Weight Gain in Pregnancy

During pregnancy you are likely experiencing a lot of unexpected (and many times uncomfortable) changes to your body. You may be going through heartburn, extreme food aversions, constipation or simply feeling puffy and bloated all over the place. (But not to worry, as these symptoms are very common and natural during pregnancy!)

However, on top of all of this, the anxiety over weight gain may be looming over your head, especially when society holds a certain unrealistic body ideal for women and there is constant pressure to quickly “snap” back in shape postpartum. Afterall, stress is the last thing we want during pregnancy, but there is an unbelievable amount of expectation that goes into carrying another human being, when all we want is to have a healthy baby.  

Thus, in today’s article, Wellspring Nutrition is going to help clear up some of the confusion surrounding gestational weight gain to hopefully make your pregnancy journey the healthiest and the most fulfilling. 

What is going on in our body? 

Gestational weight gain is a natural and healthy aspect of pregnancy as your body is supporting fetal growth and development. Some of you may be wondering why you are gaining weight rather quickly during the early phases of pregnancy when the baby is not even that big. This is due to the fact that during the first 30 weeks, maternal fat stores are increased as the body is actively storing nutrients to meet the demands of growing the placenta, a brand new organ that forms just during pregnancy to sustain the growth of the baby, and the energy needs for later in the pregnancy and lactation. During the later stages of gestation, your body will divert a lot of its nutrients to the developing fetus.  

Although total weight gain is variable for each individual, there are certain patterns that are commonly observed. In many cases, the first trimester accounts for 5 percent of the total weight gain and the remaining 95 percent is slowly gained during the last two trimesters. 

Overall, aside from the extra fat deposits, the added weight comes from the placenta, the amniotic fluid (the liquid that surrounds the fetus for protection), increase in body water, expanded blood volume, tissue development in the breasts, and uterus and mammary glands amplification. These changes to your body are driven by hormonal shifts to prepare nourishment and a home for your baby!

Why is it important to be conscious? 

We acknowledge that any topic surrounding weight, and especially discussing numbers can be extremely triggering for some. There is definitely no merit to obsessing solely over a number on a scale, when you already have a lot going on. Nevertheless, having a general idea of what a healthy pregnancy weight gain should look like is important in preventing certain pregnancy complications as well as for the long term health of you and your baby.

Insufficient gestational weight gain is linked to low birth weight and small-for-gestational-age (SGA) newborns. Babies who were born at a low birth weight are predisposed to cardiovascular and metabolic complications later in life. On the contrary, excessive gestational weight gain leads to a higher likelihood of macrosomia (infants being much larger than average) and large-for-gestational-age (LGA) newborns. These birth outcomes are associated with future obesity, diabetes and cardiovascular disease for the child. Unfortunately, for the mother, excessive weight gain is also considered to be a significant determinant for gestational diabetes and hypertension, labor complications, difficulty with breastfeeding, and even pregnancy loss. 

It has been shown that mothers with an accurate knowledge of gestational weight gain recommendation were more likely to meet those targets, indicating that having some level of awareness will lower the likelihood of the mother and the baby to have adverse long-term health outcomes.  

How much weight should I be gaining?

As mentioned earlier, there is variability in the total amount of weight gained in pregnancies among different women, and thus there is no uniform approach that is deemed appropriate for everyone. However, there are certain national standards that have been created.  

The Institute of Medicine (IOM)’s clinical recommendation range for total weight gain is categorized based on the person’s prepregnancy BMI:

Underweight (BMI of under 18.5): 28 to 40 pounds/ 12.7 to 18.1 kg

Normal Weight (BMI between 18.5 to 24.9): 25 to 35 pounds/ 11.3 to 15.8 kg

Overweight (BMI between 25 to 29.9): 15 to 25 pounds/ 6.8 to 11.3 kg 

Obese (BMI over 30): 11-20 pounds/ 4.9 to 9 kg

The BMI scale is undoubtedly not the most reliable way of determining someone’s weight category and its associated health implications, as it fails to discriminate between muscles and fatty tissues. However, it serves as a convenient ballpark estimate to figure out what you should be aiming for.    

Moreover, the recommended weight gain is higher if you are carrying twins. The recommendation is 37 to 54 pounds (16.8 kg to 24.5 kg) if you are normal weight, 31 to 50 pounds (14.1 to 22.7 kg) if you are overweight, and 25 to 42 pounds (11.3 to 19.1 kg) if you are  considered to be obese in the BMI classification. 

It is important to keep in mind that these are standards in the U.S as the IOM (now called the National Academy of Medicine) is an American non-governmental organization. Interestingly, there has not been an international consensus among what is considered to be the “appropriate” range of gestational weight gain. For instance in Japan, where low gestational weight gain is rather common, the recommendation has an upper limit of 12 kg (26.4 pounds) for underweight and normal weight women, and an individualized plan for anyone above those weight classifications. Countries like Ghana, Italy, Canada, Bulgaria, Nicaragua, and Denmark have recommendations that are similar to the U.S IOM specification. Switzerland and Brazil also have identical recommendations to those of the IOM for the underweight, normal weight and overweight category, but have an upper limit of 7 kg (15.4 pounds) for anyone in the obese classification.  Furthermore not all countries go by the pre pregnancy BMI category. Some countries in Latin America have recommendations to attain a goal BMI on the basis of gestational age.  Other countries have general guidelines that are not based on the mother’s body size or gestational age. Examples include India which has a recommendation of 10 to 12 kg (22 to 26.4 pounds) total weight gain, France which recommends an average total gain of about 12 kg (26.4 pounds) , and Myanmar which recommends an increase of 1 kg (2.2 pounds) a month from the fifth month of gestation to the end of pregnancy.   

Thus, you should keep in mind that the IOM recommendation is just one point of reference, and using your best judgment based on your health status or consulting your healthcare provider for your specific circumstance may be beneficial.     

It is important to note that for mothers in the overweight or obese category, research indicates that it may actually be beneficial to gain minimal weight or even no weight at all. For overweight and obese mothers, gaining less than the IOM’s recommendation of 15 pounds significantly reduced the risk for preeclampsia, cesarean delivery, and large for gestational age (LGA) infants.   

A key takeaway from this article should be to have a general idea of what a healthy weight gain looks like for you individually, but without dwelling too much on the number on the scale and focusing on creating a lifestyle that is healthful to you both physically and mentally. For instance, in terms of food, focusing on the nutrient density in order to nourish your baby instead of overly obsessing on calories intake would go a long way. Please feel free to check out our articles on prenatal nutrition, as they discuss crucial nutrients that are needed during pregnancy! 

Additionally, exercise during pregnancy will not only help prevent excessive weight gain but also assist with the alleviation of other pregnancy complications such as gestational diabetes and hypertension, high blood pressure, and edema. It will have a positive impact on your mental wellbeing as exercise can contribute to better sleep as well. There are certain types of exercise that pregnant women are discouraged from taking part in, so make sure to consult with your healthcare provider first.      

Looking for more support? 

Our fertility dietician Anabelle is available for one-on-one consultation and can help you address any of your concerns regarding fertility, pregnancy or hormonal imbalances like PCOS! 

References: 

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