In the journey to parenthood, genetic testing is becoming increasingly common and complex. It may start with screening before pregnancy, to see if parents carry genes that could cause devastating diseases in their children. It’s usually offered in pregnancy to detect abnormalities in the fetus, and it may be used if our children have health issues, to help decipher the cause and determine potential treatments. There is no question that this technology has brought triumphs for children’s health, but it also raises difficult questions about how much control we should have over our kids’ genetic makeup and whether it’s possible to know too much about their genetic destinies.

Bonnie Rochman asks us to ponder these questions in her new book, “The Gene Machine: How Genetic Technologies Are Changing the Way We Have Kids – And the Kids We Have.” As a health journalist and a mother, she’s a thoughtful guide. She doesn’t offer easy answers, but she gives voice to scientists, doctors, ethicists, and parents grappling with these questions so that we can better understand them.

We spoke with Rochman about the promise and perils of genetic information and what to consider before you embark on testing.

Washington Post: Why did you want to write this book?

Bonnie Rochman: What I find so fascinating about genetics is that there’s an ethical component to it, so it really makes you think. There’s a lot of emotion and morals bound up with these tests. It’s a world that is constantly evolving, and we’re only getting deeper and deeper into it. We’re kind of at the cusp now, so it felt like a good time to try to make sense of where we are, providing almost a road map to the future.

WP: Many pregnant women are now offered non-invasive prenatal screening in the first trimester, which can detect several specific chromosomal problems, including Down syndrome. How has this changed things?

BR: With that particular test, the reason it was such a big deal was the non-invasive aspect of it. Before that test was developed, you had to wait until the second trimester to do an amniocentesis or do first trimester CVS [chorionic villus sampling], which are both invasive. Now you have these blood tests that can determine fairly accurately your risk, though if you get a positive result, you still need to confirm it before you should act on it.

But this is controversial, because we’re now at a point where if you’re going to have Down syndrome, there’s never been a better time to have that extra copy of a chromosome. There’s more support and research, and life expectancies have increased. So, at the same time that there has been so much progress, you now have this test that people in the Down syndrome community are concerned makes it easier than ever to have an abortion. These issues are very complex, and they cut across disability and abortion — very difficult, complex themes that we grapple with every day in our society.

WP: What should expectant parents consider before deciding to do non-invasive prenatal screening?

BR: There are two main reasons to do this test. One is if you find out that your baby has Down syndrome, and you know that it’s not something that you feel comfortable with, then you might want to move forward with ending your pregnancy.

But the other reason why you might want to do it is simply to be prepared. If you know ahead of time that you’ll be having a baby with Down syndrome, you can choose a hospital with a NICU and specialists in case your baby has problems at delivery. You can have resources in place, seek out other parents of children who have Down syndrome, do some research ahead of time about what you might expect. You can go ahead and process it and not have that shock in the delivery room. You can’t overstate the value of that.

WP: And some people choose not to do this testing. It’s very personal.

BR: It’s really important to know who you are as a person, what your mindset is, what you think about information. Do you find lots of information empowering, or does it overwhelm you? For me, I’m a journalist; I gather lots of information before I make any decision. But other people are more spontaneous, and they get overwhelmed by information, so you should think ahead of time about those sorts of things.

Genetic counselors can help you do this. These tests can reveal so much potentially powerful information that you don’t want to go into them feeling confused or unprepared. I think it’s human nature; a lot of people go into genetic testing thinking, ‘well, I’m just going to do this for peace of mind.’ But not everyone is going to get that peace of mind, so genetic counselors can help you understand what sort of information could be revealed, and is this actually something that you want to do.

WP: That becomes even more important when you get into the more powerful genetic tests.

BR: Some people are opting for chromosomal microarrays, where you analyze cells from the fetus to determine very small deletions or duplications of genetic material. What’s interesting about that is you can find information that is not readily understood. If you’re going to do that test, you’ve got to feel comfortable with uncertainty, because it is quite likely that you will get some results, like the stories of people I share in the book, where it’s really not clear what this means. You may find it empowering, or you may find it really concerning.

I tell the story of one family who went into genetic testing because their son, Daniel, had problems with his newborn hearing test. The testing did not reveal any useful information about why Daniel had minor hearing loss, but it did reveal that he had an unrelated genetic deletion [with unknown consequences]. Daniel’s parents felt completely blindsided. They were then worried about their son and his future, and then the mother found out that she shares the genetic deletion, so she’s worried about herself, when before, her life seemed fine. It harkens back to ‘be careful what you ask for,’ because you might get it, and it might be very different from what you expected.

WP: What else do you want readers to know?

BR: The book is not supposed to be a how-to manual. It’s a musing on humanity, and on how we make babies, and who makes the rules, and what the rules are in the first place. There’s not just a focus on this test or that test, because these tests are changing. A year from now, five years from now, there’s going to be something new. The technology evolves, but the questions remain the same.

Let’s acknowledge where we are in this incredible age of access to information through genetic technology, and let’s go into this with our eyes wide open and be very aware of all the ethical components that are connected to this technology. Let’s think about who should be making decisions about what kinds of children are born, and what we should know about our kids.

This interview has been edited for length and clarity.

Alice Callahan is author of The Science of Mom: A Research-Based Guide to Your Baby’s First Year. You can find her on her on Facebook and Twitter @scienceofmom.

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