Weight gain during and post pregnancy

Weight gain during and post pregnancy is a common worry. How much should you exercise? Research shows that many postpartum women are not exercising enough.

The Journal of Physical Activity and Health have recently done a study on Predictors of Postpartum Exercise According to Prepregnancy Body Mass Index and Gestational Weight Gain.

The purpose

The study’s primary purpose was to examine the differences in postpartum (after birth) exercise and related personal/psychological correlates in women according to prepregnancy weight and pregnancy gestational weight gain (GWG) status. The second purpose was to find predictors of exercise at 2 weeks, 2 months and 6 months postpartum.

Postpartum exercise

We all know regular exercise is great for you. In fact, 150 minutes per week of moderate intensity is associated with multiple physical health benefits such as improved blood pressure, reduced risk of obesity and a decreased risk of cardiovascular disease.

Postpartum exercise also has psychological benefits such as a lower risk of, depression and the stress and anxiety of caring for a newborn. Postpartum exercise is safe and recommended for most pregnant women. Research shows that exercise during and post-pregnancy can help to reduce weight retention.

Weight gain during and post pregnancy – Who isn’t exercising?

Unfortunately, more than 60% of pregnant women are not meeting the exercise recommendations. Findings show that exercise and leisure physical activity both decline over the course of toward delivery. The American College of Obstetricians and Gynecologists recommends that women without delivery complications can return to pre-pregnancy activity levels by 6 weeks postpartum.

Recent evidence shows that most women are insufficiently active (ie, not achieving guidelines) even after this point. For example, Ainsworth et al found that, at 13 weeks postpartum, only 11% of women were classified as engaging in moderate-intensity activities. Most women (51%) were engaging in a sedentary lifestyle.

Demographics at risk

Evidence from the Pregnancy, Infection and Nutrition Postpartum Study showed that women had lower odds of participating in any moderate to vigorous physical activity when they reported having less education. Also, new mothers who feel they have little emotional support from significant others are less active.

Women who were active before pregnancy also fail to return to their pre-pregnancy exercise levels following delivery. Given that the majority of women enter pregnancy already overweight (25%) or obese (30%) and gain weight during pregnancy in excess of Institute of Medicine guidelines, exercise during the perinatal period is an important consideration for multigenerational perinatal obesity prevention efforts.

However, understanding the determinants of women’s exercise patterns across the transition to motherhood is a challenge. In recent years, conceptual models have emerged to better explain the influence of multiple correlates and risk factors related to obesity, stress and postpartum weight retention and GWG. However, to date, there is no conceptual model to understand and explain the determinants of postpartum exercise.

Perinatal obesity and high GWG are risk factors, they may elevate the risk for postpartum anxiety and depressive symptoms, particularly among obese mothers. Other known risk factors for people who are not exercising and have high GWG and poor psychological well-being include education (lower education group at higher risk), race/ethnicity (minorities at greater risk) and parity. Specific to parity, primiparous women (first-time mothers) are at greater risk for high GWG than multiparous women (mothers with 1 child or more already). This risk is observed across women of all body mass index (BMI) categories.

Few, if any, studies have examined these combined risk factors to explain women’s postpartum exercise. Given that exercise may offer protective effects against negative health outcomes, the authors of the study state that it is important to understand perinatal exercise determinants in an effort to develop behavioural interventions that effectively promote exercise during this important and transitional time for women and their babies.

Participants and Results

Participants were recruited at maternity hospitalisation and completed interviews to assess exercise (Leisure-Time Exercise Questionnaire) and personal correlates (demographics, anxiety/depressive symptoms) before/during pregnancy. Telephone interviews were conducted to assess postpartum exercise/psychological correlates. Women were categorised according to pre-pregnancy weight (normal and overweight) and pregnancy GWG status (above or within weight gain guidelines): normal-above, normal-within, overweight-above, and overweight-within.

Of the 1,154 women in the original study, 907 had complete data on the study variables; this response rate of 79% is adequate for survey-based research. Chi-square analyses were used to examine differences in demographic characteristics between women with complete data and those with missing data. No significant differences were observed across age, BMI, parity, race, marital status or education (Ps > .05). Sixteen women had GWG within the guidelines and were excluded from the analyses because of the small sample size. Thus, primary study analyses were conducted on the final sample of 891 (age: mean = 28.9, SD = 5.5; prepregnancy BMI: mean = 26.1, SD = 6.04; GWG: mean = 33.31, SD = 15.5); the women were mostly white (89%), college educated or higher (82%), were pregnant with their second or higher (53%) and had low postpartum anxiety (92%) and depressive (93%) symptoms.

The proportion of women across the categories was (1) normal-within: normal-weight women with GWG within guidelines (n = 270; 30.3%); (2) normal-above: normal-weight women with GWG above guidelines (n = 230; 25.8%); (3) overweight-within: overweight/obese women with GWG within guidelines (n = 126; 14.1%); and (4) overweight-above: overweight/obese women with GWG above guidelines (n = 265; 29.7%). No significant differences across women were observed for maternal age; however, there were significant differences for race/ethnicity, education and parity. A higher proportion of normal-weight women with GWG within guidelines were white than those above the guidelines.

Results conclusion

The authors concluded with:

Low levels of exercise minutes were observed in all women with significant differences for strenuous exercise minutes (overweight-within women had the lowest strenuous exercise; normal-weight women had more strenuous exercise than overweight women regardless of GWG).

These study findings highlight the benefits of exercise before/during pregnancy. The authors also noted that tailoring exercise interventions based on personal/psychological correlates to maximise effectiveness.

Key take away’s

Although the value of exercise is high and continued efforts for promotion are necessary, most women before, during and after pregnancy are simply not exercising regularly. This has important implications for women’s health during the childbearing years and may lead to subsequent comorbid issues (eg, the onset of obesity and diabetes) as women transition to the menopausal period. Moreover, low maternal exercise has multigenerational importance as it may impact the offspring and lead to an increased risk for childhood obesity. If you are pregnant or hoping to get pregnant soon, try to stay active before, during and after birth, for the good of yourself and your child.

To read the study in detail, including the main study analysis check out Predictors of Postpartum Exercise According to Prepregnancy Body Mass Index and Gestational Weight Gain.