#143 Medical Management of First-Trimester Abortion Flashcards
What percentage of abortions are performed before 63 days of gestation?
64%
What percentage of all abortions are medical abortions in the US? What percentage at or before 9 weeks?
16.5%. 25.2%
What is the most common medical abortion regimen used in the US and Western Europe?
Mifepristone and misoprostol
What is the mechanism of action of mifepristone?
Antiprogestin - binds to progesterone receptor with greater affinity than progesterone, but does not activate it
What are the effects of mifepristone on a uterus/cervix in a pregnant woman?
Decidual necrosis, cervical softening, and increased uterine contractility and prostaglandin sensitivity
How long after mifepristone administration does uterine contractility increase?
24-36 hours after administration
By how much does mifepristone increase the sensitivity of the myometrium to prostaglandins by 24-36 hours?
Five fold increase
What type of prostaglandin is misoprostol?
Prostaglandin E1 analogue
Which route(s) of misoprostol administration have the longer duration of action?
Buccal and vaginal
Which route(s) of administration of misoprostol are more efficacious than oral administration?
Buccal, vaginal, sublingual
Which route(s) of misoprostol administration have the most rapid onset and significant absorption?
Sublingual. More adverse effects
Is misoprostol only or combined misoprostol-mifepristone regimen more efficacious for first trimester abortion?
Combined
What is the mechanism of action of methotrexate?
Dihydrofolate reductase inhibitor. Enzyme involved in producing thymidine during DNA synthesis
What does dihydrofolate reductase do?
Enzyme involved in producing thymidine during DNA synthesis
Where does methotrexate mostly exert its abortifacient effect?
Primarily on the cytotrophoblast rather than the developing embryo, which inhibits syncytialization of the cytotrophoblast. Stops implantation
Does mifepristone have a direct effect on the trophoblast?
No
What is the mifepristone-misoprostol regimen for first trimester abortion? FDA vs evidence based regimens
FDA: 600mg mifepristone orally, followed about 48 hours later by 400mcg misoprostol orally
Evidence-based: 200mg mifepristone, followed by miso (vaginal at same time as mife or 6-8hr after, buccal and sublingual 24 hrs after)
What are the benefits of medical abortion over surgical first trimester abortion?
Usually avoids invasive procedure, usually avoids anesthesia
What are the cons of medical abortion over surgical first trimester abortion?
Days to weeks to complete, bleeding commonly not perceived as light, requires follow-up to ensure completion, patient participation through multi-step process
Benefits of surgical first-trimester abortion compared to medical abortion?
Allows use of sedation if desired, predictable time period, bleeding commonly perceived as light, does not require follow up in most cases
What is the success rate of first trimester medical abortion
~95%
What is the success rate of first trimester surgical abortion?
99%
What are the cons of surgical first trimester abortion compared to medical?
Invasive procedure
What adverse effects are commonly associated with mifepristone?
nausea, vomiting, diarrhea, headache, dizziness, thermoregulatory effects
Which method of misoprostol administration is least associated with GI side effects?
Vaginally
When counseling a patient about how much bleeding is too much during medical first trimester abortion, what do you advise?
Soaking two maxi pads per hour for 2 consecutive hours is too much, should call their provider
What percentage of women undergoing first trimester medical abortion will need emergency curettage because of excessive bleeding?
<1%
Does ibuprofen taken to improve pain during medical first trimester abortion decrease efficacy of misoprostol?
No
If a patient undergoing medical abortion presents for scheduled follow up and ultrasound shows hyperechoic tissue in uterus, what needs to be done?
Nothing. Representes blood, blood clots, and decidua. Rarely needs intervention in absence of excessive bleeding, can monitor
What is the sole purpose of the ultrasound performed for a follow up medical abortion appointment?
To determine whether a gestational sac is present
What is the next step in management for patient 1 week after initial medical abortion treatment who has persistent gestational sac without evidence of cardiac activity on ultrasound?
Option 1: Another dose of misoprostol
Option 2: expectant management
What percentage of pregnancies after mifepristone-miso regimen continue?
<1% when medical abortion began at or before 63 days of gestation
How do you treat ongoing pregnancy after first-trimester abortion regimen?
May do repeat dose of vaginal misoprostol or uterine aspiration
What percentage of patients receiving mifepristone and misoprostol for first trimester abortion require emergency curettage within the first 24 hours?
0.2% of patients
How does the medical abortion regimen change for twin gestations?
It does not. Still mife-miso same dosing
What are the transfusion rates associated with medical abortions?
0.05%
What are the transfusion rates for surgical abortion in early pregnancy?
0.01%
What are medical contraindications to abortion with mifepristone regimens?
Consider risk/benefit with anemia. Confirmed or suspected ectopic pregnancy, IUD in place, current long-term systemic corticosteroid therapy, chronic adrenal failure, known coagulopathy or anticoagulant therapy, intolerance or allergy to mifepristone. Unable to follow up. Most trials exclude pts with severe liver, renal, or respiratory disease or uncontrolled HTN or CVD
What pretreatment laboratory tests are needed prior to medical abortion?
Confirmation of pregnancy. H&H if anemia suspected. Rh testing.
Up to what gestational age can mife-miso regimen be used for med ab?
Studied up to 13 wks with 92% efficacy.
Should prophylactic antibiotics be used in medical abortion?
No strong data exist to support the universal use of prophylactic antibiotic use
What is the rate of infection after medical abortion?
0.9% (may be overestimated)
Is buccal or vaginal miso for medical abortion associated with decreased infection rates?
Buccal
What signs/symptoms should make you concerned for a clostridium infection after medical abortion?
Often resembles flu-like illness. Hemoconcentration. Significant leukocytosis without fever and can rapidly progress to refractory hypotension and death
What are signs/symptoms of infection after medical abortion?
Sustained fever, tachycardia, or severe abdominal pain or general malaise with or without fever that occurs more than 24 hours after miso administration
What is the rate of ectopic pregnancy in the general population?
19-21 per 1,000 pregnancies
How often are clinicians and patients correct on diagnosing pregnancy expulsion based on symptomatology?
Correct 96-99% of the time
What are options for clinical follow up after medical abortion?
- FDA recommended 2 wk follow up
- 1 week follow up
- hcg level before and 1 week after treatment
- Telephone follow up at 1 wk with subsequent UPT at 2 or 4wks
If TVUS 1 week after medical abortion shows no evidence of gestational sac, what % of women will need subsequent surgical evacuation?
1.6%
A decrease in serum hCG level by what %tage over 6-7 days indicates a successful medical abortion?
at least 80%
Is mifepristone teratogenic?
No evidence to suggest so yet
What anomalies are associated with first trimester misoprostol use?
Defects in the frontal or temporal bones and, most commonly, limb abnormalities with or without Mobius syndrome (mask-like fascies w /bilateral 6 and 7 nerve palsy and micrognathia)
What malformations are associated with methotrexate exposure?
Growth restriction, limb defects, and craniofacial anomalies
How soon after medical abortion can contraceptives be started?
On same day as miso administration. For IUD placement, can place as soon as 5-9 days after mifepristone admin.
