The aim of this study is to evaluate the impact of impaired awareness of hypoglycaemia (IAH) on metabolic control and pregnancy outcomes in women with type 1 diabetes. This was a single-centre prospective cohort study of singleton pregnant women with type 1 diabetes. IAH was assessed at the first antenatal visit using Clarke's test (score≥3). Data on metabolic control, hypoglycaemic events, and the lipid profile were collected from prior to pregnancy and in each trimester of gestation. Pregnancy outcomes were also recorded. A total of 77 patients with type 1 diabetes were included; 24 (31.2%) were classified as having IAH. Compared with the normal awareness of hypoglycaemia (NAH) group, the IAH group did not show differences in HbA1c , weight gain, insulin doses, or severe and nonsevere hypoglycaemia events throughout pregnancy. IAH was associated with higher triglyceride concentrations in the second trimester (IAH: 154.8±61.1mg/dL, NAH: 128.6±31.2mg/dL, P=.034) and an increased risk of neonatal respiratory distress (odds ratio [OR] 11.24; 95% CI, 1.01-124.9, P=.041) in adjusted models. Increased risk of pre-eclampsia was related to higher second trimester triglyceride concentrations (OR 1.028; 95% CI, 1.004-1.053, P=.023) adjusted for confounders. The IAH was associated with increased risk of neonatal respiratory distress and pre-eclampsia, despite showing no differences in metabolic control. Hypoglycaemia awareness in the first antenatal visit should be assessed to identify the subgroup of pregnant women with increased risk of complications.