From theory to practice: intervention fidelity in a randomized controlled trial aiming to optimize weight development during pregnancy.

BACKGROUND: Intervention fidelity is an increasingly important methodological concept in process evaluations. In this article, the authors investigated the intervention fidelity in a randomized controlled trial on excessive weight gain prevention in pregnancy. METHOD: A sample of 109 audiotaped counseling sessions, linked to 65 women in the intervention group of the New Life(style) trial, was drawn. The following criteria were quantitatively evaluated using a fidelity checklist: (a) reach, (b) dose, (c) adherence to study objectives, (d) adherence to underlying problem-solving treatment (PST) theory, and (e) counselor competence. RESULTS: A total of 60.4% received all counseling sessions. The dose of intervention components was generally moderate (50.9% to 60.4%), and the dose of PST components was low (17.3%). Adherence to study objectives was moderate (64.2%) and adherence to PST theory was low (43.2%). The counselors sufficiently stimulated the participant to optimize lifestyle (54.2% of the sessions), provided positive feedback (50.5%), and left the initiative regarding problem solving to the participant (71%). One of the two counselors performed significantly better on all measured criteria (p < .001). CONCLUSIONS: Intervention fidelity in the New Life(style) trial was generally low to moderate. In future interventions, it is recommended to put more emphasis on counselor recruitment, training, and intervention protocol contents. Fellow researchers are encouraged to embed a process evaluation into all study stages, taking into account all essential process elements, and to link process outcomes to more distal, health outcomes.

Postpartum behaviour as predictor of weight change from before pregnancy to one year postpartum.

BACKGROUND: Postpartum weight retention affects many women and increases the risk of becoming overweight. The research objective was to study modifiable factors contributing to weight change at one year postpartum. METHODS: In this prospective cohort, postpartum behavior, such as physical activity, sedentary behavior, sleep, and intake of total energy, total fat and saturated fatty acids of 118 Dutch women were assessed in 2003/2004 by self-report at 6 weeks, 6 and 12 months postpartum. Mean postpartum scores were computed for the behavioral measures. In linear regression models it was determined which factors were associated with average weight change from before pregnancy to one year postpartum. Furthermore, factors associated with substantial postpartum weight retention (≥ 5 kg) were also studied in logistic regression models. RESULTS: At one year postpartum, the average weight of participants had increased by 0.9 kg (SD 4.4). Moreover, 20% of the women retained ≥ 5 kg. Women who perceived themselves more physically active than others were almost ten times less likely to retain ≥ 5 kg than women who perceived themselves equally active (OR = 0.11, 95%CI: 0.02 - 0.66). Exceeding the guideline for saturated fatty acid intake (OR = 3.40, 95%CI: 1.04 - 11.11), total gestational weight gain (OR = 1.14/kg, 95%CI: 1.01 - 1.27), and not having completed post high school education (OR = 5.13, 95%CI: 1.66 - 15.90) increased the odds of retaining ≥ 5 kg. CONCLUSIONS: Since one in five women had substantial weight retention postpartum, effective interventions for the prevention of weight retention are much needed. Future studies should evaluate whether interventions focusing on the identified modifiable postpartum factors are successful in reducing weight retention after childbirth.

Design of the New Life(style) study: a randomised controlled trial to optimise maternal weight development during pregnancy. [ISRCTN85313483].

BACKGROUND: Preventing excessive weight gain during pregnancy is potentially important in the prevention of overweight and obesity among women of childbearing age. However, few intervention studies aiming at weight management during pregnancy have been performed and most of these interventions were not as successful as expected. In this paper the design of the New Life(style) study is described as well as the content of the individually tailored intervention program, which focuses on controlling weight development during pregnancy. METHODS: The effectiveness of the New Life(style) intervention program versus usual care by midwives is evaluated in a randomised controlled trial. Women who expect their first child and visit one of the participating midwifery practices are included. The intervention is standardised in a protocol and executed by trained counsellors with the women who are randomised in the intervention group. During 5 sessions--at 18, 22, 30 and 36 weeks of pregnancy and at 8 weeks postpartum--individual weight gain is discussed in relation to weight gain guidelines for pregnant women of the American Institute of Medicine. Counsellors coach the women to maintain or optimise a healthy lifestyle, in a period of drastic physical and mental changes. Data is collected at 15, 25, 35 weeks of pregnancy and at 6, 26, and 52 weeks after delivery. Primary outcome measures are body weight, BMI, and skinfold thickness. Secondary outcome measures include physical activity, nutrition and blood levels of factors that are associated with energy homeostasis. DISCUSSION: Results of the current RCT will improve the knowledge of determinants of weight gain during pregnancy, weight retention after childbirth and of the effectiveness of the intervention program that is described. Caregivers and researchers in the field of health promotion are offered more insight in specific elements of the New Life(style) intervention program.

The relationship of objectively measured physical activity and sedentary behaviour with gestational weight gain and birth weight.

OBJECTIVE: To evaluate the relationship of physical activity (PA) and sedentary behaviour with gestational weight gain (GWG) and birth weight. DESIGN: Combined data from two prospective studies: (1) nulliparous pregnant women without BMI restrictions and (2) overweight and obese pregnant women at risk for gestational diabetes. METHODS: Daily PA and sedentary behaviour were measured with an accelerometer around 15 and at 32-35 weeks of gestation. The association between time spent in moderate-to-vigorous PA (MVPA) and in sedentary activities with GWG and birth weight was determined. Main outcome measures were GWG between 15 and 32 weeks of gestation, average GWG per week, and birth weight. RESULTS: We studied 111 women. Early in pregnancy, 32% of women spent ≥ 30 minutes/day in at least moderate PA versus 12% in late pregnancy. No significant associations were found between time spent in MVPA or sedentary behaviour with GWG or birth weight. CONCLUSIONS: We found no relation between MVPA and sedentary behaviour with GWG or birth weight. The small percentage of women meeting the recommended levels of PA indicates the need to inform and support pregnant women to maintain regular PA, as there seems to be no adverse effect on birth weight and maintaining PA increases overall health.

Correlates of absolute and excessive weight gain during pregnancy.

OBJECTIVE: Factors associated with weight gain during pregnancy that may be linked to maternal overweight and obesity were examined. METHODS: In this observational study, 144 women reported on demographics, (prepregnancy) body weight, and lifestyles in self-reported questionnaires at 30 weeks gestation. Body weight at the end of pregnancy (self-reported at 6 weeks postpartum) was used to determine total gestational weight gain. Multivariate prediction models were developed to identify factors associated with total gestational weight gain and excessive gestational weight gain (i.e., higher weight gain than recommended by the Institute of Medicine). RESULTS: Women gained 14.4 (+/-5.0) kg during pregnancy. Obese women gained almost 4 kg less than normal weight women. Pregnant women judging themselves to be less physically active or women who reported increased food intakes during pregnancy gained significantly more weight. Over one third of women (38%) gained more weight than recommended. Being overweight, judging yourself to be less physically active than others, and a perceived elevated food intake during pregnancy were significantly associated with excessive weight gain (odds ratio [OR] = 6.33, 95% confidence interval [CI]: 2.01-19.32; OR = 3.96, 95% CI: 1.55l, 10.15; and OR = 3.14, 95% CI: 1.18, 8.36, respectively). A higher age at menarche and hours of sleep reduced the odds for excessive weight gain (OR = 0.75, 95% CI: 0.57, 0.99; and OR = 0.35, 95% CI: 0.57, 0.93, respectively). CONCLUSIONS: Mean hours of sleep, perceived physical activity, and measures of food intake at 30 weeks gestation were identified as modifiable behavioral correlates for excessive gestational weight gain. Strategies to optimize gestational weight gain need to be explored, with a focus on the identified factors.