Issues in Early Pregnancy ACOG District I Medical Student Teaching Module 2008

When a woman presents with an early pregnancy…

Where is this pregnancy?

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

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 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 FindingGestational Age Gestational Sac5 weeks Yolk sac6 weeks Embryo6 weeks Cardiac Activity7 weeks

Yolk sac by 5 weeks

Fetal Pole by 6-7 weeks

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

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, 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):