Many women do not gain healthy pregnancy weight in their first trimester. This is because most women end up suffering from morning sickness and are unable to keep any food or liquids down. This should not be too worrying.

However, to have a healthy baby at the end of nine months, it is necessary for a woman to gain approximately 25 to 35 pounds over the course of 9 months. If the woman does not gain healthy pregnancy weight or tends to diet during pregnancy, it could have severe effect on the health of the baby.

Amount of weight a woman gains differs from woman to woman. However, if the woman gains less than 20 pounds over the course of 9 months, there are chances that the baby will be small, premature and / or suffer from growth retardation.

This does not mean that a woman should gain too much weight because that too is quite risky. Gaining too much weight overworks the muscles and results in leg pain, backache, varicose veins and fatigue.

A woman is advised to gain healthy pregnancy weight in order to nourish the developing fetus and to have sufficient reserves to breastfeed the baby when it is born. Most women gain around 3 to 4 pounds in the first trimester; 12 to 14 pounds in the second and 8 to 10 pounds in the third trimester. The weight gain starts decreasing after the 35th week of pregnancy and it stops completely after the 38th week. Many women end up losing weight 7 to 10 days before they go into labor because of reduction in their hormone levels.