Weight gain during pregnancy is very normal as body undergoes many changes to support development of fetus. During pregnancy woman need more nutrition and energy to meet the needs of fetus as well as to fulfill her own bodily needs.

Mainly woman gains weight during pregnancy because now she is not only carrying her own weight but she has the weight of fetus, placenta and amniotic fluids. These three elements also constitutes in the weight gain process of woman. In most cases mother gain most of her weight during third trimester which are last three months of pregnancy because during these months fetus increases weight and becomes a complete baby.

Causes of weight Gain

As soon as woman gets pregnant there are many changes which start to occur inside the body of woman. In this regard weight gain during pregnancy is very normal. One should not worry about its gain. But if sudden abrupt weight gain occurs then it is advised to go for checkup. Normally weight gain occurs due to following reasons

1.     Fetus

As soon- as woman gets pregnant her body starts to experience many changes. When egg gets fertilized it turns into an embryo. Embryo undergoes many changes to develop into a baby. Before baby is born it is completely grown up inside the body of mother. It means that in the beginning it was fetus with less mass but before birth it will gain weight. This also contributes to weight gain during pregnancy of mother. Average weight of fetus is around 7-8 pounds.

2.     Placenta

 Another main reason of weight gain during pregnancy is weight of placenta. Placenta is a bridge which is form between mother and fetus. Primary function of this placenta is transportation. It transports materials between mother and fetus.

Fetus takes blood, water, nutrition, and other important materials which are needed for the healthy development of fetus. In return baby excretes deoxygenated blood. Uric acid and other used up materials back to mother through placenta. So this means placenta also has some weight which will be included in mother’s weight.  Average Weight of placenta is 1.5 pounds.

3.     Amniotic fluid

Third reason of weight gain during pregnancy of woman is weight of amniotic fluid. Amniotic fluid is transparent or yellowish liquids that is present around the fetus. Fetus freely moves inside this fluid as this fluid is in constant motion. This provide cushion against sudden movement or blow.

Fetus inhale and exhale this fluid while moving in this sac. This fluid is rich in nutrition as well. It does not only provide protection but also nutrition and support to the cord and fetus. Average weight of amniotic fluid is 2 Pounds. It is also common reason of weight gain during pregnancy.

4.     Larger size of uterus

During pregnancy one more change that occurs in the body of mother is size of uterus. To deliver baby safely size of the uterus also increases. Almost 2 pounds are included in total weight of pregnant woman cause of this change in size of uterus. so it also contributes to overall weight gain during pregnancy.

5.     Larger in breast size

One of the common sign of pregnancy is change in size of breast. At the start of pregnancy size of breasts starts to change. The main reason of this change is that body is getting ready to provide breastfeed to newborn baby after birth. So more tissues and hormones start to work in this area and this contributes to increase in weight of mother.  It is estimated that 1-3 pounds area added to the weight of pregnant woman.

6.     Increases blood flow

When a woman is pregnant volume of blood in the body also increases. Because now the blood will circulates in the mother as well as in the fetus. So overall volume of blood will increase to meet need of mother and developing fetus. Average increase of weight due to increases volume of blood is 3-4 pounds.

7.     Store Fat

To meet needs of body during and after pregnancy body starts to store fats. This stored fat also constitutes to overall increase of weight. Average weight of this store fat is around 6-8 pounds.

Here is a table that will provide you with overview of weight gain due to above mentioned reasons.

Average Weight gain During Pregnancy

It is not hard and stick rule that how much weight gain during pregnancy is healthy. Weight gain varies from person to person as every person is different from another and size of fetus also varies among women. Here is a rough estimate to provide you guideline on how much weight gain during pregnancy is healthy.

Weight Gain in Trimesters

Mother carries fetus for 9 months or 40 weeks in her womb. During this time period embryo converts into a complete baby. To learn changes which occur during this time period we divide these 9 months into 3 trimesters. This division is just for our better understanding of development of fetus.

1.     Weight in in 1^st trimester

1^st trimester is consists on 1^st three months of pregnancy.  This includes starting 13 weeks of pregnancy.  There is not much weight gain occur during this time period because fetus  develops vital organs during first trimester. There is very little change in weight of mother in this trimester. There may be no weight gain or mother may have 1-1.5 pounds increase in her weight.

2.     Weight gain in 2^nd Trimester

Second trimester consists on  4^th month till 6^th month. In other words it starts from week 14 and ends at week 26 or 27. During this time period weight gain occurs as now fetus is developing and more organs and bones are growing.  Average weight gain during this trimester is about 1-1.5 pounds per week. At the end of third trimester there is about 12-14 pounds of weight gain.

3.     Weight Gain in 3^rd Trimester

Last of third trimester is more important in respect of weight gain during pregnancy. Most of the weight gain occurs during this time period as baby increases in size. Last three month or from month 7-9 are included in this trimester. It starts from week 27 and ends till birth of baby or week 40. 25-25 pounds weight gain occur during last trimester

Weight management and pregnancy

It’s essential to control your weight throughout pregnancy as in case you gain extra weight throughout this time period it will be tough to lose it after pregnancy and could create fitness troubles.

In this regard balance diet is very helpful. She must take healthy and rich nutritional food. Processed food is not good as it will increase the mass of the body without giving enough nutrition.

She must take proper guideline from her nutritionist to meet calories intake. It is crucial to properly check weigh gain during pregnancy and calories intake on weekly basis to maintain a healthy pregnancy.

Exercise also helps in managing weight. Do not go for heavy exercise but for simpler exercises like walking, swimming or yoga. They will keep you healthy and will helpful for baby as well. They also help in maintaining weight gain during pregnancy.