Why do we all feel so alone with a pregnancy loss? Given that women are having babies so much later, in their 30’s and 40’s, miscarriages are so much more common that you think.
How common is miscarriage?
Studies show that 10-25 percent of all recognized pregnancies end in miscarriage. This does not however include what are called ‘chemical pregnancies’, where a pregnancy is lost shortly after implantation, around the time the expected period is due or a few days later (1).
Miscarriage rate after ultrasound confirmation of pregnancy has been studied to be approximately: (2)
- Under 15% for women age 35 or under
- 29% for women at age 40
- 60% for women at age 44
- And higher after age 44
- (remember that this does not include ‘chemical pregnancies’)
On a positive note, once a fetal heartbeat has been confirmed, women in their late 30’s and early 40’s have a very good chance of continuing a pregnancy. To be specific, after confirmation of a heartbeat at 7-10 weeks pregnancy, the risk of subsequent miscarriage for women over 40 even drops to about 10% (3).
Paternal age also increases miscarriage risk. One study found that if the father was over 40, there was a 60% increase in having a miscarriage (4). Another study found approximately a 25% increase risk of miscarriage when fathers were over the age of 35 (5).
What causes miscarriage?
At least 50% (6), and some researchers report 75-90% (7) of first-trimester miscarriages, and 20% of second-trimester miscarriages are caused by chromosomal anomalies. Read that again. What that means is that there was nothing you could have done to prevent it – your body simply lets go of a pregnancy that is not healthy.
For the remaining low percentage of pregnancy losses, there are many other potential causes which include:
- infections (a few of which include Ureaplasma, Chlamydia, Mycoplasma, cytomegalovirus)
- hormone deficiencies (especially progesterone)
- exposure to environmental toxins (called teratogens)
- thyroid hormone imbalance
- blood clotting disorders
- autoimmune conditions