If you have had two miscarriages, you can ask about recurrent pregnancy loss testing now; you do not necessarily have to wait for a third. Whether a full evaluation is offered depends on the guideline used where you live, how the pregnancies were confirmed, and your medical and pregnancy history.
Why The Number Of Miscarriages Depends On The Guideline
The European Society of Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM) define recurrent pregnancy loss as two or more losses. ASRM specifies clinical pregnancies, generally confirmed by ultrasound or examination of pregnancy tissue. ESHRE’s definition also covers two or more pregnancies, though pregnancy type and confirmation rules can affect whether a very early loss is counted.
Guidance associated with the UK’s Royal College of Obstetricians and Gynaecologists (RCOG) has traditionally used three or more miscarriages as its definition. That threshold does not mean assessment after two is never appropriate. For example, an NHS Greater Glasgow and Clyde pathway says referral after two early losses may be considered for people aged 38 or older, or when other risk factors are present. This is a local pathway, not a rule for every UK service. Access and referral criteria can differ between regions and health systems.
So, after two losses, it is reasonable to discuss an assessment with your GP, obstetrician or fertility specialist, particularly if you have other health concerns or a history that may affect pregnancy. The number is a guide for care, not a judgment about how significant your losses are.
What Recurrent Pregnancy Loss Testing May Include
A useful evaluation starts with your history: the timing and confirmation of each loss, previous pregnancies, health conditions, medications, family history and any history of blood clots. That information helps a clinician decide which tests could change care, rather than ordering the same recurrent loss panel for everyone.
- Antiphospholipid syndrome (APS): This acquired autoimmune condition is associated with pregnancy complications. Assessment may include blood tests for lupus anticoagulant and anticardiolipin antibodies. A positive result alone does not confirm APS; repeat testing is generally needed at least 12 weeks later. Timing can also matter: an NHS Scotland protocol advises waiting at least six to eight weeks after a loss before testing.
- Thyroid function: A thyroid-stimulating hormone (TSH) blood test can check for thyroid problems. Whether thyroid antibody testing is also appropriate may depend on your history and local guidance.
- Uterine structure: Imaging, often an ultrasound, can look for abnormalities in the shape of the uterus. The type of scan and whether further imaging is useful depend on the initial findings.
These checks look for specific conditions; they cannot explain every miscarriage. A normal result does not mean the losses were not real or that you did anything to cause them.
Why A Bigger Test Panel Is Not Always Better
Inherited clotting conditions such as factor V Leiden or the prothrombin gene variant are not routinely tested for after early recurrent miscarriage. Their link with repeated loss is weak, and evidence that treatment improves pregnancy outcomes is limited. A clinician may consider clotting tests in particular situations, such as a later miscarriage or a personal or family history that raises concern about blood clots.
Broad immune panels are also not routine. Many proposed immune markers have not been shown to reliably identify the cause of pregnancy loss or guide a treatment that improves outcomes. A large panel can produce results that are difficult to interpret without offering a clear next step.
Guidelines differ because evidence for many investigations is limited, and they do not use identical definitions of pregnancy loss. Even after an evaluation, no clear cause is found for many people. Ask your clinician what each proposed test is looking for, how a positive or negative result would affect your care, and whether the test is recommended for your particular history. If you have had two or more losses, a clinician can help you decide whether to start an assessment now and what support is available.