Snapshot
- A 35-year-old G3P2 at 12 weeks of gestation presents to the emergency department with 6 hours of vaginal bleeding and cramping pain. She has had 2 prior vaginal deliveries and no history of pregnancy-related complications. She has been receiving regular prenatal care.
Introduction
- Overview
- Epidemiology
- incidence
- occurs spontaneously in 15% of all pregnancies
- demographics
- more common in women of advanced maternal age (age > 35 years)
- ~11% risk in women < 35 years old
- 17% in women 35-39 years old
- 33% in women 40-44 years old
- 57% risk in women ≥ 45 years old
- more common in women of advanced maternal age (age > 35 years)
- risk factors
- advanced maternal age (> 35 years old)
- number 1 risk factor due to strong association with fetal chromosomal abnormalities
- advanced paternal age
- prior pregnancy loss
- risk increases as number of prior miscarriages increase
- maternal diabetes
- type I or type II diabetes
- gestational diabetes begins > 20 weeks, so cannot contribute to miscarriage
- obesity
- thyroid disease
- hypo- or hyperthyroidism
- stress
- acute or chronic
- conception < 3 months after live birth
- pregnancy with IUD in place
- subchorionic hematoma
- advanced maternal age (> 35 years old)
- incidence
- Causes
- fetal chromosomal abnormalities
- present in up to 70% of miscarriages
- infection
- listeria
- parvovirus B19
- ~8% cumulative incidence of pregnancy loss
- 5.6x higher risk of pregnancy loss if infection occurs in first trimester
- syphilis
- 21% increased risk of fetal loss and stillbirth if untreated
- cytomegalovirus (CMV)
- 2.5 increased odds of early pregnancy loss compared with non-infected pregnant women
- incompetent cervix
- trauma
- direct impact to uterus
- violent
- gunshot wounds
- penetrating injuries
- blunt abdominal trauma
- iatrogenic
- chorionic villus sampling
- amniocentesis
- toxins, radiation, and environmental exposures
- medications and substance abuse
- risk increases in dose-related fashion
- alcohol
- smoking
- cocaine and methamphetamines
- fetal chromosomal abnormalities
- Prognosis
- very good if patient if properly treated
- risk of future miscarriage natural history of disease
- 14% risk of future miscarriage after 1 miscarriage
- 26% after 2 miscarriages
- 28% after 3 miscarriages
Classification
| Types of Miscarriages | ||||
| Type | Vaginal Bleeding | Passage of Contents | Cervical Os | Ultrasound |
| Threatened | Yes | No | Closed | Fetus present and has cardiac activity |
| Inevitable | Yes | No | Open | Fetus present but does not have cardiac activity |
| Incomplete | Yes | Yes | Open | Retained fetal parts |
| Complete | Yes | Yes | Closed | No fetus present |
| Missed | No | No | Closed | Fetus present but does not have cardiac activity |
Presentation
- Symptoms
- vaginal bleeding
- commonly occurs in first trimester without subsequent loss of pregnancy
- abdominal/pelvic cramping pain
- asymptomatic
- may note reduction in previous pregnancy symptoms
- decreased nausea
- decreased breast tenderness
- vaginal bleeding
- Physical exam
- vitals
- may exhibit signs of shock if significant hemorrhage
- speculum exam
- assess source and quantity of bleeding
- bleeding from cervix and open cervical os suggest miscarriage
- significant hemorrhage should prompt urgent evaluation and intervention
- bimanual exam
- determine whether cervix is open
- assess presence of tissue within cervical canal
- can estimate gestational age
- handheld Doppler
- listen for fetal heart tones
- vitals
- absence of fetal heart ones in pregnancy ≥ 12 weeks suggests potential early pregnancy loss
Imaging
- Transvaginal ultrasound
- indications
- critical for diagnosis of miscarriage
- can assess fetal cardiac activity
- findings
- looking for presence of intrauterine gestation and evidence of viability
- diagnosis of miscarriage if any one of the following
- gestational sac ≥ 25 mm without yolk sac or embryo
- embryo with crown rump length ≥ 7 mm that does not have cardiac activity
- following a pelvic ultrasound that showed a gestational sac without a yolk sac
- absence of an embryo with a heartbeat in ≥ 2 weeks
- following a pelvic ultrasound that showed a gestational sac with a yolk sac
- absence of an embryo with a heartbeat in ≥ 11 days
- may begin with transabdominal ultrasound, but proceed to transvaginal ultrasound if unable to demonstrate cardiac activity in an intrauterine pregnancy
- indications
- Hysterosalpingogram
- indications
- can elucidate potential cause of miscarriage
- only performed after treatment for confirmed miscarriage
- findings
- indications
- uterine structural abnormalities
Studies
- Serum β-hCG
- not required for diagnosis
- useful in specific circumstances
- to determine concern for ectopic pregnancy if gestational sac not seen on ultrasound
- if ultrasound not available
- drop in β-hCG > 25% over 48 hours in setting of uterine bleeding highly suggestive of early pregnancy loss
- Serum progesterone
- needed for maintenance of endometrium
- low levels (< 35 nmol/L) associated with early pregnancy loss
- cannot use for definitive diagnosis due to high variability of normal levels among pregnancies
Differential
- Normal intrauterine pregnancy
- key distinguishing factors
- serial ultrasounds demonstrate viable intrauterine gestation
- can have cramping and vaginal bleeding in normal pregnancy
- key distinguishing factors
- Ectopic pregnancy
- key distinguishing factors
- ultrasound findings
- no intrauterine pregnancy visible
- may see visible pregnancy that is outside the uterine cavity
- may see bleeding in the pelvis (suggestive of ruptured ectopic)
- may have abnormal β-hCG levels
- ultrasound findings
- key distinguishing factors
- Hydatidiform mole
- key distinguishing factors
- ultrasound findings
- enlarged uterus
- “snowstorm” appearance of uterus
- ultrasound findings
- key distinguishing factors
- abnormally elevated β-hCG
Treatment
- Expectant management
- counseling and return precautions
- indications
- < 14 weeks of gestation
- threatened or inevitable abortion
- stable vital signs
- no evidence of infection
- desire to avoid surgery and/or medication
- desire to pass uterine contents at home
- majority of expulsions occur in first 2 weeks after diagnosis
- if unsuccessful after four weeks then proceed to surgical evaluation
- indications
- counseling and return precautions
- Medical
- misoprostol
- indications
- women with nonviable pregnancy up to 12 weeks + 6 days of completed gestation
- hemodynamically stable
- no evidence of hemorrhage, severe anemia, bleeding disorders
- no evidence of infection
- can be used in second trimester treatment in hospital setting
- modalities
- administered vaginally as single dose
- repeat dose in seven days if no response to first dose
- indications
- mifepristone
- indications
- pretreatment prior to misoprostol
- preferred method for first trimester miscarriage
- pretreatment prior to misoprostol
- modalities
- single oral dose followed 24 hours later by single dose of intravaginal misoprostol
- indications
- rhoGAM
- indications
- all Rh(D)-negative mothers if father is Rh(D)-positive or unknown
- modalities
- single intramuscular or intravenous dose
- indications
- misoprostol
- Surgical
- dilation and curettage (D&C)
- indications
- incomplete, inevitable, or missed abortion
- first trimester or early second trimester (< 16 weeks gestation)
- failed expectant or medical management
- modalities
- dilation of cervix and removal of pregnancy with sharp curettage and/or suction curettage
- indications
- dilation and evacuation (D&E)
- indications
- ≥ 16 weeks gestation
- modalities
- wide mechanical dilation of cervix with destruction of fetal parts and removal of tissue with large-bore vacuum curette
- indications
- hysteroscopic removal
- indications
- retained products of conception after failed expectant, medical, or surgical management
- no signs of hemorrhage
- no signs of infection
- modalities
- scope used to visualize abnormal tissue
- abnormal tissue removed with morcellator or grasper
- indications
- dilation and curettage (D&C)
- Follow-up
- weekly serum β-hCG
- after expectant or medical management
- weekly serum β-hCG
- continue to measure until serum β-hCG undetectable
Complications
- Hemorrhage
- can occur during miscarriage or during/after surgical treatment
- could lead to maternal death
- risk factors
- uterine atony after surgical treatment
- cervical injury
- uterine perforation
- subinvolution of placental implantation site
- underlying coagulopathy
- treatment
- check for/remove any retained products of conception
- uterotonics for uterine atony
- oxytocin
- misoprostol
- surgical treatment of cervical injury or uterine perforation
- intravenous (IV) fluids and blood products if hemodynamically unstable
- Retained products of conception
- suspect in patients with
- uterine bleeding that increases in volume
- uterine bleeding that persists > 2 weeks after uterine evacuation
- treatment
- IV fluids and blood products if hemodynamically unstable
- urgent surgical intervention
- suspect in patients with
- Endometritis
- presentation
- mild uterine tenderness
- empty uterus on ultrasound exam
- +/- fever
- occurs after complete miscarriage or uterine evacuation
- treatment
- oral broad-spectrum antibiotics
- presentation
- Septic abortion
- miscarriage accompanied by intrauterine infection
- risk factors
- induced abortion (as opposed to miscarriage)
- retained products of conception
- treatment
- IV fluids and blood products if hemodynamically unstable
- obtain blood and endometrial cultures
- IV broad-spectrum antibiotics
- give until afebrile for 48 hours
- oral antibiotics
- give for 10-14 days after completion of IV antibiotic course
- surgical evacuation of any retained products of conception