In utero malnutrition influences wound healing of newborn rats as measured by tensile strength and collagen deposition

Abstract

BACKGROUND: Studies have investigated the consequences of intrauterine malnutrition on birth weight and overall survival but not on wound healing. This study aims to assess the influence of in utero malnutrition on wound healing of newborn rats. METHODS: Pregnant Wistar rats were divided into 2 groups. Study rats were given 50% of the food intake of controls throughout pregnancy in a pair-fed manner. The body weight and length of the newborns were measured. Newborns were breast-fed until day 21, when a laparotomy was performed. The effect of the laparotomy was assessed by measure of the wound strength and collagen deposition at postoperative day (POD) 7 (n = 15) and POD 21 (n = 15). RESULTS: The body weight and length of newborns of malnourished mothers were significantly smaller at birth compared with controls (respectively, 4.5 +/- 0.1 g vs 5.8 +/- 0.1 g, p = .0003 and 4.6 +/- 0.1 cm vs 5.2 +/- 0.1 cm, p = .0003). Maximum, rupture, and tensile strength of malnourished newborns were smaller than controls on POD 7 (0.281 +/- 0.031 vs 0.470 +/- 0.031, p = .0061, 0.112 +/- 0.06 kgf vs 0.173 +/- 0.08 kgf, p = .0495 and 0.019 +/- 0.002 kgf/mm2 vs 0.024 +/- 0.003 kgf/mm2, p = .050, respectively). On POD 21, only tensile strength remained lower (0.044 +/- 0.003 kgf/mm2 vs 0.058 +/- 0.003 kgf/mm2, p = .0477). Type I collagen deposition of malnourished newborns was similar to controls on POD 7 (57.69 +/- 10.06 vs 48.34 +/- 15.65, p = .3187) and on POD 21 (75.6 +/- 7.21 vs 80.0 +/- 9.92, p = .4212). CONCLUSIONS: In utero malnutrition decreases the abdominal wound strength of newborn rats but not the collagen deposition, suggesting that breast-feeding nutrition is effective in recovering the collagen deposition but not overall wound strength.