It's been more than a few years now, but I remember the roller coaster ride of pregnancy like it was yesterday. Nine months of bouncing from giddy excitement to mind-bending worry, pure joy to frantic nesting. Powerful emotions are amplified by equally powerful hormones, working overtime.

As scientists report yet again this week, those churning hormones also make exposure to pesticides during pregnancy especially dangerous. Birth defects, autism, lower IQ, reduced birth weight, infertility — the risk of these life-changing impacts is higher for infants conceived during spray season or carrying pesticides in their cordblood. Yikes.

It turns out certain chemicals have a knack for confusing the hormones that guide a fetus through the delicate process of development. These 'endocrine disruptors' may be especially damaging for boys, harming development of the brain and reproductive systems of male infants at a slightly higher rate.

Doesn't take much in cordblood

One of the studies just out includes a bit of good news along with the bad. According to the Centers for Disease Control, levels of organochlorine pesticides in our bodies are much lower than they were 30 years ago. This shows that policy changes matter — these pesticides were phased out decades ago in most countries, and the bans are making a difference.

The bad news? The chemicals in question last for so long in the environment and our bodies that we're still passing them along — more than a generation later — to infants during pregnancy. And it doesn't take much to cause problems.

Scientists report in the journal Pediatrics that infants born with slightly higher levels of any of 4 organochlorine pesticides in their cordblood weighed less, and those with elevated levels of DDT had a smaller head circumference. Researchers examined nearly 500 newborns in Valencia, Spain between 2003 and 2006.

Atrazine linked to rare birth defect

But it's not just yesterday's pesticides causing trouble. Syngenta's atrazine is one of the most widely used herbicides in the U.S. today, applied mostly in corn fields. Back in 2009, researchers found that babies conceived during atrazine spray season are more likely to suffer a range of birth defects.

Now researchers in Indiana are finding that a rare birth defect called 'gastroschisis' shows up more often among babies conceived when atrazine levels are high. Gastroschisis causes an infant's intestines to grow outside the body; while survival rates are higher than they used to be, ongoing medical care can cost a family upwards of $150,000 a year.

A similar study in Washington state found women living near atrazine-contaminated water were more likely to have a baby with gastroschisis — again, with the risk especially high if the pregnancy started in spring.

Hey Syngenta, pay attention!

This story has a good news side too: there's something we can do about it. PAN is collecting signatures on a letter to the CEO of Syngenta, demanding that the company pay attention to recent evidence that their flagship herbicide causes birth defects and other harm.

Despite a growing mountain of science to the contrary, Syngenta continues to call concerns about the health effects of atrazine 'alarmist.' On behalf of moms everywhere, please sign on today and help set them straight.

This post ran previously on Pesticide Action Network's GroundTruth.