Where we have been
Originally pregnancy was not managed by the medical community, but through lay midwives, most without much if any training. Historically, weight gain was not something that was measured or addressed and folklore was the prevailing advice basis.Childbirth, though risky, was not considered pathological and the majority did not receive medical intervention, this continued well into the twentieth century. Once modern medicine became involved, varying weight gain recommendations surfaced.
In nineteenth century United States physicians recommended a restricted food intake in pregnancy in an effort to prevent a difficult labor. Obviously there was some logic and anecdotal evidence to support the recommendation – a smaller baby often results in an easier delivery. The problem is that a smaller baby may not equate to a healthy baby. The possible exception where this might help is in cases of macrosomia, often caused by unmanaged maternal diabetes. It is possible that a calorie restricted diet could also improve the blood sugar levels since refined sugar would likely be eliminated in the effort to control weight gain, thereby possibly preventing excessive growth of the infant.
In the first half of the twentieth century we began to see published studies associating weight gain and birth weight. In the 1930s excessive weight gain was seen as a possible sign of swelling and/or impending pre-eclampsia. In an effort to prevent this, it was to recommended that weight gain should not exceed15 pounds (6.8 kg) during pregnancy. As a result studies conducted during this period reported an average weight gain of less than 20 pounds (9.1 kg) and this was also considered good for “preservation of figure”.
This view was challenged in the 1960s when low birth weight concerns became apparent. In 1971 Hyten and Leitch published a review of studies from the 1950s and 1960s and concluded that the best pregnancy outcomes in terms of birth weight, infant survival and incidence of pre-eclampsia, in mothers whose total pregnancy weight gain was 27.5 pounds (12.5 kg) without consideration of pre-pregnancy weight variations .
In 1970, the National Academy of Sciences Food and Nutrition Board’s Committee on Maternal Nutrition recommended 20-25 pounds (9.1-11.3 kg) for total pregnancy weight gain without regard for pre-pregnancy weight or body mass index (BMI). It was also noted that low weight gain was associated with infant mortality, disability and mental retardation. As a result, in 1972 the American College of Obstetrics and Gynecology (ACOG) endorsed this guideline to ensure adequate weight gain. This was amended in 1981 by FNB’s Nutrition Services in Perinatal Care to define inadequate weight gain as 2.2 pounds (1 kg) or less/month in 2nd and 3rd trimesters and excessive gain as 6.6 pounds (3 kg) or more/month .
In the 1980s weight gain recommendations had nearly doubled what they were in the 30s and women were advised to gain 25-30 pounds (11-14 kg), but by 1990 a more individualized recommendation which related to the pre-pregnancy weight range was recognized in association with good clinical outcomes when a committee of the National Academy of Science, through the Institute of Medicine, made recommendations for pregnancy weight gain based on pre-pregnancy weight .BMI < 19.8 (Underweight): 28-40 pounds (12.5-18 kg) BMI 19.8 – 26 (Normal weight): 25-35 pounds (11.5-16 kg) BMI 26.1 – 29 (Overweight): 15-25 pounds (7-11.5 kg) BMI >29 (Obese): At least 15 pounds (6kg).
Where we are now
We have now witnessed a trend of an increasing percentage of women gaining excessive amounts of weight, and the percentage of women who are overweight or obese prior to pregnancy has also increased. These trends have resulted in revised recommendations for obese women by the Institute of Medicine and the National Research Council in June 2009, as a response to the growing evidence that weight gain can cause health problems for women and their infants. The current recommendations for total pregnancy weight gain, based on pre-pregnancy body mass index (BMI) are:BMI = 18.5 or less (Underweight ): 28 to 40 pounds BMI = 18.5 to 24.9 (Healthy weight ): 25 to 35 pounds BMI = 25 to 29.9 (Overweight ): 15 to 25 pounds BMI = 30 or more (Obese ): 11 to 20 pounds
Babies of pregnant women who do not gain enough weight face an increased risk of stunted growth and preterm delivery, though problems on this side of the scale is considerably less common in developed countries today. Extra weight gained in pregnancy also places mothers higher risk for conditions such as high blood pressure, pre-eclampsia, obstructive sleep apnea, gestational diabetes and blood clots. The infants are also at increased risk of being born prematurely, being larger at birth, requiring delivery by cesarean section with its surgical complications, and even stillbirth. ACOG reports:
“Obesity is associated with an increased risk of both miscarriage and stillbirth. The risk of stillbirth is 8 per 1,000 births among obese pregnant women with a body mass index (BMI) between 30 and 39.9 and is even higher among pregnant women with a BMI greater than 40 (11 per 1,000). Obesity remains an independent risk factor for stillbirth even after controlling for smoking, gestational diabetes, and preeclampsia .
Intrapartum risks include increased c-section rate, anesthesia difficulties, problems in palpating the position of the baby, and macrosomia with shoulder dystocia. During the postpartum period, complications include wound dehiscence and/or infection, pulmonary embolism, postpartum hemorrhage, and deep vein thrombosis. The infant also faces more risks including polyhydramnios, hyperglycemia, macrosomia, intrauterine growth restriction, fetal demise and congenital malformations .
Excessive weight gain can also increase a woman's risk of postpartum obesity with its associated risks for heart disease, stroke, and depression because of the difficulty in losing extra pounds gained during pregnancy, body image, self-esteem and increased risk of being overweight at the onset of a subsequent pregnancy. Following the revised weight gain guidelines will help reduce the risk of many of these pregnancy-related problems. Obesity affects 6 to 10% of all pregnancies and it causes more medical complications than smoking or alcohol abuse. Because they may be taking in an excess of calories; not necessarily nutrients, they can actually be undernourished.
Where we are going
Healthy babies start with healthy mothers and each health care visit for any purpose provides an opportunity to address weight problems with all patients. It is possible to improve pregnancy outcomes by helping the woman achieve a state of good health before she conceives. An evaluation of BMI with a plan to lose or gain weight as indicated, along with other screenings, immunizations, infection treatment and interconception or preconception multivitamin use (especially folic acid) can make a difference in the health of the future mother and baby. About 50% of pregnancies are unplanned which suggests the focus must go beyond a formal preconception visit and a reproductive life plan should be addressed with every healthcare visit in women of childbearing years. They need to know that BMI at the time of conception can have an impact on her future pregnancies. If she is overweight or obese, even modest weight loss through a structured eating plan prior to pregnancy will help reduce her risks and start her on a pattern of sensible eating. If a dietetic consultation is needed, the healthcare provider should help her to access these services. Preconception planning is the ideal time to help her set realistic goals to improve her health and decrease risks. Knowing that she is overweight is not enough to motivate her to make changes. As with other bad habits, eating and exercise changes take education, time, support, and commitment.
Reports indicate that around 33% of pregnant patients are not counseled by their provider regarding weight gain goals and the IOM revised guidelines. When included, counseling often consists of general recommendations for a healthy diet and exercise, without adequate assessment for possible roadblocks to achieving the recommended weight gain goals or referrals to supportive professionals. Adequate consultation time is a hurdle for the provider but a healthier mother-to-be will be time and cost effective in the future – a good investment.
Evaluation of the BMI and associated weight concerns or eating disorders must be done with compassion and sensitivity, but it is not in the patient’s best interest to dismiss the concern simply because it makes either party uncomfortable . The health of the mother and infant is at stake so lifestyle and risk factors must be addressed, including weight gain, smoking, alcohol, seat belt use and appropriate exercise. The patient will listen to her doctor when she ignores all other medium so what she is told in the office about weight gain is critical to her compliance. If the doctor or midwife says nothing, the assumption will be that it was not a concern or implied consent.
The doctor or midwife should also advise the patient in exercise which is safe in pregnancy, considering her overall condition. Most women don’t know what is okay and err on the side of caution, which may prevent her from getting adequate exercise. She may be hesitant to bring up the subject herself. If you have staffing to provide RN counseling of the patient, some of the time needed for this discussion could be handled by other qualified staff. Some offices have an initial visit with the registered nurse to talk about vitamins, weight gain goals, nausea and other early concerns. This comes prior to the usual onset of prenatal care visits.
Tools that may help in counseling a woman on pregnancy weight gain include dietary consultation but also discussion about nutrient dense food choices. The mother must know that she does not need to increase her calories as if “eating for two (adults)” and she should be encouraged to avoid empty calories such as sugar-sweetened drinks, cookies, candies, etc. Complex carbohydrates should replace refined grains. This will also help reduce the common pregnancy complaint of constipation. Eating a healthy diet can be difficult for some patients due to economic concerns, bad habits and nausea of pregnancy. Giving the patient some real advice for improving her food intake can make a difference. She must feel that her doctor or midwife cares about this and it cannot be assumed that she is knowledgeable about this.
The patient can be encouraged to check out free online tools such as http://www.sparkpeople.com where she can monitor her food intake and exercise, or http://www.mypyramid.gov where she can find her personalized nutritional needs in pregnancy. There may be college extension services or local health department programs, including the U.S. nutrition program for women, infants and children (WIC) that counsel women in appropriate dietary intake while assisting low income families with supplemental nutrition.
Commercial programs such as Weight Watchers will exclude pregnant women from their meetings due to liability concerns, but the patient should know that a good, balanced diet, similar to Weight Watchers is still a good guideline if they are overweight and they can resume membership and attendance after delivery. Pregnancy only requires an increase in the daily caloric intake by 300 kcals and that is based on an intake of only the calories needed for weight maintenance. These days, it is common for women in the U.S. to already consume at least 300 extra calories daily so they should not automatically be told to increase their intake just because of pregnancy. The exclusion of pregnancy from some organized weight loss programs may leave the patient feeling alone in her quest for good, low-calorie meal planning. It would be helpful if third-party payers would recognize the value of nutrition consultation in all health concerns. At this time most only cover dietitian services when the patient has a diagnosis of diabetes. Medicaid, however, has been more generous on this and a diagnosis of obesity may allow several visits with a registered dietitian.
It is important to be sensitive to the feelings of an obese patient. Often she feels ignored or judged; factors which can be roadblocks to helping her become healthier. This is a complex issue which begs compassion by all the staff – from the receptionist to the back office assistants. This might include being discreet in weighing the patient and giving her choices that will decrease her stress. The pre-exam weighing ritual may even be the cause of “white coat hypertension” if it causes anxiety. Some will even avoid their prenatal visits if they feel shunned or humiliated by the staff, however unintentional.
It is common for obese people to underestimate their excess weight and their caloric intake so education is important. There may also be serious psychological issues or eating disorders, poor self-esteem and social discrimination. Postpartum depression (and antepartum depression) is also more common in obese mothers so it is necessary to address these problems and watch for symptoms of depression. The Edinburgh Postnatal Depression Scale and the Patient Health Questionnaire (PHQ-2 or PHQ-9) are good tools for an initial assessment. The patient should be treated with respect and dignity regardless of her size and accommodations should be made (blood pressure cuff, gown size, wheel chair, waiting room chairs, etc.) to encourage her prenatal care attendance. Strict glycemic control is important and a glucose challenge test is recommended at the first visit. A diabetic educator may be indicated .
Treating the underweight woman is still a challenge, even if it is less common. The primary risk is a baby who is small for gestational age (SGA) and is not associated with other health concerns in absence of eating disorders such as anorexia or bulimia where electrolyte imbalance and starvation could adversely affect maternal health as well. These women may need extra help and counseling. Asking the right questions is imperative so you don’t make assumptions about the cause, thereby eliminating the possibility of a cure.
While most providers are aware of the growing problem of obesity and excessive pregnancy weight gain, they often feel powerless to actually affect change in their patients. Eating disorders such as anorexia nervosa and bulimia increase risk for hyperemeisis gravidarum and preterm birth. The American College of Obstetrics and Gynecology (ACOG) surveyed member providers and determined that while “most knew low birth weight (90%) and postpartum depression (90%) are associated with maternal eating disorders (EDs), over a third was unsure about several consequences” and “less than half assess ED history, body image concerns, weight-related cosmetic surgery, binging, and purging” - important information in evaluating weight gain issues. The provider’s lack of confidence and training in assessment and treatment of eating disorders is an important factor .
Providers care very much about the growing problems of excessive weight gain in pregnancy and obesity in general, but there is not enough information to help them counsel and deal with this concern. More tools are needed so providers will know what they can do to help someone heal or make needed changes in their lifestyles. Obesity should be treated like any other disease and requires effective tools to track, measure, educate and encourage.
Conflict of interest statementNo conflict of interest
CITE THIS ARTICLE:
Debbie Miller, RN. Pregnancy Weight Gain Guidelines in the US - a Historical Overview. Doctors Lounge. Available at: https://www.doctorslounge.com/index.php/articles/page/14732. Accessed April 13 2021.