Ectopic Pregnancy: Definition and Treatment

00:01 In this lecture, I'll be reviewing ectopic pregnancy.

00:04 This is important for you to listen to as you can see questions on your USLME.

00:10 In addition, you can save a life by understanding the pathophysiology of an ectopic pregnancy.

00:18 An ectopic pregnancy essentially is a pregnancy that is developing outside of the uterus.

00:24 This can happen in several locations.

00:27 Let's review some of those locations now.

00:29 An ectopic pregnancy is more likely to occur in the ampulla.

00:34 Over 70% of ectopic pregnancies occur here.

00:38 Do you know why? I'll wait for you to answer that.

00:49 If you guessed because fertilization occurs here then you are correct.

00:55 There are other regions that an ectopic pregnancy can implant including the isthmus and the fimbria.

01:03 3% of all ectopics occur on the ovary. Sometimes you can have an ectopic in the interstitium.

01:11 This is the junction between the tube and the uterus. 1% of all ectopics are abdominal.

01:18 This is extremely rare. However, we are seeing a surge in cervical ectopics.

01:25 These ectopics can be life-threatening as sometimes they look like a miscarriage.

01:30 And if you try to extract them, the patient can lose her blood supply very quickly.

01:36 And this is very life threatening.

01:39 An ectopic pregnancy looks like this upon laparoscopy.

01:42 They account for 1% to 2% of all pregnancies.

01:45 They account for 5% of all assisted reproductive technology pregnancies.

01:50 For more information about ART, please refer to that lecture slide.

01:56 There are some definitive risk factors for an ectopic pregnancy such as previous surgery on the tube.

02:03 Any surgery but especially tubal ligation can cause ectopics to occur.

02:09 Tubal pathology from pelvic infection such as PID can also lead to ectopic.

02:15 DES exposure increases the risk five-fold.

02:19 However, less patients exposed to DES are now in their perimenopause and menopausal stages.

02:25 So, you're unlikely to see this but you may be tested on your exam.

02:30 Also, patients who have infertility who have any type of ART are two-fold increased risks.

02:37 They are more likely to have a heterotopic.

02:39 That means one ectopic and one normal intrauterine pregnancy or IUP.

02:45 Patients who smoke are more likely to have an ectopic.

02:50 There's a two-fold increased risk.

02:52 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.

03:18 Again, if you've had permanent sterilization, these patients are more likely to have ectopic if they become pregnant after the sterilization.

03:26 One third of pregnancies from sterilization are an ectopic. The diagnosis is easy.

03:33 A beta positive hCG usually occurs eight to ten days after ovulation.

03:38 There is some time that is required to determine what the character of the beta-hCG will be.

03:44 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.

04:03 Let's now look at what a normal pregnancy looks like.

04:06 With an IUP, you have a gestational sac usually at 38 days after the onset of menses.

04:15 Then, you should see a fetal pole and a yolk sac.

04:19 Perhaps, you'll see the yolk sac such as the one pictured here, which is an indication that there is an intrauterine pregnancy.

04:27 However, you can't see a yolk sac in the adnexa.

04:30 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.

04:41 This is an observation of a gestational sac with a yolk sac, an embryo, and fetal cardiac activity outside of the uterus.

04:48 This establishes the diagnosis of an ectopic.

04:51 Typically, we don't always see very well like the last image.

04:58 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.

05:09 This can be done with manual vacuum aspiration or a dilation and curettage.

05:14 We typically do this when the beta-hCG is above the discriminatory zone but there is no IUP seen on ultrasound.

05:22 Typically, if you recover villi, this will exclude ectopic and will tell you it was an abnormal IUP.

05:28 However, it does not rule out the chance of a heterotopic.

05:32 Let's talk about the medical management of ectopic pregnancy.

05:36 Methotrexate is an effective first-line medical therapy.

05:39 It works by inactivating dihydrofolate reductase and inhibiting DNA and RNA synthesis.

05:46 It is the preferred alternative to surgical treatment.

05:49 The dosage depends on the protocol.

05:51 A single dose and two doses correspond to 50 mg/m2 of body surface area.

05:57 For the protocol with two doses, one dose is given on day 1, and the other on day 4.

06:03 For the multiple dose protocol, 1mg/kg/day is given on days 1, 3, 5 and 7.

06:11 However, the patient needs to meet some criteria. She needs to be hemodynamically stable.

06:17 She must not have any evidence of acute or intra-abdominal bleeding.

06:21 And she must be compliant with the medication and is scheduled to come back to check her titers of beta-hCG.

06:29 Methotrexate does have some contraindications.

06:33 If the woman is currently breastfeeding, she cannot take Methotrexate.

06:37 If she's immunodeficient such as HIV positive or has AIDS, she is not a candidate for Methotrexate.

06:45 If the patient has cirrhosis or hepatitis, she is not a candidate for Methotrexate.

06:50 If she has renal failure, she should not receive Methotrexate.

06:54 Any bleeding dyscrasias or blood dyscrasias are also a contraindication.

06:59 And sometimes patients report a history of sensitivity to Methotrexate.

07:03 They should also not receive Methotrexate.

07:07 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.

07:23 I'd now like to review the surgical treatment for ectopic pregnancy.

07:27 We traditionally do this via laparoscopy and not laparotomy.

07:32 I can either perform a salpingostomy or a salpingectomy.

07:37 A salpingostomy allows me to make a linear antimesenteric incision on the fallopian tube.

07:44 Then I remove the ectopic pregnancy through the incision sometimes with hydrodissection.

07:50 The incision is then allowed to close by secondary intention.

07:54 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.

08:06 About 65% of patients who've had an ectopic in a tube will go on to have an IUP or an intrauterine pregnancy.

08:14 Thank you for listening and good luck on your exam.