Introduction
Pregnancy in women with type 1 diabetes mellitus (T1DM) is associated with increased maternal and neonatal morbidity and mortality.1–6 In order to minimize risks to both mothers and infants, good interdisciplinary care is required between diabetologists, obstetricians, neonatologists, nursing and allied health professional specialists. Women with T1DM in pregnancy in Ireland are cared for according to ‘Adult Type 1 Diabetes Mellitus National Clinical Guideline No. 17’7 which contextualizes the NICE 2015 Diabetes in Pregnancy Guideline8 for the Irish context. Patients with T1DM in pregnancy should be cared for in a joint diabetes and antenatal clinic and should have contact every 1–2 weeks for assessment of blood glucose control throughout pregnancy.7 8
The largest Irish study to date of women with T1DM was a retrospective cohort study of pregnancies delivered in the three tertiary level maternity units in Dublin in 2006.9 This study of 25 847 pregnancies found 80 (0.31%) women had either T1DM or cystic fibrosis-related diabetes (CFRD). The severity/complexity of their T1DM/CFRD when graded according to White’s Classification10 showed n=58 (72.5%) women were class B or C (<10 years of T1DM or 10–19 years T1DM with no retinopathy or nephropathy); 14 women (17.5%) were class D (>20 years with no retinopathy or nephropathy), 6 women were class R (presence of diabetic retinopathy), 1 woman was class F (diabetic nephropathy) and 1 woman had diabetes mellitus secondary to cystic fibrosis.
The largest prospective study to date on pregnancy outcomes in T1DM is a multicenter study which took place across eight Danish centers from 1993 to 1999.4 This study of 990 women with 1218 pregnancies showed a relative risk (RR) of 4.1 (95% CI 2.9 to 5.6) for perinatal mortality, RR 4.7 (95% CI 3.2 to 7.0) for stillbirth and RR 1.7 (95% CI 1.3 to 2.2) for congenital malformation, as compared with the general population.4
The primary aim of our study was to define maternal, perinatal and neonatal outcomes of pregnancies in women with onset of T1DM <18 years age in Ireland, attending a university affiliated maternity and neonatal service. A secondary aim was to describe modifiable risk factors for adverse outcomes which might be used as a basis for quality improvement locally.