A miscarriage is when a pregnancy ends on its own before a woman has been pregnant for 20 weeks. Miscarriage most commonly occurs in the very early stages of the pregnancy, and is uncommon after 10 weeks.
Recurrent miscarriage refers to when a miscarriage has occurred two or more times, without any normal pregnancies in between. If you have experienced recurrent miscarriage, it is important to consult with a fertility specialist for an assessment of potential causes. Sometimes no cause is identified for recurrent miscarriage, but causes that should be considered are:
- A problem with the genetic makeup of the pregnancy, such as a chromosomal abnormality. This can be due to a genetic abnormality of either the egg or sperm.
- A problem with how the pregnancy implants in the uterus. This can be due to problems with the lining of the uterus or sometimes the shape of the uterus (due to a fibroid, polyp or septum)
- General medical conditions in the mother, such as clotting problems, diabetes or thyroid disease.
When I see a couple who are experiencing recurrent miscarriage, it is very important to take into account the age of the couple, a thorough history of all pregnancies in the past and medical conditions, as well as a family history of recurrent miscarriage. After this discussion, I usually order investigations to check for a potential cause. It is important to understand that most commonly there is no cause found for recurrent miscarriage. While this can be frustrating, having no identified cause confers a good prognosis. Tests that I usually arrange include:
- Pelvic ultrasound scan – to check for polyps and fibroids as well as ovarian reserve (egg numbers).
- Genetic tests – a karyotype blood test to check for chromosome imbalances for both the man and woman
- Hormone tests – blood tests for thyroid or similar hormone problems
- Haematology tests – blood tests checking for clotting problems
- Sperm test
I sometimes also recommend that the woman have a hysteroscopy (an operation where I put a camera inside her uterus to check its shape) or a laparoscopy (an operation where I put a camera through her belly button to check for abnormalities of the tubes, called a hydrosalpinx).
If a cause for recurrent miscarriage is found, it can be treated to reduce the chance of more miscarriages. The treatment is sometimes medications, such as aspirin, or surgery in the case of abnormalities within the uterus or a hydrosalpinx. Where no cause is found, I usually offer the couple very close surveillance in their next pregnancy. This usually involves blood tests performed weekly, then when the pregnancy is big enough at about 7 weeks’ gestation, weekly ultrasounds in my office. Additional treatments that might be suitable in certain situations are:
- Progesterone supplementation
- Endometrial scratch
- IVF with blastocyst transfer
Remember, the most likely pregnancy outcome by far following recurrent miscarriage is a live baby – so it’s important to never give up trying!