High sensitivity C-reactive protein (hs-CRP) is a marker of systemic low-grade inflammation and associated with chronic inflammatory diseases. It is unknown whether maternal and infant hs-CRP levels are correlated and little is known about risk factors in early childhood. Hs-CRP were measured in mothers during pregnancy week 24 (N?=?690), and one-week postpartum (N?=?675) and in their children age 6 mo (N?=?640) enrolled in the Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) cohort. The risk factor analysis included anthropometrics, environmental exposures and CRP-Genetic Risk Score (GRS). Mother's body mass index (BMI), use of antibiotics, smoking, cesarean delivery and season were associated with higher maternal hs-CRP level, whereas higher social circumstances were associated with lower hs-CRP level (p?<?0.05). Child's BMI, siblings, bacterial airway colonization, current infection, CRP-genetic risk score and season were associated with higher hs-CRP at age 6 mo (all p?<?0.05). Mother's hs-CRP level in pregnancy week 24 was associated with hs-CRP level in the child at 6 mo: ?-coefficient?=?0.11 [95%?CI: 0.01-0.20], R2?=?0.22, p?=?0.03. The association was unchanged adjusted for all significant risk factors. Systemic low-grade inflammation in pregnant mothers and their offspring is correlated independently of BMI, environmental exposures and genetic risk factors.