Pregnancy and Postpartum
Historically, pregnancy was often thought of as a time requiring rest and limited physical activity, but today the majority of pregnant women in the United States choose to engage in at least some exercise. If you are currently pregnant or thinking about becoming pregnant soon, the good news is that exercise can improve your health outcomes during pregnancy and postpartum (i.e., the first year of birth). Even better, research also indicates that exercising during pregnancy may improve child health outcomes too.
This chapter touches on some nutritional areas to consider as well as highlighting the benefits of different types of exercise during pregnancy, goes over common concerns about exercise during pregnancy and some precautions and gives tips about how to incorporate exercise and healthy nutrition into your life during pregnancy and the postpartum period.
Maintaining Health During Pregnancy
What makes a healthy pregnancy? Certainly, most pregnant women are primarily concerned with the appropriate growth and development of their baby. To ensure appropriate fetal development, it’s important to optimize mom’s health during pregnancy. Important factors during pregnancy include the mom’s weight, fasting glucose levels, and blood pressure.
Starting pregnancy with a healthy weight (i.e., body mass index [BMI] between 18.5 and 25 kg/m2) and gaining an appropriate amount of weight helps to ensure a pregnancy with fewer complications. Even if you start pregnancy underweight or overweight or obese, gaining an amount that is within the recommended weight ranges will improve your chances of experiencing a normal pregnancy with a healthy baby (see table Pregnancy for recommended weight gain during pregnancy).
The two most common pregnancy complications are gestational diabetes and hypertension (i.e., gestational hypertension or preeclampsia). Gestational diabetes affects 5 to 9 percent of U.S. pregnancies and is diagnosed as abnormally high blood glucose (sugar) occurring for the first time during pregnancy. Women who have a family history of diabetes, who are overweight or obese, or who previously delivered a large infant (i.e., greater than 4.5 kilograms [10 lb]) are at higher risk for developing gestational diabetes. Gestational diabetes increases the risk of delivering a large infant, who then has a higher risk of being obese during childhood. Women diagnosed with gestational diabetes should work closely with a Registered Dietician or other health care provider to control their blood glucose level while ensuring that optimal nutrients are available for the developing baby.
Gestational hypertension or preeclampsia affects 2 to 7 percent of U.S. pregnancies. Gestational hypertension is diagnosed as high blood pressure occurring for the first time during pregnancy, while preeclampsia is a more severe condition characterized by hypertension combined with excess protein in the urine. Both conditions increase the risk of delivering an infant who is small or premature. Women with a family history of hypertension who are African American, are overweight or obese, have gestational diabetes, or are carrying multiples (e.g., twins, triplets) are at higher risk for gestational hypertension or preeclampsia.
Healthy Approaches to Pregnancy
Physical activity and eating a healthy diet are two important lifestyle behaviors for pregnant women that can help them avoid or treat the pregnancy complications highlighted next.
Focusing on Nutrition
Nutrition during pregnancy takes on special importance since it affects both maternal and fetal health. The Academy of Nutrition and Dietetics (AND) states that the key components of a healthy pregnancy include appropriate weight gain, healthy nutrition, and safe food handling.
Appropriate Weight Gain
Recommended amounts of weight gain during pregnancy are based on prepregnancy weight status to optimize infant birth weight, avoid excessive postpartum weight retention for mom, and reduce the risk of later chronic disease development for mom and baby. Gaining either not enough or too much is associated with poorer birth outcomes. To find out how much weight you should gain during a singleton pregnancy (i.e., resulting in the birth of one infant), first calculate your BMI from your weight and height before pregnancy (see chapter 18 for details on determining your BMI) and then check table Pregnancy. For multiple births (e.g., twins, triplets), higher weight gains are needed to improve infant birth weight and length of pregnancy: Weight gain should be 40 to 54 pounds (18 to 25 kg) for women who are normal weight, more for those who are underweight (50 to 62 pounds or 23 to 28 kg), and less for those who are overweight or obese (as little as 29 to 38 pounds or 13 to 17 kg) .
Consumption of a Variety of Foods
The Dietary Guidelines, as discussed in chapter 3, are appropriate during pregnancy. The daily energy needs of pregnant women increase in the second and third trimester by about 340 calories and 450 calories, respectively, but calories add up quickly so it’s important to eat nutrient-packed foods like fruits, vegetables, and whole grains. Multiple births require additional calorie intake, but researchers have not precisely determined these energy requirements.
Appropriate Vitamin and Mineral Supplementation
Many women of childbearing age do not maintain healthy enough eating habits to meet their nutrient needs, and this continues to be a concern during pregnancy. For this reason, and because of the role folic acid plays in preventing specific birth defects when taken very early in pregnancy, all women who are capable of becoming pregnant (including adolescents) should supplement with folic acid. This includes consuming 400 micrograms of synthetic folic acid from dietary supplements or fortified foods (e.g., bread, pasta, and some breakfast cereals) in addition to eating foods like green leafy vegetables that are a good source of natural folate; pregnant women are encouraged to consume a total of 600 micrograms from all sources. Iron requirements are also higher during pregnancy. Iron supplementation is recommended to meet the increased demands during pregnancy and is particularly important for anemic women. Pregnant and breastfeeding women should ask their healthcare provider about taking these and other prenatal supplements, including omega-3 fatty acids, vitamins B12 and D, choline, calcium, iodine, and zinc, which may be warranted for women with poor diets or those who exclude entire food groups like meat or dairy from their usual diets .
Avoidance of Alcohol, Tobacco, and Other Harmful Substances
Pregnant women should not consume alcohol; drinking during pregnancy is associated with developmental and neurological birth defects. Smoking should also be avoided because it limits the oxygen available for the baby and increases the risk of spontaneous abortion, preterm birth, and sudden infant death syndrome, among other concerns.
Safe Food Handling
Pregnant women and their babies have a higher risk of developing food-borne illnesses. Therefore, it is recommended that pregnant women avoid soft cheeses not made with pasteurized milk, cold smoked fish, and cold deli salads. For any deli meats, luncheon meats, bologna, or frankfurters, the items should be reheated to steaming hot. Pregnant women should avoid any unpasteurized products or raw or undercooked eggs or meat. Due to mercury levels in fish, do not eat shark, swordfish, king mackerel, or tilefish if you’re pregnant. Lower mercury content seafood (e.g., shrimp, canned light tuna, salmon, pollock, catfish) is considered safe and encouraged because of its beneficial fatty acid content at 8 to 12 ounces (225-340 g; about three servings) per week.
Where can I get healthy meal plans for pregnancy and postpartum?
You can use www.choosemyplate.gov/moms-pregnancy-breastfeeding to help you devise a healthy meal plan during your pregnancy and postpartum. All women of childbearing age should be sure to eat foods high in folic acid (green leafy vegetables and fortified grains). During pregnancy and postpartum, talk to your healthcare provider about other dietary supplements.
Thus, although good nutrition is always important for your health, dietary choices are especially important during pregnancy when your body needs extra energy and nutrients to ensure that both you and your baby stay healthy. In addition to the recommendations regarding iron and folate supplements to ensure healthy birth outcomes, you should consume at least 8 to 10 cups (64-80 fl oz) of fluid per day to stay hydrated. You can use the Daily Food Plan for Moms to create food plans that meet energy needs (i.e., ~2200 to 2900 calories per day for most pregnant women) while ensuring that all food groups are covered.
Women who exercise during pregnancy should take additional care to make sure to balance energy expenditure with energy intake. In other words, make sure to eat extra calories to make up for the ones you burn while exercising—pregnancy is not the time to lose weight! Recall that once you know the MET value (metabolic equivalent; a unit of measure reflecting the amount of oxygen used) you can also determine the calories burned per minute during the activity. Your total number of calories burned depends on how long you exercise at a given intensity. If you choose to exercise vigorously during pregnancy or pursue athletic training for competition, you may wish to meet with a Registered Dietitian to make sure you and your developing baby’s energy and nutrient needs are being met. For more information on general nutrition, recommendations see chapter 3, which includes details on the Dietary Guidelines recommendations.
Focusing on Physical Activity
The original 1985 guidelines for physical activity during pregnancy published by the American College of Obstetricians and Gynecologists (ACOG) were cautious, advising pregnant women that heart rate “should not exceed 140 bpm”; however, there was actually no scientific basis for that recommendation. Heart rate limitations have never been mentioned in pregnancy exercise guidelines since that time, and a broad range of health benefits associated with exercise during pregnancy have been documented. The ACOG guidelines now state that “women with uncomplicated pregnancies should be encouraged to engage in aerobic and strength-conditioning exercises before, during, and after pregnancy”. The Physical Activity Guidelines for Americans recommends the following :
- Healthy women who are not already highly active or doing vigorous-intensity activity should get at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity per week during pregnancy and the postpartum period. Preferably, this activity should be spread throughout the week.
- Pregnant women who habitually engage in the vigorous-intensity aerobic activity or are highly active can continue physical activity during pregnancy and the postpartum period provided that they remain healthy and discuss with their health care provider how and when activity should be adjusted over time.
What are examples of “moderate” and “vigorous” activities?
It is recommended that pregnant and postpartum women engage in 150 minutes per week (30 minutes, five days per week) of moderate aerobic physical activity. Moderate activities you might like include walking, swimming, bicycling (10 to 13 miles per hour [16 to 21 km]), dancing, and aerobics. Women who are already vigorously active can most often maintain those activities. Vigorous activities include jogging, fast bicycling (14 miles per hour [22.5 km] or faster), hiking, and singles tennis. You can use the talk test to help determine your intensity: During moderate activities, you are able to talk in complete sentences, while during vigorous activities you may be able to say only a few words at a time. Talk to your healthcare provider and listen to your body to adjust the intensity of your physical activity.
Benefits of Exercise
Exercise before as well as during pregnancy is associated with lower risk for excessive gestational weight gain, gestational diabetes, Precambrian, and preterm delivery. Exercise during pregnancy also appears to be a safe and effective way to maintain blood glucose within normal limits among women who are already diabetic or who become so during pregnancy. Importantly, women reporting the recommended amount of physical activity during pregnancy (i.e., at least 150 minutes per week) also seem to deliver babies with healthier birth weights. Exercising women have a lower risk of delivering a large infant (i.e., over 4.5 kilograms [10 lb]) without changing their risk of delivering a small infant (i.e., less than 2.5 kilograms [5.5 lb]). This is important since both low and high birth weight has been linked to increased risk of heart disease and obesity later in life. A few small studies have shown that children of women who exercised during pregnancy had less body fat or reduced risk of obesity compared to children of women who did not exercise. Thus, participation in aerobic exercise during pregnancy not only improves maternal health; it may also contribute to better child health outcomes.
These results were based on self-reported physical activity and likely largely reflect values for women who were active before pregnancy and continued their routines, since most women do not choose to start exercise when they become pregnant. Unfortunately, research studies that have previously inactive women either start exercising (most often walking) or participate in a control group (like a health education class) have largely failed to show significant effects of exercise on risk of pregnancy complications or excessive weight gain. Importantly, most of these studies also failed to actually get women in the exercise groups to exercise regularly. Thus, the lack of effects on health outcomes most likely reflects the difficulty of getting people to change their health behaviors. More studies are needed to determine whether women who start exercising once they become pregnant will enjoy the same health benefits as women who were active beforehand and continue their activity levels during their pregnancy.
The benefits of exercise continue during the postpartum period. ACOG guidelines recommend that women resume pregnancy exercise routines gradually after birth as soon as it is physically and medically safe. The exact amount of time needed to recover after birth varies from woman to woman depending on the difficulty of labor, type of delivery (cesarean versus vaginal), preexisting fitness level, and other medical complications. Typically women can resume exercise within days of delivery if no complications are present, although women who experience cesarean deliveries should not start exercising before four to six weeks postpartum. Consulting with your health care provider will allow you to determine what is best for you and your situation.
Exercising during the postpartum period helps with weight loss and appears to have psychological benefits. Women reporting greater amounts of exercise have less weight retention at six weeks and one year postpartum compared to less active women. While being active during pregnancy or the postpartum period (or both) does not seem to reduce the occurrence of postpartum depression, exercise prescriptions have been effective at alleviating depressive symptoms among women with postpartum depression.
How to stay active after baby’s birth?
Home-based activities might include walking around the neighborhood or on a treadmill to promote aerobic fitness or using resistance bands for muscular fitness. In addition, community-based activity programs can provide social aspects in addition to opportunities to be active. For example, some communities have exercise programs specifically for mothers and their babies at shopping malls. With babies happily riding in their strollers, the moms’ power walk, resistance train with tubing or bands, and stretch. Not only are these exercise sessions invigorating, they also provide a chance to chat with other new mothers.
Therefore, current recommendations endorse regular exercise as part of a healthy pregnancy and postpartum period. Research shows that exercise is both safe and beneficial during pregnancy. While it is recommended that women get at least 150 minutes per week of moderate activity during pregnancy, more specific recommendations for aerobic fitness, muscular fitness, and flexibility training are not available. Some women choose to continue running 50+ miles (80+ km) per week during pregnancy with no ill effect, while others choose to start walking or swimming during pregnancy. Women who already have an exercise program before pregnancy are advised to continue the same program until they feel the need to modify it by decreasing intensity, frequency, or duration of exercise. Women who are not already active are advised to begin moderate exercise during pregnancy to improve their own health as well as their child’s health. As outlined throughout this book, a balanced exercise program includes aerobic and muscular fitness, along with flexibility. This section outlines some special considerations for pregnant women regarding exercise.