We all know stress is unhealthy and now one of the nation’s leading family writers lays out why during pregnancy it’s particularly bad: It may lead to premature births and developmental delays early in a baby’s life.

Sue Shellenbarger takes a bird’s eye view of a body of research that suggests stress among pregnant moms can impact their babies.

For example:This "pregnancy-specific anxiety" was linked to lower cognitive-development scores in babies at 12 months of age, based on a study published recently in Child Development by researchers at the University of California, Irvine, echoing other research. Women who experience this kind of anxiety worry excessively about potential problems with fetal development, miscarriage or giving birth. – “Why Worries About Baby Are Bad for Baby,” Wall Street Journal, 3/31/10.

Like so much of early learning research, all the answers are not yet clear.

Researchers don't yet understand the basis for this finding. Women may become excessively anxious about their pregnancies because they sense that something actually is amiss, which could account for the developmental delays. Or, a mother who is anxious and negative during pregnancy might tend to provide less nurturing and stimulating care after birth.

But, this Work & Family columnlays out findings on the dangers of pregnancy stress and offers help.

It also highlights the importance of the pregnancy-through-pre-kindergarten approach to early education. Early learning begins not in preschool or child care, but in the womb, which is why Thrive by Five Washington supports prenatal, doula, health care home visiting and nutrition programs.

The column offers another interesting idea that could be part to that approach, “prenatal-care groups,” meetings where expecting moms talk and get support from other pregnant moms. (Another group for expecting dads, where they can learn how to relieve their wife’s stress and get ready for a baby isn’t a bad idea either.) This support group could work for a variety of stressed out moms, from those struggling with poverty to those worried about all the things that can go wrong during childbirth, the column suggests.

Now, Shellenbarger tells us why this matters.

(Thanks to the Early Learning Community for highlighting this news.)