Repeat Pregnancy Loss (RPL) is defined as two or more losses.
This blog will focus on the conventional medicine perspective on repeat pregnancy loss, including causes, testing, and treatment.
15% – 20% of all pregnancies result in miscarriage, and the risk of a miscarriage increases with maternal age.
Overall the prognosis is good for a healthy, live birth.
Even after 4 – 5 consecutive losses, a patient has a greater than 60% – 65% chance of carrying her next pregnancy to term. This means a woman is more likely to carry her next pregnancy to term than to have another loss. Success can depend on comprehensive screening and treating any underlying causes of Repeat Pregnancy Loss.
Causes of Repeat Pregnancy Loss:
- Unknown – 40% – 50%
- Blood-clotting issues – 20%
- Hormonal disorders 17% – 20%
- Anatomical issues 10% – 15%
- Inherited genetic factors 2% – 5%
- Environmental and lifestyle factors
For women over 35 the most common cause of pregnancy loss is a chromosomal abnormality that is created randomly sometime after conception, once the baby is growing. Studies suggest that women >35 will go on to have successful pregnancies in the absence of other causes of repeat pregnancy loss.
Blood Clotting Issues
Blood clotting issues account for 20% of repeat pregnancy loss. Also known as thrombophilias, the most common is Antiphospholipid syndrome (APS).
Testing for APS is done via blood tests:
- Lupus anticoagulant
- Anticardiolipin ABS
- Anti-B2 glycoprotein
Other blood clotting factors that may contribute to pregnancy loss include (these are also screened via blood tests):
- Factor V Leiden
- Protein C
- Protein S
- MTHFR mutations
Treatment for blood clotting issues are blood thinners:
- Low Dose Aspirin (LDA)
- Lovenox and/or Heparin
- Folic acid supplementation
- Referral to a perinatologist for management
Hormonal causes account for 20% of repeat pregnancy loss.
- Thyroid function
Low thyroid function is a common issue for women and can contribute to both pregnancy loss and poor fetal development. With screening and treatment, it can be successfully managed.
- TSH (Thyroid Stimulating Hormone)
- Often the only thyroid marker screened
- Debate over appropriate ranges, ideally below 3.0
- Thyroid Peroxidase & Thyroglobulin Antibodies
- Included in advanced screening
- T4 and T3
- Typically screened to fine tune medication dosages
Diabetes & PCOS
These are both associated with high levels of both blood sugars and insulin, which in turn are associated with increased risk of pregnancy loss across all three trimesters for a wide variety of (complex) mechanisms. Screening is done with a blood test for Hgb A1c (Hemoglobin A1C).
- High levels are associated with repeat pregnancy loss primarily through poor egg maturation.
- No treatment – 50% Live Birth outcome
- W/ treatment – 80% Live Birth outcome
Low levels may contribute to repeat pregnancy loss and supplementation may be helpful.
Treatment for hormonal issues should be managed by a specialized clinic. This is an area where an integrated approach to health care can be most effective.
Anatomical causes account for 10% – 15% of repeat pregnancy loss, and the losses are most commonly seen in the second trimester.
- Scar tissue
- Abnormally shaped uterus
Testing for anatomical causes is done via some combination of imaging, including ultrasounds, hysterosalpingograms (HSG),
- Saline sonogram
- HSG (hysterosalpingogram)
Treatment for anatomical causes is surgery, when appropriate.
At least 50% of first trimester miscarriages are due to chromosomal abnormalities that are randomly formed sometime after conception, when the baby is growing. There is only a 2 – 5 % chance that one of the parents is a carrier of a genetic abnormality.
Genetic testing of parents and POC (products of conception) is recommended for couples with two or more pregnancy losses
Where an inherited genetic abnormality is detected, options include:
- In vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD)
- Spontaneous conception with invasive testing of subsequent pregnancies (chorionic villus sampling (CVS) or amniocentesis)
- Gamete (egg or sperm) donation
Environmental and Lifestyle Factors
Environmental and Lifestyle Factors may contribute to pregnancy loss, and include:
- Cigarette smoking
- Alcohol consumption of greater than 3 – 5 drinks per week
- Illicit drug use, i.e. cocaine
- Caffeine consumption og greater than 3 cups daily
Testing & Treatment
For couples with two or more pregnancy losses, both partners should:
- Cease smoking and alcohol consumption
- Cease illicit substance use
- Limit caffeine consumption to three or fewer cups per day
- Normalize BMI (Body Mass Index)
For women experiencing repeat pregnancy loss, the overall prognosis for a healthy live birth is good. Screening is essential, and it needs to be comprehensive. Most causes of repeat pregnancy loss can be effectively managed, allowing for a healthy, full-term pregnancy. Working with a fertility expert will guide you through the process of screening and treatment.