Exclusive breast feeding in early infancy reduces the risk of inpatient admission for diarrhea and suspected pneumonia in rural Vietnam: a prospective cohort study

Ha Nam province is located in North Vietnam, approximately 60 km from Hanoi, in the Red River Delta. Ha Nam has an area of 852.2 km², and a population of approximately 820,100 people with the majority of residents still working in subsistence agriculture [10, 11]. The main ethnic group populating this area is the Kinh, and the province is divided into 112 communes. It is a non-malarious area, with an average rainfall of 1,500 to 2,000 mm and annual average temperature of 23° Celsius. The under 1 year mortality rate in the province is 12.5 per 1000 live births [11]. Health care is provided at the primary health care level through commune health stations (CHS) which are staffed by trained health workers. The team usually consists of a doctor, pharmacist, nurses and a traditional medicine practioner. The CHS provides care and treatment for common diseases and deliveries and carries out health promotion at the village level. Residents are entitled to free services at their local CHS but not at the CHS in other communes. The CHS has a responsibility to the District Health Officer and the Commune People’s Committee, and receives technical guidance from the district hospitals.

A prospective cohort study design was used. The study was carried out in 104 communes and infants eligible for inclusion in the study were those born to women who had previously participated in a cluster randomised trial (Australian New Zealand Clinical Trials Registry: ANZCTR 12610000944033) in the same province. In the original cluster randomised trial, allocation was based on communes, and all communes in the province, other than those in the main provincial town, were randomly assigned to one of three treatment groups. Those in the main provincial town were not included as part of the trial as antenatal services differed from those of the rest of the province, with most deliveries taking place at the provincial hospital. For the original cluster randomised trial, women received either [1] one tablet of iron-folic acid (IFA) taken daily (60 mg elemental iron /0.4 mg folic acid per tablet, 7 tablets per week); or [2] one capsule of IFA taken twice a week (60 mg elemental iron /1.5 mg folic acid per capsule; 2 capsules per week); or [12] one capsule of multiple micronutrients (MMN) taken twice a week (60 mg elemental iron/1.5 mg folic acid per capsule; 2 capsules per week, as well as a variation of the dose of the micronutrients in the UNICEF/WHO/UNU international multiple micronutrient preparation (UNIMMAP) supplement including zinc, iodine, copper, selenium, vitamin A, thiamine, riboflavin, niacin, vitamin B6, vitamin B12, vitamin C, vitamin D and vitamin E [13].

Inclusion criteria for the trial were: residence in trial communes, age >16 y, confirmed pregnancy at <16 wk gestation, and registration with the commune health station. Women were excluded if they had a high-risk pregnancy—multi-fetal pregnancy (confirmed on palpation or ultrasound) or a significant medical condition—or if they had severe anemia (haemoglobin concentration [Hb] <80 g/l) at enrolment. Detailed information on the original cluster randomised trial and inclusion criteria have been reported elsewhere [14]. The trial was approved by the Melbourne Health Human Research Ethics Committee, and the Ha Nam Provincial Human Research Ethics Committee. Written informed consent was obtained from each participant.

Infant morbidity and inpatient admission was assessed at the 6-month post-partum visit to the commune health station, via a structured questionnaire using questions adapted from the World Health Organisation (WHO) Integrated Management of Childhood Illness [15] and modified for use in Vietnam. The primary outcome was inpatient admission for infant diarrheal illness or suspected pneumonia. Interviews were conducted by trained research assistants supervised by experienced Vietnamese and Australian researchers. Information on demographic, and maternal and early infant characteristics, including breast feeding, and maternal and infant nutritional status were collected at enrolment (mean gestational age 12.2 weeks), 32 weeks gestation, 6 weeks and 6 months post-partum. Information on maternal depression was collected at enrolment and 32 weeks gestation. Exclusive breast feeding was defined as- ‘since birth, the child has only received breastmilk (with the exception of oral drops/syrups of vitamins/medicines) and has not been given any other liquids or solids (including water, traditional herbs).’

Maternal mental health was assessed using the Edinburgh Postnatal Depression Scale-Vietnam Validation (EPDS-V). The EPDS-V was translated from English, culturally verified and validated against psychiatrist-administered Structural Clinical Interviews for the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM IV).

The cut-off point used to detect clinically significant symptoms in this setting was ≥4 [14, 16]. Recurrent depression was defined as a positive EPDS score at enrolment and 32 weeks gestation. Details of the collection of other data used in this study has previously been published [14].

Suspected pneumonia was defined as any episode of cough or difficulty breathing since birth, and diarrheal infection as any episode of diarrhea (3 episodes of loose stools or bloody stools) since birth [15]. Diarrhea or suspected pneumonia was classified as severe if the child required inpatient admission. All inpatient admissions between birth and 6 months were recorded. Inpatient admission was defined as an admission to any health care facility, that is, commune health centre or hospital during the first 6 months of life for suspected pneumonia or diarrheal illness.