None listed
Conditions
Brief summary
Asthma is the most common serious medical problem to complicate pregnancies worldwide, with a prevalence between 8-13%, and affecting around 12% of pregnant women in Australia or 36,000 pregnancies each year. The health expenditure on asthma is significant and the economic burden of asthma is high. A recent meta-analysis demonstrated clear associations between asthma in pregnancies and adverse perinatal outcomes, with a 22-54% increased risk for low birth weight, small-for-gestational age, preterm delivery and pre-eclampsia. Previous work the laboratory also indicates asthma exacerbation contributes to poor outcomes including preterm delivery, growth restriction and stillbirth, and occurs in up to 55% of pregnancies. Oxidative stress is a potential mechanism driving the increased incidence of asthma exacerbation in pregnancy. Oxidative stress and inflammation manifest during pregnancy; however asthma in pregnancies further intensifies oxidative stress. We have previously identified that there are altered pathways regarding oxidant and antioxidant status in pregnant women with asthma, and consumption of antioxidant rich foods are beneficial for asthma control in non-pregnant adults with asthma. It has not been investigated whether antioxidant-rich foods can improve the elevated oxidative stress that occurs with asthma in pregnancies, thereby improving asthma control. We will reverse this oxidative burden through intervening with antioxidant-rich foods. We propose that 12 weeks of increased consumption of fruits, vegetables and wholegrains will modify the maternal biochemical profile of pregnancies complicated by asthma such that markers of oxidative stress will decrease and levels of antioxidants will increase. This novel approach will counteract the added oxidative stress caused by asthma during pregnancy and subsequently improve asthma control. No dietary guidelines exist for asthma management during pregnancy. Outcomes from our study will provide an avenue for which the development of new asthma management strategies can be devised.
Interventions
At ~12 weeks gestation, asthmatic women will be recruited to participate in the 12 week intervention study, with an initial 4 week run-in period. At this initial visit, women will have the study procedures explained and have their asthma assessed (by a respiratory nurse). At 14 weeks gestation, the run-in period will commence in which all women will be provided asthma management, education and advice (by a respiratory nurse). It is important that the women in the study receive this, as previous
At ~12 weeks gestation, asthmatic women will be recruited to participate in the 12 week intervention study, with an initial 4 week run-in period. At this initial visit, women will have the study procedures explained and have their asthma assessed (by a respiratory nurse). At 14 weeks gestation, the run-in period will commence in which all women will be provided asthma management, education and advice (by a respiratory nurse). It is important that the women in the study receive this, as previous data obtained from Lyell McEwin Hospital indicate that 16% of pregnant women have asthma and it is often poorly controlled, leading to high exacerbation rates. These procedures will also occur at week 16 and at week 18, in which the women will then be randomized into a control or intervention group. The intervention group will be advised to consume increased consumption of foods containing antioxidants (i.e. at least 5 servings of vegetables/day, at least 2 servings of fruit/day) as well as antioxidant-rich nuts and wholegrains. The intervention group will receive a booklet on the current Australian Guide to Healthy Eating for pregnancy in which the desirable number of servings of food groups are outlined. Participants will be counselled and provided with a list of foods containing antioxidant-rich foods, and will be asked to identify which types of fruits and vegetables they are most likely to purchase and consume over the 12 weeks. They will also be given meal/snack suggestions to assist compliance. Every 2 weeks during the intervention (i.e. weeks 20, 22, 26 and 28), women will be phoned by the registered nutritionist who will provide additional dietary counselling and support regarding the consumption of antioxidant-rich foods and will be questioned on their fruit and vegetable intake. Telephone calls will last approximately 15 minutes. Mid-way through the intervertion (i.e. ~24 weeks gestation), women will come to Lyell McEwin Hospital to also have this dietary counseling, along with further assessments.
Sponsors
The University of Adelaide
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Educational / counselling / training
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Pregnant women with mild or moderate/severe asthma and currently using inhaled corticosteroids, >18 years of age, and poor diet quality (less than 1 serving/day fruit and less than 2 servings/day vegetable, determined from Food Frequency Questionnaire).
Exclusion criteria
Recent (past month) respiratory tract infection, intermittent asthma, current smoker, use of antioxidant supplements, or previous pregnancy complications including growth restriction, still birth or preterm delivery.
Outcome results
None listed