Background: Numerous maternal factors, such as body mass index (BMI), gestational
weight gain (GWG), diet and physical activity (PA) have been shown to impact infant
birth weight. In the UK, antenatal care tends to be based on pre-pregnancy BMI and
women are not weighed routinely during pregnancy nor are there guidelines for GWG.
However, it is widely acknowledged that maternal obesity and GWG in excess of the
American Institute of Medicine guidelines are associated with increased risk of foetal
macrosomia and recent studies have suggested a role of the timing and composition of
GWG beyond that of BMI. The purpose of this study is to examine the effects of timing
and composition of GWG on neonatal anthropometric outcomes in a prospective
cohort study amongst women with a BMI≥30 kg/m2 in Plymouth, UK.
Methods: Women (n=75) were recruited at 12 weeks gestation. Maternal height,
weight and body composition assessed using skinfolds at biceps, triceps and
subscapular were collected at baseline and repeated at 28 and 36 weeks gestation.
Four-day food diaries and four days of accelerometry were collected in the days
following each of the three study visits. Following delivery, infant weight and
gestational age were obtained, and neonatal anthropometric measurements were
recorded within 72 hours of delivery.
Results: Maternal energy intake was positively associated with GWG and rate of fat
mass (FM) accrual, in the second (r = 0.435 and r = 0.395, respectively, p<0.05) and
third trimesters (r = 0.333 and r = 0.317, respectively, p<0.05), with no associations
observed between maternal energy intake and rate of fat free mass (FFM) accrual in
either trimester. Maternal rate of FFM accrual (in both trimester 2 and over total
pregnancy), not FM nor rate of GWG, was positively associated with infant birth
weight z scores (r = 0.360 and r = 468, respectively, p < 0.05) and upper arm area
muscle estimate (UME) (r = 0.291 and r = 0.357, respectively, p < 0.05). Second
trimester intake of sugar was positively associated with infant UME (r = 0.419, p<0.05),
while third trimester intake of sugar was positively associated with both infant UME
and infant birth weight z score (r = 0.376 and r = 0.308, respectively, p<0.05).
Conclusion: The present study suggests that maternal accrual of FFM and intake of
sugar during pregnancy may be associated with increased infant birth weight and lean
mass. Further research is required to determine whether interventions should focus on
changes in maternal body composition alongside diet and lifestyle during pregnancy,
or if they should continue to focus on limiting total GWG.
Date of Award | 2018 |
---|
Original language | English |
---|
Awarding Institution | |
---|
Supervisor | Gail Rees (Other Supervisor) |
---|
- Gestational weight gain
- Pregnancy
- Maternal body composition
- Infant anthropometry
- Diet
- Birth weight
The Timing and Composition of Gestational Weight Gain and the Impact on Neonatal Anthropometry
Redfern, K. (Author). 2018
Student thesis: PhD