Obesity increases the risk of complications during pregnancy and in some cases, even moderate overweight seems to have a negative effect. It is needless to dramatize however, because the risk remains, in this case, modest.
It is better for a pregnant woman to be than obese. All studies confirm that obesity is negative for both the mother and child. It increases the risk of hypertension and diabetes during pregnancies, which are well known risk factors for premature delivery and neonatal complications. An obese woman is also more likely to have a new-born with high birth weight and cesarean delivery.
The existence of obesity increases the risk of birth of a stillborn child, while thinness is associated with a decrease in neonatal mortality, according to a Swedish study. For women that carry out their first pregnancy, being overweight, even moderate, is associated with an increased risk of stillbirth, while for those who have had one or more children, only the frank obesity seemed to play an unfavorable role. The risk of very preterm birth was also increased in obese women giving birth to their first child. The women were thin, however, more likely than obese children have low birth weight.
Logically, it is not recommend that an overweight woman to try to lose weight before becoming pregnant. However, it would be very unfair to advice against pregnancy for the sole reason that a woman is obese. Indeed, subject to adequate monitoring to detect and treat diabetes or hypertension, many obese women give birth without any problems, and their children are in good health. Furthermore, it is not uncommon for a real obesity arises during pregnancy. It is better to be careful not to take more than 9-12 pounds on top of your usual weight.
A constitutional thinness, linked to the morphology of the woman and not to dietary restriction, does not appear to cause significant risk to the pregnancy. Young women with anorexia usually have amenorrhea, which limits the risk of pregnancy. However, it may happen that a pregnant woman is anorexic or bulimic behaviors during pregnancy. Food restrictions or vomiting can lead in this case of vitamin deficiency and iron, and growth retardation in children, which are not without consequences for the future. The monitoring of infants who had a birth weight below the normal reveals that, surprisingly, they have a higher risk of obesity and cardiovascular disease in adulthood. Thus, it is better to keep a balanced weight in order to avoid any kind of troubles during pregnancy.