Pregnancy Weight Gain Calculator And Weight Chart

Why Do You Gain Weight During Pregnancy?

It is normal to gain weight during pregnancy due to the various changes happening within the mother’s body. Weight gain happens because of factors such as the growing size of the fetus, development of the placenta and amniotic fluid, changes in the shape and size of the breasts and uterus, etc. However, gaining too much or too little weight during pregnancy is a matter of concern as it may be due to underlying health issues.

Increased weight gain could lead to complications such as gestational diabetes, preeclampsia, and postpartum water retention (1). On the contrary, less weight gain may cause preterm birth or a low birth-weight baby weighing less than 2.5 kg (2).

How Much Weight Can You Gain During Pregnancy?

Weight gain during pregnancy depends upon the BMI of the individual and also the type of pregnancy (single or twin pregnancy).

A BMI of 18.5-24.9 is considered normal. If the value is above 24.9, the individual is considered overweight, and more than 30 is considered obese. The following values give you a fair idea of weight gain that is ideal during pregnancy (3).

If you are underweight, i.e., you have a BMI of less than 18.5, you should gain between 28-40 pounds during pregnancy.

If your BMI is normal (18.5-24.9), your weight gain should be 25-35 pounds. For a twin pregnancy, it should be 17-25 pounds.

In case you are overweight (BMI of 25-29.9), weight gain between 15-25 pounds for single and 14-23 pounds for twin pregnancy is ideal.

If you are obese before pregnancy (BMI >30), you should gain 11-20 pounds of weight. For twin pregnancy, the weight gain should be between 11-19 pounds and not more than that.

Pregnancy Weight Gain Calculator

Before pregnancy

The following is a list of details to be recorded from the pre-pregnancy stage.

How To Use The Weight Gain Calculator

Follow the process mentioned below to get proper results using the calculator:

1. Weigh yourself on a weighing scale wearing light clothes.
2. Enter your details, such as height in feet, inches, or centimeters.
3. Enter your pre-pregnancy weight. This will give results for your BMI range.
4. Enter your week of pregnancy.
5. Select Yes/No for single or twin pregnancy.
6. View the results.

Keep track of your weight gain with a pregnancy weight calculator and accordingly make changes to your diet. This helps manage your weight and also promotes your overall health.

Pregnancy Weight Gain By Week And Trimester

We have now established that weight gain happens during pregnancy. However, the rate of progress varies between stages by week and trimester.

The weight gain during the first trimester is quite slow compared to the other two trimesters. Most of the gain happens in the second trimester and slows down by the end of the third trimester.

Pregnancy is divided into three trimesters:

First trimester: 1-3 months (first 12 weeks)

Second trimester: 4-6 months (13-28 weeks)

Third trimester: 7-9 months (29 weeks till birth)

The expected weight gain on a trimester basis in a woman with normal pre-pregnancy weight (4) –

First trimester: 0.5 pounds

Second trimester: 0.3-1.5 pounds per week

Third trimester: 0.4-1.5 pounds per week

Total Weight Gain During Pregnancy By Pre-Pregnancy BMI

The Institute of Medicine of Academics, based on the guidelines laid out by the World Health Organization (WHO), suggests a week-by-week estimate of the ideal pregnancy weight gain, as illustrated in the following chart.

Pregnancy Weight Gain Distribution Chart

Most of the weight gain during pregnancy is not because of fat accumulation but due to the increased maternal tissues and the growing fetus. The following table shows the weight gain distribution.

Changes In The Body During Pregnancy

During pregnancy, the female body goes through many changes, such as changes in the uterus, cervix, vagina, cardiovascular system, gastrointestinal system, urinary system, changes in the skin and breasts, and more. Let us look at some of these changes in detail.

Changes In Hormones

Estrogen and progesterone are the hormones that play a major role throughout pregnancy. High estrogen levels promote blood flow within the uterus and placenta, whereas high levels of progesterone cause an increase in maternal tissues, such as the breasts and the uterus, to accommodate the growing baby (3). These changes may also lead to mood swings, anxiety, depression, restlessness, and more.

Changes In The Cardiovascular System

Research has shown that the heart may expand in size due to increased load on it. During the second trimester, the heart works 40% harder in pregnant women than in non-pregnant women due to an increase in blood volume (4). There is a gradual increase of 30-50% in pregnant women. So at the end of pregnancy, she has 1.6 liters of blood compared to non-pregnant females (5).

Low Blood Pressure In Pregnancy

Many women feel dizzy in the first trimester due to a decrease in blood pressure. The hormone progesterone causes sudden relaxation in the blood vessels, decreasing vascular resistance (6). This may cause pooling of blood in the leg veins, a temporarily reduced blood supply to the brain, a feeling of acute dizziness, and brief periods of unconsciousness. Small and frequent meals and proper hydration can help combat low blood pressure.

Water Retention In Pregnancy

Fluid often builds up in the legs and feet of pregnant women in the first trimester, leading to a condition called edema (7). This is a very common condition and happens due to long periods of standing or being on foot.

Changes In Respiratory System

During pregnancy, the individual finds it difficult to breathe normally as the growing fetus pushes up toward the lungs (8).

Changes In The Gastrointestinal System

Many women experience nausea and morning sickness in the initial weeks of pregnancy (9). As the pregnancy progresses, indigestion and heartburn are also common occurrences because the growing baby crowds the mother’s stomach and pushes it higher than usual. This causes acid reflux in the chest. In such cases, pregnant individuals should have small and frequent meals and should not lie down until 2 hours after a meal.

Frequent Urination And Constipation

Frequent urination is a major change that happens in pregnant individuals, especially in the first and third trimesters of pregnancy ( 10). The growing baby puts a lot of pressure on the bladder, causing an urge to urinate often. Excessive water retention in the feet and legs is also responsible for frequent urination, especially at night. On one hand, the pregnant individual has bladder incontinence, and on the other hand, the increased pressure on the bladder muscles causes constipation.

Changes In Skin

Some individuals develop brownish or yellowish patches on the forehead and face – a condition called chloasma or mask of pregnancy (11). It usually begins during the 16th week of pregnancy, i.e., in the second trimester, and goes away after delivery. Other changes in the skin would be acne due to the production of excessive sebum, heat rashes over the skin, and stretch marks on the abdomen, thighs, and breasts due to the expansion of the skin.

Some individuals may also observe a dark line near the umbilicus and pubic bone called the linea nigra. It is hormone-induced and causes increased pigmentation but fades away after delivery.

Changes In The Breasts

A change in the bra size is the first thing one might observe in the initial months of pregnancy, all thanks to high levels of estrogen and progesterone hormones (12). This may keep changing throughout the pregnancy as there is also an increase in the size of the ribcage and the formation of milk-producing glands to account for.

The areola around the nipples darkens and Montgomery’s glands enlarge and tend to produce lubrication in the nipples and areola.

During the 16th week of pregnancy, the breasts start producing colostrum, also known as immature milk, that is high in nutrients and antibodies. It is a blessing for the newborn babies.

What To Eat During Pregnancy

Although it is not necessary to eat for two during the first trimester of pregnancy, there is an increased requirement for foods rich in nutrients such as folic acid, calcium, vitamin D, iron, and protein.

The most important thing to remember is that you need not go on a special diet. However, try to include a variety of foods that can provide essential nutrients. This is where a well-planned pregnancy diet comes into play. The following is a list of the nutrients to include in your diet (13):

• Folate And Folic Acid
  Folate and folic acid are essential B vitamins required throughout pregnancy as they help prevent neural tube defects and abnormalities in the brain and spinal cord of the growing fetus. They are found in foods such as spinach, oranges, dried beans, and peas.
• Calcium And Vitamin D
  Calcium and vitamin D are essential for the formation of strong bones and teeth and also for the proper functioning of the nervous, muscular, and circulatory systems. The lack of vitamin D hampers calcium absorption, so one must include foods like dairy products, egg yolk, green leafy vegetables, and fish in their diet alongside gaining the required nutrition from supplements.
• Protein
  This is an important nutrient that is vital for the overall growth and development of the baby. It is found in foods such as poultry, fish, meat, soy products, beans, legumes, and dairy products.
• Iron
  Iron deficiency, also known as anemia, is a very common problem during pregnancy due to increased blood volume. Avoid this condition by including iron-rich foods in your diet, such as lean meats, green leafy vegetables, poultry, dry fruits, and so on.

Apart from including the above-mentioned foods in your diet, it is also important to obtain such nutrients in the form of supplements as prescribed by your healthcare provider.

Foods To Avoid

The following are the types of foods that you must avoid during pregnancy to ensure good health for you and your baby (14):

• Raw, uncooked foods, and unwashed fruits and vegetables.
• Unpasteurized milk products that carry the risk of food contamination.
• Sea foods such as shark, swordfish, tuna, and mackerel that have high mercury content.
• Excessive caffeine and alcohol as their toxic compounds cross the placental barrier and harm the baby.

Smoking is also not at all advisable as it impacts the baby’s health and leads to premature outcomes.

Additionally, one must be careful and check for any aversions and allergies to any foods apart from the above-mentioned ones and speak to a medical professional or their dietitian for proper guidance.

In Conclusion

Weight gain is a normal part of the pregnancy process as it supports the nutrition and changes a body requires to birth babies. However, in certain cases, the weight gain may be too much or too little, which may be a cause for concern. Our special pregnancy gain calculator helps you keep track of your weight gain rate and estimate if things are progressing smoothly. Consult your doctor to discuss any concerns and ensure adequate nutrition and rest to maintain steady and normal weight gain during pregnancy.