As the crystal probe slides across her belly, Hilda Manzo, 33, stares wide-eyed at the video monitor mounted on the wall. She can make out a head with a mouth and two eyes. She can see pairs of arms and legs that end in tiny hands and feet. She can see the curve of a backbone, the bridge of a nose. And best of all, she can see movement. The mouth of her child-to-be yawns. Its feet kick. Its hands wave.
Dr. Jacques Abramowicz, director of the University of Chicago's ultrasound unit, turns up the audio so Manzo can hear the gush of blood through the umbilical cord and the fast thump, thump, thump of a miniature heart. "Oh, my!" she exclaims as he adjusts the sonic scanner to peer under her fetus' skin. "The heart is on the left side, as it should be," he says, "and it has four chambers. Look--one, two, three, four!"
Such images of life stirring in the womb--in this case, of a 17-week-old fetus no bigger than a newborn kitten--are at the forefront of a biomedical revolution that is rapidly transforming the way we think about the prenatal world. For although it takes nine months to make a baby, we now know that the most important developmental steps--including laying the foundation for such major organs as the heart, lungs and brain--occur before the end of the first three. We also know that long before a child is born its genes engage the environment of the womb in an elaborate conversation, a two-way dialogue that involves not only the air its mother breathes and the water she drinks but also what drugs she takes, what diseases she contracts and what hardships she suffers.
One reason we know this is a series of remarkable advances in mris, sonograms and other imaging technologies that allow us to peer into the developmental process at virtually every stage--from the fusion of sperm and egg to the emergence, some 40 weeks later, of a miniature human being. The extraordinary pictures on these pages come from a new book that captures some of the color and excitement of this research: From Conception to Birth: A Life Unfolds (Doubleday), by photographer Alexander Tsiaras and writer Barry Werth. Their computer-enhanced images are reminiscent of the remarkable fetal portraits taken by medical photographer Lennart Nilsson, which appeared in Life magazine in 1965. Like Nilsson's work, these images will probably spark controversy. Antiabortion activists may interpret them as evidence that a fetus is a viable human being earlier than generally believed, while pro-choice advocates may argue that the new technology allows doctors to detect serious fetal defects at a stage when abortion is a reasonable option.