It's no secret that humans need food to survive. For a growing fetus, proper nutrition is especially important. When the mother eats a regular diet, nutrients are automatically passed from her to the baby. However, if food is restricted for some reason, the unborn fetus could be at risk for some serious health problems.
As long as they have water, adult human beings can survive an average of four or five weeks without food. However, some individual characteristics can affect this, including how healthy the person is before he stops eating, his physical size, particularly muscle mass and how much body fat he has, and his will to live. Other considerations are how much the person moves around during starvation, and the type of weather he is exposed to at the time.
A fetus might be in danger of starving for two reasons. First, there is a problem with the mother's internal organs. A life-threatening condition called pre-eclampsia sometimes occurs late in pregnancy, where the placenta has not formed correctly and the fetus is cut off from its food supply. The second reason a fetus would be in danger of starving is much more common: the mother stops eating. This might happen if food is unavailable to the mother, or if the mother is sick (including depression and eating disorders), decides to start a diet or purposefully wants to hurt the baby.
Drs. D.L. Hard and L.L. Anderson conducted a study in 1979 to see what the effects of starvation would be on an unborn fetus. A sample of pregnant swine, all in their second or third trimester, were given nothing but water for 40 days straight. Seventy-four percent of these pigs ended up giving birth normally, meaning their babies did not die even after a month and a half of complete starvation. Pigs are not humans, of course, but biologically they are very similar to humans. This experiment shows that a fetus has a good chance of surviving starvation for the same amount of time as an adult. Therefore, if a mother stops eating, her baby will probably not die until she does.
While death is a possibility, a much more likely outcome from fetal starvation is birth defects. One of the best documented cases of fetal starvation available to modern scientists involves the Dutch Hunger Winter. During the winter of 1944 to1945 in the Netherlands, World War II was raging and most people in certain Dutch populations survived on about 1,000 calories a day, including pregnant women. The effects on babies born during this winter starvation have been studied extensively. Problems include low birth weight, a small head, poor brain development, and mental disorders later in life. In a separate study done by Dr. A.L. Schaefer and his colleagues in 1984, the effects of starvation on unborn sheep included genetic malformations of the brain, kidneys, liver, lungs and muscles.
No pregnant mother should go on a diet to lose weight without consulting a doctor first. Pregnancy is a time where you want to gain weight, not lose weight. The Mayo Clinic suggests eating a regular balanced diet, adding foods rich in folate (folic acid) and calcium, and taking prenatal vitamins. Expectant mothers are the only link their baby has to the outside world, and it's up to future moms everywhere to provide the best diet they can for their unborn child.