Diet and lifestyle interventions in postpartum women in China: study design and rationale of a multicenter randomized controlled trial
© Bao et al; licensee BioMed Central Ltd. 2010
Received: 31 December 2009
Accepted: 27 February 2010
Published: 27 February 2010
"Doing the month", or "sitting month", is a traditional practice for postpartum women in China and other Asian countries, which includes some taboos against well-accepted healthy diet and lifestyles in general population. Previous studies have shown this practice may be associated with higher prevalence of postpartum problems. The current multicenter randomized controlled trial (RCT) aims to evaluate outcomes of diet and lifestyle interventions in Chinese postpartum women.
The current multicenter RCT will be conducted in three representative areas in China, Shandong province, Hubei province and Guangdong province, which locate in northern, central and southern parts of China, respectively. Women who attend routine pregnancy diagnosis in hospitals or maternal healthcare centers will be invited to take part in this study. At least 800 women who meet our eligibility criteria will be recruited and randomly assigned to the intervention group (n > = 400) and the control group (n > = 400). A three-dimension comprehensive intervention strategy, which incorporates intervention measures simultaneously to individual postpartum woman, their family members and community environment, will be utilized to maximize the effectiveness of intervention. Regular visiting and follow-up will be done in both group; nutrition and health-related measurements will be assessed both before and after the intervention.
To our knowledge, this current study is the first and largest multicenter RCT which focus on the effectiveness of diet and lifestyle intervention on reducing the incidence rate of postpartum diseases and improving health status in postpartum women. We hypothesize that the intervention will reduce the incidence rates of postpartum diseases and improve nutrition and health status due to a balanced diet and reasonable lifestyle in comparison with the control condition. If so, the results of our study will provide especially important evidence for changes in both the concept and action of traditional postpartum practice in China.
ClinicalTrials.gov ID NCT01039051.
The postpartum period, or puerperium, which starts about an hour after the delivery of the placenta and includes the following six weeks, covers a critical transitional time for a woman, her newborn and her family, on a physiological, emotional and social level. However, the postpartum period is often neglected by maternity care in both developing and developed countries . In addition, women's needs during this period have been all too often eclipsed by the attention given to pregnancy and birth . The lack of postpartum care ignores the fact that the majority of maternal deaths and disabilities occur during the postpartum period and that early neonatal mortality remains high [3, 4].
"Doing the month", or "sitting month", is a well-accepted and obeyed traditional practice among postpartum women and their families in China, which is also common in other Asian countries, such as Korea, Thailand, and Singapore [5–7]. According to traditional customs, women who are "doing the month" are advised to lie in bed all the time with doors and windows closed, and consume plenty of eggs or meat, drink bowels of chicken soup, brown sugar water, and millet gruel every day, while avoid eating any raw and cold food (mainly refers to fruits, vegetables), because cold food were thought to be unfavorable for postpartum recovery [8–10]. This practice seems to be believed more or less by almost all Chinese population worldwide, rather than only by local people in China mainland. Immigration studies showed that Chinese women who immigrated to Australia, Canada or United States still think that the traditional puerperium practice of "doing the month" is very important, and this belief is not subject to their level of education, acculturation level and the duration of immigration [11–14].
We have ever conducted a preliminary study in three regions of Hubei province in China to investigate prevalence of puerperium practice and their effect on postpartum women's health [15, 16]. We found that 18% of women never ate vegetables, 78.8% never ate fruit and 75.7% never drank milk during the puerperium while, in contrast, the consumption of eggs and brown sugar were as high as 365.0 g/d and 81.3 g/d in rural postpartum women, which is associated with postpartum problems including constipation, backaches, breast problems, oral diseases and anemia, et al .
However, as indicated in a Cochrane systematic review , evidence is too limited at present to confirm the effect of diet and lifestyle modification on outcomes for the postpartum women and their offspring. Therefore, we initiate this multicenter randomized controlled trial (RCT) with large-scale sample size to elucidate whether a diet and lifestyle intervention can improve the health status in Chinese postpartum women.
This multicenter RCT is designed to assess the effectiveness of a diet and lifestyle intervention in postpartum women in China, including a short-term effect on reducing health problems during puerperium period and a long-term effect on improving health status in women and their offspring over a two-year period.
The current multicenter study will be conducted in three representative areas in China, Shandong province, Hubei province and Guangdong province, which locate in northern, central and southern parts of China, respectively. Women who attend routine pregnancy diagnosis in hospitals or maternal healthcare centers will be invited to take part in the randomized controlled intervention trial.
Sample size has been calculated as the following formula :
, in which p 1 indicates incidence rate in control group, p 2 indicates incidence rate in intervention group and indicates average of p 1 and p 2 . Zα/2 is 1.96 when significance level (α) is 0.05 and Zβ is 1.64 for power (1 - β) is 0.90.
Take constipation, a typical diet-related digestive disorder, for example. The incidence rate of constipation in our previous study is 20.95% in the control group . We aim to reduce the incidence rate by 50%, which is 10.475%, the sample size N = = 309.89 ≈ 310 for each group. On the basis of the above calculation, a sample size of 800 participants (400 in the intervention group and 400 in the control group) has been determined, considering a certain attrition rate. This sample size is adequate, with statistical power >80%, for nearly all the major outcomes, including changes in nutritional status and health status.
Overview of the Questionnaires
Age, residence, occupation, education level, family economic situation, height, body weight, diagnosis of diseases, family history of diseases
Basic knowledge in nutrition and health
- Food guide pyramid knowledge
- Nutrient-food association knowledge
- Special nutritional requirement during postpartum period
- Frequency and amount of cereals intake
- Frequency and amount of vegetables intake
- Frequency and amount of fruits intake
- Frequency and amount of meat intake
- Frequency and amount of eggs intake
- Frequency and amount of milk and its products intake
- Frequency and amount of soybean and its products intake
- Frequency and amount of brown sugar intake
- Frequency and amount of dietary oil intake
- Frequency and amount of salt intake
- Frequency and amount of other substance intake (alcohol, strong tea, coffee, et al.)
Health-related behaviors and Physical activities
Teeth brushing, Bathing and Hair washing
Always lie in the bed or Get up for wandering
Maternal keep-fit exercises
Light physical activity or Heavy physical activity
Basking in the sun
Comparison between Traditional Practices for "Doing the Month" and Expected Diet and Lifestyle that We Advocated during the Postpartum Period
Traditional practices for "doing the month"
Expected diet and lifestyle during the postpartum period
Eat plenty of food
Increase total amount of food in accordance with energy expenditure
Meat-based diet components
Diverse food with both animal foods and plant-derived foods
Eat "hot" or "Yang" food (referred to meat, sugar, eggs, chicken soup, et al)
Ensure sufficient protein intake from fish, poultry meat, lean meat and eggs
Enjoy milk, soybeans, or their products daily Restrict fat intake from animal foods
Avoid "cold" or "Yin" food (referred to fruit, vegetables, cold water, et al)
Eat more vegetables fruits and nuts in various species
Drink sufficient quantity of water and juice every day
Have liquid food, such as non-greasy soup, before or between meals
Keep dietary taboos in mind
Advise the woman against dietary taboos about foods which are nutritionally healthy. Reassure the mother that she can eat any normal foods.
Talk to family members such as husband and mother-in-law, to encourage them to helpensure the woman eats enough.
Eat more foods rich in dietary fiber
Supplement with vitamins and minerals
Restrict salt consumption in diet
Avoid drinking alcohol, strong tea or coffee
Other Health-related behaviors
Never brush teeth
Brush teeth twice per day
Never bathe or wash hair
If possible, take a shower every day in a warm room and wash hair at least once a week
Shut well all windows or doors all the time
Ventilate regularly, but avoiding the cold wind blowing directly to the mother and child
Always lie in bed without any physical activity almost all day and night
Do maternal keep-fit exercises and increase physical activities gradually to maintain a healthy weight
Recruited women will be randomly allocated to either intervention group or control group according to a random number generated by a computer-based procedure. Then, a unique code for each participating woman and her allocation will be recorded.
Although it is impossible to ensure blinding for intervention conductor and the participating women, we will ensure blinding for the outcome measurements and biochemical analyses by independent examiners unaware of group allocation. Participants cannot be blinded for the intervention, but they are asked not to reveal information about their allocation to the examiners. The key of coding concerning group assignment is only known by the programmer of the database that is used during the study.
On the basis of our previous study in postpartum women from Hubei province of China and the latest WHO recommendation , we have formed a set of recommendations for women's diet and lifestyle during the postpartum period, which is the guideline for the current intervention study. A comparison between traditional practices for "doing the month" and expected diet and lifestyle that we advocated during the postpartum period are shown in Table 1. It is obvious that our guideline emphasizes the importance of increasing consumption of vegetables and fruits, which is regard as a diet taboo for postpartum women in traditional Chinese practice. In addition, it also emphasizes the importance of maintaining energy balance through reducing excessive energy from meat, eggs and brown sugar and increasing energy expenditure from appropriate physical activity, such as doing maternal keep-fit exercises.
Summary of our three-dimension comprehensive intervention strategy
Strategies and Measures
- Participatory training for woman who expects to childbirth with 1 month
- Providing specially prepared release of "Chinese women's postpartum reasonable diet and lifestyle program" (Universal Edition) and supporting VCD, to facilitate self-learning at home
- Setting up a specialized counseling hotline to answer the questions from postpartum woman and their family members
- Individual bedside guidance for postpartum woman, focusing on how to correctly adjust her diet and life style during postpartum period
Inviting every postpartum woman's husband and mother to take part in workshops or seminars, making them know some basic knowledge of postpartum care, and persuading them to promote adoption of the diet and lifestyle we advocated by the postpartum woman
- General population educating via putting up posters about basic knowledge of postpartum care in the community bulletin boards
- Mobilizing community leaders and heads from and maternal and child health centers for maximum support
Overview of the Measurements before and after the Intervention
Nutrition and health knowledge
Puerperium diet and lifestyle
24-hour dietary recording and FFQ
Assessment of nutritional status
Macronutrients intake (protein, lipid and carbohydrate, and dietary fiber from cereals, sugar, vegetables, fruits, meat, eggs, milk, soybeans, etc.)
24-hour dietary recording and FFQ, which include both food categories and amount
HPLC for vitamin A and vitamin D, load test for B vitamins and vitamin C
AAS for serum calcium, iron and zinc
Blood glucose and lipid profiles, including total cholesterol, HDL-C, LDL-C, triglycerides
Automatic biochemical analyzer
Postpartum recovery and health status
Anthropometric measurements, including height, body weight, and BMI
BMI = body weight (kg)/height (m2)
Body recovery, including duration for lochia, amount and duration of postpartum hemorrhage, degree of uterine involution
Diagnosis by specialized obstetricians
Diseases prevalence, including puerperal infection, fever, constipation, hemorrhoids, anal fissure, breast disease, oral ulcers, gum bleeding, anemia, pains (headache, heel pain, back pain, leg pain, joint pain, leg cramps, etc.)
Diagnosis by specialized doctors
Assessed by the Edinburgh Postnatal Depression Scale
Milk secretion and neo development
Assessed by specialized doctors
Data management and quality assurance
Data entry will be independently done by two researchers, and then a computer software-based error detection will be carried out to check the consistency of these data. If inconsistency occurs, the original questionnaire will be referred and the error will be corrected via a re-entry.
This study will be carried out in accordance with requirements documented in the Declaration of Helsinki. Ethics approval has been obtained from the local Health Department and the research ethics boards of Tongji Medical College, China.
Descriptive statistics will be calculated and checked for balance in intervention and control groups in demographic, health and outcome measurements at baseline. Comparisons between intervention group and control group will be performed by Chi-square (categorical variables), t test (continuous variables, normal distribution) or Mann-Whitney U test (continuous variables, skewed distribution). Final analyses will be undertaken using generalized linear mixed models to investigate changes over time in the two groups in the major outcomes. These models allow for repeated measures and can be used for normally distributed, binomial, and ordinal data . All statistical analyses will be performed using SPSS 12.0 statistical software package (SPSS Inc, Chicago, IL, USA).
It is generally accepted that a balanced diet comprising abundant intake of whole cereals, fruits, vegetables and a suitable amount of fish, meat, eggs and milk is essential for maintaining our health. However, postpartum women in China are traditionally advised to follow a special dietary and lifestyle pattern, which is quite different from the dietary and lifestyle patterns they maintain before and after postpartum period . Several studies have paid attention to explore the relationship of postpartum practice and consequent health problems in Chinese women [23, 24]; however, as we know, it is hard to draw a clear causation in cross-sectional studies.
To our knowledge, this study is the first and largest multicenter RCT which focus on the effectiveness of diet and lifestyle intervention on reducing the incidence rate of postpartum diseases and improving health status in postpartum women. This evidence-based study is designed on the basis of data from our previous study in three regions in Hubei province of China [15, 16], incorporating with the latest WHO recommendations . The major limitation of this study is that the participants that we will recruit are mainly Chinese Han women, whereas the postpartum practices vary among different national minorities in China. Further research on different minority populations will be very interesting.
We hypothesize that the intervention will reduce the incidence rates of postpartum diseases and improve nutrition and health status due to a balanced diet and reasonable lifestyle in comparison with the control condition. If so, the results of our study will provide especially important evidence for changes in postpartum diet and lifestyle. The fantastic reform in both the concept and action of traditional postpartum practice in China will be expected.
List of abbreviations
randomized controlled trial
world health organization
The authors gratefully acknowledge all the participants for their support. This study was supported by the National Key Technology R&D Program of China (2008BAI58B07).
- WHO: Postpartum Care of the Mother and Newborn: a practical guide. 1998, Geneva: World Health OrganizationGoogle Scholar
- WHO: The world health report 2005: make every mother and child count. 2005, Geneva: World Health OrganizationGoogle Scholar
- WHO: Maternal Mortality in 2000: Estimates Developed by WHO, UNICEF, and UNFPA. 2003, Geneva: World Health OrganizationGoogle Scholar
- WHO: Maternal Mortality in 2005: Estimates developed by WHO, UNICEF, UNFPA, and The World Bank. 2007, Geneva: World Health OrganizationGoogle Scholar
- Kim-Godwin YS: Postpartum beliefs and practices among non-Western cultures. MCN Am J Matern Child Nurs. 2003, 28: 74-78. 10.1097/00005721-200303000-00006. quiz 79-80.View ArticlePubMedGoogle Scholar
- Kaewsarn P, Moyle W, Creedy D: Traditional postpartum practices among Thai women. J Adv Nurs. 2003, 41: 358-366. 10.1046/j.1365-2648.2003.02534.x.View ArticlePubMedGoogle Scholar
- Chee CY, Lee DT, Chong YS, Tan LK, Ng TP, Fones CS: Confinement and other psychosocial factors in perinatal depression: a transcultural study in Singapore. J Affect Disord. 2005, 89: 157-166. 10.1016/j.jad.2005.09.004.View ArticlePubMedGoogle Scholar
- Chan SM, Nelson EA, Leung SS, Cheung PC, Li CY: Special postpartum dietary practices of Hong Kong Chinese women. Eur J Clin Nutr. 2000, 54: 797-802. 10.1038/sj.ejcn.1601095.View ArticlePubMedGoogle Scholar
- Kartchner R, Callister L: Giving birth. Voices of Chinese women. J Holist Nurs. 2003, 21: 100-116. 10.1177/0898010103021002002.View ArticlePubMedGoogle Scholar
- Leung SK, Arthur D, Martinson IM: Perceived stress and support of the Chinese postpartum ritual "doing the month'. Health Care Women Int. 2005, 26: 212-224. 10.1080/07399330590917771.View ArticlePubMedGoogle Scholar
- Callister LC: Doing the Month: Chinese Postpartum Practices. Global Health and Nursing. 2006, 31: 390-Google Scholar
- Matthey S, Panasetis P, Barnett B: Adherence to cultural practices following childbirth in migrant Chinese women and relation to postpartum mood. Health Care for Women International. 2002, 23: 567-575. 10.1080/07399330290107331.View ArticlePubMedGoogle Scholar
- Chu C: Postnatal experience and health needs of Chinese migrant women in Brisbane, Australia. Ethnicity and Health. 2005, 10: 33-56. 10.1080/1355785052000323029.View ArticlePubMedGoogle Scholar
- Brathwaite AC, Williams CC: Childbirth Experiences of Professional Chinese Canadian Women. J Obstet Gynecol Neonatal Nurs. 2004, 33: 748-755. 10.1177/0884217504270671.View ArticlePubMedGoogle Scholar
- Liu N, Mao L, Sun X, Liu L, Chen B, Ding Q: Postpartum practices of puerperal women and their influencing factors in three regions of Hubei, China. BMC Public Health. 2006, 6: 274-10.1186/1471-2458-6-274.View ArticlePubMedPubMed CentralGoogle Scholar
- Liu N, Mao L, Sun X, Liu L, Yao P, Chen B: The effect of health and nutrition education intervention on women's postpartum beliefs and practices: a randomized controlled trial. BMC Public Health. 2009, 9: 45-10.1186/1471-2458-9-45.View ArticlePubMedPubMed CentralGoogle Scholar
- Amorim AR, Linne YM, Lourenco PM: Diet or exercise, or both, for weight reduction in women after childbirth. Cochrane Database Syst Rev. 2007, CD005627-Google Scholar
- Wolfgang A, Pigeot I: Handbook of Epidemiology. 2005, Berlin Heidelberg: Springer-VerlagGoogle Scholar
- WHO: Pregnancy, Childbirth, Postpartum And Newborn Care: A guide for essential practice, second edition. 2006, Geneva: World Health OrganizationGoogle Scholar
- Niederer I, Kriemler S, Zahner L, Burgi F, Ebenegger V, Hartmann T, Meyer U, Schindler C, Nydegger A, Marques-Vidal P, Puder JJ: Influence of a lifestyle intervention in preschool children on physiological and psychological parameters (Ballabeina): study design of a cluster randomized controlled trial. BMC Public Health. 2009, 9: 94-View ArticlePubMedPubMed CentralGoogle Scholar
- Raven JH, Chen Q, Tolhurst RJ, Garner P: Traditional beliefs and practices in the postpartum period in Fujian Province, China: a qualitative study. BMC Pregnancy Childbirth. 2007, 7: 8-10.1186/1471-2393-7-8.View ArticlePubMedPubMed CentralGoogle Scholar
- Rose SB, Lawton BA, Elley CR, Dowell AC, Fenton AJ: The 'Women's Lifestyle Study', 2-year randomized controlled trial of physical activity counselling in primary health care: rationale and study design. BMC Public Health. 2007, 7: 166-10.1186/1471-2458-7-166.View ArticlePubMedPubMed CentralGoogle Scholar
- Wang X, Wang Y, Zanzhou S, Wang J, Wang J: A population-based survey of women's traditional postpartum behaviours in Northern China. Midwifery. 2008, 24: 238-245. 10.1016/j.midw.2006.12.010.View ArticlePubMedGoogle Scholar
- Wang X, Wang Y, Zhou S, Wang J, Wang J, Lofstedt P: Women's postpartum practices and chronic pain in rural China. Matern Child Health J. 2009, 13: 206-212. 10.1007/s10995-008-0336-2.View ArticlePubMedGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2458/10/103/prepub