Recurrent Pregnancy Loss

The term recurrent pregnancy loss is used when a woman experiences the loss of two or more clinical pregnancies¹. It affects approximately 1 in 200 couples² and the emotional toll can be huge. 

There are many proposed causes, however what can often be most difficult for women emotionally, is that in a number of cases, the cause will remain unknown. Generally, after having experienced several losses in a row, a couple will be referred to a fertility specialist for investigative testing. Some GPs will be able to provide a referral for these tests, but it’s more likely that you will see a specialist. 

Below is a list of what is generally tested during investigations for recurrent pregnancy loss:

• Male and female karyotype
• AMH, LH, FSH, oestradiol
• TSH Prolactin, Testosterone
• Full Blood Count
• Cardiolipin antibodies, Lupus anticoagulant
• Protein C, Protein S, anti-thrombin III
• APCR
• Factor V Leiden
• Prothrombin gene mutation
• MTHFR mutation
• Fasting glucose, insulin, homocysteine
• Thyroid antibodies
• Peripheral blood activated natural killer cells
• Uterine natural killer cells and other endometrial pathology
• Pelvic ultrasound scan
• Hysteroscopy (and sometimes laparoscopy)
• Semen analysis and sperm DNA fragmentation
• Causes of Recurrent Pregnancy Loss

One of the most common causes of recurrent pregnancy loss is chromosomal abnormalities in the developing baby. In some cases this is a random occurrence, but in 2-5% of couples, one of the partners carries a balanced chromosomal abnormality².  It’s for this reason that one of the first lines of investigation for couples experiencing recurrent pregnancy loss is karyotype testing. If an abnormality is detected, the couple can proceed to IVF with PGD embryo testing, or they may choose to continue to conceive naturally, but undertake CVS testing in any future pregnancy.

Anatomical causes of recurrent pregnancy loss include uterine fibroids, a septate uterus and Asherman’s syndrome. In these cases, surgical treatment can be considered and especially in the case of a septate uterus, improved pregnancy outcomes can be seen.

Endocrinological investigations include thyroid function, glucose metabolism, polycystic ovary syndrome (PCOS), progesterone and prolactin. Evidence suggests that hypothyroidism may contribute to recurrent pregnancy loss, and treatment for such may be beneficial. 

There remains controversy among healthcare professionals as to the role that immunology plays in recurrent pregnancy loss, so it is best to speak to your specialist in regards to what is appropriate in your particular situation.

Unexplained Recurrent Pregnancy Loss

Recurrent pregnancy loss remains unexplained in up to 50–75% of cases¹.  This can be extremely difficult for couples to accept, and specialist advice and treatment is advised, along with emotional support and understanding. The good news is that in many cases, with specialist intervention and the use of Assisted Conception, a couple’s chance of a successful pregnancy can be increased.

1. Li YH, Marren A. Recurrent pregnancy loss: A summary of international evidence-based guidelines and Practice. Australian Journal of General Practice. 2018;47(7):432–6. doi:10.31128/ajgp-01-18-4459
2. Royal College of Obstetricians and Gynaecologists. The Investigation and Treatment of Couples with Recurrent First Trimester and Second Trimester Miscarriage. London: RCOG, 2011.