This story is part of a week-long series on reproduction, from preventing premature births to childfree Reddit.

Most nights, talk around Kristin Hamann’s dinner table eventually turns to genetics. Her husband, Rodrigo Martinez, works for George Church’s whole genome sequencing company outside of Boston, so that’s hardly a surprise. When their 4-month-old daughter Julia started getting a rash on her face recently, Hamann wondered if maybe something in her own diet was triggering it. That’s when her husband, who had recently had all 6 billion base pairs in his genome sequenced, told her that he had a genetic variation that made him sensitive to gluten. Hamann stopped eating wheat and her daughter’s rash seemed to clear up. “For a first-time parent I’m fretting all the time and it would be so helpful to know these little things instead of just guessing,” she says.

But back when Julia was still just a 10-week-old fetus inside her womb, Hamann wasn’t so keen on having a giant mountain of information. Not that prenatal whole-genome sequencing is commercially available yet (though it’s definitely coming). But what is available is something called noninvasive prenatal genetic screening (NIPT). Based on a blood sample from mom, they have been used for several years to tell expectant parents if their baby might have, say, a chromosomal abnormality. Then the parents might make the choice to terminate the pregnancy—or to prepare for a child with disabilities. Makers of those tests, though, are already pushing the technology beyond its recommended uses to flag a rapidly expanding list of the unborn’s potential genetic flaws. But these bigger and bigger menus of genetic testing also come with less and less information about how predictive the data they reveal actually is. And as these types of tests become routine, women like Hamann have to figure out what they want to know, and what they’ll do with the information they receive.

Here’s an example of some of their options, from a New York–based company called Sema4, which launched its NIPT line in August of last year. There’s a standard screen that tells you about three disorders that result from having three copies of chromosomes 21, 18, or 13—Down syndrome, Edwards syndrome, and Patau syndrome. The next step up is a screen that also detects any missing or extra Xs and Ys, associated with common intersex conditions. These are not usually life-threatening, and in fact many people don’t know they have one until they hit puberty; the main features include infertility, altered sexual development, and, in some cases, intellectual disabilities. Some can be treated with hormone therapies during childhood. The American College of Obstetricians and Gynecologists doesn’t think NIPT screens should be used for anything beyond these conditions (though it is currently reviewing that position). But Sema4 also offers a test that looks for trisomies in chromosomes 15, 16, and 22. And finally there’s the Expanded package—Sema4’s most frequently ordered test. It also detects microdeletions—chunks of missing DNA—that cause rare but serious developmental disorders like Prader-Willi and Cri-du-chat syndromes. Symptoms for some of these microdeletions vary widely, from potentially fatal to quite mild. A few are commonly associated with attention deficit disorders and certain forms of autism.

Sema4 is not alone in offering screens for microdeletions, which, while relatively rare, show up equally in pregnancies for women of all ages. Leading sellers of NIPT screens, Natera and Sequenom, both introduced similar products back in 2014. Sequenom's latest version of the test also goes one step further, picking up any large missing or extra chunks of DNA, even if those sections are not known to be associated with any medical problems. In 2017, Natera launched a new test that reports on 30 rare, single-gene disorders, marketed to "women who want to know 'everything.'" Hamann and her husband didn’t opt for any of these; they were only interested in a potential Down syndrome diagnosis, so went with the standard NIPT trisomy screen. “I was really pretty choosy about only taking a test that would give us the information we needed to know at the time, to help us prepare for the baby’s arrival," she says.

Megan Molteni covers biotechnology, medicine, and genetic privacy for WIRED.

Because NIPT screens can be performed earlier than other kinds of prenatal genetic tests—as soon as 9 weeks into a pregnancy—it gives women and their partners more of a head start for coping with the implications of any abnormalities that might turn up. But those decisions get more complicated as NIPTs start being used to identify genetic conditions that are not as severe as, say, Trisomy 13. (Survival rates for those babies are very, very low.) Many people want as much information about their babies as they can possibly get, but what do you do if you discover your kid might have not a major chromosomal defect but a more minor one? Few people know as much about genetics as Hamann to know that more information doesn't come with more wisdom about how to wield it. As companies amass these valuable stockpiles of prenatal DNA, should there be limits to how much data they can report back to prospective parents? And what about people without the means to join in the genetic data sprint to the womb? Noninvasive prenatal testing was supposed to make the modern pregnancy easier, safer, and less anxiety-ridden. But what if all it did was move the age of information overload in utero?