MEDICAL EVALUATION PRIOR TO ASPIRATION

History and Physical

  • Review medical history, obstetrical and gynecologic history, medications, substance use and allergies. A screening tool can ensure a thorough history is obtained (sample here).
  • Review information for the following medical conditions (Guiahi 2012):
    • Cardiovascular (hypertension, valvular disease, arrhythmias)
    • Pulmonary (asthma, active respiratory infection)
    • Hematologic (bleeding and clotting disorders, anticoagulants, severe anemia)
    • Hemorrhage risk factors: See Chapter 5: Managing Complications Table.
    • Endocrine (diabetes, hyperthyroidism)
    • Renal and hepatic disease (affecting drug metabolism & clearance) 
    • Neurologic (seizure disorder) or psychiatric (severe depression or anxiety)
  • Abortion is an essential and urgent service. Delays should be minimized, especially in people with significant medical problems, as risk increases with advancing gestational age. Medical conditions occasionally warrant management or referral prior to abortion (see table below).
  • Complete physical exam as indicated by history and patient symptoms.
  • Patients choosing medication abortion with sure LMP do not need a pelvic exam.
  • Pelvic and bimanual exam may be performed immediately prior to the procedure.
    • Bimanual for uterine size and position (may be affected by fibroids or anomalies)
    • Speculum exam can assess cervicitis warranting testing / treatment

Lab Tests if Indicated

Patients without underlying medical conditions do not need routine pre-abortion lab testing. Lack of testing is not a barrier to abortion access. Some labs indicated by history, exam or dating.

  • Tests pertinent to underlying conditions
    • Glucose for patients with IDDM
    • INR for patients on certain anti-coagulants (Warfarin) > 12 weeks
  • Rh (D) testing:
    • Patients > 56 days from LMP with unknown Rh status. (NAF CPGs 2020)
    • Medication abortion patients may forego Rh testing <70 days LMP.
    • Document Rh status or informed waiver declining Rh testing >56 days.
    • Can use donor card if Rh negative, chart, patient report, or lab.
    • If patient wants no future children or declines testing, may forego Rh testing.
  • Hemoglobin / Hematocrit
    • Only if history or symptoms of anemia, (fingerstick; not complete CBC).
  • Chlamydia (CT) / Gonorrhea (GC):
    • For asymptomatic patients 25 or at increased risk (i.e. new or multiple sexual partners in last year). If not offered at facility, may refer for testing.
    • If cervicitis on exam, test for GC/CT, and initiate empiric prior to aspiration.
    • Universal antibiotic prophylaxis is supported by available evidence for aspiration abortion (Low 2012; Achilles 2011), and less clear for aspiration for EPL (Lissauer 2019). See Chapter 5 for regimens.

Selected Health Condition Considerations and Management in First Trimester Aspiration Abortion

Adapted from Ipas 2016

Health Condition Considerations
Hypertension (HTN)
  • Mild – moderate is not contraindicated; referral for treatment as needed.
  • Symptomatic and / or severe HTN (>160/110) should be treated prior to procedure or referred for additional management.
  • Methylergonavine (Methergine) should be avoided for patients with HTN.
Seizure Disorder
  • Anti-seizure medications should be taken as prescribed on day of uterine aspiration, and resumed as usual following procedure.
  • No contraindication to receiving procedural benzodiazepines or opiates.
  • Uncontrolled seizure disorder or seizure in last 2 weeks is a contraindication to in-clinic abortion.
  • Some anti-seizure medications interact with hormonal contraception; options should be reviewed for medical eligibility.
Anemia
  • If recent sx / hx, check pre-procedure Hgb. If very low (<10 for first trimester, <12 for second trimester), refer or be prepared to manage bleeding appropriately.
Blood-clotting disorders
  • For active clotting disorders, aspiration can be performed in outpatient setting with appropriate preparation (i.e. IV access, available uterotonics).
  • Anticoagulation medications can be continued with relatively low risk of additional blood loss up to 12 weeks (Kaneshiro 2011)
Insulin-Dependent Diabetes
  • No changes in diet or medications are recommended for vacuum aspiration, but consider scheduling early in the day.
  • Low glucose levels (<70) require dextrose or food prior to procedure.
  • High glucose levels (200-400) are not a contraindication, but levels >400 warrant evaluation for DKA; require treatment or referral prior to procedure.
Heart Disease
  • If symptomatic of underlying heart disease, or severe disease, aspiration may be performed in operating room with monitoring by anesthesiologist or anesthetist.
Asthma
  • Patients with mild asthma may have routine vacuum aspiration. Advise taking routine asthma meds before procedure bringing meds along to the clinic.
  • Patients with an acute or poorly controlled asthma may need to delay abortion care until better controlled.
  • Misoprostol is safe for use in patients with asthma.
Active respiratory infection
  • Consider delaying procedure. If unable, consider PPE for patient & staff.
  • In context of COVID-19 community transmission, recommend PPE that assumes infection if status is unknown.
Cervical Stenosis
  • Consider use of os finder, or performing aspiration under ultrasound guidance.
  • A cervical preparation agent such as misoprostol or laminaria may be helpful.
  • Medication abortion may be offered.
Uterine Fibroids
  • Fibroids may inhibit ability to complete aspiration abortion depending on size and location in relation to pregnancy. US guidance may be a helpful adjunct.
  • Consider referral to a higher level of care with an experienced provider.
  • Medication abortion may be considered as an alternative.
Previous Cesarean Delivery
  • Patient may be at increased risk of hemorrhage. Ensure uterotonic medications are readily accessible. Consider performing ultrasound guidance.
  • Additional rare risk of uterine scar pregnancy if multiple previous cesarean deliveries; consider ultrasound and / or referral to higher-level facility.
Alcohol or substance use disorders>
  • Alcohol use disorder: may need larger benzodiazepine doses due to tolerance.
  • Opiate use disorder: may need larger opiate doses due to tolerance.
  • See Chapter 5 for more information

ULTRASOUND: OVERVIEW, METHODS, TIPS & IMAGES

Ultrasound can be used for pregnancy dating when clinical dating is uncertain. Ultrasound can also be used to determine pregnancy location, viability, and / or provide procedural support. Ultrasound is not a requirement for medication abortion or uterine aspiration.

Whether to use transabdominal or transvaginal ultrasound depends on patient preference, pregnancy dating, and the skill of the sonographer. Transabdominal ultrasound may be used to confirm intrauterine pregnancy (IUP) and date a pregnancy, although if landmarks are unclear or pregnancy is early, transvaginal ultrasound may be helpful. Generally, transvaginal ultrasound gives a good view of the pregnancy landmarks and can be helpful to rule out ectopic pregnancy or early pregnancy failure.

Transabdominal Probe Transvaginal Probe
  • External probe
  • Easy to prepare and clean probe
  • Better view with full bladder
  • Difficult to detect pregnancy <6 weeks LMP
  • Good for later pregnancy scanning
  • Body habitus and bladder may affect image quality
  • Internal probe
  • Need to prepare and clean probe properly
  • Better view with empty bladder
  • Can detect pregnancy as early as 4.5-5 weeks LMP
  • Can see early pregnancy landmarks
  • With probe close to pregnancy, body habitus does not affect images
  • Improved ability to perform systematic scan
  • A limited first trimester ultrasound exam must include: (NAF CPGs 2020)
    • Uterine scan in both longitudinal and transverse planes to confirm IUP
    • Evaluation of pregnancy number (singleton or multiple gestation)
    • Measurements to document pregnancy dating
    • Evaluation of pregnancy landmarks, such as yolk sac, embryonic pole, or the presence or absence of fetal/embryonic cardiac activity

When Performing US

  • Ask if the patient wants to view image, be informed of multiple gestations or other pregnancy findings.
  • Inform the patient that ultrasound is being used only to confirm the location and dating of the pregnancy and is not a diagnostic ultrasound.
  • Consider starting your scan with transabdominal US, and switching to vaginal US only if you are unable to effectively visualize the pregnancy.
  • For vaginal ultrasound, use a non-latex probe cover or condom, with ultrasound gel inside and lubricating jelly outside, where in contact with patient.
  • Ask if the patient would prefer to self-insert the ultrasound probe.
  • Use clear and simple language to discuss ultrasound findings with the patient.
  • Systematically scan in the longitudinal and transverse planes.
transvaginal_scan_positions_arms_chap4.3

TVUS planes (Image ARMS 2007)

  • Longitudinal view is used to confirm pregnancy is intrauterine. For longitudinal view, notch is up (at 12 o’clock) and uterus is scanned side to side, from ovary to ovary. This view should show uterine fundus connected to cervix with pregnancy inside the uterus.
ultrasound longitudinal view
  • Transverse view is used for dating and pregnancy landmarks, to evaluate for multiple gestations, and get full 3D image of the uterus. For transverse view, the probe is turned 90 degrees to the patient’s right (counterclockwise or notch turned to 9 o’clock) and uterus is scanned anterior to posterior, from fundus to cervix.

Clinicians should understand the sonographic pregnancy features that should be visible based on the patient’s last menstrual period.

Pregnancy Landmarks by Weeks LMP
Gestational Sac 4.5 – 5 weeks LMP
Yolk Sac 5.5 weeks LMP
Embryonic Pole 6 – 6.5 weeks LMP
Cardiac Activity 6 – 6.5 weeks LMP

     *Above landmarks are better characterized using transvaginal ultrasound

ULTRASOUND LANDMARKS IN EARLY PREGNANCY

The Gestational Sac

  • Gestational Sac (GS) is first single US evidence of pregnancy, can appear as early as 4.5 weeks LMP; should always be seen by 5 weeks 5 days LMP (Barnhart 2012).
  • Although location of a pregnancy cannot definitely be diagnosed as intrauterine until a yolk sac or embryo is seen (Richardson 2015), a gestational sac still has a high likelihood of being an IUP even in the absence of certain sonographic features if there is no adnexal mass (Benson 2013, Phillips 2020).
  • A true gestational sac should be located in the mid to upper portion of the uterus, be eccentric (not midline) to the endometrial canal, be round or oval in shape, and have the double decidual (or double ring) sign, as demonstrated by the FEEDS mnemonic below.
    • Meeting these criteria does not completely exclude the possibility of ectopic pregnancy (Fjerstad 2004).
    • F – Fundal (in mid to upper uterus)
    • E – Elliptical or round shape in 2 views
    • E – Eccentric to the endometrial stripe
    • D – Decidual reaction (surrounded by a thickened choriodecidual reaction; appears like fluffy white cloud or ring surrounding sac)
    • S – Size > 4 mm (soft criteria)

Gestational Sac vs. Pseudosac

Gestational-Sac-vs.-Pseudosac

Gestational Sac

Compared to the GS, the pseudosac is more irregular, central, smaller, and without a decidual reaction, and can be seen with an ectopic pregnancy. Note the “beak-shaped” appearance of the sac. This can look similar to an early GS, although only may meet the F (fundal) criteria of FEEDS. Pseudosac may also appear as a mid- uterine small fluid collection.

Image: 2020

 

Pseudosac

(May be associated with ectopic)

Psuedosac with labels Psuedosac 2 with labels
Image: Fjerstad M, et al. CAPS, 2004 Image: Dr Matt A. Morgan, Radiopaedia.org, rID: 34217

The Yolk Sac

The Yolk Sac (YS) is first single US finding that confirms an IUP. The YS is a round echoic ring with anechoic (dark) center seen within GS. It appears typically at 5 ½ weeks when the MSD is 5-10 mm. The YS should not be included when taking a measurement of the embryo.

The size of the YS is not diagnostic.

The Embryo and Cardiac Activity

The embryo follows a predictable path of development and therefore can be used to date a pregnancy based on its size. The embryo appears at approximately 6 weeks and grows 1 mm per day thereafter until 12-14 weeks. See below for pregnancy dating using embryonic and fetal measurement. Cardiac activity appears around 6 ½ weeks.

The Embryo and Cardiac Activity

Image from AIUM 2018

Determining Pregnancy Viability

The following data on viability evaluated patients with desired pregnancies (Doubilet 2013). If a pregnancy is undesired, there is no reason to delay an abortion to wait for confirmation of viability. If a pregnancy is desired, and findings are suggestive of early pregnancy loss (see table below), recheck ultrasound in 7-10 days.

 

Guidelines for TVUS Diagnosis of Early Pregnancy Loss in a Patient with an IUP of Uncertain Viability

(Adapted from Doubilet 2013, ACOG 2018)

US findings DIAGNOSTIC of EPL US findings HIGHLY SUGGESTIVE of EPL †
  • CRL 7+mm and no cardiac activity
  • MSD 25+mm and no embryo
  • Absence of embryo with heartbeat:
    • 2+ weeks after a scan that showed a gestational sac without a yolk sac
  • 11+ days after a scan that showed a gestational sac with a yolk sac
  • CRL 5-7mm and no cardiac activity
  • MSD 16-24mm and no embryo
  • MSD 13 mm or more and no YS
  • Absence of embryo with heartbeat:
    • 7-13 days after a scan that showed a gestational sac without a yolk sac
    • 7-10 days after a scan that showed a gestational sac with a yolk sac
  • Absence of embryo 6+ weeks after LMP
  • Empty amnion (amnion seen adjacent to yolk sac with no visible embryo).
  • Enlarged yolk sac (>7mm)
    • Small gestational sac in relation to the size of the embryo (<5mm difference between MSD and CRL)

EARLY PREGNANCY DATING USING ULTRASOUND

Gestational Sac Measurement and Calculation of Gestational Age:  
Used for pregnancy dating before embryo is visible.

Measure 3 dimensions in 2 planes (from inside double ring to inside double ring):

  • Longitudinal Plane: Length (L) & Height (H)
  • Transverse Plane: Width (W)
Gestational sac with measurement
Length and height measured in longitudinal view.
Gestational sac with measurement
Width measured in transverse view.
Calculate the Mean Sac Diameter (MSD):

  • MSD = (L + W + H)/3
Calculate the Gestational Age (GA):

  • GA (in days) = MSD (in mm) + 30
Crown Rump Length (CRL) Measurement and Calculation of Gestational Age:
  • CRL = fetal pole (in mm)
  • Long axis not including limbs or YS

Calculate: GA (days) = CRL (mm) + 42

Crown Rump Length

Image: AIUM 2018

Biparietal Diameter (BPD) Measurement
  • > 14 weeks, using the fetal biparietal diameter (BPD) is preferred to CRL.
  • Inside to outside of skull circumference
  • At the level of the thalamus
  • No nuchal or eye structures
GestationalSacultrasound.ai edited

Image: AIUM 2018

 

 

 

 

 

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