evaluation of psychosocial measures for understanding weight-related behaviors in pregnant women

Evaluation of Psychosocial Measures for UnderstandingWeight-Related Behaviors in Pregnant Women Kendall et al.Psychosocial Measures for Pregnancy

Anne Kendall, Ph.D., R.D., Christine M. Olson, Ph.D., R.D.,and Edward A. Frongillo, Jr., Ph.D.

Cornell University

ABSTRACTThe greatest weight gain for U.S. women occurs during the

childbearing years of 25 to 34, and many obese women attributetheir adult weight gain to childbearing. Few studies have exam-ined psychosocial influences on womens behaviors duringpregnancy, in part because of the lack of valid and reliable mea-sures of psychosocial constructs relevant to pregnant women.Based on existing theory and an in-depth interview study, thepsychosocial constructs of locus of control, self-efficacy, bodyimage, feelings about motherhood, and career orientation wereidentified. Scales for each construct were constructed by draw-ing items from existing validated scales and writing items basedon the in-depth interviews; their content validity assessed usingfactor analysis with oblique rotation and their reliability usingCronbachs alpha. Construct validity was assessed by examin-ing the associations between scale scores and preexisting condi-tions of participants. Data for evaluating the scales came from astudy of 622 pregnant women in a rural health care system whocompleted questionnaires and whose medical records were au-dited. Cronbachs alpha of the scales ranged from 0.73 to 0.89.Scale scores were strongly associated with lifestyle behaviors,body weight, and demographic characteristics of the partici-pants. The analysis provides evidence of the validity of measuresof psychosocial factors related to health behaviors of pregnantwomen. These measures should be useful in studying weight-re-lated behaviors in pregnant women.

(Ann Behav Med 2001, 23(1):5058)

INTRODUCTIONOverweight and obesity are problems of increasing public

health importance in the United States. It is estimated that cur-rently over one half of U.S. adults are overweight and nearly onefourth are obese (1). There has been a 20% increase in the preva-lence of overweight and 50% increase in the prevalence of obe-sity over the past 20 years (1). Among women, 33% of 20- to29-year-olds are classified as obese, whereas 47% of 30- to39-year-olds are obese. The period of greatest weight gain forU.S. women occurs between 25 and 34 years of age, frequentlythe childbearing years (2), and many obese women attributetheir adult weight gain to childbearing (3). Pregnancy, espe-

cially among women with high gestational weight gains (Afri-can American women, rural women, and women of lower socio-economic status), has been associated with weight retention inexcess of that normally gained with age (47). Pregnancy-re-lated weight gain, therefore, may increase a womans risk oflonger term obesity, which may in turn increase risk of develop-ing chronic diseases that are major causes of mortality in theUnited States.

Few studies have comprehensively examined factors thatinfluence health behaviors of pregnant women related to bodyweight, despite the recognition that this approach is important(8,9). In particular, only limited research is available on thepsychosocial influences on womens behaviors during preg-nancy and the postpartum period that might affect outcomes,such as gestational weight gain and postpartum weight reten-tion. Psychosocial influences have been increasingly recog-nized as important factors to address in health promotion plan-ning. One widely used model of health promotion, thePRECEDEPROCEED model of Green and Kreuter (10), rec-ommends that factors that predispose individuals to adopthealthy behaviors be assessed during the diagnosis phase ofhealth promotion planning and become the targets of interven-tion during the implementation phase. Predisposing factors arethe antecedents to behavior that provide the motivation or ratio-nale for the behavior and include psychosocial factors such asattitudes, beliefs, and values.

Accurate measurement of psychosocial constructs is a chal-lenging task and requires measures that are reliable (i.e., repeat-able) and valid (i.e., measure what they are intended to mea-sure). Reliability is assessed using Cronbachs alpha, whichtests the internal consistency of items in a scale (11). Threetypes of validity are typically assessed in evaluating new mea-sures: content, criterion, and construct validity (12). Content va-lidity is concerned with whether the items adequately cover thedomain of interest. Criterion validity is the correspondence ofthe proposed new measure with a well-established measure orthe so-called gold standard measure of the same construct. Con-struct validity is concerned with the extent to which a measure isrelated to other variables in expected ways. In this study, con-struct validity of the measures was evaluated by examining theassociation of each measure with variables that theory or previ-ous research indicates should be related to the measure. This ap-proach is consistent with the hypothesis testing approach to as-sessing construct validity as described by Streiner and Norman(12).

Given the lack of a well-developed theory of psychosocialinfluences on weight-related behaviors of pregnant women, wetook two different approaches to identifying relevant

50

The article was funded by the National Institute of Child Health andHuman Development Grant RO1 HD29549.

Reprint Address: C. M. Olson, Division of Nutritional Sciences, 376MVR Hall, Cornell University, Ithaca, NY 14853.

2001 by The Society of Behavioral Medicine.

psychosocial constructs. A conceptual framework guided thisresearch and drew heavily from socialcognitive theory (13)and theory about how changes in social roles influence psy-chological characteristics and health behaviors (1416). In ad-dition to relying on theories, an in-depth interview study wasconducted to obtain information about the relative importanceof different psychosocial constructs as influences on theweight-related behaviors or pregnant women (17). Thepsychosocial constructs evaluated in this research includeweight locus of control; self-efficacy related to food intake,controlling weight, and performing regular exercise; attitudesabout body image before pregnancy and weight gain duringpregnancy; and feelings about the motherhood role and careerorientation. Whenever possible, we drew items from existingvalidated scales to measure these constructs (1820). How-ever, with the exception of the items from Palmer, Jennings,and Massey (20) that measure attitudes about weight gain dur-ing pregnancy, these scales had not been evaluated for usewith pregnant women. Furthermore, we developed items as-sessing feelings about the motherhood role, attitudes towardbody image, and self-efficacy related to weight control basedon the in-depth interview study (17,21); these items had notbeen evaluated previously.

Thus, this article describes the evaluation of measures ofpsychosocial constructs that based on theory and in-depth inter-views were expected to influence dietary and exercise behaviorsand body weight of women in the prenatal and postpartum peri-ods. The article presents results from an assessment of their reli-ability and content and construct validity.

METHOD

Population and ParticipantsWomen 18 years of age and older receiving prenatal care

through a rural clinic and hospital system in upstate New Yorkwere recruited for the study from March 1995 to December1996. After the screening of medical records, 1,090 womenwere eligible for the study and were contacted by telephone orby mail. Women were ineligible if they had medical problemsprior to pregnancy that might influence body weight, planned toterminate the pregnancy or give the baby up for adoption, in-tended to deliver outside the health care system, or registered forprenatal care after the 28th week of gestation. Women whoagreed to participate were mailed a more complete study de-scription with an informed consent form and a prenatal ques-tionnaire. One hundred fifty-three women could not be locatedagain despite intensive efforts, most likely because they left thegeographic area or terminated the pregnancy. Two hundredsixty-nine women refused participation (24.7%). All women re-turning consent forms and prenatal questionnaires prior to deliv-ery were enrolled in the study (N = 656). Thirty-four of the en-rollees moved out of the area, had twins or a fetal death, andwere excluded, resulting in 622 participants in the sample.

The population from which the sample was drawn is largelyWhite and lives in rural upstate New York (96%). The age rangeof the women was 18 to 48 years, with an average of 28.8 years.

Seventy-three percent of the women were married or living witha partner, and 79% were employed outside the home. Sixty-onepercent of those employed were in service or sales occupations,23% were in professional or managerial occupations, and therest were in other kinds of occupations. Forty-four percent of thesample reported household incomes 185% less than the FederalPoverty Index Ratio. Only 8% of the participants had not com-pleted high school, 31% were high school graduates, 26% hadcompleted some higher education or technical training, and35% were college graduates.

Data CollectionThe prenatal questionnaire was completed by 3.5% of the

sample during the first trimester, by 68% in the second trimester,and by 28.5% in the third trimester. Exploratory analyses indi-cated that the results did not vary by trimester. Height, bodyweight measurements from each prenatal visit, and informationfrom the health history completed at the initial prenatal visitwere extracted from the medical record shortly after delivery.Body weight was measured on a Seca Integra scale that was cali-brated by the research staff. The study was reviewed and ap-proved by the Cornell University Human Subjects Committeeand the Institutional Review Board of Bassett Healthcare.

Measures of Psychosocial Constructs: Sourcesand Construction of Items

The prenatal questionnaire contained items designed tomeasure the psychosocial constructs. Generally speaking, theoverall strategy was to select items, from existing validatedscales, that were judged to be sensible to ask of pregnant womenbased on our in-depth interviews.

Locus of control. Four items indicative of whether a womanbelieves she has control over body weight (internal locus of con-trol) or whether weight is something over which she has littlecontrol (external locus of control) were drawn from the scales ofSaltzer (18).

Self-efficacy. Eight items measured self-efficacy. Two itemsreflecting control of food intake (Items 9 and 10 in the Appen-dix) and two addressing confidence about getting regular exer-cise after pregnancy (11 and 12) were taken from Hofstetter,Sallis, and Hovell (19). Three additional statements relating toconfidence about returning to prepregnancy weight and shapeand one related to food intake were developed based on state-ments made by the women in the in-depth interview study (17).

Weight attitudes. Ten statements were taken from Palmer etal. (20) to measure attitudes about weight gain during preg-nancy. We developed three additional items based on the resultsfrom the in-depth interview study (Items 20, 24, and 25 in theAppendix).

Body image. Devine, Olson, Sobal, and Acharya (21) foundthat younger women with a thin body identity prior to pregnancywere more likely to retain weight in the postpartum period than

Volume 23, Number 1, 2001 Psychosocial Measures for Pregnancy 51

those with a heavier body identity. She also found that, for manywomen, body shape rather than body weight was the more im-portant determinant of a womans perception of her body sizeand her satisfaction with her body. Based on these findings, wedeveloped questions about a womans perception of and satis-faction with her weight and shape to measure body image on theprenatal questionnaire.

Feelings toward motherhood. Devine et al. (21) also foundthat women pregnant for the first time who were anxious abouttaking on the motherhood role were more likely to retain weightin the postpartum period. Based on these results, a series ofstatements were taken from the in-depth interviews that ex-pressed feelings about the role of mother.

Career orientation. Another of Devine et al.s (21) findingswas that women with a strong career orientation who returned towork early were more likely to lose the weight they gained dur-ing pregnancy than women who identified more strongly withtheir roles as mothers. To measure career orientation, statementswere taken from Hemmelgarn (22).

The locus of control, weight attitudes, self-efficacy, andmotherhood items were administered in the form of 5-pointLikert scales with responses ranging from 1 (strongly agree) to 5(strongly disagree) with a neutral choice of neither agree nordisagree, or, for self-efficacy, 1 (very sure) to 5 (very unsure).The body image items included two related to a womans per-ception of her weight and shape with possible responses of tooheavy (big for shape perception), about right, too light (thinfor shape perception), and two related to a womans satisfac-tion with her weight and shape with four possible responsesranging from 1 (very satisfied) to 4 (not at all satisfied). The ca-reer orientation items had four possible responses with no neu-tral choice, ranging from 1 (strongly agree) to 4 (stronglydisagree). Prior to analysis, the coding of response categorieswas reversed for some items so that all items measuring a con-struct were coded so that higher scale scores indicated higherlevels of the construct being measured.

Data Analysis: Content Validity and ReliabilityContent validity of each psychosocial scale was assessed

using factor analysis with oblique rotation in the principal com-ponents procedure in SAS for Windows Version 6.12 (SAS In-stitute, Cary, NC). Decisions about the number of factors to con-sider were based on the percentage of variability explained byeach factor under varimax rotation. Reliability was assessedwith Cronbachs alpha, which measures the internal consistencyof items in a scale (11,23,24). We examined the interfactor cor-relation between the subscales, the variability explained by thefirst factor prior to rotation, and the Cronbachs alpha statisticfor all of the items included in a scale to assess whethersubscales could be combined.

Hypothesis Testing for Assessment of ConstructValidity

Construct validity was assessed by examining associationsof psychosocial scale scores with variables that we hypothesizedwould be related.

Locus of control and self-efficacy. We expected successwith previous attempts at weight loss to be associated withscores on the Locus of Control and Self-Efficacy Scales. On theprenatal questionnaire, participants had been asked if they hadever tried to lose 10 or more pounds in the past. Those who hadwere asked to rate their success with these previous attempts us-ing a 4-point Likert scale ranging from 1 (very unsuccessful) to 4(very successful), with no neutral response possible.

Hofstetter et al. (19) observed associations between four ofthe self-efficacy items we used and exercise practices andknowledge of a healthy diet, so we also used information on ex-ercise practices and fruit and vegetable consumption prior topregnancy to assess construct validity for the Self-EfficacyScale. On the prenatal questionnaire, respondents were askedhow often they participated in regular exercise that made themsweat or breathe hard with responses of daily, sometimes, rarely,or never. Respondents were also asked how many fruits and veg-etables they consumed each day and could respond, < 1, 1 to 2, 3to 4, or 5 or more.

Weight attitudes and body image. We hypothesized that at-titudes toward weight gain during pregnancy and body imagewould be associated with body mass index (weight in kilogramsdivided by height in meters squared) as measured during thefirst 3 months of pregnancy.

Feelings toward motherhood. Based on the study ofDevine, Bove, and Olson (17) and Devine et al. (21), we ex-pected that attitudes toward assuming the motherhood rolewould differ between women having their first child and womenwho already had children. Parity was dichotomized asnulliparous or having one or more children and used for compar-ison with attitudes toward motherhood.

Career orientation. Women in professional careers wouldbe expected to have a stronger career orientation than womenholding jobs in the service sector, so Career Orientation Scalescores were examined by the type of job women held. Re-sponses to a question about job type were dichotomized as pro-fessional or other for this analysis.

Data Analysis: Construct ValidityAfter examining the distribution of the responses to each

scale and finding them to be normal, the construct validity anal-yses were performed. For locus of control and self-efficacy,mean scale scores for each variable for those reporting successor lack of success with weight loss in the past were comparedusing t tests. For the scales for attitudes toward the maternal roleand career orientation, means were calculated for parity and jobtype and compared using t tests. For body image and attitudes

52 Kendall et al. Annals of Behavioral Medicine

toward weight gain during pregnancy, scores were used as thedependent variables in the general linear models procedure inSAS with body mass index used as the independent variable. Allanalyses were conducted using SAS for Windows Version 6.12(SAS Institute, Cary, NC).

RESULTS

Content Validity and ReliabilityThe table presented in the Appendix shows the standard-

ized regression coefficients (i.e., factor loadings) under obliquerotation from the factor analysis and the Cronbachs alpha forthe items in each factor for each scale. This analysis resulted insix scales, each having two subscales. Each scale is described inthe following sections.

For the locus of control measure, the two items assessinginternality (Items 1 and 2 in the Appendix) strongly loaded to-gether to form an Internal Locus of Control Scale, and the twoitems assessing externality (Items 3 and 4 in the Appendix)formed an External Locus of Control Scale. The Cronbachs al-pha was 0.71 for the Internality Scale and 0.69 for theExternality Scale.

For the self-efficacy items, Factor 1 included the three state-ments that related to how sure an individual was about beingable to lose weight postpartum, and this subscale had an alpha of0.90 (Appendix). Factor 2 included the three statements relatedto control of food intake ( = 0.81), and Factor 3 included thetwo statements about exercise ( = 0.94).

For the items assessing attitudes toward weight gain duringpregnancy, Factor 1 included five statements that express nega-tive attitudes about weight gain during pregnancy. Factor 2 in-cluded statements suggesting a healthy attitude toward weightgain, whereas Factor 3 included statements related to the controla pregnant woman has over weight gain. Item 25 (Appendix)loaded equally on Factors 1 and 3 but did not have a high factorloading for either factor. Although all three factors explainedsufficient variability to be retained, the Cronbachs alpha of thetwo items expressing control over weight gain was only 0.36, sothese items were eliminated from further analysis. They were

not combined to make a subscale. The Cronbachs alpha of theFactors 1 and 2 subscales was 0.80 and 0.65, respectively.

For the body image items, Factor 1 included the two items re-lated to weight and shape satisfaction, whereas Factor 2 includedthe two items related to perception (Appendix). The factor load-ings for both subscales were very high, and the Cronbachs alphasof the subscales were 0.94 and 0.92, respectively.

For the items assessing attitudes toward motherhood, Fac-tor 1 included four statements that express anxiety about themotherhood role and one about confidence in being a goodmother and had an alpha of 0.70 (Appendix). Factor 2 includedtwo items about the initial reaction to the pregnancy. Althoughboth factors explained sufficient variation to be retained, theCronbachs alpha of 0.55 for the items in Factor 2 suggested thatthese items may not be reliable enough to function as a subscale.Thus, this subscale was dropped and not included in furtheranalysis.

For the items assessing career orientation, Factor 1 includedthe items relating to the importance of career and Factor 2 in-cluded the items expressing the dominance of family needs. TheCronbachs alpha of these two subscales was 0.75 and 0.67, re-spectively.

Combining SubscalesThe results of the factor and reliability analyses provide ev-

idence of the content validity of the sets of items developed tomeasure the selected psychosocial constructs in pregnantwomen. The sets of items appear to measure the underlying con-structs they were intended to measure in an internally consistentmanner. This analysis resulted in 12 subscales from a possibletotal of 14. Table 1 shows the descriptive characteristics of theconstructs that were considered.

For each construct, Factor 1 explained a substantial por-tion of the variability in the items. The subscales correspond-ing to each factor were correlated with each other, which is notsurprising as they measure different domains of a single over-arching construct. A large number of intercorrelated subscaleswill present practical problems in analyses that examine pre-dictors of outcomes, such as gestational weight gain and


TABLE 1Characteristics of Psychosocial Scales

ScalesInterfactorCorrelation

Variability Explained(5) by Factor 1 Combined M SD Range

Locus of control 0.43 72 0.73 3.98 0.68 1.05.0Self-efficacy 61 0.85 3.92 0.68 1.15.0

Factor 1: Factor 2 0.42Factor 1: Factor 3 0.42Factor 2: Factor 3 0.31

Weight attitudes 71 0.78a 3.38 0.63 1.64.9Factor 1: Factor 2 0.30

Body image 0.63 86 0.89 2.06 0.67 2.05.0Feelings toward motherhood 0.37 75 0.74 3.77 0.58 1.23.9Career orientation 0.28 71 0.81 2.56 0.39 1.03.5

aAlpha for Factor 1 and Factor 2 items combined.

postpartum weight retention. Furthermore, the Cronbachs al-pha for the combined subscales indicated that the combinedscales were reliable. These results supported combining thesubscales into a set of measures (scales) of psychosocial con-structs that very likely had greater content validity than thesmaller subscales.

Construct ValidityTable 2 shows the results of the construct validity analysis

on the six scales measuring the psychosocial constructs. Nearlytwo thirds of the sample (64%) reported trying to lose weight inthe past. Among these women, scores on the Locus of ControlScale (p < .0001) and the Self-Efficacy Scale (p = .03) were sig-nificantly higher for women who had been successful with pre-vious attempts at weight loss. Responses on the Self-EfficacyScale were also positively associated with the frequency of reg-ular exercise prior to pregnancy (p < .0001) and consumption offruits and vegetables (p < .0001). Similarly, women who hadchildren previously had significantly higher scores on the Moth-erhood Scale (p < .0001), indicating less anxiety about themotherhood role. Women whose jobs were classified as profes-sional had significantly higher scores on the Career Scale (p =.001). There was a very strong inverse relation between bodymass index and responses to the Body Image Scale (p < .0001)and the Weight Attitudes Scale (p < .0001).

DISCUSSIONThis article provides evidence for the content and construct

validity and the reliability of six scales developed to measurepsychosocial characteristics of pregnant women that may influ-ence adoption of behaviors consistent with a healthy bodyweight. Scores on the resulting six scales were significantly as-sociated with the variables used to assess construct validity.

These results are important because these psychosocial charac-teristics may be amenable to interventions promoting behavioralchanges that result in improvements in health status and de-crease risk of developing chronic disease. Based on thePRECEDEPROCEED model, these scales could be used dur-ing educational diagnosis to assess factors that predispose indi-viduals to adopt or reject healthy behaviors (10). Those factorsidentified as barriers to change could then become the immedi-ate targets for intervention during the implementation phase ofhealth promotion programs.

Locus of Control and Self-EfficacyScales measuring locus of control and self-efficacy have

been widely used in research on health behaviors, but their usewith pregnant women has been limited (25). Individuals with aninternal locus of control believe that attainment of a particularoutcome is within their control, whereas those with an externallocus of control believe that outcomes are outside their control.The items evaluated in this study were initially developed to as-sess locus of control related to weight management and weretested in a sample of college undergraduates and a group ofwomen attending a weight control clinic (18). The Cronbachsalpha of these items was only 0.56 and 0.58 when administeredtwice to a group of 113 college students. When administered tothe women attending a weight control clinic, women classifiedas internals were significantly more likely to complete theprogram. Internals who placed a high value on health and physi-cal appearance were significantly more likely to achieve theirweight goals than externals (18), indicating that these itemscan be used to predict weight-related outcomes. Based on theCronbachs alpha obtained in this study, these items appear to bebetter measures of locus of control for the pregnant women inour study than in the group with which they were originally de-


TABLE 2Construct Validity of Measures of Psychosocial Constructs

Psychosocial Construct (Scale) M SEM F pFeelings toward motherhood

Parity = 0 3.64 0.58 21.51 .0001Parity 1 3.86 0.57

Career orientationProfessional job 2.73 0.35 10.90 .001Other job type 2.62 0.33

Locus of controlSuccessful weight loss 4.13 0.59 15.14 .0001Unsuccessful weight loss 3.82 0.75

Self-efficacySuccessful weight loss 3.93 0.67 4.96 .03Unsuccessful weight loss 3.74 0.70Fruit and vegetable intake 0.16a 0.04b 21.80 .0003Exercise patterns 0.27a 0.03b 71.88 .0001

Weight attitudesBMI 0.03a 0.004b 68.23 .0001

Body imageBMI 0.08a 0.003b 628.21 .0001

Note. SEM = standard error of measurement; BMI = body mass index (weight in kilograms divided by height in meters squared).aValue is coefficient. bValue is standard error.

veloped. In this study, this scale was very strongly associatedwith success with weight loss in the past, further supporting itsability to predict weight-related outcomes of intervention pro-grams.

Two other studies have examined locus of control in preg-nant women. One used the same scale that was used in this re-search but examined only the outcome of satisfaction with bodyweight in the postpartum period and found no association be-tween locus of control and feelings about body weight (26). Thesecond study used items that addressed dietary behaviors ratherthan attitudes about weight (27), so the results cannot be com-pared to those of this study. Another study assessed mastery inpregnant women, a construct similar to locus of control that re-lates to the extent to which individuals see themselves as beingin control of the forces affecting their lives. This study foundthat low-income White women with mastery scores in the low-est quartile were more likely to gain less weight than is recom-mended (28). Although this scale did not specifically addressweight, and the focus of the study was inadequate weight gainduring pregnancy, the results support the idea that apsychosocial construct such as locus of control is related to bodyweight changes associated with pregnancy.

Self-efficacy is one of the most important determinants ofbehavior in socialcognitive theory (13), but to our knowledgerelations between self-efficacy and health behaviors have notbeen tested in pregnant women. According to Bandura (29),self-efficacy reflects ones confidence in her ability to performspecific behaviors in specific situations. The four items derivedfrom the work of Hofstetter et al. (19) had been tested in a ran-dom sample of 525 adults in San Diego, CA and were found toload together heavily on factors specific to diet and exerciseself-efficacy. In that study, responses to these items were alsocorrelated with knowledge of healthy diets and exercise prac-tices (19). The factor analysis on the items used in this studysupport the behavioral specificity of self-efficacy as three sepa-rate factors emerged: one for weight management, one for con-trolling food intake, and one for exercise. However, the highinterfactor correlations for these three subscales strongly sug-gested combining them into one scale. Scores for this singlescale were highly associated with previous success with weightloss and with exercise practices and fruit and vegetable con-sumption, behaviors that would be expected to promote healthyweight.

Weight Attitudes and Body ImageSocialcognitive theory hypothesizes that human behavior

is determined by interactions between behavior, personal fac-tors, and environmental influences (13). For the purposes of thisstudy, attitudes and beliefs about weight gain during pregnancy,and about body image, were considered personal factors thatwould influence behaviors related to gestational weight gain andpostpartum weight retention. Weight attitudes were measuredusing most of the items on an instrument developed previouslyand tested in a group of 29 pregnant women (20). No assessmentof the construct validity of this instrument was reported, but atti-tude scores were found to be significantly associated with

weight gain during pregnancy. Results of this research supportthe validity of these items for measuring attitudes of pregnantwomen about gestational weight gain.

Of the six psychosocial constructs examined in this study,body image has received the most attention in research on preg-nant women. Body image changes in pregnancy may vary fornormal weight and overweight women (30). Using the 34-itemBody Shape Questionnaire, Fox and Yamaguchi (30) found thatin the third trimester of pregnancy, normal weight women weremore likely to experience a negative change in body image, andoverweight women experience a positive change in comparisonto their prepregnant body image. Using the pictures of body sil-houettes to assess current body image and desired body image,Harris, Ellison, and Clement (31) found that women who wereless satisfied with their bodies had significantly greater weightgain postpartum than women who had no increase in dissatisfac-tion with their bodies after pregnancy. In this study, the items de-veloped by the authors to measure perception of and satisfactionwith body weight and shape separated into two conceptuallymeaningful factors and were reliable based on their Cronbachsalpha. Both of these scales were strongly associated with bodymass index early in the first trimester of pregnancy. These fouritems assess the same features of body image that were assessedby Harris et al. with body silhouettes, so we expect womenwhose scores on this scale indicate dissatisfaction with body im-age to retain significantly more weight in the postpartum periodthan women who are satisfied with their body image.

Career OrientationRole theory hypothesizes that social roles and norms and

expectations for those roles influence behaviors, includinghealth-related behaviors (16). Women pregnant for the first timeare adopting the maternal role, a role that carries expectationsfor lifestyle behaviors and self-image (14,15). In this study,scores on the scale assessing anxiety about the maternal rolewere higher for those pregnant with their first child. Anxiety hasbeen examined extensively in childbearing populations and hasbeen found to influence psychological outcomes of pregnancysuch as maternalfetal attachment; maternal sensitivity to herinfant; maternal adaptation to parenthood; and, later, childpsychopathology (32). Only one study has examined anxiety asit relates to weight gain during pregnancy and found that low-in-come White women with high scores on the Spielberger TraitAnxiety Inventory gained significantly less weight during preg-nancy than women with lower scores (28). Although this scalemeasures anxiety as a personality trait rather than anxiety re-lated to taking on the maternal role, the results from that studysuggest that anxiety may influence weight changes related topregnancy.

Previous research has documented an association of earlyreturn to work with decreased postpartum weight (4), indicatingthat the career role may have an important influence onweight-related behaviors that influence weight during and afterpregnancy. In this study, women who held professional jobs hadhigher scores on the career scale than those who held other kindsof jobs. Therefore, this scale may be a useful tool to classify


women who have a strong commitment to their careers andthose for whom family needs are more important.

LimitationsThe scales described in this research have a high level of re-

liability and construct validity in the sample in which they weredeveloped. The women included in our study came from a ruralarea with a relatively homogeneous population in terms of raceand ethnicity. However, the educational attainment, age, and in-come were fairly diverse, a counterbalancing strength of thisstudy. Because nearly all of the women were in the second orthird trimester of pregnancy at the time the scale items were ad-ministered, there was a shared experience that might influenceresponses to the scale items. It is not known whether these itemswould perform similarly in a more ethnically diverse populationor in a survey of nonpregnant women.

SUMMARY AND CONCLUSIONThis article describes the validation of items designed to

measure psychosocial constructs believed to influence womensweight-related behaviors based on socialcognitive theory androle theory. Evidence of the construct validity and reliability ofthe items is provided by the factor analysis and assessment ofCronbachs alpha. The examination of the subscales within eachconstruct indicated that these subscales were correlated witheach other. For example, although the factor analysis identifiedthree distinct domains within the items measuring self-efficacy,all of the items relate to behaviors that one would expect to con-tribute to overall weight management strategies. Thus, for thesescales to be useful in predicting outcomes such as gestationalweight gain or postpartum weight retention, a smaller set isneeded to reduce the intercorrelation among the scales. Exam-ining relations of the reduced number of scales to preexistingcharacteristics and lifestyle behaviors of participants providedevidence of the construct validity of the scales. Using thesepsychosocial scales in research on weight-related issues in preg-nant women will allow a more comprehensive understanding ofthe relative contributions of social, behavioral, and biologicalfactors to important health outcomes for women in the prenataland postpartum periods, and foster development of more effec-tive interventions to ensure postpartum health.

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APPENDIXContent Validity and Reliability of Psychosocial Constructs

Items Factor 1 Factor 2 Factor 3

Measures of locus of control1. Whether my weight changes is up to me. 0.88 0.012. If I eat right, and get enough exercise and rest, I can control my

weight the way I want.0.87 0.02

3. Being the right weight is mainly good luck. 0.00 0.884. No matter what I try to do, if I gain or lose weight, or stay the same, it

is just going to happen.0.03 0.86

Cronbachs 0.71 0.69Measures of self-efficacy

How sure are you that you can:5. Fit into your regular clothes 0.96 0.05 0.076. Take off any extra weight you gain 0.91 0.02 0.017. Get back in shape 0.85 0.05 0.128. Eat balanced meals 0.12 0.90 0.069. Eat foods that are good for you and avoid foods that are not 0.03 0.85 0.0310. Eat foods that are good for you even when family or social life takes

a lot of your time0.18 0.76 0.05

11. Get regular exercise 0.00 0.02 0.9812. Get regular exercise even when family or social life takes a lot of

time0.00 0.01 0.97

Cronbachs 0.90 0.81 0.94Measures of attitudes toward weight gain during pregnancy

13. The weight I gain during my pregnancy makes me feel ugly. 0.83 0.09 0.1114. I worry that I may get fat during this pregnancy. 0.76 0.01 0.1015. I am embarrassed at how big I have gotten during this pregnancy. 0.80 0.07 0.1616. Im embarrassed whenever the nurse weighs me. 0.75 0.05 0.0717. I am trying to keep my weight down so I dont look so pregnant. 0.50 0.18 0.1218. I would like to gain between 25 and 35 pounds during this

pregnancy.0.23 0.78 0.31

19. I would gain 40 pounds if it meant a healthier baby. 0.13 0.62 0.2420. I will feel badly if I gain more than 20 pounds during this pregnancy. 0.37 0.57 0.06521. I like being able to gain weight for a change. 0.22 0.54 0.0722. As long as Im eating a well-balanced diet, I dont care how much I

gain during this pregnancy.0.20 0.54 0.19

23. I am sure that I will be able to fully control the amount of weight Iwill gain during this pregnancy.

0.15 0.00 0.73

24. You cant totally control the amount of weight you gain when youare pregnant.

0.01 0.06 0.66

(continued)

58 Kendall et al. Annals of Behavioral MedicineAPPENDIX (continued)

Items Factor 1 Factor 2 Factor 3

25. I feel that women have to be very careful about getting fat duringpregnancy.

0.42 0.17 0.39

Cronbachs 0.80 0.65 0.36Measures of body image

26. Shape satisfaction 0.95 0.0427. Weight satisfaction 0.90 0.1028. Weight perception 0.02 0.9529. Shape perception 0.13 0.87Cronbachs 0.94 0.92

Measures of feelings about motherhood30. Having a baby brings a lot of stress into a womans life. 0.84 0.2831. I am not sure how I will manage after I have the baby. 0.67 0.1532. I am afraid I will lose my identity after I have the baby. 0.60 0.2633. After a woman has a baby, she is mainly just somebodys mother. 0.59 0.2034. I am sure that I will be a good mother. 0.41 0.2235. I felt proud when I found out that I was going have a baby. 0.01 0.8236. I felt scared when I found out I was going to become a mother. 0.03 0.80Cronbachs 0.70 0.55

Measures of career orientation37. I want a job that will help me grow. 0.82 0.1438. Being able to express myself through my job means a great deal to

me.

0.78 0.01

39. I am determined to achieve my educational and work goals. 0.71 0.0740. Success in my work is very important to how I feel about myself. 0.71 0.1041. I see myself as working for pay for my whole adult life. 0.62 0.0342. The responsibilities for home and family should be equally shared

when both partners work.0.49 0.34

43. I need more in life than what being a wife and mother can give me. 0.47 0.2644. Women who hope to be successful in a job must do so at the expense

of home and family.0.46 0.04

45. Women should seek work that will fit in family needs in terms ofwork hours, leave time, etc.

0.27 0.76

46. Women must make changes in their careers for family needs. 0.06 0.7047. Women should not work full-time when their children are young. 0.22 0.6248. Feeling loved and needed is more important to me than having a

career.

0.17 0.58

49. I would be very happy staying at home and not working at a job. 0.40 0.46Cronbachs 0.75 0.67

Note. Underscored values are the standardized regression coefficients (factor loadings) under oblique rotation for the items included in each numberedfactor.

evaluation of psychosocial measures for understanding weight-related behaviors in pregnant women

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