Approach to First Trimester Vaginal Bleeding

Patients presenting with first trimester vaginal bleeding (<20 weeks of gestation) can be scary but with an algorithmic approach you can be sure not to miss anything life threatening.

Start by confirming that your patient is even pregnant via point of care urine pregnancy test. If the test is positive then you can build your critical differential diagnosis.

Critical Differential Diagnosis:

  • Ectopic pregnancy

  • Threatened abortion

  • Inevitable abortion

  • Incomplete abortion

  • Complete abortion

  • Septic abortion.

Now let’s get started with the patient

Get a history. Find out the Gs and Ps. Ask for LMP. If there have been other pregnancies find out if the delivery was vaginal or c-section and if there were any complications.

Then perform your abdominal exam looking for signs of peritonitis. If there is pain on abdominal exam consider performing a fast exam. If you see free fluid in the abdomen of a pregnant patient, ectopic pregnancy alarms should be ringing uncontrollably in your head. Call OB/GYN immediately. If there is no abdominal tenderness then you can proceed to your pelvic exam.

Perform a pelvic exam looking to see if there are any external causes for the bleeding. On the bimanual exam pay attention to whether the patient has adnexal tenderness, as this could be a result of an ectopic pregnancy. Just another remember, ectopic is on your critical differential diagnosis. Next determine if the cervical os is open or closed. Knowing if the os is open or closed and whether there has been passage of fetal tissue will allow you to characterize the type of abortion and will allow you to let the patient know the chance of miscarriage.

Efficiency Tip: Plan to do the pelvic exam right after you get the history and physical. This will involve bringing all of your pelvic exam supplies in the room. You will also have to coordinate with a chaperone to come into the room when you anticipate being done with the h and p. Do not walk out of the room without completing a pelvic exam. Delaying your pelvic exam will add one more task on your already full to do list. A longer to do list will cause your shift to feel overwhelming. Don’t delay when possible.

Types of First Trimester Abortions

  • Threatened = closed os + no passage of tissue

  • Inevitable = open os + no passage of tissue

  • Incomplete = open os + passage of some tissue + US showing some retained products of conception.

  • Complete = closed os + passage of tissue + US showing empty uterus

  • Septic = open os +/- passage of tissue + US showing reatined POC + sepsis

The Work Up

  • Urine pregnancy test:  This should be done when you first making contact with your patient to determine if you even need to go down this path.

  • CBC:  to make sure the patient is not anemic and to ensure that the patient is not thrombocytopenic

  • Coags: to make sure the patient is not prone to bleeding

  • Quantitative beta hcg: Will be trended

  • Rh status: Determines whether to give rhogam

  • UA: to assess for UTI

  • Wet mount

  • Pelvic US


If the pelvic US reveals an ectopic, get on the horn with OB/GYN and begin resuscitation with blood if necessary.

If the patient has a threatened or completed abortion the patient can be discharged home with gyn f/u.

If there is evidence of an inevitable or incomplete abortion a d and c may need to be performed in order to prevent the patient from becoming septic

If the patient is septic she should be admitted for antibiotics and d and c.

If the patient is so early in the pregnancy that the ultrasound can’t find the baby what should you do? Refer the patient for a 48 hour OB/GYN f/u for a repeat beta HCG. This is important because ectopic has not been ruled out yet.

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Approach to Vaginal Bleeding

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