A Cost Accounting of Birth

BIPEDALISM

In contrast to the Old Testament, which blamed the pain of childbirth on sin, evolutionary biologists in the late twentieth century proposed the obstetrical dilemma: the human birth process was difficult and dangerous because the baby’s encephalized head had to pass through a mother’s bipedal birth canal. This hypothesis, well accepted through the turn of the century, and even still accepted by some, contended that the change in pelvic shape when humans began to walk, and the increase in brain size of the infant, pushed the birthing process to the edge of what was possible.

It’s an edge most birthing women have experienced. “The ring of fire,” they say of the moment the infant’s head crowns. Each of the times I give birth—clenching and shuddering on a hospital bed, and later biting the edge of a mattress—my body burns and rips and I think, This is what it feels like to die. I’m going to die. My body can’t do this.

CRANIUM

The newborn cranium, broken into five not-yet-ossified plates that shift and slide against each other, protects a brain that is only 28 percent of its adult size, unlike most other mammals, who by birth have already developed at least 40 percent of their adult brains. Baby gorillas are blessed with 45 percent of their adult brains. The domestic llama: 72 percent.

Despite its relative smallness, however, the human infant’s cranium barely escapes the bones of the birth canal—a tighter fit, biologists admit, than most other primates.

DANGERS

When I am pregnant, health practitioners give me a long list of things to avoid, including but not limited to caffeine, alcohol, unpasteurized cheese, sushi, excessive exercise, and almost any medication stronger than Tylenol. I pee in a cup before each appointment, and midway through each pregnancy, I am told to drink a thick, sugary drink that makes me nauseous and brings on a migraine, all to test if I have gestational diabetes. I don’t, but as my blood pressure ticks up, the nurses frown and say we’ll have to watch for preeclampsia.

I’m not afraid of childbirth, but there is fear in this room, and it seems the danger is me.

DEATH

In Brought to Bed: Childbearing in America, 1750–1950, Judith Walzer Leavitt describes childbearing as a “shadow” that followed women throughout their childbearing years: “Young women perceived that their bodies, even when healthy and vigorous, could yield up a dead infant or could carry the seeds of their own destruction.”

They of course had a reason. Early in the twentieth century, one mother died for every 154 births. Which means, from a group of thirty young women, childbirth would kill at least one.

FISTULAS

In addition to death, women often feared physical debility. Some women suffered from vesicovaginal or rectovaginal fistulas: holes between the vagina and either the bladder or the rectum. Before physicians knew to repair these holes—and before J. Marion Sims, the so-called father of modern gynecology, perfected the procedure by practicing on enslaved African Americans—women simply suffered, living the rest of their lives with urine or feces leaking through the vaginal opening, impossible to control.

Walzer Leavitt writes in Brought to Bed that some of these fistulas resulted from “the violence of childbirth.” Others, however, were caused by forceps, the metal tool physicians clamped around the emerging infant’s head. Sometimes the forceps punctured the infant’s skull. Sometimes they tore through the woman’s flesh.

GESTATION

It makes no sense. For nine months, the fetus spins and kicks and shifts and grows in the womb. One would think, as its head grows to the point where it may not escape, that the female body would simply evict it earlier. Too big for the door? Out you go!

Recent work by evolutionary biologists, however, has disproved the obstetrical dilemma: a pelvis large enough to accommodate a newborn’s head would not, actually, limit a woman’s ability to walk. Instead, new research suggests that metabolism, perhaps even more than the pelvis, constrains...