Teenage pregnancy in type 1 diabetes mellitus

Younger maternal age at delivery has been linked to adverse reproductive outcomes. Pregnancy complicated by type 1 diabetes mellitus (T1DM) is also associated with adverse pregnancy outcomes. Optimising diabetic glycaemic control prior to pregnancy is known to reduce the rate of congenital abnormalities and improve pregnancy outcomes. Teenage pregnancies are not usually planned and little data exist on teenage pregnancy complicated by T1DM. We sought to identify the glycemic control achieved in teenage pregnancy with T1DM and to clarify if there is an associated increase in adverse pregnancy outcomes compared to those seen in older women with T1DM. We compared outcomes in 18 teenagers (TG) with 582 older women with T1DM (CON) from 1995-2007. TG booked to the combined diabetes-obstetrical service at a median gestational age of 11 weeks (range 6-22) compared to 7 weeks in CON (range 4-40, p < 0.02). Glycaemic was worse in TG compared to CON at 13, 26 and 35 weeks gestation, despite higher insulin doses. First trimester miscarriage rate did not differ between groups. Major congenital anomaly rate was 6.2% (1/16) compared to 3.2% in CON. This preliminary study has demonstrated that pregnant teenage women with T1DM book later to specialised care and have worse glycaemic control in pregnancy compared to older women with T1DM. This group also appear to be more insulin resistant than older women in early pregnancy. Our data would suggest that teenagers with type 1 diabetes mellitus may constitute a high-risk group for adverse pregnancy outcomes.