Human chorionic gonadotrophin hormone for preventing recurrent miscarriage

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.

Authors' conclusions: 

The evidence supporting hCG supplementation to prevent RM remains equivocal. A well-designed randomised controlled trial of adequate power and methodological quality is required to determine whether hCG is beneficial in RM.

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Background: 

Recurrent miscarriage (RM) is defined as the loss of three or more consecutive pregnancies. Further research is required to understand the causes of RM, which remain unknown for many couples. Human chorionic gonadotrophin (hCG) is vital for maintaining the corpus luteum, but may have additional roles during implantation which support its use as a therapeutic agent for RM.

Objectives: 

To determine the efficacy of hCG in preventing further miscarriage in women with a history of unexplained RM.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2012) and reference lists of retrieved studies.

Selection criteria: 

Randomised controlled trials investigating the efficacy of hCG versus placebo or no treatment in preventing RM. Quasi-randomised trials are included. Cluster-randomised trials and trials with a cross-over design are excluded.

Data collection and analysis: 

Two review authors independently assessed trials for inclusion and assessed the methodological quality of each study. Date were extracted by two review authors and checked for accuracy.

Main results: 

We included five studies (involving 596 women). Meta-analysis suggested a statistically significant reduction in miscarriage rate using hCG.The number of women needed to treat to prevent subsequent pregnancy loss was seven. However, when two studies of weaker methodological quality were removed, there was no longer a statistically significant benefit (risk ratio 0.74; 95% confidence interval 0.44 to 1.23). There were no documented adverse effects of using hCG.