The importance of childbearing in the development of obesity in women has been recognized for over a decade [
1]. Pregnancy is a time of significant physiological and physical change for women. In particular, it is a time at which many women are at risk of gaining excessive weight and hence a time where interventions to address overweight/obesity in women should be conducted [
2].
Excessive weight gain during pregnancy
Excessive weight gain in pregnancy is a common health-related problem in Western countries [
3]. Women who gain excessive weight during pregnancy have an increased risk of postpartum obesity in themselves and their children [
2,
4]. Furthermore, 20% of women retain at least 5 kg of gestational weight gain at 6-18 months post birth [
5,
6], and this weight retention is a strong predictor of maternal overweight and obesity a decade or more after birth [
7].
In 2009 the United States (US) Institute of Medicine (IOM) published revised guidelines for how much weight a woman should gain during pregnancy and highlighted the importance of intervention in pregnancy to prevent both postpartum weight retention and childhood obesity [
8]. The US IOM recommends that women with a normal weight (Body Mass Index, BMI, of 18.5-24.9 kg/m
2) should gain between 11-16 kg during their pregnancy; women who are overweight (BMI of 25-29.9 kg/m
2) should gain 7-11 kg, and obese women (BMI of 30 kg/m
2 and above) should gain between 5 to 9 kg [
8]. Women who are underweight (BMI less than 18.5 kg/m
2) should gain between 13 to 18 kg during pregnancy [
8]. Excessive gestational weight gain (GWG) is defined as weight gain above these recommended guidelines. The specific cost of excessive gestational weight gain is related to ensuing maternal health problems and fetal outcomes [
9], such as preeclampsia [
10], maternal hyperglycemia [
11], complications with labor/delivery [
12,
13], infant macrosomia [
12,
13], late fetal death [
14], birth defects [
15], and an increased risk of caesarean [
10].
Determinants and correlates of gestational weight gain
The biological and behavioral determinants of excessive GWG include high pre-pregnancy BMI, primiparity, advanced maternal age, higher energy intake, a reduction in physical activity, and lack of advice in relation to recommended guidelines for weight gain during pregnancy [
9,
16]. The psychological correlates of excessive gestational weight gain include higher depressive [
17] and anxiety symptoms [
18,
19], lower self-esteem [
18], misperceived pre-pregnancy body size [
17], and greater body image dissatisfaction [
20]. Furthermore, it has been shown that greater gestational body image dissatisfaction is associated with higher depressive symptoms in pregnancy (
rs range from .23-.46) [
21‐
24] and in the postpartum (
rs range from .26-.54) [
24,
25] and with higher BMI during pregnancy [
20‐
23]. Therefore, managing weight gain during pregnancy might be more effective if it includes the management of psychological factors, such as body image concerns and depressive symptoms.
Interventions designed to prevent excessive weight gain during pregnancy: a systematic review of the literature
We conducted a systematic review of interventions designed to prevent excessive GWG in pregnant women across all BMI categories [
26]. Our search, which was limited to English papers published between January 1999 and January 2010, revealed 10 intervention studies; three of these studies were conducted in the US [
27‐
29], two in Canada [
30,
31] and one in Sweden [
32,
33], Finland [
5], Denmark [
34], Australia [
35], and Belgium [
36]. Only one of these studies tracked women from early pregnancy until 12 months post birth [
28]; the other studies did not evaluate the effect of the intervention on weight retention in the postpartum, with the exception of Wolff et al., Gray-Donald et al., and Polley et al., who followed women through pregnancy to 4 weeks, 6 weeks, and approximately 8 weeks post birth, respectively [
27,
28,
34]. In the published studies, excessive gestational weight gain was prevented only in: normal-weight women [
27], low-income women [
28], obese women [
33,
34], overweight women [
35], or not at all [
5,
30,
31,
37]. These interventions have focused primarily on behavioral changes in relation to physical activity and/or to eating. Some research findings emphasize the importance of targeting both behavioral and psychological factors in order to maintain weight loss postpartum [
20,
21,
24,
25]. In her review of interventions to manage excessive gestational weight gain, Walker also concluded that interventions to date had limited success possibly because psychological factors were not considered [
37]. That is, interventions have not included dedicated behavior-change assistance aimed at identifying and addressing behavioral, emotional, cognitive, and situational barriers that might impede behavior change; the lack of consideration of psychological factors was also identified by the US IOM [
8].
Since January 2010, seven additional intervention studies have been published [
38‐
44]. The weight status of women targeted (BMI category) and the guidelines used to determine excessive GWG varied between studies. One intervention referred to guidelines recommended by the Swedish Births Registry (weight gain of 6 kg or less for all women) [
39] while another did not refer to GWG guidelines at all [
38]. A majority of studies included nutritional and/or physical activity behavior components as part of the intervention program [
38‐
42,
44] and four of the six interventions included a psychological component in the form of counseling or support [
38,
39,
41,
43]. A majority of the seven studies found positive effects of the intervention on the restriction of GWG [
39,
41‐
43] but results were obtained for women in different BMI categories. For example, GWG was restricted amongst normal weight women but not overweight or obese women [
43], in obese women with a BMI greater than 35 kg/m
2 (compared to women with a BMI between 30 kg/m
2 and 35 kg/m
2) [
39] and in less than half of overweight or obese women (31%) [
42]. Further, one study reclassified obese women (BMI > 30 kg/m
2) as overweight and found no effect of an exercise intervention on GWG, when comparing normal/overweight women to controls using intention-to-treat analyses [
44]. Only one adequately powered randomized controlled trial (RCT) [
43] examined the effectiveness of an intervention to reduce excessive GWG among normal weight, overweight and obese women. Significant effects were not found for the intervention in restricting GWG in overweight or obese women according to US IOM (1990) guidelines [
45], however significant effects were found for normal weight women. Further, a greater percentage of women across all weight categories reached at or below their preconception weight six months after the birth of their baby [
43].
The recent literature reflects the findings of the review by Skouteris et al. [
26] that GWG was reduced only in some populations, and often not according to those levels recommended by the US IOM [
8,
45]. Furthermore, similar limitations to those present in previously reviewed interventions continue to be evident. The effect of the intervention on postpartum weight retention was not evaluated in three studies [
38,
39,
41], and in one study intervention women were compared to an historical control group [
40] and another did not refer to a control group at all [
39]. Importantly, none of the recent interventions incorporated psychologically-based components of behavior change: only targeting behavior change associated with diet and physical activity. The current study addresses this gap.
A specialized health coaching intervention
In recent times the emphasis on using a combination of psychological and behavioral interventions in addition to patient education has been stressed, given the growing recognition that information/education/advice alone is not sufficient to produce significant changes in health behavior [
46] and that adoption of new behaviors is more likely if patients are encouraged to be involved in behavioral intention at the time of being provided with health information [
47]. Indeed, a recent study showed, with a large cohort of non-pregnant women, that only a very small proportion of women planning a pregnancy followed the recommendations for nutrition and healthy lifestyle, when this was given as advice alone [
48].
Health Coaching (HC) is one strategy that is likely to engage women in the behavior change necessary to prevent excessive weight gain during pregnancy [
49,
50]. HC provides individual, one-on-one interventions (face to face, telephonic, internet or multimodality), and the principles can also be used in small group education situations to help participants to integrate new knowledge into their personal behavior change plans. The result is to create an immediate intention to act, and increases the likelihood of behavior change [
47]. The major tasks for the HC health professional are to: (1) assist the client to engage in behavior change for self-motivating reasons; (2) increase the client's chances of successful and lasting behavior change once he/she has decided to make particular changes; and (3) provide health information and education and to correct misinformation as required, in a way that increases adherence and avoids creating resistance to change. The results of the only study evaluating this approach among 56 obese pregnant women (
n = 56) found that the majority of women made positive changes to their eating and exercise habits during pregnancy, and just under half of the women gained within the US IOM [
8] recommended weight gain during pregnancy of about 5 to 9 kg; all of the women also stated they would recommend the program to a friend [
32]. Whether these women were able to maintain their change in attitude, eating habits and weight control in the postpartum was not investigated.
The Health Coaching Australia (HCA) Model [
49] is an integrated Health Coaching model drawing on evidence-based psychological theories, practices and principles, such as Social Cognitive Theory [
51], Readiness to Change, Importance, and Confidence [
52], the Transtheoretical Model [
53], and the Theory of Planned Behavior [
54]. The HCA Model offers a unique intervention approach for preventing excessive gestational weight gain and weight retention in the postpartum because it provides behavioral, cognitive, situational, and emotional change facilitation: not just behavioral change facilitation [
49].
We have developed a novel pregnancy HC intervention that has two components. (1) One-on-one sessions with a Health Coach that a) promote women's adoption of healthy lifestyle behaviors for the purpose of weight management, and b) address mood management and body image issues that commonly arise during pregnancy. (2) Educational group sessions, that augment the one-on-one sessions; the aim is to provide new mothers with additional information related to healthy behaviors and mood, and to support and assist them in initiating, maintaining, and achieving their goals for healthy behavior change.
Specific aim 2
To evaluate the mechanisms by which our HC intervention impacts on weight management both during pregnancy and post birth by tracking the relationships among the following variables: (1) shifts in motivation to adopt healthy lifestyle behaviors (including managing mood changes and body image concerns) for the purposes of weight management; (2) confidence in adopting healthy lifestyle behaviors for the purposes of weight management; (3) actual behavior changes (goal behavior initiation, achievement, and maintenance); (4) physiological and psychological outcomes - i.e., Body Mass Index (BMI), waist circumference, depressive symptoms, anxiety, and body image concerns. Hypothesis: It is hypothesized that, in comparison to education alone, the intervention will promote a shift in motivation to adopt, and an improvement in women's confidence and ability to overcome barriers to, healthy eating and physical activity, and better management of mood and body image. These changes are predicted to lead to an initiation of healthy behavior changes for weight management and then to sustained healthy behavior changes, lower levels of depressive and anxiety symptoms, and lower body dissatisfaction.