First Trimester Bleeding

See Also

Epidemiology

Prevalence: First Trimester Bleeding in 25% of pregnant women

History

Quantity and rate of blood loss
1. Bleeding similar or worse than Menstrual Bleeding is associated with Early Pregnancy Loss
Pelvic Pain or cramping
1. Exclude Ectopic Pregnancy!
2. Bleeding associated with pain is associated with Early Pregnancy Loss
Symptoms of pregnancy
Positive Pregnancy Test
Fever

Physical Exam

Vital Signs
1. Temperature
  1. Fever suggests Septic Abortion
2. Orthostatic Blood Pressure and Pulse
  1. Hypotension raises suspicion for hemoperitoneum
Assess pregnancy and dating
1. Fetal Heart Tones (if >10-11 weeks gestation)
2. Determine Uterine Size by bimanual exam
  1. Smaller than expected size in Miscarriage
3. Chadwick Sign (Cervix cyanotic)
4. Hegar's Sign (soft isthmus)
Abdominal exam (always consider Ectopic Pregnancy)
1. Peritoneal signs (e.g. Rebound Tenderness)
2. Abdominal Distention
Pelvic and vaginal exam
1. Cervical motion tenderness (Cervicitis or Pelvic Inflammatory Disease)
2. Abnormal Vaginal Discharge (Vaginitis)
3. Adnexal Mass or pelvic mass
4. Non-uterine source of bleeding
  1. Cervical erosions
  2. Cervical polyps
5. Cervix dilated
  1. Undilated Cervix will not pass ring forceps
  2. Dilated Cervix suggests Inevitable Abortion
6. Material at cervical os
  1. Blood from os
    1. Removal of clot from within cervical os may reduce uterine bleeding
  2. Tissue at cervical os (products of conception)
    1. Remove with ring forceps if accessible
    2. May confirm intrauterine pregnancy loss (Incomplete Abortion)

Differential Diagnosis

Threatened or Incomplete Abortion
Ectopic Pregnancy
Twin loss
Placenta consolidation
Cervicitis (may cause Friable Cervix)
Vaginitis
Cervical or vaginal neoplasia
Hydatiform mole (complete or partial Molar Pregnancy)
Chorionic cyst
Subchorionic Hemorrhage

Labs
General

Quantitative bhCG
1. Detectable as early as 8 days after Ovulation
2. Anticipate roughly doubling every 48-72 hours, weeks 4-8 (plateaus after 10 weeks)
3. Minimal expected HCG increases
  1. HCG <1500 mIU/ml: Increases at least 49% in 48 hours
  2. HCG 1500-3000 mIU/ml: Increases at least 40% in 48 hours
  3. HCG >3000 mIU/ml: Increases at least 33% in 48 hours
  4. Barnhart (2016) Obstet Gynecol 128(3): 504-11 [PubMed]
4. Precaution: Inadequate HCG increase does not distinguish ectopic from failing pregnancy
5. HCG has its primary utility when no intrauterine pregnancy seen on Ultrasound
  1. In resolving pregnancy of unknown location, follow HCG to <5 mIU
Examine passed products of conception
1. Examining physician should evaluate any tissue
2. Also send to pathology for complete exam
3. Findings that confirm intrauterine pregnancy with Miscarriage
  1. Chorionic villi (rinse and float with saline)
  2. Embryo
  3. Intact Gestational Sac
Complete Blood Count or Hemoglobin Indications
1. Obtain a baseline Hemoglobin in all women with pregnancy related bleeding
2. Hemodynamically Unstable Patient
3. Hemoperitoneum
4. Suspected Ectopic Pregnancy
5. Heavy Vaginal Bleeding
Blood Type and Antibody screen Indications
1. Obtain if hemodynamically unstable (also obtain cross-match for units)
2. Obtain if not already performed in pregnancy and bleeding more than spotting (warranting RhoGAM, see below)
Serum Progesterone (typically for obstetrician use)
1. Predicts pregnancy outcome <10 weeks
2. Serum Progesterone >25 ng/ml suggests live IUP
3. Serum Progesterone <6 ng/ml suggests non-viable pregnancy (Negative Predictive Value 99%)
  1. Ectopic Pregnancy
  2. Spontaneous Abortion
STD Screening Indications
1. Obtain if high suspicion or not yet performed in current pregnancy
2. Gonorrhea DNA probe
3. Chlamydia DNA Probe
4. Saline preparation (Wet Prep)
Urinalysis
1. Indicated for Urinary Tract Infection symptoms
2. Urinary Tract Infection is not associated with pregnancy

Imaging

FAST Exam
1. Hemoperitoneum
Transvaginal Ultrasound (start with transabdominal Ultrasound)
1. Gestational Sac
  1. Seen by bHCG 1800 mIU/ml on Transvaginal Ultrasound (4-5 weeks after LMP)
  2. Seen by bHCG 3500 mIU/ml on transabdominal Ultrasound
  3. Consistent with Early Pregnancy Loss if mean sac diameter >25 mm without Embryo seen
2. Yolk Sac
  1. Seen on Transvaginal Ultrasound by 5.5 weeks after LMP
3. Embryo
  1. Seen on Transvaginal Ultrasound by 6 weeks after LMP
  2. Fetal cardiac activity by bHCG 20,000 mIU/ml (6.5 weeks after LMP)
    1. Early Pregnancy Loss if no heart activity and Crown-Rump Length >=7mm
    2. Early Pregnancy Loss if no heart activity >11 days after Gestational Sac and Yolk Sac seen
    3. Risk of pregnancy loss <11% once a live fetus has been seen on Ultrasound
4. Emergency Bedside UltrasoundTest Specificity >98%
  1. ED providers may safely exclude Ectopic Pregnancy with Bedside Ultrasound and discharge home
  2. McRae (2009) CJEM 11(4): 355-64 +PMID:19594975 [PubMed]

Management
General

Precautions
1. Assume Ectopic Pregnancy if no prior Ultrasound confirmation of intrauterine pregnancy
2. Do not HCG discriminatory values (e.g. 1800-2000) to decide if Ultrasound is indicated
  1. Ectopic Pregnancy signs (mass, cul-de-sac fluid) may be seen well under discriminatory levels
General
1. Bedside Ultrasound is highly accurate (98% Test Specificity) at identifying intrauterine pregnancy at 5.5 weeks
  1. Additional testing (unless other indication) is not needed if IUP confirmed
  2. RhoGAM is not needed for spotting and Quantitative hCG is not needed if IUP is confirmed
  3. Patient may safely be discharged home (see reference above under Ultrasound)
2. Give RhoGAM if mother is Rh Negative
  1. Dose prior to 12 weeks gestation: 50 mcg dose
    1. Controversial, especially for Threatened Abortion, especially if <12 weeks gestation
    2. However there is a 1-2% Rh Sensitization risk <12 weeks, and safest to administer RhoGAM
  2. Dose after 12 weeks gestation: 300 mcg dose
    1. In some regions, 300 mcg dose is given regardless of Gestational age
Quantitative bhCG >1800 to 2000
1. Transvaginal Ultrasound shows no Gestational Sac
  1. Evaluate for Ectopic Pregnancy
  2. Bright endometrial stripe suggests complete SAB
2. Transvaginal Ultrasound shows Gestational Sac
  1. Follow for Threatened Abortion
  2. Subchorionic Hemorrhage
    1. Hematoma between chorion and uterine wall
    2. Miscarriage risk: 9% (with risk up to 30% for older maternal age)
  3. Gestational Sac >2 cm should contain an Embryo
  4. Embryo >5 mm in crown-rump should have heart beat
    1. Risk of Miscarriage if heartbeat present and mild bleeding
      1. Maternal age under 35 years: 2.1%
      2. Maternal age over 35 years: 16.1%
Quantitative bhCG <1800 to 2000
1. Patient unstable
  1. Presumed to be Ectopic Pregnancy
  2. Immediate consult obstetrics for possible surgery
2. Patient stable
  1. Follow serial Quantitative bhCG every 48 hours
  2. Confirm Quantitative bhCG doubles in 48 hours
  3. Confirm intrauterine pregnancy when bHCG >1800-2000

Management
Specific Conditions

See Pregnancy Loss (Miscarriage)
See Ectopic Pregnancy

Precautions
Immediate Return Indications

Anemia symptoms (Light Headedness, Near Syncope or Dizziness)
Heavy bleeding (2 sanitary pads per hour for 2 consecutive hours)
Pelvic Pain (Ectopic Pregnancy)

References

Orman and Glaser in Herbert (2017) EM:Rap 17(2): 13-4
Simpson in Gabbe (2002) Obstetrics, p. 729-44
Stenchever (2001) Gynecology p. 156-7
Deutchman (2009) Am Fam Physician 79(11): 985-92 [PubMed]
Hendriks (2019) Am Fam Physician 99(3): 166-74 [PubMed]
Nadukhovskaya (2001) Am J Emerg Med 19(6):495-500 [PubMed]
Paspulati (2004) Radiol Clin North Am 42(2):297-314 [PubMed]
Prine (2011) Am Fam Physician 84(1): 75-82 [PubMed]