How many miscarriages does it take to be considered as recurrent pregnancy loss?
The modern definition of Recurrent Miscarriage or Recurrent Pregnancy Loss (RPL) is two or more miscarriages. In the past it was thought that three was ‘too many’, but we find the same number of problems if we test after 2, 3, or more miscarriages.
The good news is that women with multiple miscarriages still have a chance of a healthy pregnancy.
The chances of success are higher if you already have at least one child, before or in between your miscarriages, compared to women who have multiple miscarriages but no child.
If we do a relatively thorough set of tests for miscarriage (see below) we find a cause in most couples with two or more pregnancy losses. Once properly diagnosed, appropriate treatments to fix and/or work around the issue can be suggested.
Causes of Recurrent Pregnancy Loss / Multiple Miscarriages
There are many possible causes of miscarriage, and it is not uncommon for some women to have multiple issues present. We recommend thorough testing be carried out after a pregnancy loss because the more information we can obtain about the issue(s) affecting you, the more closely we can tailor our treatment and improve your odds of a successful pregnancy.
Major causes of miscarriage
- Diminished ovarian reserve (low egg supply) – if there are less eggs left in your ovaries there will be more genetically abnormal eggs, and a greater chance of miscarriage. Age is a primary factor for egg quality and older women are more likely to have diminished ovarian reserve. A diminished ovarian reserve can occur in young women as well. Risk factors for diminished ovarian reserve include smoking, ovarian surgery, STDs such as Chlamydia or Pelvic Inflammatory Disease, fallopian tube problems, endometriosis, or a mom with early menopause. However, many women who have diminished ovarian reserve do not have any known risk factors.
- Problems with the uterus – some women are born with a congenital uterine abnormality like a septate uterus, a dividing wall of tissue inside the uterus. Other problems with the uterus are acquired such as polyps of the lining of the uterus, and/or fibroid tumors (leiomyoma). Up to 25-50% of women have fibroids, but not all cause fertility issues or miscarriages – the number, size and location of the fibroids all matter. Scar tissue, especially from previous D & C procedures, can also be a problem. These uterine issues can generally be surgically corrected
- Autoimmune conditions – antiphospholipid antibodies and lupus anticoagulant are autoimmune conditions where a woman can make proteins that can attack normal tissue in the body, including the baby’s placental tissue when you’re pregnant. These increase the chances of miscarriage and, in some rare cases, can cause serious blood clots in the mother. We have treatments to prevent miscarriage in women with these antibodies. Immune system-related thyroid problems are more common in women with miscarriages, and serious autoimmune diseases like lupus also increase the risk of miscarriage, but are not common.
- Blood clotting disorders – most, but not all of these are genetically based. You may be born with genes that can increase your risk of both miscarriage and blood clots (like blood clots in the leg veins, deep venous thrombosis or DVT, which can spread to the lungs and be dangerous, especially in pregnancy). The most common blood clotting disorders don’t often cause blood clots in the mom, but they do increase the risk of miscarriage compared to women without the clotting problem several times over. More serious blood clotting disorders exist, with a much higher chance of miscarriage or blood clots, but these are rare.
- Hormonal problems – Thyroid problems or too much prolactin hormone may increase the risk of miscarriage, and untreated thyroid problems can increase the chance of OB complications.
- Genetic rearrangements in either parent’s genetic makeup – such as translocations, where part of one chromosome is swapped or joined with part of another, are rare. This occurs in approximately 3-5% of women with multiple miscarriages.
- Male factor – men that exhibit abnormal sperm quality (low counts, or poor morphology) tend have more genetically abnormal sperm, increasing the chance for genetic abnormalities in the embryo.
- Lifestyle factors – Smoking, heavy drinking and drug use can all increase the chances of a miscarriage. Caffeine intake beyond 1 cup of regular brewed coffee a day may also increase a woman’s chance of miscarriage.
- Infections – certain infections may increase miscarriages – this is controversial.
Are treatments available to prevent another miscarriage?
The treatments available to reduce your chance of another miscarriage will vary, depending on your diagnosis.
Diminished ovarian reserve, depending on how severe it is as well as the woman’s age, may respond well to fertility treatments with a woman’s own eggs, or may require egg donation.
Treatment for autoimmune conditions or blood clotting disorders can lower your chance of another miscarriage by a large amount, but we can never get you down to a zero chance of miscarriage. For example, if you have a blood clotting disorder and we treat you with a ‘baby aspirin’ a day (81 mg low-dose aspirin) combined with blood thinner shots (such as Heparin or Low Molecular Weight Heparin), your next pregnancy could still be genetically abnormal and end up as a miscarriage – the shots can’t fix the genetic abnormality. Blood thinners are given as small shots under the skin of your stomach area, and women or their partners can be taught to give these at home.
Problems in the uterus may need surgery.
If one partner has a genetic rearrangement we can do IVF (In Vitro Fertilization) with Preimplantation Genetic Diagnosis (PGD) to select healthy embryos without the genetic rearrangement. IVF with PGD testing of all 24 chromosomes – Comprehensive Chromosome Screening or CCS – can help some couples even without a known genetic rearrangement. We now perform genetic testing on all IVF embryos as our standard of care. Another option for a couple with a translocation is to use donor eggs or donor sperm instead of the partner’s eggs/sperm who is carrying the genetic abnormality.
Should I do anything different next time I’m pregnant?
We can check your progesterone levels and thyroid function early in pregnancy, with progesterone supplements or thyroid medication given if needed. Your pregnancy should be watched more closely with ultrasounds to check for normal growth and to find baby’s heartbeat in the first weeks of pregnancy. If unfortunately, you do have another miscarriage, we can offer genetic testing to see if the pregnancy was genetically abnormal or not – e.g. if the baby had an extra chromosome (a trisomy; trisomy 21 is Down’s syndrome). We can tell if the genetic problem came from the egg or the sperm.
Who should I see for miscarriage testing?
Although some might say there isn’t a ‘fertility issue’ if you are getting pregnant easily each time, we disagree. The outcome you want is a baby, not another miscarriage.
If you have experienced two or more miscarriages we recommend you see a fertility specialist (Reproductive Endocrinology / Infertility doctor or REI MD). They will be able to more accurately diagnose the root cause(s) behind your miscarriages more effectively than a regular OBGYN. If you are currently undergoing miscarriage testing it’s recommended that you do not to try to get pregnant until we know the results.
Miscarriage tests may be expensive, but we will work with you to determine your insurance coverage.
Diminished ovarian reserve (low egg supply) is just as common in women with multiple miscarriages as it is in women who are having trouble getting pregnant (infertility), and we perform a specialized ultrasound to look at the number of small follicles in your ovaries (antral follicle count or AFC) and the size of your ovaries, and blood tests including FSH, Antimullerian Hormone (AMH) and possibly a Clomid Challenge Test (CCT).
Recurrent Loss FAQs
Psychological support from friends and family is important. Counselors are available: Your OB or fertility clinic can give recommendations. Support is available from others with experience of infertility or pregnancy loss in online communities. Medically, see a Fertility specialist (Reproductive Endocrinology and Infertility or REI MD) to look for possible causes of miscarriage. Two losses is considered recurrent miscarriage not three losses. Many causes of miscarriage can be treated to reduce the chances of another pregnancy loss in your next pregnancy.
After one miscarriage, it’s best to wait a month; there is some evidence of a higher chance of another loss in the first month. After two or more miscarriages (recurrent pregnancy loss) you should see a Reproductive Endocrinology and Infertility (REI) specialist to look for causes of recurrent miscarriage before you get pregnant again. After one loss you should see an REI if it took a year or more to conceive.
Recurrent pregnancy loss is defined as two or more miscarriages. Low dose ‘baby’ aspirin – 81mg a day plus heparin or enoxaparin shots may be needed for antiphospholipid antibodies or blood clotting disorders. Surgery is indicated for a uterine septum (a dividing wall inside the uterus) or for polyps or fibroids affecting the cavity of the uterus. We treat any thyroid or prolactin hormone issues. IVF may be needed for women with significantly diminished ovarian reserve. PGD (preimplantation genetic diagnosis) may be offered and is a good idea if either partner carries a chromosome translocation where part of a person’s DNA is switched between two chromosomes. See a Reproductive Endocrinology and Infertility (REI) specialist.
There are many possible ‘risk factors’ for miscarriage but some women have no risk factors that can be identified ahead of time. Prior miscarriage(s), extremes of female age – early teens or 35 or over, smoking, uncontrolled diabetes or thyroid disease, a personal or family history of blood clots, or autoimmune diseases like lupus may all increase the risk of miscarriage. At least one previous child decreases the risk.
Many possible causes of miscarriage exist. You have more chance of another success than multiple miscarriages with no child. With 2 or more miscarriages we look for low egg supply (diminished ovarian reserve), uterine problems like polyps or fibroids or an abnormally shaped uterus, abnormal antibodies in your blood and other immune system problems, blood clotting disorders, or hormonal problems. Rarely, infections may increase the risk of another miscarriage. Genetic tests can be performed on both partners if needed. See a Reproductive Endocrinology and Infertility (REI) specialist for testing and treatment to reduce the chances of another miscarriage.
Sex when pregnant doesn’t increase the risk of miscarriage, but we usually advise women who are bleeding in the early part of pregnancy (a ‘threatened miscarriage’) not to have sex until the bleeding has stopped; if more bleeding follows after sex it just adds to the anxiety of the situation. A woman who’s had two or more miscarriages needs testing to look for a cause, by a Reproductive Endocrinology and Infertility or REI specialist if you’re trying again, or an OB doctor if you’re already pregnant.
You may still have a healthy baby: you’ve been pregnant 4 times already. Abortions rarely cause problems, but any surgical procedures (D&C) may cause scar tissue inside the uterus. After 2 miscarriages you should see a Fertility MD (Reproductive Endocrinology and Infertility or REI) to look for causes of recurrent miscarriage, including problems inside your uterus like polyps or fibroids or an abnormally shaped uterus, blood clotting disorders, immune system problems, or low egg supply (diminished ovarian reserve). Rarely, infections may increase the risk of another miscarriage.
If you have gone through the ordeal of multiple miscarriages and want help please get started here.