Nutrition education and counselling (NEC) is a commonly applied strategy to improve maternal nutrition during pregnancy. However, with the exception special populations and specific diets, the effect of NEC on maternal, neonatal and child health outcomes has not been systematically reviewed. Using a modified Child Health Epidemiology Reference Group method we systematically reviewed the literature and identified and abstracted 37 articles. We conducted meta-analyses for the effect of NEC on maternal, neonatal and infant health outcomes including gestational weight gain, maternal anaemia, birthweight, low birthweight and preterm delivery. NEC significantly improved gestational weight gain by 0.45 kg, reduced the risk of anaemia in late pregnancy by 30%, increased birthweight by 105 g and lowered the risk of preterm delivery by 19%. The effect of NEC on risk of low birthweight was not significant. The effect of NEC was greater when provided with nutrition support, for example, food or micronutrient supplements or nutrition safety nets. The overall quality of the body of evidence was deemed low for all outcomes due to high heterogeneity, poor study designs and other biases. Additional well-designed research that is grounded in appropriate theories of behaviour change is needed to improve confidence in the effect of NEC. Further, cost-effectiveness research is needed to clarify the added benefit and sustainability of providing NEC with nutritional support and/or safety nets, especially in areas where food insecurity and gender bias may limit women's capacity to adhere to NEC messages.