Recurrent Pregnancy Loss

Recurrent Pregnancy Loss

Recurrent pregnancy loss is defined as the termination of pregnancy before the 20th week of gestation occurring two or more times. Approximately 15% of all pregnancies end in miscarriage, while 1–2% of fertile couples experience recurrent pregnancy loss. Maternal age and a history of previous pregnancy losses significantly increase the risk.

Causes

Multiple factors may contribute to recurrent pregnancy loss, including:

• Uterine factors
• Endocrine disorders
• Immune system abnormalities
• Blood clotting disorders (thrombophilia)
• Genetic factors

Genetic Causes

• Fetal chromosomal abnormalities
• Parental chromosomal abnormalities
• Single-gene disorders
• Multigenic (polygenic) disorders

Most Common Genetic Abnormalities

• Trisomy
• Polyploidy
• Monosomy X
• Balanced or unbalanced chromosomal translocations

Key considerations

• Unidentified fetal chromosomal abnormalities account for 50–70% of pregnancy losses.
• Chromosomal incompatibility in the first pregnancy increases the risk of recurrence in subsequent pregnancies.
• If one or both parents are carriers of chromosomal rearrangements, the risk of embryo loss is significantly increased.
• The level of risk depends on the chromosome involved, the location of the abnormality, and the mode of inheritance.

Genetic Approach in Recurrent Pregnancy Loss

• Genetic testing is performed on fetal tissue and both parents to identify the underlying cause.
• Based on test results, families are informed about the risks associated with future pregnancies.
• In cases of previous pregnancy losses, prenatal diagnostic methods are selected according to the identified fetal abnormalities.
• Throughout the entire process, genetic counseling is provided to support families and assist them in informed decision-making.