Patient will present as → a 35-year-old G3P2 with cervical dilatation >3 cm, ruptured membranes, bleeding >7 days, and the presence of cramping (inevitable abortion)
Fetal death and early delivery are classified as follows:
- Abortion: Death of the fetus or passage of products of conception (fetus and placenta) before 20 weeks gestation
- Fetal demise (stillbirth): Fetal death after 20 weeks
- Preterm delivery: Birth of a live fetus between 20 weeks and 36 weeks + 6 days
"In modern clinical practice and patient-centered communication, the term miscarriage is preferred when referring to spontaneous (non-induced) pregnancy loss, as it is clearer and less stigmatizing for patients. The terms may be used interchangeably on exams depending on context. The terms may be used interchangeably on exams depending on context."
Classification of Abortion (Pregnancy Loss < 20 Weeks)
By Gestational Age
- Early: < 12 weeks
- Late: 12–20 weeks
By Etiology
- Spontaneous: Non-induced pregnancy loss
- Induced: Termination of pregnancy for medical or elective reasons
- Therapeutic: Termination due to maternal life/health risk or fetal anomalies incompatible with life
| Clinical Classification of Spontaneous Abortion (Miscarriage) | |
| Early | Abortion before 12 weeks gestation |
| Late | Abortion between 12 and 20 weeks gestation |
| Spontaneous | Noninduced abortion |
| Induced | Termination of pregnancy for medical or elective reasons |
| Therapeutic | Termination of pregnancy because the woman’s life or health is endangered or because the fetus is dead or has malformations incompatible with life |
| Threatened | Vaginal bleeding occurring before 20 weeks gestation without cervical dilation and indicating that spontaneous abortion may occur |
| Inevitable | Vaginal bleeding or rupture of the membranes accompanied by dilation of the cervix |
| Incomplete | Expulsion of some products of conception |
| Complete | Expulsion of all products of conception |
| Recurrent (habitual) | ≥ 2 to 3 consecutive spontaneous abortions |
| Missed | Undetected death of the fetus before 20 weeks of gestation, with products of conception remaining intrauterine |
| Septic | Serious infection of the uterine contents during or shortly before or after an abortion |
Recurrent Spontaneous Abortion (2-3 or more consecutive spontaneous abortions): Recommended Evaluation
- Genetic testing of parents
- Thyroid disorders (hypothyroidism or hyperthyroidism)
- Autoimmune conditions, including:
- Systemic lupus erythematosus (SLE)
- Antiphospholipid syndrome (anticardiolipin antibodies)
Spontaneous abortion:
- > 80% occur in the first trimester (< 12 weeks)
- ~60% are due to chromosomal abnormalities
- Remaining cases are often idiopathic
Increased Risk Factors
- Increasing parity
- Advanced maternal age (≥ 35) and paternal age (≥ 45)
- Conception within 3 months of a term delivery
- Cigarette smoking
- Substance use (alcohol, cocaine)
- Poorly controlled chronic maternal disease, including:
- Diabetes mellitus
- Hypertension
- Overt thyroid disorders
All women with early pregnancy bleeding and pain are assumed to have an ectopic pregnancy until this diagnosis has been excluded by laboratory and imaging studies.
Diagnosed by ↓ βHG and classified based on ultrasound findings
- Transvaginal ultrasonography is the cornerstone of the evaluation of bleeding in early pregnancy
- The US demonstrates inappropriate development or interval growth, poorly formed/unformed fetal pole, and fetal demise
- The βHG should double every 48 hours in a viable intrauterine pregnancy
- Blood type and Rh status are necessary tests to preclude Rh sensitization in the mother
Miscarriage (Early Pregnancy Loss) Classifications
| Type | Bleeding | Cervical Os | Products of Conception | Key Clinical Feature |
|---|---|---|---|---|
| Threatened | Present | Closed | None passed | Viable intrauterine pregnancy |
| Inevitable | Present | Open | None passed | Miscarriage cannot be prevented |
| Incomplete | Present | Open | Some passed | Retained products remain |
| Complete | Resolved | Closed | All passed | Empty uterus on ultrasound |
| Missed | Minimal or none | Closed | None passed | Non-viable embryo or fetus |
Traditionally managed by D&C only, monitor progress with B-HCG levels or ultrasound examination
- Comprehensive management of early pregnancy loss includes addressing the emotions of women and their partners, inquiring about future plans for pregnancy, and offering contraceptive or preconception planning as appropriate
Elective abortion:
- Medical abortion: Mifepristone and Misoprostol up to first 7-9 weeks LMP
- Suction Curettage: safest and most effective for 12 weeks or less. Surgical procedure 3-12 weeks LMP. local anesthesia on the cervix
- Surgical Curettage (D&C) Aspiration: a surgical abortion up to 16 weeks LMP
- Dilation and Evacuation (D&E) up to 18 weeks outpatient
- Induction of labor with intraamniotic installation after 16 weeks
- Induction of labor with vaginal prostaglandins after 16 weeks
Picmonic
Spontaneous abortion is defined as loss of pregnancy before 20 weeks gestation. Excessive bleeding before 20 weeks gestation in a pregnant women may indicate a nonviable fetus. Types of spontaneous abortion include threatened, inevitable, incomplete, complete, and missed. Identifying the type of spontaneous abortion is critical for determining subsequent treatment. Interventions include promoting bed rest and providing emotional support. Since fluid imbalance may occur in spontaneous abortion, monitoring for hemorrhage includes saving the patient’s pads and linens. The administration of RhoGAM may be necessary for Rh- women exposed to R+ blood of nonviable fetuses. Dilation & curettage and cerclage may be done to remove fetal tissue from inside the uterus.
| Spontaneous abortion types | Play Video + Quiz |
| Spontaneous abortion overview | Play Video + Quiz |
Question 1 |
Which of the following is a maternal risk factor for spontaneous abortion?
uterine intramural myomata | |
progesterone deficiency elevated serum beta HCG | |
tobacco use | |
controlled diabetes |
Question 1 Explanation:
Maternal risk factors for a spontaneous abortion include maternal infections (e.g., herpes simplex), uterine defect, endocrine abnormalities, drug use (including tobacco use), immunologic factors, and physical trauma.
Question 2 |
You receive a call at 3 AM from your prenatal patient who is worried about bleeding and cramping that began several hours ago. This is the fourth pregnancy for your patient, which was a planned pregnancy. She has had two uncomplicated, spontaneous vaginal deliveries and one elective abortion in the past. Her prenatal course to date has been uncomplicated. Two weeks ago, you obtained a first-trimester ultrasound study for dating purposes that revealed a 6-week intrauterine pregnancy. She denies any fever, nausea, vomiting, dizziness, lightheadedness, shortness of breath, or arm or chest pain. Her cramps are becoming more intense, but she is managing to control the pain with a heating pad. She reports using approximately three sanitary pads in the past 6 hours for bleeding, none of which were soaked through. The patient is home with her husband, who is a well-known patient of yours as well. They are very anxious and want to know what to do next.
You advise your patient to
come to your office first thing in the morning for an evaluation | |
take some ibuprofen and see you at her next scheduled prenatal visit | |
rush to the emergency department because of suspected ectopic pregnancy | |
rush to the emergency department for an immediate dilation and curettage (D& C) | |
call an obstetrician-gynecologist to schedule an outpatient consultation |
Question 2 Explanation:
This patient is most likely experiencing an early pregnancy loss (also called a spontaneous abortion, nonviable pregnancy, or early pregnancy failure), which is defined as a spontaneous pregnancy loss at less than 20 weeks of gestation based on the last menstrual period. Because the patient appears to be hemodynamically stable on the basis of your phone conversation, it is reasonable to have her evaluated first thing in the morning in your office. Furthermore, you already have preexisting documentation of an intrauterine pregnancy, which makes the possibility of an ectopic pregnancy highly unlikely. The concomitant presence of an ectopic and intrauterine pregnancy (referred to as a heterotopic pregnancy) is possible but is a very rare occurrence, with an incidence of 1: 30,000 pregnancies. Reports estimate that heterotopic pregnancies are on the rise, with an incidence as high as 1: 2600 pregnancies among certain high-risk subgroups, such as women who have undergone assisted reproductive interventions (e.g., in vitro fertilization). Although sending the patient to the emergency department immediately is a possible option, this will likely cause unnecessary waiting and anxiety for the couple. An immediate D& C is not necessary, given the fact that the patient is stable and not bleeding excessively. Most early pregnancy losses can be managed safely and effectively in the family medicine setting; a consultation with an obstetrician-gynecologist is not mandatory and will depend on the clinician’s level of clinical comfort. Telling the patient to take ibuprofen and follow up at her next prenatal visit is not appropriate in the setting of undiagnosed first-trimester bleeding.
Question 3 |
She follows your advice. The next day you see the patient and her husband in your office. She appears tearful but calm. Her temperature is 98.4 ° F, blood pressure is 120/ 80 mm Hg, pulse is 80 beats/ minute, and respiratory rate is 16 breaths/ minute. She reports that since she spoke to you, she has passed a few dime-sized clots but no obvious tissue. She continues to have lower abdominal cramping. You perform a speculum examination, which reveals some blood in the vaginal vault and a small amount of tissue protruding from an open, dilated cervical os. A bimanual examination reveals a 6-week-size uterus with minimal tenderness but no peritoneal signs. The most likely diagnosis is
missed abortion | |
recurrent spontaneous abortion | |
complete abortion | |
incomplete abortion | |
inevitable abortion |
Question 3 Explanation:
The patient is experiencing an incomplete abortion. The terminology to describe nonviable pregnancies was devised before the advent of ultrasonography and can be confusing. Traditionally, nonviable pregnancies are divided into different categories based on physical examination findings: (1) a threatened abortion refers to vaginal bleeding, with or without cramping, in the presence of a closed cervix; (2) an inevitable abortion refers to a dilated cervical os without the passage of tissue; (3) an incomplete abortion refers to a dilated cervical os with the passage of some but not all products of conception; and (4) a complete abortion refers to the complete expulsion of the products of conception. Recurrent spontaneous abortion refers to three or more consecutive pregnancy losses. In clinical trials, an embryonic or fetal demise has been sonographically defined as an embryonic pole or crown-rump length between 5 and 40 mm without cardiac activity. An anembryonic pregnancy (commonly called a blighted ovum) refers to a gestational sac with a mean diameter between 16 and 45 mm without evidence of a fetal pole, inadequate growth of the gestational sac, or an increase in β-hCG levels of less than 15% during a 2-day period in the presence of a yolk sac visualized on ultrasound examination.
Question 4 |
All of the following would be appropriate management strategies except
expectant management | |
uterine aspiration | |
medical management with vaginal misoprostol | |
exploratory laparoscopy | |
serial β-human chorionic gonadotropin (β-hCG) measurements |
Question 4 Explanation:
Traditionally, clinicians performed immediate D& Cs to treat spontaneous abortions. Recent evidence provides support for the role of expectant management and medical management instead of surgical intervention. Expectant management allows the patient time to complete the process of spontaneous abortion on her own. This process can occur during the course of 2 to 4 weeks, depending on the patient’s clinical symptoms and the patient’s and clinician’s level of comfort with waiting. Clinicians can monitor the progress of an ongoing pregnancy loss with serial β-hCG levels or ultrasound examination. The β-hCG level should double approximately every 48 hours in a viable intrauterine pregnancy. A rise of less than 50% is associated with an abnormal pregnancy. A change of less than 15% is considered to be a plateau, which is most predictive of an ectopic pregnancy. For incomplete spontaneous abortions, the success rate of expectant management is excellent at 82% to 96%. However, the success rate of expectant management declines with anembryonic pregnancy or fetal or embryonic death (25% to 76%).
Question 5 |
A 25-year-old female, G2 P1001, presents to your office at 11-weeks gestation with vaginal bleeding, mild lower abdominal cramping, and bilateral lower pelvic discomfort. On examination, blood is noted at the dilated cervical os. No tissue is protruding from the cervical os. The uterus by palpation is 8-9 weeks gestation. No other abnormalities are found. Which of the following is the most likely diagnosis?
Threatened abortion Hint: Threatened abortion is characterized by bleeding in the first trimester without loss of fluid or tissue. | |
Inevitable abortion | |
Incomplete abortion Hint: Complete abortion refers to a documented pregnancy that spontaneously passes all of the products of conception. | |
Incomplete abortion Hint: Incomplete abortion is when the cervical os is open and allows passage of blood. The products of conception may remain in utero or may partially extrude through the open os. |
Question 5 Explanation:
Inevitable abortion is the gross rupture of membranes in the presence of cervical dilation.
There are 5 questions to complete.
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References: Merck Manual · UpToDate