Comprehensive Overview of Spontaneous Abortion (Miscarriage)
Definition and Overview
Spontaneous abortion, also known as miscarriage, is the loss of a pregnancy before 20 weeks' gestation. Within the medical context, pregnancy is defined as the status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. It is important to note that the layperson use of the term “abortion” is often intended to refer to induced termination of a pregnancy, whereas “miscarriage” is preferred for spontaneous loss.
Epidemiology
Spontaneous abortion is a common complication of early pregnancy. Statistics indicate that it accounts for pregnancy loss in 10%–20% of clinically recognized pregnancies. This condition occurs in all age groups, but the incidence is higher in women > 35 years of age. Currently, there is conflicting data on racial predilection.
Etiology and Timing
Most spontaneous abortions occur within the 1st 12 weeks of gestation. These events can be caused by several factors such as infection, trauma, and genetic and autoimmune causes.
Classification and Clinical Presentation
Spontaneous abortion can be classified into the following types based on clinical findings:
- Threatened abortion
- Inevitable abortion
- Incomplete abortion
- Complete abortion
- Missed abortion
Summary of Spontaneous Abortion Types
| Classification | Description |
|---|---|
| Threatened | Potential pregnancy loss with specific clinical signs |
| Inevitable | Pregnancy loss that cannot be prevented |
| Incomplete | Partial expulsion of products of conception |
| Complete | Total expulsion of products of conception |
| Missed | Fetal death without expulsion of tissue |
Diagnosis and Management
Spontaneous abortions are diagnosed based on history, physical examination, and ultrasound findings. Once a diagnosis is confirmed, various management options include expectant, medical, or surgical therapy.