During pregnancy, the pregnant woman's body adapts. First, it builds up "maternal reserves", which it will then deliver to the fetus. Certain nutrients are therefore essential for the proper development of the fetus.
The effects of undernutrition on pregnancy are well documented, thanks in particular to the work of work1 by Stein Zand Susser M. (1975) and Painter RC et al. (2006)² on the Rotterdam famine (1944).
Children conceived during this period of food deprivation showed low birth weight and height, as well as reduced cranial circumference. These effects are easy to explain, as the women were unable to build up reserves, consuming almost all the energy ingested through their diet for their own survival. Children were also more likely to suffer from coronary heart disease, especially those conceived at the start of the famine.
Folic acid (vitamin B9) is the micronutrient essential for the synthesis of nucleic acids (including DNA) and proteins in the fetus. A folate deficiency in pregnant women can lead to spina bifida3 in the infant.
Iron is a mineral element and a constituent of hemoglobin (the blood protein responsible for transporting oxygen to the cells). If this trace element is not provided in sufficient quantities in the mother's diet, she will develop anemia.
This lack of iron in the red blood cells will have serious consequences on the health of the fetus, and may cause intrauterine growth retardation (IUGR)4 potentially responsible for attention and learning disorders in the growing child.
We all know the harmful effects of alcohol on adult human beings. However, we might think that an occasional glass is harmless for a pregnant woman, and that her liver will take care of eliminating the alcohol. But this would be a serious mistake.
Alcohol is a powerful teratogen, meaning that it considerably increases the risk of malformations in the fetus. This can range from a simple facial deformity to irreversible, disabling psychomotor retardation. Alcohol is therefore strictly inadvisable for pregnant women.
Finally smoking5 in pregnant women remains one of the main causes of ectopic pregnancy and in utero mortality. Smokers expose the fetus to a higher risk of IUGR. Carbon monoxide (CO) from cigarettes binds to fetal hemoglobin. Nicotine constricts the vessels of the uterus, preventing oxygen from circulating properly. The risk of asthma or other respiratory problems is greater in children exposed to smoke in utero, etc.
Yet in France, the rate of pregnant smokers is the highest in Europe. Quitting smoking is always beneficial, whatever the stage of pregnancy. It is therefore advisable to stop smoking as soon as possible, and preferably before conception.
More than just an omega-3 requirement, a pregnant woman's body needs to take precautions in terms of diet (sufficient energy, folate and iron intake) and behavior (stopping smoking and alcohol consumption), in order to give birth to a healthy baby.
1: Stein Z. and Susser M., "The Dutch Famine, 1944-1945, and the Reproductive Process. II. Interrelations of Caloric Rations and Six Indices at Birth." (1975).
2 : Painter RC et al (2006), "Early onset of coronary artery disease after prenatal exposure to the Dutch famine", August 2006.
3: Le Centre de Référence Spina Bifida - Dysraphismes, "Spina Bifida: La maladie".
4: Institut national de la santé et de la recherche médicale, "Atteinte cérébrale en cas de retard de croissance intra-utérin : un mécanisme dévoilé?", November 2016.
5: Tabac Info Service, "Pregnancy".
