Recurrent pregnancy loss

Definition

Definition and causes

• Common groups of causes include chromosomal, uterine, endocrine, immunological and thrombophilic and male factors.
• In about half of all couples, the cause remains without clear explanation despite a comprehensive work-up.

• In the United States, recurrent pregnancy loss is defined as two or more consecutive pregnancy losses documented by ultrasound or histology, in the United Kingdom as three or more consecutive early losses.
• Primary recurrent pregnancy loss affects women without a previous live birth, secondary recurrent pregnancy loss women with at least one earlier live birth.

Occurrence & epidemiology

Epidemiology

• Only about 2% of pregnant women have two consecutive pregnancy losses.
• In up to 50% of affected women no clearly defined cause is found.

Aetiopathogenesis

Aetiology and risk factors

• Genetic: fetal chromosomal abnormalities account for a large share of miscarriages; one parent may carry a balanced translocation.
• Anatomical: uterine or cervical abnormalities such as uterine malformations (for example a septate uterus), polyps, fibroids, intrauterine adhesions or cervical insufficiency may be involved.
• Medical: poorly controlled chronic disorders such as hypo- or hyperthyroidism, diabetes mellitus, hypertension or chronic kidney disease are possible causes.
• The risk of pregnancy loss is lowest between 20 and 35 years of age and rises rapidly after 40.

Clinical features

Clinical features and complications

• Recurrent pregnancy loss is psychologically distressing; anxiety and apprehension are common, especially when the cause remains unclear.
• Stress is associated with recurrent pregnancy loss, but there is no evidence that it is a direct cause.

Diagnosis

History and basic diagnostics

• The basic endocrine work-up includes the measurement of TSH and TPO antibodies.

Further diagnostics

• To investigate uterine anomalies such as a septum or submucosal fibroids, ultrasound, 3D sonography of the cavity and hysteroscopy are suitable.

• The diagnosis is clinical and based on a history of two or more previous miscarriages.
• Genetic analysis of miscarriage tissue can complement the work-up.

Keep learning in the app

Further reading (selection)

1. StatPearls: Recurrent Pregnancy Loss (NCBI Bookshelf)
2. MSD Manual Professional Edition: Recurrent Pregnancy Loss
3. ESHRE guideline: recurrent pregnancy loss, Hum Reprod Open 2018 (PMC, open access)
4. DocCheck Flexikon, Habitueller Abort

Cross-references