Modifiable risk factors of maternal postpartum weight retention: an analysis of their combined impact and potential opportunities for prevention.
Pregnancy triggers a physiological change in weight status. Postpartum weight retention in the childbearing years can substantially alter a woman's weight gain trajectory, with several potential contributing factors identified. Most research has relied on women's recall of pre-pregnancy weight during pregnancy or later, and not considered risk factors in combination. Using measured pre-pregnancy weight, this study aimed to examine the associations of maternal postpartum weight retention with parity, pre-pregnancy BMI, excessive gestational weight gain (GWG), maternal serum vitamin D concentration and dietary Glycaemic Index in early and late pregnancy, and breastfeeding duration, including analysis of the combined impact of potentially modifiable risk factors.



Prospective cohort study of 12 583 non-pregnant women aged 20-34 years in Southampton (UK) who were assessed prior to pregnancy, with those who subsequently became pregnant followed up in early and late gestation, and after delivery (n=2559 in the final sample). Linear regression models examined potential predictors of weight retention in adjusted individual and multivariate analyses, and as a risk factor score.



Compared with pre-pregnancy weight, 73% of women retained some weight at 6 months postpartum (mean (s.d.): 3.5 (6.2) kg). In the adjusted multivariate model, women who were primiparous, had a lower pre-pregnancy BMI, excessive GWG, a lower early pregnancy vitamin D concentration and breastfed for <6 months had greater weight retention 6 months postpartum (P<0.05 for all variables). For each additional modifiable risk factor (excessive GWG, low vitamin D concentration in early pregnancy and short breastfeeding duration; scale 0-3), women retained an additional 2.49 kg (95% CI: 2.16, 2.82; P<0.001).



Having a greater number of modifiable risk factors was associated with greater weight retention 6 months postpartum. Initiatives supporting women to target these risk factors in the years prior to, during and after pregnancy could impact on their weight gain trajectory and later risk of adverse weight-related outcomes.
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
J L
JL
Hollis
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
S R
SR
Crozier
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
H M
HM
Inskip
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.|NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK.
C
C
Cooper
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
K M
KM
Godfrey
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
N C
NC
Harvey
Priority Research Centre in Physical Activity and Nutrition, School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, New South Wales, Australia.|Faculty of Health and Medicine, School of Health Sciences, University of Newcastle, Callaghan, New South Wales, Australia.
C E
CE
Collins
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
S M
SM
Robinson
D000328:Adult; D015992:Body Mass Index; D000068959:Body Weight Maintenance / Q000502:physiology*; D004739:England / Q000453:epidemiology; D005260:Female; D038321:Glycemic Index / Q000502:physiology; D006801:Humans; D050177:Overweight / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D010298:Parity / Q000502:physiology; D049590:Postpartum Period / Q000502:physiology*; D016742:Preconception Care; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000097:blood; D015430:Weight Gain / Q000502:physiology*; D055815:Young Adult
D014807:Vitamin D