Managing expectations for the expecting

Short White Coat is a blog about learning to be a doctor. Posts appear here as part of White Coat Notes. Ishani Ganguli is a third-year Harvard medical student. E-mail her at shortwhitecoat@gmail.com.

Jarring headlines on in vitro fertilization (IVF) and birth defects caught my eye the other week. Since the start of my obstetrics and gynecology rotation, I've been fascinated by how couples conceive of the black box that is their unborn child. Here was yet another piece of data thrown into the dizzying mix of uncertainties that surrounds a pregnancy.

The retrospective CDC study featured in these articles found that babies conceived by IVF and similar techniques have two to four times the odds of having congenital problems such as cleft lip and heart wall defects. But when you read well beyond the headlines, it becomes clear that the baseline odds are still pretty low (about 1% of babies without defects that they studied had been conceived through such technology, compared to 2.4% of babies with defects).

Such number acrobatics are recapitulated in the conversations I've had and observed with expecting couples on the rotation. I spent a morning on genetic counseling--a service that intercepts parents as early as pre-conception. Counselors play a particularly important role when positive screening tests beg more definitive diagnostic tests, including amniocentesis, that come with their own set of risks to mother and fetus.

The pitfalls in communicating risk were thrown into relief with our second patient of the morning: a Dominican woman in her late 30s. She was accompanied by her feisty three-year-old and a hospital-hired Spanish translator. As the little girl repeatedly spilled out the office's stash of toys, the counselor laid out the odds for her brother or sister-to-be: The levels of biochemical markers found in the mother's blood quadrupled her age-based risk of having a baby with Down's Syndrome--to 2%. "Is this bad or good?" she asked in Spanish. The answer, of course, was not this simple, and I wondered if she would have responded differently if the counselor had cited her 98% chance of having a healthy baby.

Ideally, genetic counselors present multiple ways of understanding risk (out of 200 pregnant women undergoing amniocentesis, one will miscarry as a result, versus a 0.5% miscarriage rate), but language is just one of the reasons why this doesn't always happen.

We dispelled her misconception that she was required to have an amniocentesis (was this language related as well?) and sent her to ultrasound to get more data on her child's risk of having Down's and other issues. This patient planned to have her baby regardless of the results, it turns out, and the emotional stakes were somewhat lowered. But what if her decision to terminate had rested on these figures?

There is a unique challenge in guiding women through such intensely personal decisions shaped by newspaper clippings, value systems, what happened to their best friend's baby, and so many other intangibles. Whether it's for a single teen deciding between college and motherhood or a couple on their third round of IVF, I look forward to my role in sorting through the numbers.