Q I am 35 years old and have suffered three miscarriages in two years, with both happening in the first trimester.
Are there any tests to find out the cause of the recurrent miscarriage. Are there treatments to prevent another miscarriage?
Can I use in-vitro fertilisation (IVF) or intrauterine insemination(IUI) to prevent miscarriages?
A The repeated loss of pregnancy is traumatic and devastating.
There are a few known causes of recurrent miscarriage.
Your doctors can try to identify the cause of your recurrent miscarriage and, hopefully, treating this can reduce the likelihood of another miscarriage.
The causes of recurrent miscarriage are:
•Anti-phospholipid syndrome (APS) , which is sometimes called the sticky blood syndrome: It occurs when your body's immune system mistakenly attacks some normal protein in your body and increases the risk of blood clotting in your blood vessels. The blood clots can occur in the veins in your leg, causing deep-vein thrombosis, and clots can also form in the placenta, causing miscarriages or stillbirths.
•Abnormal chromosome arrangements in the parents: While about 50 per cent of repeated miscarriage are due to abnormal chromosomes in the foetus, only 2 to 5 per cent of recurrent miscarriage is because one of the parents carries a structural chromosome anomaly.
•Abnormality in the uterus (the womb): The womb lining is where an embryo implants and develops. An abnormality in the womb can lead to recurrent miscarriage. The miscarriage may be due to poor blood supply to the pregnancy or due to the distortion of the womb lining. Some women may be born with an irregularly- shaped womb, such as a womb divided by a septum within. This septum has no blood supply and implantation there will lead to miscarriage. Some women can develop abnormalities in their womb, such as a fibroid, which is a benign growth in the womb or scarring from previous womb operations.
•Hormonal/endocrine disorders which include thyroid disease and diabetes: These can cause recurrent pregnancy loss. Polycystic ovarian syndrome (PCOS) is also a common condition where the affected woman has irregular periods and sometimes high levels of male hormones. PCOS is associated with recurrent miscarriage although the mechanism of how it causes miscarriage is poorly understood.
•Abnormalities in the mother's blood clotting can also cause repeated pregnancy loss: Despite extensive investigations for all these possible causes, sometimes a reason cannot be found for recurrent miscarriage.
TESTS AND TREATMENTS
For anti-phospholipid syndrome (APS), your doctor can test your blood. If APS or clotting disorders are confirmed, treatment during your next pregnancy with blood thinners such as baby aspirin and/or heparin can help you to avoid a miscarriage.
Your doctor can take blood from you and your partner to do a chromosome culture (karyo- typing) to look for chromosomal abnormalities. If you or your part- ner have a chromosomal abnormality, the chance of a subsequent healthy pregnancy is very low.
In that case, the best treatment is pre-implantation genetic diagnosis, where you undergo test-tube baby treatment and the embryos which are formed from the treatment are biopsied to examine their chromosomes.
Only embryos with normal chromosome content are then placed into your womb.
For womb abnormality, doctors can do an ultrasound to look for fibroids.
During ultrasound exam- ination, saline can be infused into the cavity of the womb to look for other abnormalities like a septum, scarring or polyps.
When these abnormalities are identified, doctors can perform minimally invasive surgery (laparoscopy/hysteroscopy) to effectively restore the womb to its normal condition.
While IVF and IUI (artificial insemination) increase the chances of pregnancy in a treatment cycle, compared to trying naturally, it does not decrease the chances of miscarriage.
Managing the timing of certain procedures during IVF/IUI sessions, such as injection of anti- clotting medicine, could treat some of the underlying causes of recurrent miscarriage.
As about 50 per cent of miscarriages are due to chromosomal anomaly in the embryos, pre- implantation genetic screening is an option that can allow healthy embryos with normal chromosomal content to be implanted in the mother's womb.
Dr Loh Seong Feei
Medical director at the Thomson Fertility Centre.
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