Issues in Early Pregnancy

ACOG District I Medical StudentTeaching Module 2008

When a woman presents with an early pregnancy…

• Ask yourself two questions…

Where is this pregnancy?Where is this pregnancy?

Is it viable?Is it viable?

Where is this pregnancy?

In a woman with an early pregnancy you must determine if the pregnancy is intrauterineintrauterine or an ectopicectopic, 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 ectopicectopic 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 95% are in the fallopian tube 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 possibilities1- Normal2 - 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 AgeGestational Sac 5 weeksYolk sac 6 weeksEmbryo 6 weeksCardiac Activity 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• 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