Background Although the benefi ts of exclusive breastfeeding for child health and survival, particularly in the
post-neonatal period, are established, the independent benefi cial eff ect of early breastfeeding initiation remains
unclear. We studied the association between timing of breastfeeding initiation and post-enrolment neonatal and postneonatal
mortality up to 6 months of age, as well as the associations between breastfeeding pattern and mortality.
Methods We examined associations between timing of breastfeeding initiation, post-enrolment neonatal mortality
(enrolment 28 days), and post-neonatal mortality up to 6 months of age (29–180 days) in a large cohort from three
neonatal vitamin A trials in Ghana, India, and Tanzania. Newborn babies were eligible for these trials if their mother
reported that they were likely to stay in the study area for the next 6 months, they could feed orally, were aged less than
3 days, and the primary caregiver gave informed consent. We excluded infants who initiated breastfeeding after 96 h,
did not initiate, or had missing initiation status. We pooled the data from both randomised groups of the three trials
and then categorised time of breastfeeding initiation as: at ≤1 h, 2–23 h, and 24–96 h. We defi ned breastfeeding
patterns as exclusive, predominant, or partial breastfeeding at 4 days, 1 month, and 3 months of age. We estimated
relative risks using log binomial regression and Poisson regression with robust variances. Multivariate models
controlled for site and potential confounders.
Findings Of 99 938 enrolled infants, 99 632 babies initiated breastfeeding by 96 h of age and were included in our
prospective cohort. 56 981 (57·2%) initiated breastfeeding at ≤1 h, 38 043 (38·2%) at 2–23 h, and 4608 (4·6%) at
24–96 h. Compared with infants initiating breastfeeding within the fi rst hour of life, neonatal mortality between
enrolment and 28 days was higher in infants initiating at 2–23 h (adjusted relative risk 1·41 [95% CI 1·24–1·62],
p<0·0001), and in those initiating at 24–96 h (1·79 [1·39–2·30], p<0·0001). These associations were similar when
deaths in the fi rst 4 days of life were excluded (1·32 [1·10–1·58], p=0·003, for breastfeeding initiation at 2–23 h, and
1·90 [1·38–2·62], p=0·0001, for initiation at 24–96 h). When data were stratifi ed by exclusive breastfeeding status at
4 days of age (p value for interaction=0·690), these associations were also similar in magnitude but with wider
confi dence intervals for initiation at 2–23 h (1·41 [1·12–1·77], p=0·003) and for initiation at
24–96 h (1·51 [0·63–3·65], p=0·357). Exclusive breastfeeding was also associated with the lower mortality during the
fi rst 6 months of life (1–3 months mortality: exclusive vs partial breastfeeding at 1 month 1·83 [1·45–2·32], p<0·0001,
and exclusive breastfeeding vs no breastfeeding at 1 month 10·88 [8·27–14·31], p<0·0001).
Interpretation Our fi ndings suggest that early initiation of breastfeeding reduces neonatal and early infant mortality
both through increasing rates of exclusive breastfeeding and by additional mechanisms. Both practices should be
promoted by public health programmes and should be used in models to estimate lives saved
