Prevention and management of excessive gestational weight gain: a survey of overweight and obese pregnant women

Obesity is a consequence of energy imbalance, when energy intake exceeds energy expenditure over a prolonged period of time. Most people tend to gain weight gradually in adulthood for numerous reasons including declining physical activity plus small increases in dietary intake. Certain life stages have been identified as critical periods during which weight gain is likely to be more rapid and includes pregnancy [1]. The prevalence of maternal obesity has increased over time and is positively associated with parity, black ethnic group, age and unemployment [2]. Many women attribute their obesity to large weight gains during pregnancy, [3, 4], gains which they often never lose. Excess weight gain and failure to lose weight gained during pregnancy are established predictors of long-term obesity [5‐7]. Postpartum weight retention increases with greater gestational weight gain [8, 9] and gestational weight gain is positively associated with later body mass index (BMI) [10]. Excessive gestational weight gain is associated with increasing deprivation [2] and with adverse infant, childhood and maternal outcomes [2, 11, 12]. Institute of Medicine guidelines [13] have defined limits for weight gain in pregnancy according to initial BMI. These weight limits vary according to BMI, from 12.7-18.1 kg in those with a BMI<18.5 kg/m [2], 11.3-15.8 kg for those with a healthy BMI (<24.9 kg/m [2]) to 6.8-11.3 kg in the overweight (BMI 25.0-29.9 kg/m [2]) and 4.9 -9.0 kg in the obese. However, while more liberal than previous recommendations, many overweight and obese women still exceed these guidelines [2, 13, 14].

Pregnant women are potentially receptive to health care advice and may be motivated to implement lifestyle changes [15]. However, currently women’s views on gestational weight gain and its management are largely unknown. The aim of this survey was to determine newly pregnant women’s views on their current body weight and potential gestational weight gain. Opinions on resources that might be considered helpful in preventing excessive weight gain were sought together with any barriers to their use. These data will inform future interventions designed to limit excessive weight gain during pregnancy.

This survey was carried out in two hospitals in Fife, Scotland, (Forth Park, Kirkcaldy and Queen Margaret Hospital, Dunfermline) between December 2009 and June 2010. All women attending their booking appointment (at around 12 weeks gestation), whose BMI was in excess of 25 kg/m [2] were invited by their midwife to complete a short questionnaire entitled “weight, health and nutrition during pregnancy”. The questionnaire was devised to address the following research questions:

The questionnaire (Additional file 1) comprised eight questions which asked about: 1) number of previous pregnancies (parity) 2) what happened to body weight during these pregnancies; 3) how respondents felt about their current weight and potential weight gain throughout their current pregnancy; 4) which resources would be considered helpful in minimising excessive weight gain. Two questions inquired about potential barriers women felt would prevent them taking advantage of these resources and what, if anything, could help overcome these.

The majority of questions were closed to minimise the burden on respondents. However six questions offered respondents an opportunity to expand on the choices offered and record a resource/option not already listed. Respondents were also invited to record any other comments/views that they might have.

A questionnaire was developed for use in the present study as it was not possible to find a validated questionnaire that addressed the specific area of investigation. Questionnaire content was informed by existing studies of body weight in both pre and post-natal women, by clinical guidelines, and by the clinical experience of the study researcher (AG) [14, 16‐18].

Formal reliability or validity testing of the survey questionnaire was not performed. However, individual questions and the questionnaires as a whole were reviewed by, and views sought from colleagues working within NHS antenatal clinical service. The calculated Fog index (http://​www.​thelearningweb.​net/​fogindex.​html) of 7, classified the questionnaire as very readable.

The questionnaire was informally piloted, by reviewing the first 20–30 completed questionnaires to determine any consistent omissions or errors which would have indicated difficulties with any aspect of the questionnaire.

Height, weight, BMI and postcode were recorded by midwives. Postcodes were used to derive a Scottish Index of Multiple Deprivation (SIMD) decile score [19]. SIMD is calculated using key indicators of income, employment, health, education, skills and training, housing, geographic access and incidence of crime. Each post code is allocated an SIMD code.

Questionnaires were completed by respondents on-site at the conclusion of their booking appointment. Completed questionnaires, which were anonymous, were returned in person by respondents to the hospital reception and collected weekly by the study researcher.

Between December 2009 and June 2010, 443 women completed the questionnaire. Fifteen respondents were excluded from the analyses, 7 with a BMI below 25 kg /m² and 8 as height and weight were not recorded, thus precluding calculation of BMI.

The mean BMI of the 428 study participants was 31.6 kg/m² (Table 1), with 54% categorised as obese. It was a first pregnancy for 41% (175) of women. The majority of respondents, 60%, resided in areas of deprivation as categorised by SIMD decile 1–5 [19] (Table 1).

Sixty percent of women expressed some concern about their current weight (Table 2). Forty three percent of the 252 women with a previous pregnancies reported they had not lost the weight gained during previous pregnancies. However, 19% (49) of these women felt that despite their previous weight gain and retention they were comfortable with their current weight. Of 39 women who reported “gaining a lot of weight but not losing it in a previous pregnancy” 32, (82%) currently had a BMI >30 kg/m².

Thirty nine percent (n=162) of participants reported being unconcerned about potential weight gain in their current pregnancy, and this included 34 (22%) that had not lost weight gained in previous pregnancies. Responses differed little according to deprivation index. However, comparison by BMI category of participants views on their current weight showed obese respondents to be less happy with their current weight than those who were overweight (p<0.001).

Among those who expressed concern about potential weight gain, advice on physical activity was most frequently cited as the resource which would be most helpful in minimising weight gain followed by access to sports/leisure facilities (Table 3). Fewer women, 12%, indicated that other group sessions on healthy eating or attending a clinic for individualised advice (14%) would be helpful.

The most frequently cited barrier to accessing resources other than leaflets was “getting time off work” (48%). The provision of sessions nearer to participant’s homes and/or at weekends/evenings was cited by respondents as a way of challenging this barrier. There were no “other responses” recorded, for any questions.

Responses regarding resources did not differ by BMI category or deprivation index.

The majority of women who participated in the present survey expressed some concern over the weight gain that might be experienced during their current pregnancy. Previous research carried out amongst a diverse sample of mothers also found many had concerns about gestational weight gain [20, 21].

In the present survey women who expressed concern about weight gain reported more interest in increasing their physical activity than receiving targeted dietary advice. Physical activity is something known to have health benefits during pregnancy [22] and specific practical advice to increase activity is available [23]. However evidence suggests that interventions which focus solely on increasing physical activity during pregnancy have little effect on minimising excessive gestational weight gain, as activity levels often fall, the decrease in activity persisting at 6 months post partum [24, 25]. It remains an area where further research is justified [26]. Respondents may have viewed physical activity as being relatively easy to incorporate into daily life, however in practice this may not be the case. Compliance with the physical activity component of a recent study was reported as difficult to sustain [27] due to self reported minor ailments leading women to refrain from activity. Numerous barriers to engaging in physical activity during pregnancy have also been cited including: work, lack of motivation and lack of time [22]. It is unlikely that interventions that rely solely on changes to physical activity would be effective in minimising excessive gestational weight gain. Successful weight management interventions, in non-pregnant individuals, require changes to both diet and physical activity and these principles would apply to the prevention of excessive gestational weight [18, 28].

In the UK elements of antenatal care such as prenatal “birth groups” have, for many years, traditionally been delivered in a group format. In the present study both group based and one to one interventions were not popular. A low intensity intervention targeting diet and physical activity, with minimal face to face contacts achieved an 82% retention rate six months post-partum. Study outcomes were encouraging with more overweight women returning to their pre-pregnancy weight, than those in receipt of usual care [29]. However, 60% of women who were eligible and contactable either declined to participate or failed to attend. Uptake to this study was therefore only slightly better than in other research which used a group approach [14]. The low uptake to either form of intervention for weight management during pregnancy suggests other barriers that may preclude participation. It may be that contrary to opinion pregnancy is in fact not a time when women are receptive to change. Anderson [30] described pregnancy as a time when good dietary choices are maintained, but not as an opportunity for implementing dietary or other health changes. The present survey findings appear to support this assertion. However, it must be noted that the present data represent only the views of those who chose to participate in the survey. Non-participants may have held opposing views.

Getting time off work was the most frequently reported barrier to accessing resources to minimise gestational weight gain. This concurs with other research which explored the reasons women declined to participate in an intervention to address obesity in pregnancy [31]. This study also found that the location of services was also a barrier to participation. In the present survey women indicated they may be more likely to attend a service that was held near to their home and out-with working hours. These barriers may be difficult to address within the current NHS service provision. However, increasing opening hours for general practitioners surgeries/health centres could circumvent these barriers; some are now open out-with conventional working hours. Successful uptake may also be facilitated by use of a low intensity approach similar to that used by Phelan et al. [29], where many of the barriers to participation reported by study participants, were overcome.

Evidence regarding the efficacy of interventions to reduce excessive gestational weight gain is conflicting. One review of interventions concluded that the quality of published trials was insufficient to allow evidence based recommendations for clinical practice to be developed [17]. Two more recent systematic reviews were more positive, both finding a 2 kg weight difference at six months partum, and one also finding a significant fall in the incidence of caesarean section in those women in receipt of a dietary intervention [23, 24].

Around 40% of women in the present survey, including those who had not lost weight gained in previous pregnancies, reported being unconcerned about potential weight gain during their pregnancy, a finding that is not unique. Earlier research carried out to elicit the views of pre and post-natal women on gestational weight gain found that in general the women interviewed were unconcerned about potential weight gain with many assuming that weight loss would occur in the post natal period as a result of breast feeding [32].

Many women do not acknowledge that their weight is an issue [14]. This may, in part, be due to the “normalisation” of obesity among the general population [31]. Comparison of perceptions of weight from two population surveys in the UK found that increasingly, overweight and obese individuals fail to recognise their weight as a cause for concern [31] This was also found to be the case in the United States [32].

Attitudes regarding gestational weight gain may reflect a lack of awareness of the potential implications of excessive gestational weight gain [33]. The present study did not explore women’s beliefs regarding the impact of gestational weight gain, however previous research suggests that while women acknowledge that insufficient weight gain may adversely affect their child few recognise the impact that excessive weight gain could have on infant health [21, 22]. Unawareness of the potential consequences of excessive gestational weight gain on both maternal and infant health suggests that engaging women in interventions to prevent excessive gestational weight gain is likely to be difficult [21]. If weight is not viewed as a concern by patients, then weight management interventions are unlikely to be seen as personally relevant [31] and destined to failure.

Lack of concern regarding gestational weight gain may also reflect a lack of emphasis on lifestyle issues by the healthcare professionals delivering care. Clinical guidelines [18, 28] advocate that as part of their antenatal care women should routinely receive advice on becoming physically active and consuming a healthy diet. Midwives have acknowledged that raising the issue of a pregnant women’s weight is something they find difficult, and often causes offence [14]. The CMACE Project reported that evidence of discussion regarding the risks of obesity in pregnancy was documented in less than one-fifth of cases audited. It is likely that issues of weight are not raised or addressed with many women [22]. Lack of knowledge among health professionals regarding appropriate gestational weight gain has also been reported [21] and is likely to reflect the lack of formal recommendations in the UK [22].

In the UK the regular measurement of maternal body weight during pregnancy is not advocated, and is therefore measured infrequently [15]. There is reluctance among women to have their weight measured regularly as they do not wish to know how much weight has been gained [21]. However, regular measurement of body weight could highlight to patients that changes in weight are important during pregnancy, and also offer midwives the opportunity to raise and discuss diet and physical activity. Midwives themselves have reported that women are more likely to engage when they consider weight measurements to be part of routine care and that integrating weight monitoring into routine care avoids women feeling stigmatised [34]. New services in Australia have shown that midwives, when trained, have integrated issues related to weight gain into usual care [14]. In the UK midwives have expressed a need for training specific to obesity to enable them to provide targeted advice [34, 35]. Since this survey was completed a UK wide campaign highlighting the issue of obesity and pregnancy has been launched [36].

Population strategies for the prevention and treatment of obesity are a priority and pregnancy and post partum are well recognised as risk periods for the onset and aggravation of overweight and obesity [1, 28, 38]. Pregnant women are therefore an appropriate target population for interventions to avoid excessive gestational weight gain. Research on approaches for the management of weight gain at this time is a growing area, reflecting its importance and considerable implications for maternal and infant health. There is only scant research on the concerns, if any, of pregnant women regarding weight gain during pregnancy and the resources they may value in trying to address this. The present study provides some insight into the thoughts and perceived needs of a largely deprived sample of overweight and obese pregnant women, many of whom were unconcerned about gestational weight gain. Our findings highlight a need to formally integrate discussions on weight gain and its management into routine antenatal care. Barriers to the uptake of resource to address weight gain are numerous but must also be considered in the design of future interventions and services. Training and education in weight management is required before midwives feel adequately equipped to raise and address the issue of gestational weight gain with their patients.