Physical activity and diet are both known to have favorable effects on insulin resistance during pregnancy.
To investigate, whether counseling on diet, physical activity and gestational weight gain during pregnancy could prevent gestational diabetes.
Pilot study (2007–2008)
Results 1: Feasibility of the trial
Excessive gestational weight gain and postpartum weight retention may predispose women to long-term overweight and other health problems. Intervention studies aiming at preventing excessive pregnancy-related weight gain are needed. The feasibility of implementing such a study protocol in primary health care setting was evaluated in this pilot study.
A non-randomized controlled trial was conducted in three intervention and three control maternity and child health clinics in primary health care in Finland. Altogether, 132 pregnant and 92 postpartum women and 23 public health nurses (PHN) participated in the study. The intervention consisted of individual counselling on physical activity and diet at five routine visits to a PHN and of an option for supervised group exercise until 37 weeks’ gestation or ten months postpartum. The control clinics continued their usual care. The components of the feasibility evaluation were
1) recruitment and participation,
2) completion of data collection,
3) realization of the intervention and
4) the public health nurses’ experiences.
1) The recruitment rate was slower than expected and the recruitment period had to be prolonged from the initially planned three months to six months. The average participation rate of eligible women at study enrolment was 77% and the drop-out rate 15%.
2) In total, 99% of the data on weight, physical activity and diet and 96% of the blood samples were obtained.
3) In the intervention clinics, 98% of the counselling sessions were realized, their contents and average durations were as intended, 87% of participants regularly completed the weekly records for physical activity and diet, and the average participation percentage in the group exercise sessions was 45%.
4) The PHNs regarded the extra training as a major advantage and the high additional workload as a disadvantage of the study.
The study protocol was mostly feasible to implement, which encourages conducting large trials in comparable settings.
Current Controlled Trials ISRCTN21512277
Kinnunen TI, Aittasalo M, Koponen P, Ojala K, Mansikkamäki K, Weiderpass E, Fogelholm M, Luoto R. Feasibility of a controlled trial aiming to prevent excessive pregnancy-related weight gain in primary health care. BMC Pregnancy and Childbirth 2008;8:37
BMC Pregnancy Childbirth. 2008 Aug 11;8:37. doi: 10.1186/1471-2393-8-37
Results 2: Effects on weight gain
To investigate whether individual counselling on diet and physical activity during pregnancy can have positive effects on diet and leisure time physical activity (LTPA) and prevent excessive gestational weight gain.
A controlled trial.
Six maternity clinics in primary health care in Finland. The clinics were selected into three intervention and three control clinics.
Of the 132 pregnant primiparas, recruited by 15 public health nurses (PHN), 105 completed the study.
The intervention included individual counselling on diet and LTPA during five routine visits to a PHN until 37 weeks’ gestation; the controls received the standard maternity care.
The counselling did not affect the proportion of primiparas exceeding the weight gain recommendations or total LTPA when adjusted for confounders. The adjusted proportion of high-fibre bread of the total weekly amount of bread decreased more in the control group than in the intervention group (difference 11.8%-units, 95% confidence interval (CI) 0.6–23.1, P=0.04). The adjusted intake of vegetables, fruit and berries increased by 0.8 portions/day (95% CI 0.3–1.4, P=0.004) and dietary fibre by 3.6 g/day (95% CI 1.0–6.1, P=0.007) more in the intervention group than in the control group. There were no high birth weight babies (4000 g) in the intervention group, but eight (15%) of them in the control group (P=0.006).
The counselling helped pregnant women to maintain the proportion of high-fibre bread and to increase vegetable, fruit and fibre intakes, but was unable to prevent excessive gestational weight gain.
Kinnunen TI, Pasanen M, Aittasalo M, Fogelholm M, Hilakivi-Clarke L, Weiderpass E, Luoto R. Preventing excessive weight gain during pregnancy. A controlled trial in primary health care. Eur J Clin Nutr 2007;61:884-891
Results 3: Effects on physical activity
Three maternity and child health clinics signed up for the experimental group and three for the control group. The participants were 132 pregnant women and 92 women after the birth of their first child. In the experimental group the nurses integrated a primary and four booster physical activity counseling sessions into routine visits. An option for supervised group exercise was offered. In the control group former practices, usually including brief physical activity advice, were continued. Leisure-time physical activity prior to pregnancy was elicited by questionnaire and followed 16–18 and 36–37 weeks’ gestation in maternity clinics and 5 and 10 months after childbirth in child health clinics. Feasibility included safety, participant responsiveness, realization of counseling and applicability.
According to analysis of covariance adjusted for baseline leisure-time physical activity and possible confounders, no relative between-group differences in leisure-time physical activity were found at the first follow-up in either maternity or child health clinics.
At the last follow-up in maternity clinics the weekly number of at least moderate-intensity leisure-time physical activity days was 43% higher and the weekly duration of at least moderate-intensity leisure-time physical activity 154% higher in the experimental group compared with the control group. Counseling proved feasible in both maternity and child health clinics.
Counseling encouraged pregnant women to sustain their moderate-intensity leisure-time physical activity and was feasible in routine practices. No effects were observed if counseling was initiated postpartum.
Aittasalo M, Pasanen M, Fogelholm M, Kinnunen T, Ojala K, Luoto R. Physical activity counseling in maternity and child health care. A controlled trial. BMC Women’s Health 2008:8:14. doi:10.1186/1472-6874-8-1
Minna Aittasalo, Senior Researcher
Main study (2009–2017)
A cluster-randomized controlled trial was conducted in 14 municipalities in the southern part of Finland. Pairwise randomization was performed in order to take into account socioeconomic differences. Recruited women were at 8–12 weeks’ gestation and fulfilled at least one of the following criteria: body mass index ≥25 kg/m², history of earlier gestational glucose intolerance, macrosomic newborn (> 4500 g), age ≥ 40 years, first or second degree relative with history of type 1 or 2 diabetes. Main exclusion criterion was pathological oral glucose tolerance test (OGTT) at 8–12 weeks’ gestation.
In the intervention clinics the trial included several counseling sessions embedded into routine maternity visits: one on physical activity at 8–12 weeks’ gestation, one on diet at 16–18 weeks’ gestation and 3–4 booster sessions during other routine visits. In the control clinics women received usual care.
Information on height, weight gain and other gestational factors was obtained from maternity cards. Physical activity, dietary intake and quality of life were assessed with questionnaires during pregnancy and at 1-year postpartum. Blood samples for lipid status, hormones, insulin and OGTT were taken at 8–12 and 26–28 weeks’ gestation and 1 year postpartum.
Original publication ;on study design
Luoto R, Kinnunen T, Aittasalo M, Ojala K, Mansikkamäki K, Toropainen E, Kolu P, Vasankari T. Prevention of gestational diabetes: design of a cluster-randomized controlled trial and one-year follow-up. BMC Pregnancy and Childbirth 2010;10(1):39.
Effects on the prevention of gestational diabetes mellitus and large-for-gestational-age newborns
Our objective was to examine whether gestational diabetes mellitus (GDM) or newborns’ high birthweight can be prevented by lifestyle counseling in pregnant women at high risk of GDM.
Method and Findings
We conducted a cluster-randomized trial, the NELLI study, in 14 municipalities in Finland, where 2,271 women were screened by oral glucose tolerance test (OGTT) at 8–12 wk gestation. Euglycemic (n = 399) women with at least one GDM risk factor (body mass index [BMI] ≥25 kg/m2, glucose intolerance or newborn’s macrosomia (≥4,500 g) in any earlier pregnancy, family history of diabetes, age ≥40 y) were included. The intervention included individual intensified counseling on physical activity and diet and weight gain at five antenatal visits. Primary outcomes were incidence of GDM as assessed by OGTT (maternal outcome) and newborns’ birthweight adjusted for gestational age (neonatal outcome). Secondary outcomes were maternal weight gain and the need for insulin treatment during pregnancy. Adherence to the intervention was evaluated on the basis of changes in physical activity (weekly metabolic equivalent task (MET) minutes) and diet (intake of total fat, saturated and polyunsaturated fatty acids, saccharose, and fiber). Multilevel analyses took into account cluster, maternity clinic, and nurse level influences in addition to age, education, parity, and prepregnancy BMI. 15.8% (34/216) of women in the intervention group and 12.4% (22/179) in the usual care group developed GDM (absolute effect size 1.36, 95% confidence interval [CI] 0.71–2.62, p = 0.36). Neonatal birthweight was lower in the intervention than in the usual care group (absolute effect size −133 g, 95% CI −231 to −35, p = 0.008) as was proportion of large-for-gestational-age (LGA) newborns (26/216, 12.1% versus 34/179, 19.7%, p = 0.042). Women in the intervention group increased their intake of dietary fiber (adjusted coefficient 1.83, 95% CI 0.30–3.25, p = 0.023) and polyunsaturated fatty acids (adjusted coefficient 0.37, 95% CI 0.16–0.57, p<0.001), decreased their intake of saturated fatty acids (adjusted coefficient −0.63, 95% CI −1.12 to −0.15, p = 0.01) and intake of saccharose (adjusted coefficient −0.83, 95% CI −1.55 to −0.11, p = 0.023), and had a tendency to a smaller decrease in MET minutes/week for at least moderate intensity activity (adjusted coefficient 91, 95% CI −37 to 219, p = 0.17) than women in the usual care group. In subgroup analysis, adherent women in the intervention group (n = 55/229) had decreased risk of GDM (27.3% versus 33.0%, p = 0.43) and LGA newborns (7.3% versus 19.5%, p = 0.03) compared to women in the usual care group.
The intervention was effective in controlling birthweight of the newborns, but failed to have an effect on maternal GDM.
Luoto R, Kinnunen TI, Aittasalo M, Kolu P, Raitanen J, et al. (2011) Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial. PLoS Med 8(5): e1001036. doi:10.1371/journal.pmed.1001036
Effects on gestational weight gain
Healthy diet, physical activity and modest weight gain during pregnancy may prevent developing gestational diabetes mellitus (GDM). We examined whether a lifestyle intervention designed to prevent GDM was effective in reducing excessive gestational weight gain (GWG).
A cluster-randomised controlled trial (n=399) was conducted in maternity clinics in 14 municipalities in Southern Finland. Pregnant women with at least one risk factor for GDM (for example, overweight) but no pre-existing diabetes were recruited at 8–12 weeks’ gestation. The intervention included counselling on GWG, physical activity and healthy eating at five routine visits. Usual counselling practices were continued in the usual care municipalities. Statistical analyses were performed using multilevel linear and logistic regression models adjusted for weeks’ gestation at last weight measurement, pre-pregnancy body mass index and smoking status.
The intervention group had a lower mean GWG by weeks’ gestation than the usual care group (adjusted coefficient for the between-group difference −0.016 kg per day, P=0.041). There was no difference in mean (±s.d.) GWG between the intervention and the usual care groups (13.7±5.8 vs 14.3±5.0 kg, P=0.64). In total, 46.8% of the intervention group and 54.4% of the usual care group exceeded the GWG recommendations. The adjusted odds ratio for excessive GWG was 0.82 (95% CI 0.53–1.26, P=0.36) in the intervention group as compared with the usual care group.
The intervention had minor effects on GWG among women who were at increased risk for GDM. In order to prevent excessive GWG, additional focus on restriction of energy intake may be needed.
Kinnunen TI, Raitanen J, Aittasalo M, Luoto R. Preventing excessive gestational weight gain – a secondary analysis of a cluster-ranodmised controlled trial. Eur J Clin Nutr 2012;66:1344-1350
Effects on physical activity
Fourteen municipalities were randomized to intervention (INT) and usual care group (UC). Nurses in INT integrated five PA counseling sessions into routine maternity visits and offered monthly group meetings on PA instructed by physiotherapists. In UC conventional practices were continued.
Feasibility evaluation included safety (incidence of PA-related adverse events; questionnaire), realization (timing and duration of sessions, number of sessions missed, attendance at group meetings; systematic record-keeping of the nurses and physiotherapists) and applicability (nurses’ views; telephone interview). Effectiveness outcomes were weekly frequency and duration of total and intensity-specific LTPA and meeting PA recommendation for health self-reported at 8-12 (baseline), 26-28 and 36-37 weeks’ gestation. Multilevel analysis with adjustments was used in testing for between-group differences in PA changes.
The decrease in the weekly days of total and moderate-to-vigorous-intensity LTPA was smaller in INT (N = 219) than in UC (N = 180) from baseline to the first follow-up (0.1 vs. -1.2, p = 0.040 and −0.2 vs. -1.3, p = 0.016). A similar trend was seen in meeting the PA recommendation (−11%-points vs. -28%-points, p = 0.06). INT did not experience more adverse events classified as warning signs to terminate exercise than UC, counseling was implemented as planned and viewed positively by the nurses.
Physical activity counseling had no effects on the duration of total or intensity-specific weekly LTPA. However, it was able to reduce the decrease in the weekly frequency of total and moderate-to-vigorous-intensity LTPA from baseline to the end of second trimester and was feasibly embedded into routine practices.
Aittasalo M, Raitanen J, Kinnunen TU, Ojala K, Kolu P, Luoto R. Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland. Int J Behav Nutr Phys Act 2012;9:104
Minna Aittasalo, Senior Researcher
Effects on food habits and dietary intake
The incidence of gestational diabetes mellitus (GDM) is increasing and GDM might be prevented by improving diet. Few interventions have assessed the effects of dietary counselling on dietary intake of pregnant women.
This study examined the effects of dietary counselling on food habits and dietary intake of Finnish pregnant women as secondary outcomes of a trial primarily aiming at preventing GDM. A cluster‐randomized controlled trial was conducted in 14 municipalities in Finland, including 399 pregnant women at increased risk for developing GDM.
The intervention consisted of dietary counselling focusing on dietary fat, fibre and saccharose intake at four routine maternity clinic visits. Usual counselling practices were continued in the usual care municipalities. A validated 181‐item food frequency questionnaire was used to assess changes in diet from baseline to 26–28 and 36–37 weeks gestation. The data were analysed using multilevel mixed‐effects linear regression models. By 36–37 weeks gestation, the intervention had beneficial effects on total intake of vegetables, fruits and berries (coefficient for between‐group difference in change 61.6 g day−1, 95% confidence interval 25.7–97.6), the proportions of high‐fibre bread of all bread (7.2% units, 2.5–11.9), low‐fat cheeses of all cheeses (10.7% units, 2.6–18.9) and vegetable fats of all dietary fats (6.1% ‐units, 2.0–10.3), and the intake of saturated fatty acids (−0.67 energy‐%‐units, −1.16 to −0.19), polyunsaturated fatty acids (0.38 energy‐%‐units, 0.18–0.58), linoleic acid (764 mg day−1, 173–1354) and fibre (2.07 g day−1, 0.39–3.75). The intervention improved diet towards the recommendations in pregnant women at increased risk for GDM suggesting the counselling methods could be implemented in maternity care.
Kinnunen T, Puhkala J, Raitanen J, Ahonen S, Aittasalo M, Virtanen S, Luoto R. Effects of dietary counselling on food habits and dietary intake of Finnish pregnant women at increased risk for gestational diabetes – a secondary analysis of a cluster-randomized controlled trial. Maternal & Child Nutrition 2014;10(2):184-97. doi: 10.1111/j.1740-8709.2012.00426.x
Results 5: Validity and repeatability of short pregnancy leisure time physical activity questionnaire
Seventy-nine women with uncomplicated pregnancies and maximum of 33 weeks’ gestation participated in the study. After the first questionnaire they entered 7-day leisure time physical activity and pedometer counts in a logbook and completed the second leisure time physical activity questionnaire.
Validity was assessed with Spearman’s rank correlation coefficients by comparing the second leisure time physical activity questionnaire with pedometer counts and logbook. For describing repeatability, change in the mean, geometric mean ratio, typical error, coefficient of variation (CV,%) and Bland-Altman plots were used.
Forty-five (57%) and 47 (59%) women were available for pedometer and logbook comparisons and 49 (62%) for repeatability assessment. The second leisure time physical activity questionnaire showed no correlation with pedometer but moderate correlation with the logbook for the frequency of moderate to vigorous-intensity leisure time physical activity. In repeatability, the typical error for frequency estimates varied from 1.2 to 3.7 sessions and CV for duration from 119 to 369 percent. The corresponding values for systematic error were -1.0 to 0.3 sessions and 4 to 36 per cent. The 95% limits of agreement for single variables were large.
The questionnaire was valid for assessing moderate to vigorous-intensity leisure time physical activity but its individual repeatability proved weak.
Aittasalo M, Pasanen M, Fogelholm M, Ojala K. Validity and repeatability of a short pregnancy leisure time physical activity questionnaire. Journal of physical activity and health 2010;7:109-118
Minna Aittasalo, Senior Researcher
Results 6: Cost effectiveness
The aim was to evaluate the cost-effectiveness of primary prevention of gestational diabetes mellitus (GDM) through intensified counselling on physical activity, diet, and appropriate weight gain among the risk group.
Materials and Methods
The cost-effectiveness analysis was based on data from a cluster-randomised controlled GDM prevention trial carried out in primary health-care maternity clinics in Finland. Women (n = 399) with at least one risk factor for GDM were included. The incremental cost-effectiveness ratio (ICER) was calculated in terms of birth weight, 15D, and perceived health as measured with a visual analogue scale (VAS). A bootstrap technique for cluster-randomised samples was used to estimate uncertainty around a cost-effectiveness acceptability curve.
The mean total cost in the intervention group was €7,763 (standard deviation (SD): €4,511) and in the usual-care group was €6,994 (SD: €4,326, p = 0.14). The mean intervention cost was €141. The difference for costs in the birth-weight group was €753 (95% CI: −250 to 1,818) and in effects for birth weight was 115 g (95% CI: 15 to 222). The ICER for birth weight was almost €7, with 86.7% of bootstrap pairs located in the north-east quadrant, indicating that the intervention was more effective and more expensive in birth weight terms than the usual care was. The data show an 86.7% probability that each gram of birth weight avoided requires an additional cost of €7.
Intervention was effective for birth weight but was not cost-effective for birth weight, 15D, or VAS when compared to the usual care.
Kolu P, Raitanen J, Rissanen P, Luoto R. Cost-effectiveness of lifestyle counselling as primary prevention of gestational diabetes mellitus: findings from a cluster-randomised trial. PLOS one 2013;8(2):e56392
Work ability, sickness absence and return to employment
The impact of lifestyle modification on pregnant women’s work ability, well-being and return to employment. The study started in 2009 and it investigated the factors that promote and prevent women’s return to work after family leave.
Gestational diabetes is a significant risk to the health of both the mother and the child. Mothers diagnosed with gestational diabetes are known to have triple the risk of postnatal metabolic syndrome compared to other mothers.
The aim of the study was to investigate the impact of lifestyle choices during pregnancy on women’s work ability, well-being and ability to return to work. The study started in 2009 and it investigated the factors that affect women returning to work after family leave and it also examined the impact of the appeal of work and home, the perceived health and ability to work of the women as well as how social ties and networks affected the women’s ability to return to work after family leave.
The study was conducted using group interviews with the aim of investigating what mothers associate with the words work, family and child care. The interview also discussed other matters that affect women. The aim of the randomized clinical trial was to prevent gestational diabetes in mothers who have at least one risk factor for developing gestational diabetes. The clinical trial was conducted in 14 regions within Pirkanmaa and ended in the autumn of 2009.
The mothers in the trial were given intensive nutrition and exercise guidance as part of their regular maternity clinic visits. Almost 1000 mothers participated in the first stage of the trial, 410 of which participated in the rest of the trial. The trial results are now available.
The other sections of the study were a qualitative study (focus group interviews regarding return to work), a follow-up study and combining the results with birth register data. The mothers who participated in the randomized clinical trial were examined one year after giving birth.
The aim of the follow-up study was to assess the effectiveness of the prevention of gestational diabetes based on birth register data and to investigate:
• the permanence of favourable lifestyle changes
• the incidence of metabolic syndrome
• health, especially lipid metabolism
• work ability and factors affecting returning to work
• quality of life.
The follow-up included material collected through a mail survey and asking the mothers to undergo laboratory tests. The aim of the follow-up study was to assess the effects of the mothers’ lifestyle changes during pregnancy on their health later in life. The results are important when developing maternity clinics’ guidance practices to prevent various chronic diseases (diabetes, cardiovascular diseases, breast cancer).
The study was funded by the Academy of Finland as well as the Ministry of Education and Culture.
7-year follow-up study
Kolu P, Raitanen J, Puhkala J, Tuominen P, Husu P, Luoto R. Effectiveness and cost-effectiveness of a cluster-randomized prenatal lifestyle counseling trial: a seven-year follow-up. PLoS One. 2016 Dec 9;11(12):e0167759. doi:
For all the ;publications (international and Finnish) of this research see the Finnish description.
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Last updated: 19.11.2020