Table 4. Summary of studies of the association between early breastfeeding initiation and morbidity outcomes (*Reference group).
| Diarrhea | ||||||
| Study | Sample Size | Study Design | Exposure Definition | Outcome Definition | Effect Estimate | Quality |
| Clemmens | 198 | Prospective | Early (<3 days) vs. Late (≥3 days)* | Diarrhea | aRR: 0.74 (95% CI: 0.56–0.98) | Low |
| 1999 | Cohort | breastfeeding initiation | at <6 months | |||
| Clemmens | 198 | Prospective | Early (<3 days) vs. Late (≥3 days)* | Diarrhea | aRR: 0.95 (95% CI: 0.70–1.31) | Low |
| 1999 | Cohort | breastfeeding initiation | at 6–12 months | |||
| Hajeebhoy | 6068 | Cross-Sectional | Early (<1 hr) vs. Late (>1 hr)* | Diarrhea | aOR: 0.74 (95% CI:0.58–0.93) | Very low |
| 2014 | breastfeeding initiation | at <6 months | ||||
| ARI | ||||||
| Hajeebhoy | 6068 | Cross-Sectional | Early (<1 hr) vs. Late (>1 hr)* | ARI | aRR: 0.91 (95% CI: 0.80–1.03) | Very low |
| 2014 | breastfeeding initiation | at <6 months | ||||
| Hypothermia | ||||||
| Mullany | 19180 | Prospective | Early (<24 hrs)* vs. Late (>24 hrs) | Prevalence of axillary measures <35.0°C at <28 days | aRR: 1.19 (95% CI: 1.08–1.30) | Moderate |
| 2010 | Cohort | breastfeeding initiation | ||||
| Van den Bosch | 160 | Randomized Trial | Immediate* vs. Mother's choice of breastfeeding initiation time | Rectal temperatue <36.5°C at 2, 4, and ~24 hrs after birth | RR: 2.45 (95% CI: 1.36–4.41) | High |
| 1990 | ||||||
| Umbilical Cord Infection | ||||||
| Mullany | 1653 | Prospective Cohort | Early (<1 hr) vs. Late (≥1 hr)* | 1. Pus with any redness (Broad) | 1. aRR: 0.74 (95% CI: 0.38–1.47) | Moderate |
aRR