A gentle birth relies on the understanding that labor is part of a mysterious continuum of physiological events, beginning with conception and continuing well into the first year of life. Mother and baby, inseparable and interdependent, work together as a unit from the fertilization of the egg until weaning from breastfeeding takes place. Mothers the world over know that the physical and psychological connections that bind our children to us last a lifetime.
How babies are created is nothing short of miraculous and women’s bodies are perfectly designed to bring forth this new life. The hormonal changes that a woman’s body experiences assist her in letting her baby be born gently. Early in pregnancy her body doubles its blood volume to be able to pump nutrient-rich blood to her growing baby.
Once the baby is implanted in the wall of the uterus, a hormone called human chorionic gonadotrophin hormone, or hCG, is released into the blood stream. The hCG level starts off very low but rapidly increases, producing physical pregnancy signs in the woman. Within two weeks of conception the breasts begin to grow larger, due to the increase in blood volume and also to the hormonal signal to start mammary gland production of milk.
A gentle birth is dependent on growing a healthy and vibrant placenta. The placenta, a pancake-shaped organ, attaches to the inside wall of the uterus and is connected to the fetus by the umbilical cord. The placenta produces many pregnancy-related hormones, including estrogen, hCG, and progesterone. Nourishing the placenta with the right foods and supplements will help to ensure a normal pregnancy and a gentle birth. Folic acid has been identified in the past few years as being a vital link to preventing early birth defects in the neurological growth of the baby.
Every placenta is a life-support system that supplies the baby with the essential nutrients for critical brain and body growth. Small blood vessels carrying the fetal blood run through the placenta, which is full of maternal blood. Here a wondrous exchange takes place: Nutrients and oxygen from the mother’s blood are transferred to the fetal blood, while waste products are transferred from the fetal blood to the maternal blood, without the two blood supplies ever mixing.
The umbilical cord is the tether that connects the baby to the life-supporting placenta. The thick, beautifully crafted ribbonlike rope has three internal strands of blood vessel—two small arteries from the baby to the placenta and a larger returning vein from the placenta to the baby. The umbilical cord can grow up to a length of about twenty-four inches. Most cords are shorter. But even short cords give the baby plenty of room to be active—rolling, turning twisting, and somersaulting within its protected home, the amniotic sac.
The fluid-filled bubble that protects and nurtures the baby for the duration of its stay begins with about six teaspoons of fluid at ten weeks and by the thirty-sixth week there can be as much as 200 teaspoons. Where does all this fluid come from? The baby makes all of its fluid and recycles it, too. Fetal urine and lung secretions make up most of the fluid in later pregnancy. The baby swallows almost as much as it pees and toward the very end of pregnancy, it swallows even more, decreasing the amount of fluid. Today there are tests which assess the volume of fluid present around the baby, but this varies on a day-by-day basis.
Progesterone, produced by the placenta, keeps the uterus relaxed, as well as the bladder, bowels, and veins, so they can adjust to more volume. This hormone is no longer needed in high doses at the end of pregnancy, so its production drops off just when the baby is signaling that it is time to be born. Oxytocin, like the CEO of a major corporation, then steps in and orchestrates the progress of labor, birth, and breastfeeding. Oxytocin is produced in the hindbrain, or “back office,” where the pituitary and hypothalamus work overtime secreting all the necessary chemicals to make labor normal. The “front office,” the neocortex, is the thinking part of the brain, which must take a break—vacation—for the duration of labor. This process starts during late pregnancy and causes women to become less intellectually focused, sometimes forgetful, but more focused within. This condition of late pregnancy is affectionately termed “placenta brain.”
The mother’s ligaments stretch more in pregnancy because of another hormone, relaxin. The softened ligaments open up the bones of the pelvis to allow the baby to pass through.
This incredible interplay of hormones, changing body, and the growing baby all culminate with the labor and birth.