CHAPTER 3 TEACHING POINTS: PRE-ABORTION EVALUATION

EXERCISE 3.1

Purpose: To review key steps in early pregnancy evaluation and dating.

1. A person calls your office for a telehealth visit about options for an undesired pregnancy, following a positive home pregnancy test.
   1. How will you establish their pregnancy duration?
      • In early pregnancy, LMP alone has been shown to be an accurate means of pregnancy dating with low rates of under- or overestimation in abortion evaluation to 13 weeks (Ipas 2023, Kapp 2020, Macaulay 2019, Raymond 2015, Schonberg 2014).
      • Pairing a bimanual exam with LMP may increase accuracy of EGD assessment but is not required to proceed with a medication or aspiration abortion.
      • If LMP is unknown, a series of questions (Are you >10 weeks pregnant? Have you missed >2 periods? Are you >2 months pregnant?) may be used to determine MAB eligibility (Ralph 2021).
      • If pregnancy duration is uncertain, or if there are any signs or symptoms of ectopic pregnancy, US may be warranted (Raymond 2020).
   2. What additional diagnostic data would you consider obtaining?
      • Most people do not require additional labs. Certain tests may be indicated based on history while others may be considered or offered based on patient preferences.
      • Rh if indicated (See Chapter 4 Rh-D IG for MAB or Chapter 5: Rh Isoimmunization)
      • Hgb or Hct only if history and / or recent symptoms of anemia
      • CT/GC if symptoms or risk factors
      • Tests pertinent to underlying conditions if needed. For example:
        • Glucose for patients with IDDM, although limited evidence regarding universal testing but may be considered based on clinical scenario in those with labile glucose.
        • INR for patients > 12 weeks on Warfarin

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EXERCISE 3.2

Purpose: To review appropriate uses for different types of pregnancy tests. For each scenario, indicate whether you would use clinical assessment alone, a high sensitivity urine pregnancy test (HSPT), or a serum quantitative hCG test and why; and/or answer related questions.

1. A person at 5 weeks by LMP comes to your office requesting pregnancy confirmation and to discuss options.
   • A HSPT is the most useful test to confirm an early pregnancy, both for home and office-based confirmation of pregnancy.
   • A HSPT can detect levels as low as 10 mIU/ml, which may be seen in urine as early as 8-10 days after ovulation. By the time of missed menses, the hCG level is typically 50-100
   • Not all HSPT tests are equal, with detection hCG levels varying from 10-30 mlU/ml. When hCG levels aretrended, the same lab should be used due to differences in specific assays across labs (Larraín 2024).
   • If positive, assess if they desire to continue the pregnancy, and proceed with clinical dating.

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2. A person is 6 weeks with a pregnancy of unknown location (transvaginal US examination shows no intrauterine gestational sac and no ectopic pregnancy). They have been spotting intermittently but are otherwise asymptomatic. A quantitative hCG is 1000,48 hours later it is 1400.
   1. What is the differential diagnosis?
      • Research indicates that the minimum expected hCG rise for a viable IUP is 49% at 48 hours when the starting hCG is <1500 (Barnhart 2016). This person’s hCG rise is 40% in 48 hours. The differential still includes EPL, ectopic, and less likely early viable pregnancy. The hCG patterns need to be combined with EGD and symptoms during clinical management of PUL.
   2. Would your approach to care differ if the person desires to terminate vs continue the pregnancy?
      • If the person desires to terminate the pregnancy, offer a diagnostic uterine aspiration, because that will expedite the evaluation for possible ectopic pregnancy (Borchert 2023). If pregnancy tissue is found in the aspirate, an ectopic pregnancy can be ruled out. In the more likely case that pregnancy tissue is not found, a repeat hCG level 24-48 hours after the aspiration will be helpful. If the gestational sac was aspirated, the hCG level will drop by more than 50%. If the person is symptomatic or the hCG does not drop by 50%, an ectopic pregnancy becomes more likely, and a referral is warranted.
      • If the person prefers to continue the pregnancy, a third hCG measurement and/or repeat ultrasound would be indicated given the broad range in hCG rise seen even in normal pregnancies (Barnhart 2021, Larraín 2024).
      • If the person desires to terminate the pregnancy but prefers medication management to an aspiration, <9 weeks MAB protocols may be safely used; clinicians should provide ectopic precautions & trend serum hCG within 48-72 hours of using misoprostol to confirm completion (Brandell 2024, Goldberg 2022). While mifepristone and misoprostol will not treat ectopic pregnancies, they will not cause harm nor interact with treatments for ectopic, should additional management be needed.

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3. A person returns for a follow-up visit 5 weeks after a first trimester aspiration because of intermittent bleeding since their procedure, and has been sexually active since the aspiration.
   • The HSPT is helpful if negative, but can stay positive 4-6 weeks post-abortion.
   • If there are ongoing symptoms or signs of pregnancy or retained tissue, consider serial hCGs to assess the trend. Repeat US may also be helpful.

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EXERCISE 3.3

Purpose: To review key information about ultrasound in early pregnancy.

1. What is the differential diagnosis of the following ultrasound findings? What steps would you take to clarify the diagnosis?
   1. A person at 5 weeks by LMP. In the longitudinal view of the uterus, a gestational sac is elliptical, fundal and eccentric to the midline. Mean sac diameter is 18 mm with no yolk sac or embryo visible.
      • This is an intrauterine gestational sac. The mean sac diameter of 16-24 mm with no yolk sac or embryo is highly suggestive of a non-viable pregnancy in this case, although early viable pregnancy and ectopic are still in the differential. If the mean sac diameter was ≥25 mm without an embryo, it would be diagnostic of early pregnancy loss (anembryonic pregnancy).
      • If they desire termination, offer either aspiration procedure or medications. Procedure should not be delayed for diagnosis and can help confirm pregnancy location (SFP 2025b). If they prefer medication, that can be offered (with ectopic precautions) and paired with serum hCG trend and close follow-up.
      • If they desire to continue the pregnancy, repeat US in 7-10 days to confirm diagnosis.
   2. Embryonic pole length 8 mm with no visible cardiac activity
      • Embryonic pole length > 7 mm with no cardiac activity is diagnostic for early pregnancy loss (Rodgers 2024). Management options including aspiration, medication, or expectant management. See Chapter 8: EPL Management Options.
   3. A person at 5 weeks by LMP reports having intermittent right-sided pelvic pain and cramping. On the US, you visualize a small 3 mm x 3 mm intrauterine fluid collection in the endometrial canal. The shape of the collection is triangular and there is no double decidual sign.
      • This case is concerning for ectopic pregnancy. By 5 weeks 3 days, or 38 days, the mean sac diameter should measure 8 mm. A normal sac should also be eccentrically placed and not centrally located in the uterine cavity.
      • Combined with the unilateral cramping pain, an intrauterine fluid collection that does not meet criteria for being a gestational sac (previously known as “pseudosac”) should prompt ectopic pregnancy workup and management.
   4. A person at 10 weeks by LMP with intermittent spotting. On US, there is a flattened gestational sac without embryo or yolk sac, with cystic changes in the decidua present resembling “swiss cheese.”
      • This suggests gestational trophoblastic disease (GTD), a spectrum of placental tumors including benign conditions (partial and complete hydatidiform mole, or molar pregnancy) as well as gestational trophoblastic neoplasias with malignant potential. GTD may appear with heterogeneous echoes on the US. The classic moth-eaten, “swiss cheese” or “snowstorm” appearance may not be visible until 9-10 weeks EGD.
      • For suspected GTD, tissue diagnosis is needed, so uterine aspiration is recommended over medication abortion. If uterine size is over 12 weeks, refer for inpatient management or a higher level of care due to increased bleeding risk.
      • When aspiration is performed for suspected GTD, tissue should be sent for pathologic examination, and baseline serum hCG obtained. If molar pregnancy is confirmed, hCGs should be monitored carefully and according to established protocols due to the risk for gestational trophoblastic neoplasia (Horowitz 2021, Soper 2021).

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EXERCISE 3.4

Purpose: To consider management of case scenarios prior to uterine aspiration. Not all material is covered in this Chapter.

1. A person presents for aspiration at 5 weeks by LMP. Pelvic examination reveals an irregular uterus that is 17 weeks in size. Ultrasound examination shows a 5 week intrauterine gestation and multiple uterine fibroids. What further evaluation and management would you recommend?
   • Discuss additional considerations for aspiration vs. medication in setting of fibroids, given increased risk of incomplete aspiration procedures. A small gestational sac can occasionally be high in the fundus “behind” the curve of large or multiple fibroids, and it may be very difficult to reach.
   • Consider performing the procedure under US guidance. Refer to a higher-level setting with an experienced clinician if necessary.
   • Consider checking hemoglobin if symptomatic, as people with fibroids can have anemia, and may have a higher risk of increased bleeding during abortion.

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2. A person who is 5 weeks pregnant presents for uterine aspiration. As you insert the speculum, the cervix looks inflamed and friable and has pus at the os.
   • CT / GC testing and initiation of empiric pre-procedural treatment is indicated, as cervical infection with these pathogens increases risk of post abortion endometritis (SFP 2025a). Uterine aspiration should not be postponed. An appropriate treatment regimen (CDC 2021 Guidelines) includes:
     • Chlamydia: Doxycycline 100 mg orally twice daily for 7 days is the recommended regimen. Alternatively can use Azithromycin 1 gm single oral dose OR Levofloxacin 500 mg daily for 7 days
     • Gonorrhea: Ceftriaxone 500 mg intramuscular* PLUS treatment for Chlamydia. *For persons weighing ≥ 150 kg dose is Ceftriaxone 1 g intramuscular.
   • Symptomatic BV at the time of aspiration should be treated with metronidazole 500 mg orally twice daily for 7 days, without need to delay the abortion. Routine screening for bacterial vaginosis is not recommended (SFP 2025a).

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3. A person at 7 weeks presenting for an abortion procedure has a history of 3 previous cesareans.

• • The person’s previous cesarean sections put them in the moderate risk category for hemorrhage (SFP 2024) and a possibly challenging uterine aspiration.
  • Carefully evaluate pre-abortion US to confirm normal fundal placement of GS and no evidence of implantation at cesarean section scar niche.
  • May consider MAB for this individual if able to assess for and rule out CSEP, which is a contraindication to MAB due to bleeding risk (SMFM 2022).
  • If proceeding with procedural abortion, the following should be considered:
    • Consider US guidance in case of a challenging uterine aspiration.
    • Have uterotonic medications and supplies accessible to manage bleeding.
    • Add vasopressin to the paracervical block.
    • With additional hemorrhage risk factors, consider referring to a center with transfusion capability, anesthesia, and/or interventional radiology.

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4. A person presents for aspiration, with history of venous thromboembolism, now anticoagulated on warfarin; last INR was in the therapeutic range. How would your management change if 10 wk vs. >14 wk EGD?
   • Procedural abortion is generally preferred over medication abortion for individuals with bleeding disorders or who are on anticoagulation. First-trimester procedural abortion in an individual on anticoagulation can generally be done without interruption of anticoagulation (Lee 2021). Additional blood loss in anticoagulated individuals was not clinically significant in a small study of people seeking aspiration < 12-weeks gestation compared with matched controls (Kaneshiro 2011). A likely explanation is that myometrial contraction is the primary mechanism of hemostasis after uterine aspiration.
   • If 14+ weeks EGD or has other bleeding risks, consider referring to a higher level of care.