Alan Frischer, MD, MPH
If you have had a pregnancy that ended in miscarriage, you are not alone. Some 20% to 25% of pregnancies end prematurely. The question I hear most frequently: What could have been done differently?
The term miscarriage refers to a spontaneous abortion, or natural death of the embryo. 80% occur in the first trimester of pregnancy, and many occur so early on that a woman might not have even be aware that she was pregnant. The symptoms of miscarriage could include severe abdominal pain, cramps, vaginal bleeding, discharge of tissue with clots, fever, lower back pain, and weakness.
There are so many misconceptions around the causes of miscarriage. Some common beliefs are that they are caused by a stressful event, lifting a heavy object, having an STD, past use of an IUD, or oral contraception. Ultimately, the most common cause of miscarriage is simpler. The embryo doesn’t form properly and the body eventually rejects it. Researchers are learning more about the process that cells undergo following conception, and how things go wrong. In the very beginning, embryonic stem cells can turn into any cell in the body. At about two weeks, when the embryo should implant in the uterine wall, the cells begin to adopt particular functions. If there is a glitch along the way, the embryo will not become viable.
There are different types of miscarriages. The most common is referred to as a “blighted ovum,” when a fertilized egg is attached to the uterine wall but does not develop into an embryo. A “chemical” miscarriage occurs when the egg is fertilized but unable to survive any further, and occurs very early on in a pregnancy. An “ectopic” miscarriage happens when the embryo is implanted outside the uterus, where an embryo cannot survive.
What do we know?
Miscarriage is most common in women over 35, and when the partner is over 40, the risk is even higher. Women 20 to 24 years old have a miscarriage risk of 9%, compared to 35 year olds, who have a risk of 20%. This rises to 54% by age 42, and about 75% by age 45 or older.
Certain behaviors put a pregnancy at risk, including smoking, drug use, and extremely high amounts of caffeine.
Some medications could be a factor when used around the time of conception. These include non-steroidal anti-inflammatory drugs (aspirin and ibuprofen).
Certain health conditions, including obesity, diabetes, thyroid disease, infections, hormonal issues, autoimmune disease, and uterine abnormalities increase the risk of miscarriage.
Environmental factors include natural or man-made chemicals that may interfere with the endocrine system. This impacts hormones and the course of a pregnancy.
Genetics may play a role. When a woman has had multiple miscarriages, tests are run to look at both partners’ chromosomes.
Whether the cause of the miscarriage is known or not, there is usually little that can be done to prevent it. Feelings of grief and loss are normal, and counseling and support are more available then ever before. Sadly, one post-miscarriage study showed that 47% of women felt guilt, 41% felt they had done something wrong, 41% felt alone, and 28% felt ashamed. 45% of women did not feel they had enough emotional support.
Even though a woman may have little control over whether a pregnancy is carried to term, she (and her partner) can decide how to handle the grieving process, whether emotional help is sought out, and how to approach future pregnancies. For those of you who are pregnant or working on getting pregnant, I urge you to keep in mind that the odds of carrying a healthy baby to full term are on your side.