Exercise Training in Pregnancy for Obese Mothers

Harvard Medical School (HMS and HSDM), Norwegian School of Sport Sciences, Karolinska Institutet, St. Olavs Hospital

Observational studies demonstrate that overweight in pregnancy is a risk factor for adverse pregnancy outcomes as fetal macrosomia, prolonged labor, low Apgar score, shoulder dystocia, nerve plexus injuries, increased proportion of instrumental deliveries and perineal ruptures. There is a 2.6 fold risk for gestational diabetes mellitus (fourfold in morbidly obese women) and a recent study has shown that fetuses of obese mothers develop insulin resistance in uterus. Main aims of this study are to assess if regular exercise in pregnancy among obese women can prevent or influence weight gain; impaired cardiac function in mother and fetus/newborn; impaired vascular function in mother; insulin resistance/sensitivity; body composition in mother and offspring; lumbopelvic pain; urinary and/or fecal incontinence; prolonged labor

Women with a self-reported pre-pregnancy BMI of 28 or more will be eligible for our study. Woman are eligible if they are 18 years or older, with a singleton live fetus at an early (week 12-14) ultrasound scan. Exclusion criteria are pregnancy complications with high risk for preterm labour or diseases that could interfere with participation. Primary outcome measure is weight increase based on weight measured at 14 weeks and immediately before labour. Assessments are done at baseline at 14 (12-18) weeks of pregnancy, and again in week 38, as well as 3 months postpartum. Some measurements are also done at other points in time. The maternal secondary outcome measurements include fasting glucose, glucose tolerance assessed by 2-h, 75 mg per-oral glucose tolerance test, insulin resistance assessed by HOMA-IR, weight, height, body composition estimated by skinfold measurements in pregnancy and by dual energy x-ray absorptiometry postpartum, blood markers, lumbopelvic pain, urin- and fecal incontinence, quality of life, psychological wellbeing, depression, and diet.

Supervised exercise training at the hospital during pregnancy: the women will attend at least 2 weekly sessions consisting of aerobic exercise (walking on treadmills), strength training (for upper body, back, abdomen and legs) as well as pelvic floor muscle exercises. Each session is 60 minutes and lead by a physiotherapist or experienced exercise physiologist. The women will also go through motivational interviewing sessions throughout the intervention period and are encouraged to do home exercise training in addition to the exercise at the hospital

Usual care as provided by the health services in Norway. The investigators will not advice the women to be inactive

2 hour 75 mg per-oral glucose tolerance test. Gestational diabetes is diagnosed as fasting glucose = or > 6.9 mmol/L or 2h concentration = or > 7.8 mmol/L.

Skinfold measurements, done by an experienced investigator using Harpenden kaliper. At the 3 months postpartum testing, also dual energy x-ray absorptiometry (DEXA scan) will be used.

Inflammation markers, cytokines (leptin, resistin, adiponectin, tnf-alfa). Blood will be collected and stored for later analyses.

Clinical assessment (active straight leg raising, pelvic provocation test), and validated questionnaire.

Pelvic floor muscle function will be assessed by clinical assessment and by 2D and 3D ultrasound. The prevalence and severity of urin- and fecal incontinence will also be assessed by a validated questionnaire

Level of physical activity will be assessed by activity registration (armbands) and by validated questionnaires

Cord blood will be sampled and stored for later analysis of relevant markers of inflammation and metabolism (including resistin, leptin, adiponectin)

Inclusion Criteria: Pre-pregnancy body mass index of 28 or more 18 years or more singleton live fetus at the routine ultrasound scan Exclusion Criteria: high risk for preterm labor or diseases that could interfere with participation

Garnaes KK, Morkved S, Salvesen O, Moholdt T. Exercise Training and Weight Gain in Obese Pregnant Women: A Randomized Controlled Trial (ETIP Trial). PLoS Med. 2016 Jul 26;13(7):e1002079. doi: 10.1371/journal.pmed.1002079. eCollection 2016 Jul.

Garnaes KK, Nyrnes SA, Salvesen KA, Salvesen O, Morkved S, Moholdt T. Effect of supervised exercise training during pregnancy on neonatal and maternal outcomes among overweight and obese women. Secondary analyses of the ETIP trial: A randomised controlled trial. PLoS One. 2017 Mar 21;12(3):e0173937. doi: 10.1371/journal.pone.0173937. eCollection 2017.

Garnaes KK, Morkved S, Salvesen KA, Salvesen O, Moholdt T. Exercise training during pregnancy reduces circulating insulin levels in overweight/obese women postpartum: secondary analysis of a randomised controlled trial (the ETIP trial). BMC Pregnancy Childbirth. 2018 Jan 8;18(1):18. doi: 10.1186/s12884-017-1653-5.

Nyrnes SA, Garnaes KK, Salvesen O, Timilsina AS, Moholdt T, Ingul CB. Cardiac function in newborns of obese women and the effect of exercise during pregnancy. A randomized controlled trial. PLoS One. 2018 Jun 1;13(6):e0197334. doi: 10.1371/journal.pone.0197334. eCollection 2018.

Garnaes KK, Helvik AS, Stafne SN, Morkved S, Salvesen K, Salvesen O, Moholdt T. Effects of supervised exercise training during pregnancy on psychological well-being among overweight and obese women: secondary analyses of the ETIP-trial, a randomised controlled trial. BMJ Open. 2019 Nov 21;9(11):e028252. doi: 10.1136/bmjopen-2018-028252.

Woodley SJ, Lawrenson P, Boyle R, Cody JD, Morkved S, Kernohan A, Hay-Smith EJC. Pelvic floor muscle training for preventing and treating urinary and faecal incontinence in antenatal and postnatal women. Cochrane Database Syst Rev. 2020 May 6;5(5):CD007471. doi: 10.1002/14651858.CD007471.pub4.

Ingul CB, Loras L, Tegnander E, Eik-Nes SH, Brantberg A. Maternal obesity affects fetal myocardial function as early as in the first trimester. Ultrasound Obstet Gynecol. 2016 Apr;47(4):433-42. doi: 10.1002/uog.14841. Epub 2016 Mar 14.

Moholdt TT, Salvesen K, Ingul CB, Vik T, Oken E, Morkved S. Exercise Training in Pregnancy for obese women (ETIP): study protocol for a randomised controlled trial. Trials. 2011 Jun 17;12:154. doi: 10.1186/1745-6215-12-154.