Pregnancy and Weight Gain — Too much, too little and just right
What does bodyweight have to do with healthy pregnancy? A lot.
When women weigh too much or too little, their bodies, pregnancies and babies can suffer serious consequences. Indeveloped countries, being overweight and obesity are major problems. In some developingcountries obesity rates are on the rise, but women also struggle with not gaining enough weight and both are considered malnutrition.
Body weight isn’t just a reflection of our nutritional and fitness statuses, but also an indicator for cardiovascular, musculoskeletal, metabolic and reproductive health as well as how our body works as an integrated system. Bodyweight is not a “fat thing,” but something that may impact our overall health and general wellbeing.
Here at EMC, we batted around the idea of whether or not to use the word “normal” when we talked about weight in relation to maternal health. We recognize what’s “normal” for one woman is not normal for another. We know that every woman has her best weight, the one that makes her feel and look healthiest. We also know that in any group of women, some will be heavier, some will be thinner and there will be no “normal.” That’s why, for the sake of this article, we decided to go with the definitions created by the pros — the Institute of Medicine(IOM) and National Institutes of Health.
The IOM designates weight categories by measuring Body Mass Index (BMI) — a measure of body fat based on height and weight.
- Underweight = <18.5
- Normal weight = 18.5–24.9
- Overweight = 25–29.9
- Obesity = BMI of 30 or greater
Obesity and Pregnancy
In the United States, more than a third of all women and more than half of pregnant women are overweight or obese. These rates have spiked in the past 25 years and had a huge impact on maternal health. While overweight women can and do have entirely healthy pregnancies, their increased weight places them at higher risk for complications.
The link between obesity and maternal mortality flew under the radar until studies pointed out direct connections. For example, from 1999 to 2004, 255 pregnancy-associated deaths among pregnant women were reported to the Virginia Maternal Mortality Review Team and 80 were considered to be directly pregnancy-related. Pre-pregnancy BMI among these women ranged from 17.1 to 58.5, with a median of 30.7 (obese). Researchers determined that these obese women died of diseases known to be associated with obesity, including cardiac disease, cardiomyopathy and pulmonary embolism. Obesity-related co-morbidities (additional diseases) like diabetes and hypertension were prevalent among obese mothers, but not normal weight mothers:
According to the American Congress of Obstetricians and Gynecologists, obesity is greatest among non-Hispanic black women (50%) compared with Mexican American women (45%) and non-Hispanic white women (33%). This is partly why African American women die from pregnancy-related complications four times more often than women of other races.
Obesity related pregnancy complications include:
- Gestational diabetes
- Hypertension
- Preeclampsia
- Cesarean delivery
- Postpartum weight retention
- Prematurity
- Stillbirth
- Congenital anomalies
- Extra-large babies who experience/cause possible birth injuries
- Childhood obesity
- Labor, vaginal and cesarean birth complications
- Difficulties related to anesthesia management
- Complications initiating and sustaining breastfeeding
Doctors used to require pregnant women to adhere to strict weight restrictions, which were enforced by scolding and threatening women who gained too much. This punitive tactic went by the wayside when the natural childbirth movement gained traction and women demanded more respectful maternity care. Gradually, however, women started taking “eating for two” way too far. We’ve seen an increase in recent decades of women gaining fifty, sixty, even eighty pounds during pregnancy.
An overweight/obese woman’s heart, uterus and muscles work harder than normal to facilitate labor under excess weight. Babies have a tougher time too when labor becomes obstructed by an extra-padded birth canal that leaves them no room for baby to descend. When labor doesn’t progress normally, women wind up in the operating room. Their C-sections are more complicated by cardiac and respiratory problems, bleeding, infections, anesthesia complications and poor healing. In most cases, once she has one C-section, subsequent babies will also be delivered via C-section and risks get even higher.
Underweight, Malnutrition and Pregnancy
Underweight comprises a much smaller group of women in developed countries, but represents a large group of women in developing countries where it’s difficult for women to access food, where HIV is prevalent and where women have limited access to healthcare.
Women who are extremely underweight or suffer from malnutrition are at increased risk for infertility (extreme weight loss causes them to stop menstruating and ovulating), miscarriage and anemia. The World Health Organization says in developing countries, 50% of pregnant women are anemic, a condition that contributes to 20% of all maternal deaths. When women are given nutritional supplements, however to boost their caloric and nutrient intake during pregnancy, both mother and baby are healthier and have better chances for survival of childbirth.
What’s the solution?
Whenever possible, women must take responsibility for their health by watching what they eat, following their providers advice, seeing a nutritionist or enrolling in nutrition support services if necessary, getting enough exercise and keeping their pregnancy weight gain between these recently revised parameters:
For women whose pre-pregnant weight is:
- Normal (BMI 18.5–24.9) — gain 25–35 pounds
- Underweight (BMI less than 18.5) — gain 28–40 pounds
- Overweight (BMI 25–29.9) — gain 15–25 pounds
- Obese (BMI over 30) — gain 11–20 pounds
Where does this weight go?
- Baby: 7–8 pounds
- Placenta: 1–2 pounds
- Amniotic fluid: 2 pounds
- Uterus: 2 pounds
- Maternal breast tissue: 2 pounds
- Maternal blood: 4 pounds
- Fluids in maternal tissue: 4 pounds
- Maternal fat and nutrient stores: 7 pounds
What can you do?
- If you’re considering pregnancy, take advantage of your pre-pregnancy time to reach a healthy body weight, learn about nutrition and exercise and consult your provider to make sure you’re doing all you can to sustain a healthy pregnancy.
- If someone you love is pregnant, support her to make healthy food and exercise choices throughout pregnancy.
- Support organizations like Save The Children and GAIN (Global Alliance for Improved Nutrition) who are investing in nutrition programs for mothers and babies.
- Support programs that increase pregnant women’s access to health care including Every Mother Counts, Midwives in Haiti, UNFPA and Saving Mothers, Giving Life.
Resources:
American Congress of Obstetricians and Gynecologists
Committee Opinion, Obesity in Pregnancy
Number 549, January 2013
World Health Organization
WHO, nutrition experts take action on malnutrition
March 16, 2011
MedPageToday
Obesity Ups Risk of Death in Pregnancy
By Nancy Walsh, Staff Writer, MedPage Today
Published: February 13, 2012
