What science knows - and doesn’t know - about miscarriages

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Roughly a quarter of all women experience a miscarriage during the lifetimes. And while most go on to successfully conceive and have children, it’s often difficult to know exactly why the pregnancy failed.

A big part of why is down to simple timing and circumstance: Most miscarriages occur early on and at home, before the patient makes her first prenatal care visit eight or 10 weeks into the pregnancy. As a result, there’s nothing left for a doctor to test.

The most common reason for a miscarriage is a genetically or structurally abnormal baby that simply isn’t viable, says Zeynep Alpay-Savasan, M.D., a maternal-fetal medicine specialists and OB-GYN at Beaumont. “If it’s a very abnormal human being, it’s not going to survive,” she says. “Very abnormal ones get rejected very early in the pregnancy.”

Then there are other, less common causes:

  • a structurally abnormal uterus
  • hormonal problems, such as diminished ovarian reserve (or capacity to provide viable egg cells)
  • obesity
  • glucose intolerance
  • thyroid problems
  • immunologic problems
  • genital infections
  • environmental or lifestyle factors, such as exposure to medications or toxic substances, malnutrition, smoking or alcohol use

One other possible factor is psychological problems, such as stress, depression or medication use - though Dr. Alpay-Savasan cautions that it’s difficult if not impossible to establish linkages between one specific psychological disease or medication to miscarriage. “We know that psychological problems increase the risk of miscarriage,” she says.

Dr. Alpay-Savasan heads up Beaumont’s new Recurrent Pregnancy Loss Clinic, which is taking a unique, multi-disciplinary approach to helping women and couples who are struggling to carry a pregnancy to term. Yet she estimates she can only identify causes of miscarriage in patients up to 40 percent of the time.

Some genetic tests aren’t good enough to detect some of the genetic problems, so providers have to know what type of test you need to detect problems, Dr. Alpay-Savasan says. And many structural problems, such as a brain anomaly, won’t show up in tiny fetuses at eight weeks.

There are also the mysteries of the uterus - and specifically the endometrium where a fertilized egg attaches.

“There’s still a lot of things unknown about this uterine environment,” Dr. Alpay-Savasan says. “There’s lot of research that’s going on, and that’s one of the things that we’d like to work on in this clinic too, is start some research projects, first to identify any further problems in the mom or in the baby, and the second is to offer some treatment. These are going to be on the research protocol.”