Miscarriage is the loss of a pregnancy before 24 weeks of gestation. Recurrent miscarriage (RM) is the loss of three or more consecutive pregnancies, which can cause significant physical and psychological harm with increased depression, anxiety and lowered self-esteem. RM can be linked to systemic maternal disease, such as diabetes mellitus, thyroid disease and polycystic ovary syndrome. In many cases, the cause of RM may remain unknown despite thorough investigations. Current strategies for preventing RM include the administration of hormones involved in maintaining pregnancy, one of which is human chorionic gonadotrophin (hCG). This hormone is important for the continued production of progesterone from the corpus luteum and may have a role in the implantation of the embryo.

This review included five randomised controlled studies, involving 596 women. When comparing the women who were treated with hCG versus placebo or no treatment, we found a benefit in using hCG. However, when two of the older studies with weaker methodology were excluded, there was no longer evidence of benefit in using hCG for preventing RM. As a result, we were unable to make firm recommendations. There were no documented adverse effects associated with using hCG. More good quality studies with larger sample sizes are needed in order to evaluate the use of hCG compared with other treatments and non-pharmacological strategies, such as early and accessible carer contact and support.