Issues in Early Pregnancy
ACOG District I Medical Student
Teaching Module 2008
When a woman presents with an early
pregnancy…
• Ask yourself two questions…
Where is this pregnancy?
Is it viable?
Where is this pregnancy?
In a woman with an early pregnancy you must
determine if the pregnancy is intrauterine or
an ectopic, because her life could depend on
it!
How to you determine location of the
pregnancy?
• First determine dating by LMP
• Then perform ultrasound
• If you can see location of the pregnancy, you
are done!
• If you cannot…it becomes more complicated…
Early pregnancy with unknown
location
• Check a serum BHCG
• If it is above the discriminatory zone (DZ)—
(this is different at every hospital) an
intrauterine pregnancy should be seen
• Then do an ultrasound to see if you see the
pregnancy
Early pregnancy with unknown
location
• If BHCG>DZ and pregnancy seen in the uterus,
you are done
• If BHCG>DZ and no pregnancy seen in the
uterus, it is an ectopic until proven otherwise!
Ectopic pregnancy
• 2% of all pregnancies
• Risk factors include prior tubal surgery, prior
ectopic, current IUD use, history of PID, or DES
exposure
• A woman can present with abdominal pain or
bleeding or be asymptomatic!
Ectopic Pregnancy
• 95% are in the fallopian
tube (70% ampulla, 12%
isthmus, 11% fimbria,
2% interstitial/cornual)
• Ovarian occurs about
3% of the time,
abdominal 1% of the
time and cervical <1%
of the time
Seeber 2006
Early pregnancy with unknown
location
• If BHCG< DZ and you do not see the
pregnancy on the ultrasound consider your
patient…
• Is she….
– Unstable or stable
– Have pain? Have risk factors for ectopic?
– Your differential diagnosis is :intrauterine
pregnancy just too small to see on ultrasound vs
ectopic
Early pregnancy with unknown
location
• Generally, BHCG will double in 48 hours
• If the patient is stable you can have her return
in 48 hours for repeat BHCG
• If is doubling appropriately, likely normal
intrauterine pregnancy and can order
ultrasound when >DZ
• If not doubling appropriately consider
treatment for ectopic (methotrexate or
surgery)
Now you know location…now what?
• An ectopic pregnancy can be treated either
medically with methotrexate or surgically
• The next step with an intrauterine pregnancy
is determining viability…
Viability
• When you have an intrauterine pregnancy
there are several possibilities
1- Normal
2 - Miscarriage (there are different types!)
3 - Molar pregnancy
• A viable pregnancy is an intrauterine
pregnancy that has cardiac motion-should see
by 7-8 weeks
Intrauterine pregnancy
• First finding on US is an empty gestational sac
• But cannot say that it is an intrauterine
pregnancy until you see a yolk sac or a fetal
pole
Intrauterine Pregnancy
Finding
Gestational Sac
Yolk sac
Embryo
Cardiac Activity
Gestational Age
5 weeks
6 weeks
6 weeks
7 weeks
Yolk sac by 5 weeks
www.advancedfertility.com
Fetal Pole by 6-7 weeks
www.advancedfertility.com
Types of nonviable intrauterine
pregnancies
•
•
•
•
•
Anembryonic (blighted ovum)
Threatened abortion
Inevitable abortion
Complete abortion
Missed abortion
Anembryonic gestation
• No yolk sac or fetal pole
• Mean gestational sac
diameter of 30 mm
www.gloriaspregnancyinfo.com
Threatened abortion
• First trimester bleeding
• Fetal pole with a heartbeat
• If there is a heartbeat there is less than 10%
chance of miscarriage
Inevitable abortion
• Deformation and/or descent of gestational sac
with a dilated cervix
Complete abortion
• Products of conception completely expelled
Missed abortion
• Intrauterine pregnancy with an embryo, but
no cardiac activity by 8 weeks gestation
Now you know the basic issues in
early pregnancy!!
Algorithm that might help you…
Seeber 2006
Sources
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•
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•
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Frishman, Gary, et al. Women and Infants’ Beta book.
Merz, Eberhard. Ultrasound in Obstetrics and Gynecology Vol 1: Obstetrics.
Stuttgart: Georg Thieme Verlag, 2005.
Mukul, Liberato and Stephanie Teal. “Current Management of Ectopic Pregnancy.”
Obstetrics & Gynecology Clinics of North America. 34 (2007): 403–419.
Seeber, Beata E, and Kurt T Barnhart. “Suspected Ectopic Pregnancy.” Obstetrics &
Gynecology. 107 (2006): 399-413 .
www.advancedfertility.com
www.gloriaspregnancyinfo.com