Recurrent Pregnancy Loss - Overview and Endocrine Aspects

Recurrent pregnancy loss (RPL) is defined by the American Society for Reproductive Medicine (ASRM) as two or more consecutive pregnancy loss. Most RPL is not due to chance alone and should be investigated clinically.

Extensive research has been performed in order to determine the etiologies of recurrent loss. However, epidemiologic inconsistencies across studies and lack of power in many studies have made diagnostic and therapeutic recommendations scarce.

Completing the recommended workup for RPL, etiology is determined in approximately 50% of couples with RPL. This includes endocrine abnormalities, acquired and congenital thrombophilia, uterine anomalies and parental balanced translocation factors. Still, 50% of couples have no known etiology after a full diagnostic workup. Therefore, a multifaceted approach is warranted to generate for each couple a specific prognosis for a live birth in the index pregnancy.

In RPL, an effort should be made in order to determine if the fetus karyotype is normal and this can be done by referring the patient to cytogenetic evaluation of the product of the conception before evacuating the uterus.

Maternal age and the number of previous pregnancy losses are among the most important factor to determine the prognosis for livebirth after RPL. In addition, each etiology confers its own rate of live birth, and varies based on whether it is treated or untreated. For example, controlled diabetes mellitus doesn’t increase the risk to pregnancy loss, while others, like PGD for parental chromosomal aberrations, are more controversial.

The endocrinological evaluation in couples with RPL includes thyroid function test, glucose level prolactin However, the significance of thyroid antibodies (mainly anti thyroid peroxidase), thyroid autoimmunity and subclinical hypothyroidism is controversial. In addition, progesterone is well known in its impact on the immune system to help for pregnancy success. However, studies on progesterone supplements for RPL patients were with conflicting results. Finally and similarly the impact of vitamin D on the immune system in RPL was reported but routine evaluation and treatment with vitamin D is not recommended yet.

In conclusion, each couple with RPL, should be referred to a RPL clinical, carefully evaluated and treated according to the godliness and evidenced based medicine and advised with emotional support in order to provide the best outcome.