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How much weight should a woman of normal pre pregnancy bmi gain during the first trimester?

Pregnancy Weight Gain - The American Pregnancy Associatio

  1. utes of exercise a week should strive for a caloric intake of: 1,800 during the first trimester; 2,200 during the second trimester; 2,400 during the third trimester; These calories should be attained by eating a diet of grains, dairy, protein, fruits/vegetables, and healthy fats and oils
  2. g pregnant, then ideally you should gain between 11.5 and 16 kilograms during your pregnancy. You should expect to gain 1-1.5 kilograms in the first three months, then 1.5-2 kilograms each month until you give birth. If you're overweight or underweight, the goal posts will shift a little
  3. You may have heard that you should gain 25 to 35 pounds while you're pregnant. But that range is for people whose body mass index (BMI) falls into the normal weight category before pregnancy. Your BMI is calculated using your height and weight

How much weight will I gain during pregnancy? Queensland

  1. How much weight should a woman of normal pre-pregnancy BMI gain during the first trimester? 0.5 pounds 3 to 5 pounds no more than 8 pounds at least 10 pounds. B. Which pregnancy-specific organ is responsible for delivering nutrients and oxygen to the fetus and removing waste products
  2. imal weight gain, regardless of your pre-pregnancy BMI. As you near the end of your first trimester, and begin the second, weight gain is expected to increase. Some providers like to see women with a healthy BMI prior to pregnancy, gain 10 pounds by 20 weeks
  3. If you have a BMI of 30 or higher and are carrying one baby, the recommended weight gain is 11 to 20 pounds (about 5 to 9 kilograms)

A healthy amount of weight gain during pregnancy is 25-35 lbs (11.3-15.9 kgs) for normal weight women.During the first trimester, total weight gain is only 1 to 4 pounds. After the first trimester, a gain of approximately 1 lb. per week is normal Women who are of normal weight before pregnancy and are pregnant with twins should try to gain between 25 to 35 pounds during pregnancy. Answer: FALSE Alcohol consumption during pregnancy is dangerous only during the first trimester Despite what you might have heard, you don't gain too much weight in the first trimester, with the standard recommendation being 1 to 4 pounds. And unlike the second and third trimester (when body.. Pregnancy weight gain is a healthy part of fetal gestation. As the placenta forms, fluid is retained, blood volume increases, and the baby grows. With all of these changes, weight gain is expected. Typical weight gain for a pregnant woman of normal weight is 25 to 35 pounds

Putting on the pounds In the first trimester, most women don't need to gain much weight — which is good news if you're struggling with morning sickness. If you start out at a healthy or normal weight, you need to gain only about 1 to 4 pounds (0.5 to 1.8 kilograms) in the first few months of pregnancy Weight gain should be minimal in the first trimester (0.5 to 2.0 kilograms or 1.1 to 4.4 pounds). If you lose or gain a significant amount of weight in the first trimester (more than five to 10 per cent of your pre-pregnancy weight), talk with your healthcare provider for support. 2nd Trimester Use our pregnancy weight gain chart to find out what a healthy weight range is for you during pregnancy. If you're starting pregnancy at a healthy weight, you can expect to gain 1 to 5 pounds in the first trimester and about 1 pound per week after that. Gaining more or less than recommended puts you at a higher risk for complications

You may even lose some weight during the first trimester. Some women A 2017 study found that women who maintained their pre-pregnancy BMI after their first If you gain the average amount. While it's noted that a gain of one to four pounds is acceptable, most information hubs will tell you that many women actually lose weight during their first trimester due to morning sickness Though weight gain will vary, most women gain about 1 to 4 pounds total during the first trimester. Some gain less if they have morning sickness. Others gain more due to decreased activity and increased water weight. During the second and third trimesters, your doctor may suggest you gain about 3 to 4 pounds per month Underweight women should gain 28 to 40 pounds. And overweight women may need to gain only 15 to 25 pounds during pregnancy. In general, you should gain about 2 to 4 pounds during the first 3.

Pregnancy Weight Gain Chart — How Much Weight You Should

This is the Gestational Weight Gain Monitoring Chart for underweight. This graphic shows the appropriate range of rate of gain per week for a woman with a pre-pregnancy BMI under 18.5. The rate shown is 0.44 to 0.58 kg (1.0 to 1.3 pound) per week in the 2 nd and 3 rd trimester. Trimester is shown on the x-axis and weight gain is shown on the y. BMI= (150/3,844) x 703. BMI= 0.03902 x 703. BMI=27.4. Your BMI would be 27.4, which is in the overweight range. Recommended weight gain would be 15-25 lbs. As a standard, many doctors and books simply say that 25-35 lbs gained during pregnancy is acceptable, but that is based on a woman of normal, healthy weight prior to pregnancy 50 to 62 pounds. Normal weight: BMI 18.5 to 24.9. 37 to 54 pounds. Overweight: BMI 25 to 29.9. 31 to 50 pound. Obese: BMI 30 or greater. 25 to 42 pounds. About one-third of women gain the recommended amount of weight during pregnancy and most women gain weight outside the recommendations (21% gain too little, 48% gain too much). It is important. Similarly, women who gain a large amount of weight in the first trimester (much more than 2 kg or 4 lbs) should be assessed. These women may be at increased risk for gestational diabetes, particularly women with a pre-pregnancy BMI greater than 25 (Hedderson et al., 2010) A woman with an average BMI will gain around 30-35 pounds during pregnancy. Let's break down exactly where all this weight is going: 7.5 pounds is about how much the baby will weigh by the end of pregnancy. 1.5 pounds is how much the placenta weighs. 4 pounds is attributed to increased fluid volume. 2 pounds is the weight of the uterus

Nutrition Chapter 14 Flashcards Quizle

Your pregnancy weight gain is not going to be even all the way through. You may even lose some weight during the first trimester. Some women drop a few pounds because of serious morning sickness. Once you have your BMI, the chart below will tell you how much weight gain you should be aiming for. How much weight you should gain during pregnancy: BMI less than 19.8 - 28lb to 40lb; BMI 19.8-26 - 25lb to 35lb; BMI 26.1-29 - 15lb to 25lb; BMI more than 29 - 15lb; If you're gaining a bit more or less than this, don't panic Pregnancy weight gain is a healthy part of fetal gestation. As the placenta forms, fluid is retained, blood volume increases, and the baby grows. With all of these changes, weight gain is expected. Typical weight gain for a pregnant woman of normal weight is 25 to 35 pounds. Women who are overweight can expect to gain less - 11 to 20 pounds

In general, you should gain about 2 to 4 pounds during the first three months you're pregnant and 1 pound a week during the rest of your pregnancy. What trimester do you gain the most weight? The Third Trimester of Pregnancy: Weight Gain and Other Changes. Your baby changes most rapidly during your third trimester of pregnancy If you're at a healthy starting weight, expect to gain about 3 kgs during the first trimester of pregnancy and 500 gms each week during the remainder of your pregnancy weeks. Doctors recommend intake of 340 extra calories a day during the second trimester and 450 extra calories every day during the third trimester of pregnancy But this practice could lead to above-average weight gain. Second and Third Trimester Gains. From the beginning of your second trimester until you give birth, follow these guidelines. If your pre-pregnancy BMI was: Less than 18.5, you should gain ½kg/week; 5 to 24.9, you should gain 400g/week; 25 or more, you should gain less than 300g/wee Category Your Body Mass Index (BMI) Total Weight You Should Gain While Pregnant Amount of Weight to Gain Each Week, Beginning in the 4th Month Underweight Less than 18.5 28-40 pounds 1½ pounds Normal weight 18.5-24.9 25-35 pounds 1 pound Overweight 25-29.9 15-25 pounds 2/ 3 pound Obese 30 and higher Around 15 pounds ½ poun How much weight did you gain by 20 weeks? As you near the end of your first trimester, and begin the second, weight gain is expected to increase. Some providers like to see women with a healthy BMI prior to pregnancy, gain 10 pounds by 20 weeks. During the second and third trimester, guidelines often suggest gaining 1/2 to 1 pound per week

Weight gain recommendations are higher for those having twins, with the target range depending on the woman's pre-pregnancy BMI: 18.5-24.9 (weight gain: 17-25 kg), 25-29.9 (weight gain: 14-23 kg. The amount of weight gain differs by trimester: During your first 12 weeks of pregnancy—the first trimester—you might gain only 1 to 5 pounds or none at all. If you were a healthy weight before pregnancy, you should gain a half-pound to 1 pound per week in your second and third trimesters

How much weight should I gain while pregnant? HealthPartner

Weight Gain Guidelines. Weight gain guidelines are based on a woman's BMI before pregnancy. The amount of weight gained depends on which category the pre-pregnancy BMI lands in: Underweight: BMI below 18.5; Normal weight: 18.5 to 24.9; Overweight: 25.0 to 29.9; Obese: 30.0 and above; The weight ranges below are for a full-term pregnancy. On the flip side, if you are slightly underweight prior to pregnancy, you need to gain slightly more. Underweight pre-pregnancy (BMI less than 18.5)- 28-40 pounds. Average prepregnancy weight (BMI 18.5-24.9): 25-35 pounds. Overweight pre-pregnancy (BMI 25-29): 15-25 pounds. Obese prior to pregnancy (BMI 30+)- 11-20 pounds (1) If you are. Weight gain in the third trimester - the importance of BMI. As was the case in the second trimester, the amount of weight you need to gain during the third trimester is dependent on your pre-pregnancy Body Mass Index (BMI).. To calculate your pre-pregnancy BMI, add your height and pre-pregnancy weight into the calculator below and it will work out the BMI for you This calculator help pregnant women track their weight gain at the beginning and regularly throughout their pregnancy period. Your ideal weight gain during pregnancy depends on your pre-pregnancy BMI and whether or not you are having a single birth or multiple births (twins).How much weight you should gain during pregnancy is important for the health of your pregnancy and for the long-term.

Video: Pregnancy and obesity: Know the risks - Mayo Clini

Being underweight before becoming pregnant may indicate the need to gain more weight during pregnancy than a woman at an average or above weight. Additionally, women with a history of eating disorders, like anorexia or bulimia nervosa, who may have had nutritional deficiencies prior to conception, will need additional nutrients during pregnancy Women who are considered in the normal weight range prior to getting pregnant-with a BMI of 18.5 to 24.9-should gain between 25 and 45 lbs. during the pregnancy. Average woman should gain between 1 lb. and 4.5 lbs. during the first trimester and 1 lb. per week thereafter. Gaining more than 45 lbs. during the pregnancy would be considered. How much weight should women gain during pregnancy? In a healthy pregnant women with a singleton (one baby) pregnancy, there is minimal weight gain in the first trimester (approximately 2-4 lbs). The majority of the weight gain is in the second and third trimester, where women have been reported to gain approximately 0.6 kg per week

Below is a table of how much weight a woman should gain during pregnancy based on her pre-pregnancy BMI. Underweight (BMI less than 18.5) Healthy weight (BMI 18.5 to 24.9 Typically, little weight gain occurs during the first trimester. However, many women gain 1 pound or more per week during their 2 nd and 3 rd trimesters. Check out your body mass index ( BMI ) using your pre-pregnancy weight, and discuss with your healthcare provider to determine how much weight gain is healthy for you

Pre pregnancy. BMI. BMI. Total gain. range. Rate of gain in 2nd and 3rd. trimester. Underweight. less than 18.5. 28-40 lbs. 1 (1-1.3) lbs/week. Normal Weight. 18.5-24. How much weight gain is normal at 21 weeks? Recommended weight gain during pregnancy. Generally, it is recommended that pregnant women gain only 1-4 pounds during the first 3 months of pregnancy, and 1 pound per week during the remainder of the pregnancy

Weight gain for women with normal pre-pregnancy weight: First trimester: 1 - 4.5 pounds total. Second trimester: 0.5 - 1.5 pounds per week. Third trimester: 0.5 - 1.5 pounds per week. Don't worry if you're a little over or under. Your body knows the right amount of weight to gain Normal weight to gain during pregnancy depends on some factors such as health and BMI of a pregnant woman before getting pregnant. BMI is body mass index that is a measure of body fat based on your height and weight. A healthy and well-balanced diet plays a major role in the proper growth and development of the unborn baby in the womb. Learn how much weight is normal for you to gain during. While weight gain during pregnancy is normal and necessary, studies have shown that certain ranges of weight gain given a specific body mass index (BMI) result in more positive outcomes for both fetus and mother. 1. Generally, it is recommended that pregnant women gain only 1-4 pounds during the first 3 months of pregnancy, and 1 pound per week.

BMI Calculator for Pregnant Women, Calculate weigh gain

Second trimester. Weight gain in the second trimester is a strong indicator of total weight gain at the end of your pregnancy. These values are based on your pre-pregnancy BMI. BMI less than 18.5: 20 lbs. (9 kg) by the end of second trimester. BMI between 18.5 - 24.9: 15 - 20 lbs. (6.8 - 9 kg) by the end of second trimester how the f*ck can you keep the same weight if you are creating a human being inside you? You want to eat what's needed for you and your child so he is born in good health. Only after can you take care of your appearance. Are you sure you're ready t.. How much weight do women gain during pregnancy? Only 30-40% of pregnant women gain weight within the recommended ranges for their BMI ().Some women fail to gain enough weight during pregnancy, although in developed countries over-nutrition before and during pregnancy is more of a concern. For example, in the United States 18-38% of women are obese when they become pregnant and the majority. Average healthy pregnancy weight gain varies from woman to woman based on pre-pregnancy BMI. The current recommendations include: Less than 18.5 pre-pregnancy BMI- 28 to 40 pounds. 5 to 24.9 pre-pregnancy BMI- 25 to 35 pounds. 25 to 29.9 pre-pregnancy BMI- 15 to 25 pounds. 30 or higher pre-pregnancy BMI- 11 to 20 pounds

Pregnancy Weight Gain Timeline. During the first trimester, you can expect to gain approximately 1-5 lbs. It is during the second and third trimester where the weight will start to add up. Based on your pre-pregnancy BMI you should expect to gain anywhere from 0.5-1 lb per week during the 2nd and 3rd trimester Women pregnant with multiples need to gain more weight to help support the growth of multiple babies. Normal weight women should gain 37-54 pounds, overweight, 31-50 pounds and obese, 25-42 pounds during pregnancy. Risks of Gaining Too Much Weight. Women who gain extra weight during pregnancy are more likely to hav The pattern of Weight Gain. Weight, gain or loss, should not be sudden; it should occur gradually. Weight gain during the first trimester is minimal. It is restricted to 5-6 pounds only and even less in a few women. Some women also tend to lose weight. The reasons are morning sickness and decreased appetite

This is approximately 300 calories/day above that for a singleton pregnancy. After 20 weeks of gestation, weight gain should be approximately 1.75 pounds/week for underweight women and approximately 1.5 pounds/week for normal weight women, with the same or slightly lower weekly weight gain in overweight and obese women. 2 How much weight you'll gain during pregnancy depends on your pre-pregnancy weight, and varies a great deal from person to person. Most women gain between 10kg and 12.5kg (22-28lb) while they're pregnant 1. The weight gain chart below gives a general guide to healthy weight gain during pregnancy 2: BMI. Approximate weight you should gain. The easiest way to gain the right amount of weight for your baby is to increase your calories by eating larger portions of nutritious foods. A typical woman with a normal BMI who does 30 minutes of daily exercise should eat around 1800 kcal in the first trimester, 2200 kcal in the second trimester, and 2400 kcal in the third trimester

Nutrition Ch 14 Flashcards Quizle

'In the first trimester (up to 12 weeks gestation) you can expect to gain around 2-4lbs in total. 'During the 2nd and 3rd trimester, you will gain around 1lb/week, this weight gain is from the. Weight gain during pregnancy is not only an inevitable nuisance of being pregnant.It is a physical manifestation of pregnancy development, which can be measured and monitored to prevent complications and ensure baby's well-being.A woman with a normal BMI before conceiving is recommended to gain no more than 25-35 pounds during all three trimesters. . However, no matter a woman's weight prior. The following description gives you a fair idea of weight gain that should happen during pregnancy . If you are underweight i.e BMI less than 18.5 you should gain between 28 and 40 pounds during pregnancy. If your BMI is normal(18.5-24.9), the weight gain should be 25 to 23 pounds and incase of twin pregnancy it should be 37 to 54 pounds

A lot of factors determine just how much weight a woman will gain during her pregnancy. Among these factors are the amount of amniotic fluid and blood volume present during this time. One of the more important factors is the mother's body mass index or BMI. Pregnant women with a higher BMI will gain more body fat during their pregnancy If you begin your pregnancy at a healthy weight (BMI 18.5-24.99) gaining 11.5-16kg during pregnancy is normal and healthy. If you're underweight you should gain at least 12 kg and up to 18kg. You should never attempt to lose weight while you're pregnant, however if you are overweight or obese, you should restrict how much weight you gain The recommended weight gain for women expecting twins is: women in the normal weight range (BMI of 18.5-24.9) are recommended to put on between 37-54 lbs (16.8-24.5kg) women who are overweight (BMI between 25 and 29.9) are recommended to put on between 31-50 lbs (14.1-22.7kg) women who are affected by obesity (BMI of 30 or more), are.

Find out your pre-pregnancy BMI and recommended weight gain using the Pregnancy Weight Gain Calculator . If you know your pre-pregnancy BMI, you can also use the following chart to determine how much weight you should gain. Body Mass Index. Recommended Weight Gain. below 18.5. 12.5 - 18 kg (28 - 40 lbs) 18.5 - 24.9 The lower your BMI, the more weight gain you should aim for: Most women will gain only 1.1 to 4.4 lb during the first trimester regardless of BMI. During the second and third trimesters, underweight and normal weight women should gain 1 lb per week, overweight women should gain 0.6 lb per week, and obese women should gain 0.5 lb per week Average healthy pregnancy weight gain estimates are based on your pre-pregnancy BMI ( body mass index calculator ). For a BMI below 18.5: Pregnancy weight gain should be roughly 28 to 40 lbs. in a singleton pregnancy. BMI between 18.5 and 24.9: 25 to 35 lbs. BMI between 25 and 29.9: 15 to 25 lbs. BMI above 30: 11 to 20 lbs What is the normal weight gain for a pregnant woman? Weight Gain Recommendations For Women Pregnant With One BabyIf before pregnancy, you wereYou should gainUnderweight BMI less than 18.528-40 poundsNormal Weight BMI 18.5-24.925-35 poundsOverweight BMI 25.-29.915-25 poundsObese BMI greater than or equal to 30.011- 20 pound

How much weight should you gain while pregnant? During pregnancy, you only need about 300 extra (healthy) calories a day in order to sustain your baby and help them develop. Based on studies, the average and normal weight that should be gained around pregnancy (if you are considered normal weight) is from 25-35 pounds First trimester weight gain: During the first trimester, it's unlikely you'll see much of a change in your weight. If you're on track to gain between 1 and 4.5 pounds by the end of week 12. The message that women should strive toward a healthy GWG should be given to women from all pre-pregnancy BMI-groups, including women with a normal pre-pregnancy BMI. Furthermore, women who need extra attention are non-Caucasian women and women who stopped smoking Body Mass Index. Assessing body mass index (BMI) is the first step in determining how much weight gain is healthy during pregnancy. BMI is a measure of body fat in adults based on their weight and height. Generally, physicians consider a pre-pregnancy BMI of 18.5 to 24.9 to be a healthy range, with 25 being overweight

Weight Gain in First Trimester: How Much Is Normal

Conventional wisdom says that you should gain 1-5 pounds in the first trimester and 1 pound per week for the rest of the pregnancy. However, few women follow this pattern exactly, so don't stress out about it. Some women gain little or no weight (or even lose weight) in the first trimester. Some women gain as much as 10 pounds in the first. Underweight women (BMI of less than 18.5): between 12.5 and 18 kg of weight gain during pregnancy. Women of an average weight (BMI of between 18.5 and 24.9): between 11.5 and 16kg of weight gain during pregnancy. Overweight women (BMI of between 25 and 29.9): between 7 and 11.5kg of weight gain throughout pregnancy Your weight gain during pregnancy month by month with a normal pre-pregnancy weight is expected to be as follows: First trimester: 1-2 kgs; Second trimester: 3 kgs per month; Third trimester: 2 kgs per month; Weight Gain Chart During Pregnancy. The intake of the calories and the corresponding weight gain highly depends on your pre-pregnancy BMI.

Pregnancy Weight Change Calculator babyMed

Managing your weight gain during pregnancy. Most women should gain somewhere between 25 and 35 pounds (11.5 to 16 kilograms) during pregnancy. Most will gain 2 to 4 pounds (1 to 2 kilograms) during the first trimester, and then 1 pound (0.5 kilogram) a week for the rest of the pregnancy. The amount of weight gain depends on your situation Make sure you are gaining weight gradually. According to the American College of Obstetricians and Gynecologists (ACOG), the weight gain rate for a woman with healthy pre-pregnancy weight is: First Trimester: 0-0.5 kg per month for a total of 0.5-2 kg. Second Trimester: 0.5-1 kg per week for a total of 5 to 6 kg Weight is a sensitive topic no matter what size you are. Society sends women messages about how they should look. But if you're pregnant and clinically overweight or obese—meaning you have a body mass index (BMI) of 25 kg/m 2 or greater—and your doctor brings up the topic of weight, they're interested in the medical implications of obesity on mom and baby Ideal weight gain during pregnancy. It is generally expected that a woman should gain 10-15 kilos in her entire pregnancy. But, it varies from person to person and is based on a range of factors. To calculate the ideal weight gain, the first step is to—determine the personal weight gain goal If your pre-pregnancy BMI was between 19 and 24, you may put on around 2kg (4lb) during the first trimester. In the second and third trimesters, you may gain as much as 0.5kg (1lb) a week, though this will decrease to just 0.5-1kg (1-2lb) during the final month of the pregnancy

Pregnancy weight gain: What's healthy? - Mayo Clini

Overweight women (BMI of 25 to 29.9) are advised to gain no more than 15 to 25 pounds during pregnancy. Obese woman (BMI of 30 and higher) should gain 11 to 20 pounds during pregnancy. Obese women should be offered and should consider nutrition consultation and are encouraged to follow an exercise program The American College of Obstetricians and Gynecologists' (ACOG) guidelines advise women with a pre-pregnancy body mass index (BMI) of 18.5 to 24.9 to gain 25 to 35 pounds, those that are. Focus should not be so much on how much weight you are gaining in pregnancy; but how well you are eating in pregnancy! It is recommended that women should aim for a weight gain related to their pre-pregnancy BMI: If BMI was above 26, you should aim for a weight gain of between 15 and 25lb (7 and 11.5kg)

Weight Gain During Pregnancy, By Trimester Healthy

A pregnancy weight gain calculator can be a huge help to determine how much weight you should gain during your pregnancy. Some calculators are more specific than others. They may break down your weight gain by week, month, trimester, or just overall pregnancy weight gain A woman should gain 10 to 14 kg during pregnancy, an average of 12 kg, in order to elevate the likelihood of giving birth to a healthy baby, with less risk of fetal and maternal complications. Use your pre-pregnancy weight to calculate your Body Mass Index. BMI uses a formula to compare weight with height. Calculate this online here. Underweight pre-pregnancy - BMI of less than 18.5 should gain 28-40 pounds Normal weight pre-pregnancy - BMI of 18.5-24.9 should gain 25-35 pound

Pregnancy weight gain: What to expect BabyCente

Keep in mind, too, that what is considered healthy weight gain in the first trimester is typically only a few pounds depending on your pre-pregnancy weight—usually 2 to 4 pounds. If you lose a couple of pounds, rather than gain, the net loss will only be several pounds During the first trimester of pregnancy, weight gain will be minimal - 10.5 to 2kg. This is due to morning sickness and/or the fact that the fetus and everything else associated with the pregnancy is still small. Your second and third trimesters should show a weight gain of 500g to 1kg per week. The majority of this will be taking place that. Weight gain in your first three months should be minimal (0.5 to 2.0 kilograms or 1.1 to 4.4 pounds). If you lose or gain a significant amount of weight (more than five to 10 per cent of your pre-pregnancy weight), talk with your healthcare provider for support Only women who start in the underweight category, a BMI less than 18.5, should increase their overall calorie intake and increase protein consumption during the first trimester. The first trimester represents about 93 days, and if you start eating more for the baby during this time, you'll unintentionally start gaining at too fast a pace

For pre-pregnancy BMI (25.0 - 29.9), your weight gain goal is 31 - 50 lbs (14 - 23 kg) For pre-pregnant BMI (30+), your weight gain goal is 25 - 42 lbs (11 - 19 kg) For a pre-pregnancy BMI (<18.5), talk to your healthcare professional about how much weight is good to gain Jul 26, 2021 at 2:48 PM. You can always try to eat healthy but I'm about the same weight as you and roughly have gained the same. My doctor told me he thinks I'm going to gain 40 pounds through the whole pregnancy during my first trimester and it's looking that way. He said you need to have fat for the baby The relationship between height and body mass can be calculated via the BMI index. For example, those women whose pre pregnancy weight was in the healthy range then they should gain anywhere between 25 to 35 pounds during the nine months of pregnancy. Those women who were underweight before pregnancy should gain anywhere between 28 to 40 pounds. The guidelines for weight gain in pregnancy are aimed at optimizing good outcomes for both you and your baby. How much (or how little) you should gain is determined by your pre-pregnancy body mass index (BMI). Your BMI is a function of your height and weight