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In this lecture, I'll be reviewing ectopic pregnancy.
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This is important for you to listen to as you can see questions on your USLME.
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In addition, you can save a life by understanding the pathophysiology of an ectopic pregnancy.
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An ectopic pregnancy essentially is a pregnancy that is developing outside of the uterus.
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This can happen in several locations.
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Let's review some of those locations now.
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An ectopic pregnancy is more likely to occur in the ampulla.
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Over 70% of ectopic pregnancies occur here.
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Do you know why? I'll wait for you to answer that.
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If you guessed because fertilization occurs here then you are correct.
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There are other regions that an ectopic pregnancy can implant including the isthmus and the fimbria.
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3% of all ectopics occur on the ovary. Sometimes you can have an ectopic in the interstitium.
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This is the junction between the tube and the uterus. 1% of all ectopics are abdominal.
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This is extremely rare. However, we are seeing a surge in cervical ectopics.
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These ectopics can be life-threatening as sometimes they look like a miscarriage.
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And if you try to extract them, the patient can lose her blood supply very quickly.
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And this is very life threatening.
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An ectopic pregnancy looks like this upon laparoscopy.
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They account for 1% to 2% of all pregnancies.
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They account for 5% of all assisted reproductive technology pregnancies.
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For more information about ART, please refer to that lecture slide.
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There are some definitive risk factors for an ectopic pregnancy such as previous surgery on the tube.
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Any surgery but especially tubal ligation can cause ectopics to occur.
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Tubal pathology from pelvic infection such as PID can also lead to ectopic.
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DES exposure increases the risk five-fold.
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However, less patients exposed to DES are now in their perimenopause and menopausal stages.
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So, you're unlikely to see this but you may be tested on your exam.
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Also, patients who have infertility who have any type of ART are two-fold increased risks.
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They are more likely to have a heterotopic.
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That means one ectopic and one normal intrauterine pregnancy or IUP.
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Patients who smoke are more likely to have an ectopic.
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There's a two-fold increased risk.
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So, you should encourage all of your patients to stop smoking for their own health benefit
but of course, for the benefit of any pregnancy that may occur.
03:01
Contraception, we think that taking contraception decreases the incidence or absolute risk of ectopic.
03:07
However, there are some times when the contraceptive method may fail
and there's an increased risk of ectopic if you conceived with an IUD in place.
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Again, if you've had permanent sterilization,
these patients are more likely to have ectopic if they become pregnant after the sterilization.
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One third of pregnancies from sterilization are an ectopic. The diagnosis is easy.
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A beta positive hCG usually occurs eight to ten days after ovulation.
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There is some time that is required to determine what the character of the beta-hCG will be.
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Will it double normally every two to three days or will it plateau?
Serial beta-hCG determinations are more difficult to interpret in the setting of ART
possibly because there may be more than one gestation and therefore, the beta-hCG is elevated.
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Let's now look at what a normal pregnancy looks like.
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With an IUP, you have a gestational sac usually at 38 days after the onset of menses.
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Then, you should see a fetal pole and a yolk sac.
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Perhaps, you'll see the yolk sac such as the one pictured here,
which is an indication that there is an intrauterine pregnancy.
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However, you can't see a yolk sac in the adnexa.
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So, it's important to look at the ultrasound pictures to determine where the yolk sac
and therefore the IUP should be. An abnormal pregnancy would actually look like this.
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This is an observation of a gestational sac with a yolk sac, an embryo,
and fetal cardiac activity outside of the uterus.
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This establishes the diagnosis of an ectopic.
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Typically, we don't always see very well like the last image.
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So, sometimes if we suspect an abnormal pregnancy
which could be an abnormal IUP, intrauterine pregnancy or an ectopic,
we recommend doing some type of uterine curettage.
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This can be done with manual vacuum aspiration or a dilation and curettage.
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We typically do this when the beta-hCG is above the discriminatory zone
but there is no IUP seen on ultrasound.
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Typically, if you recover villi, this will exclude ectopic and will tell you it was an abnormal IUP.
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However, it does not rule out the chance of a heterotopic.
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Let's talk about the medical management of ectopic pregnancy.
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Methotrexate is an effective first-line medical therapy.
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It works by inactivating dihydrofolate reductase and inhibiting DNA and RNA synthesis.
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It is the preferred alternative to surgical treatment.
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The dosage depends on the protocol.
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A single dose and two doses correspond to 50 mg/m2 of body surface area.
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For the protocol with two doses, one dose is given on day 1, and the other on day 4.
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For the multiple dose protocol, 1mg/kg/day is given on days 1, 3, 5 and 7.
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However, the patient needs to meet some criteria. She needs to be hemodynamically stable.
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She must not have any evidence of acute or intra-abdominal bleeding.
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And she must be compliant with the medication
and is scheduled to come back to check her titers of beta-hCG.
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Methotrexate does have some contraindications.
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If the woman is currently breastfeeding, she cannot take Methotrexate.
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If she's immunodeficient such as HIV positive or has AIDS, she is not a candidate for Methotrexate.
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If the patient has cirrhosis or hepatitis, she is not a candidate for Methotrexate.
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If she has renal failure, she should not receive Methotrexate.
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Any bleeding dyscrasias or blood dyscrasias are also a contraindication.
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And sometimes patients report a history of sensitivity to Methotrexate.
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They should also not receive Methotrexate.
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Any active pulmonary disease such as an ongoing asthma exacerbation
should not permit the use of Methotrexate in these patients.
07:16
Also, if a patient has active peptic ulcer disease,
she should not receive Methotrexate to treat her ectopic.
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I'd now like to review the surgical treatment for ectopic pregnancy.
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We traditionally do this via laparoscopy and not laparotomy.
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I can either perform a salpingostomy or a salpingectomy.
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A salpingostomy allows me to make a linear antimesenteric incision on the fallopian tube.
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Then I remove the ectopic pregnancy through the incision sometimes with hydrodissection.
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The incision is then allowed to close by secondary intention.
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For a salpingectomy, the entire tube is removed.
07:58
With salpingectomy, we try to avoid this
so the patient can have access to both her tubes even after having an ectopic.
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About 65% of patients who've had an ectopic in a tube
will go on to have an IUP or an intrauterine pregnancy.
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Thank you for listening and good luck on your exam.