Established Evidence Results

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: This randomized controlled trial assigned women to receive either an organized, consistent program of intensive dietary and lifestyle counseling or routine prenatal care. The control group received routine prenatal care per American College of Obstetricians and Gynecologists standards and was given a prenatal booklet that included advice on diet and exercise during pregnancy. The intervention group underwent a complete history and physical examination with specific attention paid to prepregnancy weight, current weight, height, and BMI. At the initial visit, the study group met with a registered dietician to receive a standardized counseling session, including information on pregnancy-specific dietary and lifestyle choices. Patients were instructed to engage in moderate-intensity exercise at least three times per week and preferably five times per week. They also received information on the appropriate weight gain during pregnancy using the IOM guidelines. Participants' weight was measured during routine appointments, and if it was not within IOM guidelines they were advised to increase or decrease their dietary intake and increase or decrease exercise.

Intervention Results: A total of 100 women were randomized to the study (lifestyle counseling 57, routine prenatal care 43). Baseline demographic characteristics were similar between the study groups. The lifestyle counseling group gained significantly less weight than did the routine prenatal care group (28.7+/-12.5 lb compared with 35.6+/-15.5 lb, P=.01). The routine prenatal care group had significantly more cesarean deliveries due to "failure to progress" (routine prenatal care 58.3% compared with lifestyle counseling 25.0%, P=.02). Across groups, patients who were not adherent to the IOM guidelines had significantly heavier neonates (adherent 3,203.2+/-427.2 g compared with not adherent 3,517.4+/-572.4 g, P<.01). Nulliparous women gained significantly more weight than did parous women (36.5+/-14.5 lb compared with 27.7+/-12.7 lb, P<.01). The most predictive factor of IOM adherence was having a normal prepregnancy body mass index. No statistically significant differences were noted between the groups in adherence to IOM guidelines, rate of cesarean delivery, preeclampsia, GDM, operative vaginal delivery, or vaginal lacerations.

Conclusion: An organized, consistent program of dietary and lifestyle counseling did reduce weight gain in pregnancy.

Setting: Carolinas Medical Center, Charlotte, North Carolina

Population of Focus: Obese nulliparous and multiparous pregnant women with singleton gestrations

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: A randomized controlled trial was conducted with 290 healthy pregnant Caucasian (Spanish) women with a singleton gestation who were randomly assigned to either an exercise (n=138) or a control (n=152) group. The physical conditioning exercise included a total of three 40-45 minute sessions per week, beginning at the start of the pregnancy (weeks 6–9) until the end of the third trimester (weeks 38–39). Each session included a 25-minute core portion that was preceded and followed by a gradual warm-up and cool-down period, both of 7–8 minutes in duration and consisting of walking and light, static stretching (to avoid any muscle pains) of most muscle groups (upper and lower limbs, neck and trunk muscles).

Intervention Results: The percentage of cesarean and instrumental deliveries in the exercise group were lower than in the control group (15.9%, n = 22; 11.6%, n = 16 vs. 23%, n = 35; 19.1%, n = 29, respectively; p = 0.03). The overall health status of the newborn as well as other pregnancy outcomes was unaffected.

Conclusion: Based on these results, a supervised program of moderate-intensity exercise performed throughout pregnancy was associated with a reduction in the rate of cesarean, instrumental deliveries and can be recommended for healthy women in pregnancy.

Setting: University Hospital in Madrid, Spain

Population of Focus: Low risk Caucasian (Spanish) women with singleton gestations

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: 1108 women were randomised to a comprehensive dietary and lifestyle intervention delivered by research staff; 1104 were randomised to standard care and received pregnancy care according to local guidelines, which did not include such information. Women randomized to lifestyle advice participated in a comprehensive dietary and lifestyle intervention that included a combination of dietary, exercise, and behavioral strategies delivered by a research dietician and trained research assistants. Participants were provided with dietary advice consistent with current Australian standards to maintain a balance of carbohydrates, fat, and protein and to reduce intake of foods high in refined carbohydrates and saturated fats, while increasing intake of fiber and promoting consumption of two servings of fruit, five servings of vegetables, and three servings of dairy each day. Physical activity advice primarily encouraged women to increase their amount of walking and incidental activity.

Intervention Results: 2152 women and 2142 liveborn infants were included in the analyses. The risk of the infant being large for gestational age was not significantly different in the two groups (lifestyle advice 203/1075 (19%) v standard care 224/1067 (21%); adjusted relative risk 0.90, 95% confidence interval 0.77 to 1.07; P=0.24). Infants born to women after lifestyle advice were significantly less likely to have birth weight above 4000 g (lifestyle advice 164/1075 (15%) v standard care 201/1067 (19%); 0.82, 0.68 to 0.99; number needed to treat (NNT) 28, 15 to 263; P=0.04). There were no differences in maternal pregnancy and birth outcomes between the two treatment groups.

Conclusion: For women who were overweight or obese, the antenatal lifestyle advice used in this study did not reduce the risk delivering a baby weighing above the 90th centile for gestational age and sex or improve maternal pregnancy and birth outcomes.

Setting: Three public maternity hospitals across South Australia

Population of Focus: Nulliparous and multiparous women with a BMI ≥25 and singleton gestation

Intervention Components (click on component to see a list of all articles that use that intervention): Diet/Exercise, PATIENT_CONSUMER

Intervention Description: The research team sought to assess the effects of pre-pregnancy physical fitness of AD soldiers as measured by the Army Physical Fitness Test (APFT) on the incidence of CD in AD women, in addition to examining known demographic and pregnancy risk factors in this cohort.

Intervention Results: Neither total APFT performance nor performance on the individual push-up, sit-up or run events in the 15 months prior to pregnancy was associated with mode of delivery. Excessive gestational weight gain (EWG) and neonatal birth weight were the only two factors independently associated with an increased rate of cesarean delivery. Women who had excessive gestational weight gain, were twice as likely to undergo CD as those who had adequate or insufficient weight gain (24% vs. 12%, p = 0.004). Soldiers delivering a neonate ≥4,000 g were 2.8 times as likely to undergo CD as those delivering a neonate <4,000 g (47% vs. 17%, p < 0.001). Age, race, and rank, a surrogate marker for socioeconomic status, were not associated with mode of delivery.

Conclusion: Pre-pregnancy fitness levels as measured by the APFT among healthy physically active nulliparous AD women showed no association with the incidence of labored CD. EWG is one modifiable factor which potentially increases the risk for CD in this cohort and has been documented as a risk factor in a recent metanalysis (RR-1.3). Counseling on appropriate weight gain in pregnancy may be the most effective way to reduce the rate of CD among this population of healthy and physically active women.

Intervention Components (click on component to see a list of all articles that use that intervention): Diet/Exercise, PATIENT_CONSUMER

Intervention Description: This multicenter cohort study examined the association between leisure time physical activity the year before pregnancy and during pregnancy and mode of delivery.

Intervention Results: The odds of emergency caesarean section decreased with increasing levels of physical activity with statistically significant trends at all four time stages except the third trimester. This tendency was confirmed in the proportional odds model showing 28% higher odds of a more complicated mode of delivery among women with a low activity level compared to moderately active women.

Conclusion: We found increasing leisure time physical activity before and during pregnancy associated with a less complicated delivery among low-risk, nulliparous women.

Setting: Hospitals in Denmark

Population of Focus: Nulliparous women who delivered a singleton infant in cephalic presentation at term after spontaneous onset of labor

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: Participants in this study included both normal-weight (NW; n = 201) and overweight or obese (OW/OB; n = 200) women, who were randomly assigned to receive standard care (n = 200) or a behavioral intervention to prevent excessive gestational weight gain. The intervention included one face-to-face visit; weekly mailed materials that promoted an appropriate weight gain, healthy eating, and exercise; individual graphs of weight gain; and telephone-based feedback. 

Intervention Results: Intent-to-treat analyses showed that the intervention, compared with standard care, decreased the percentage of NW women who exceeded IOM recommendations (40.2% compared with 52.1%; P = 0.003) and increased the percentages of NW and OW/OB women who returned to their pregravid weights or below by 6 mo postpartum (30.7% compared with 18.7%; P = 0.005).

Conclusion: A low-intensity behavioral intervention during pregnancy reduced excessive gestational weight gains in NW women and prevented postpartum weight retention in NW and OW/OB women. This trial was registered at clinicaltrials.gov as NCT01117961.

Setting: Six obstetric offices in Providence, RI

Population of Focus: BMI between 19.8 and 40

Intervention Components (click on component to see a list of all articles that use that intervention): Outreach (Provider), PATIENT_CONSUMER, Diet/Exercise

Intervention Description: The intervention program consisted of two individual counseling modules given by trained researchers at the 20th and 30th week of gestation. The sessions were structured and comprised three main topics: nutrition, physical activity, and gestational weight gain monitoring. The dietary intervention aimed at decreasing the intake of energy-dense foods and high-fat foods (e.g. fast food, sweets, and sugar-sweetened beverages) by substituting them with low-fat alternatives, and increasing the consumption of fruit, vegetables, and whole grain products. The advice on physical activity was in accordance with the current guidelines for physical activity during pregnancy from the Society of Obstetricians and Gynecologists of Canada (SOGC) and the American College of Obstetricians and Gynecologists (ACOG). The following recommendations were introduced for women using the FITT (frequency, intensity, time, type) criteria: thirty minutes of moderate intensity activity on most days of the week at an appropriate heart-rate zone. Non weight-bearing or low-impact endurance exercises using the large muscle groups like walking, cycling, swimming, or aquatic exercises were proposed. Participants were provided with a list of adequate local prenatal exercise programs and advised to participate in programs like these. 

Intervention Results: The intervention resulted in a lower proportion of women exceeding IOM guidelines among women in the intervention group (38%) compared with the control group (60%) (odds ratio (OR): 0.5; 95% confidence interval (CI): 0.3 to 0.9) without prompting an increase in the proportion of pregnancies with suboptimal weight gain (19% vs. 21%). Participants in the intervention group gained significantly less weight than those in the control group. Only 17% of the women in the intervention group showed substantial weight retention of more than 5 kg compared with 31% of those in the control group at month four postpartum (pp) (OR: 0.5; 95% CI: 0.2 to 0.9). There were no significant differences in obstetric and neonatal outcomes.

Conclusion: Lifestyle counseling given to pregnant women reduced the proportion of pregnancies with excessive GWG without increasing suboptimal weight gain, and may exert favorable effects on pp weight retention.

Setting: Eight gynecological practices in Munich Germany

Population of Focus: Healthy nulliparous and multiparous pregnant women

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: This study was a randomized controlled trial of 425 obese pregnant women comparing 3 groups: (1) physical activity plus a dietary intervention (n = 142); (2) physical activity intervention (n = 142); and (3) a control group receiving standard care (n = 141). All participants had an initial dietary counseling session and were advised to limit their gestational weight gain to less than 5 kg. Physical activity intervention included encouragement to increase physical activity, aiming at a daily step count of 11,000, monitored by pedometer assessment on 7 consecutive days every 4 weeks. Dietary intervention included follow-up on a hypocaloric Mediterranean-style diet. Instruction was given by a dietician every 2 weeks.

Intervention Results: The study was completed by 389 patients (92%). Median values of GWG (ranges) were lower in each of the intervention groups (PA plus D, 8.6 [-9.6 to 34.1] kg, and group PA, 9.4 [-3.4 to 28.2] kg) compared with the control group (10.9 [-4.4 to 28.7] kg [PA+D vs C]; P = .01; PA vs C; P = .042). No significant difference was found between the 2 intervention groups. In a multivariate analysis, physical activity intervention decreased GWG by a mean of 1.38 kg (P = .040). The Institute of Medicine's recommendations for GWG were more frequently followed in the intervention groups.

Conclusion: Physical activity intervention assessed by pedometer with or without dietary follow-up reduced GWG compared with controls in obese pregnant women.

Setting: Hvidovre Hospital, University of Copenhagen

Population of Focus: Obese pregnant women with singleton gestations (both nulliparous and multiparous)

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Outreach (Provider), Diet/Exercise, HEALTH_CARE_PROVIDER_PRACTICE

Intervention Description: The NFFD trial was a population-based antenatal combined lifestyle intervention consisting of dietary counseling and supervised exercise classes, evaluated in a randomized controlled trial. Normal weight, overweight and obese participants were recruited by midwifes from eight healthcare clinics in the southern part of Norway, encompassing both cities and rural areas, between September 2009 and February 2013. The intervention group had access to a twice-weekly standardized exercise program. Classes were provided for groups at five different fitness centers, led by qualified instructors and consisted of 10 min of warm-up, 40 min of cardiovascular and strength exercises at moderate intensity, with emphasis on core and pelvic floor musculature, and finally 10 min of stretching. Exercise intensity was measured by ratings of perceived exertion set to 12–14 (somewhat hard) on the 6–20 Borg rating scale 18. Additionally, the participants were encouraged to undertake at least 30 min of cardio exercises at moderate intensity at least three times a week, in accordance with current physical activity recommendations 19. The dietary component of the intervention consisted of 10 dietary recommendations designed by the NFFD team

Intervention Results: The intervention group had a longer first stage of labor compared with the control group (293 ± 202 min vs. 257 ± 181 min, p = 0.030). No differences between the randomization groups were seen for time spent in second stage of labor, prolonged labor or mode of delivery. In the total sample, women with the highest physical activity level had lower odds ratio (OR) of acute cesarean delivery (OR 0.33, 95% CI 0.11-0.97, p = 0.044) than did those with the lowest physical activity-level.

Conclusion: A significantly longer first stage of labor was observed in the intervention group than in the control group. A high physical activity level in late pregnancy was associated with lower odds of acute cesarean delivery compared with a low physical activity level.

Setting: Southern Norway

Population of Focus: Healthy nulliparous women with a singleton pregnancy

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: 114 obese women (BMI ≥30 kg/m2) between 7–21 weeks’ gestation were randomized to receive the intervention (n=56) or usual care control conditions (n=58). The intervention program included a combination of dietary and exercise recommendations, along with the use of behavioral self-management techniques to help participants initiate and maintain behavior changes. A study dietician advised intervention participants to follow an energy reduced eating plan, based on Dietary Approaches to Stop Hypertension (DASH) -- without sodium restriction. The intervention leaders encouraged participants to accumulate at least 30 minutes of moderate physical activity per day in the absence of medical or obstetrical complications, a goal consistent with the recommendations of the American College of Obstetricians and Gynecologists (ACOG). They gave each intervention participant a pedometer, and encouraged them to record their physical activity in their daily food and activity records. 

Intervention Results: Intervention participants gained less weight from randomization to 34 weeks gestation (5.0 vs. 8.4 kg, mean difference = -3.4 kg, 95% CI [-5.1-1.8]), and from randomization to 2 weeks postpartum (-2.6 vs. +1.2 kg, mean difference = -3.8 kg, 95% CI [-5.9-1.7]). They also had a lower proportion of LGA babies (9 vs. 26%, odds ratio = 0.28, 95% CI [0.09-0.84]).

Conclusion: The intervention resulted in lower GWG and lower prevalence of LGA newborns.

Setting: Prenatal care unit at Kaiser Permanente, Northwest (KPNW)

Population of Focus: Nulliparous and multiparous pregnant women with a BMI ≥30

Intervention Components (click on component to see a list of all articles that use that intervention): PATIENT_CONSUMER, Diet/Exercise

Intervention Description: The intervention consisted of two major components: dietary counseling and physical activity. Dietary counseling was performed by trained dietitians on four separate occasions, at 15, 20, 28, and 35 weeks’ gestation. The aim was to limit GWG to 5 kg. Women in the intervention group were encouraged to be moderately physically active 30–60 min daily and were equipped with a pedometer to motivate and improve daily activity. Women in this group also had free full-time membership in a fitness center for 6 months, where they had closed training classes with physiotherapists for 1 h each week. Training consisted of aerobic (low-step), training with light weights and elastic bands, and balance exercises. After physical training, the women were grouped 4–6 times in pregnancy with the physiotherapist using coaching-inspired methods for improving participants’ integration of physical activities in pregnancy and daily life. The women in the control group received the same initial information about the purpose and content of the study, including access to a website with advice about dietary habits and physical activities in pregnancy, but no additional intervention.

Intervention Results: A total of 360 obese pregnant women were included, and 304 (84%) were followed up until delivery. The intervention group had a significantly lower median (range) GWG compared with the control group of 7.0 (4.7-10.6) vs. 8.6 kg (5.7-11.5; P = 0.01). The Institute of Medicine (IOM) recommendations on GWG were exceeded in 35.4% of women in the intervention group compared with 46.6% in the control group (P = 0.058). Overall, the obstetric outcomes between the two groups were not significantly different.

Conclusion: Lifestyle intervention in pregnancy resulted in limited GWG in obese pregnant women. Overall obstetric outcomes were similar in the two groups. Lifestyle intervention resulted in a higher adherence to the IOM weight gain recommendations; however, a significant number of women still exceeded the upper threshold.

Setting: Two university hospitals in Denmark

Population of Focus: Obese pregnant women with singleton gestations (both nulliparous and multiparous)