Miscarriage/Recurrent Pregnancy Loss

I have always been amazed at what we don’t know about the causes and treatments of miscarriages.  It is such a common occurrence and yet remains a bit of a medical mystery.  Recurrent pregnancy loss is devastating to the couples involved and hearing that the cause or the preferred treatment is simply not known is beyond frustrating.  Doctors tell me that patients often demand action (“Do something, anything, don’t just stand there!”), but medical history is full of stories of unsuccessful and sometimes harmful “treatments”.  Think of the DES debacle of the 1940s through 1960s, where an estimated 5-10 million pregnant women were given this drug that not only was not effective at preventing miscarriage, but was later found to cause cancer and infertility in the daughter exposed inter-utero.  Sometimes nothing is better than something, but the hope is that medical science will learn more about the causes and treatment of recurrent miscarriages.  I was anxious to hear about some of the latest research when I attended the European Infertility Conference (ESHRE).

We did a recent show on Miscarriage/Recurrent Pregnancy Loss and one of the questions we received was whether to take aspirin to prevent miscarriage.  The attitude of the questioner was that basically nothing else was working, so what do I have to lose.  Some recent research addressed this question.  One well designed study in The Netherlands followed 364 women with unexplained recurrent miscarriage.  This was a randomized, placebo-controlled trail, which is the gold standard for research.  The study lasted four years.  Some women were given low dose aspirin, some women were given low dose aspirin combined with low molecular weight heparin, and some women were given a placebo.  The doctors, patients, and nurses did not know which medications the women received.  The researchers found that neither aspirin, nor aspirin combined with low molecular weight heparin, improved live birth rate more than the placebo.

However, another study found that for certain women with recurrent miscarriages, low dose aspirin with low molecular weight heparin did improve pregnancy outcomes.  This study followed 156 women in India, 75 with Polycystic Ovarian Syndrome (PCOS) and 81 without PCOS.  All the woman in the study received intravaginal micronized progesterone twice daily.  The women with insulin resistant PCOS took metformin throughout their pregnancies.  The researchers found that the only group that benefited from the low dose aspirin and low molecular weight heparin were women with very high levels of homocysteine in their blood (classified as hyperhomocysteinemia).  Hyperhomocysteinemia was more prevalent in woman with PCOS.

One of my favorite sessions that I attended at the European Infertility Medicine Conference (ESHRE) answered the question of how long should you wait after a pregnancy loss before trying again.  To me, this is science at its best—answering a real life question faced by millions.  Couples are often counseled to wait 6 to 12 months before trying to conceive again after a miscarriage.  Scottish researchers looked back at 30, 937 women between 1981 and 2000 that conceived after a miscarriage.  They found that woman who conceived less than 6 months after a miscarriage were less likely to have another miscarriage, less likely to have an ectopic pregnancy, less likely to have a pre-term delivery, less likely to deliver by caesarean, and less likely to have a baby with low birth rate. The researchers concluded that there were no advantages to waiting to conceive after a miscarriage.