterations in the tubal environment, which enables abnormal implantation to occur
- This all leads to tubal ectopic pregnancy
What is the incidence rate of intramural pregnancy?
Rare (Less than 2%)
Where can intramural pregnancies be found?
It could be located anywhere within the uterine corpus
Are intramural pregnancies easy to detect?
Can be hard to detect
When do intramural pregnancies typically occur?
It typically occurs after previous myomectomy (surgical removal of uterine leiomyomas, also known as fibroids), uterine perforation (complication of
uterine curettage) or after classical (upper segment vertical) caesarean section or rarely in a focus of adenomyosis
What is the defining feature of intramural pregnancies?
The defining feature is extension beyond the endometrial–myometrial junction above the level of the internal os (which differentiates them from cervical and caesarean section scar pregnancies)
