OUTCOMES OF PREGNANCY IN INSULIN-DEPENDENT DIABETIC WOMEN - RESULTS OF A 5-YEAR POPULATION COHORT STUDY

Objective: To monitor pregnancies in women with pre-existent insulin d ependent diabetes for pregnancy loss, congenital malformations, and fe tal growth in a geographically defined area of north west England. Des ign: Population cohort study. Setting: 10 maternity units in Cheshire, Lancashire, and Merseyside which had no regional guidelines for the m anagement of pregnancy in diabetic women. Subjects: 462 pregnancies in 355 women with insulin dependent diabetes from the 10 centres over fi ve years (1990-4 inclusive). Main outcome measures: Numbers and rates of miscarriages, stillbirths, and neonatal and postneonatal deaths; pr evalence of congenital malformations; birth weight in relation to gest ational age. Results: Among 462 pregnancies, 351 (76%) resulted in a l iveborn infant, 78 (17%) aborted spontaneously, nine (2%) resulted in stillbirth, and 24 (5%) were terminated. Of the terminations, nine wer e for congenital malformation. The stillbirth rate was 25.0/1000 total births (95% confidence interval 8.9 to 41.1) compared with a populati on rate of 5.0/1000, and infant mortality was 19.9/1000 live births (5 .3 to 34.6) compared with 6.8/1000. The prevalence of congenital malfo rmations was 94.0/1000 live births (63.5 to 124.5) compared with 9.7/1 000 in the general population. When corrected for gestational age, mea n birth weight in the sample was 1.3 standard deviations greater than that of infants of non-diabetic mothers. Infants with congenital malfo rmations weighed less than those without. Conclusion: In an unselected population the infants of women with pre-existent insulin dependent d iabetes mellitus have a 10-fold greater risk of a congenital malformat ion and a fivefold greater risk of being stillborn than infants in the general population. Further improvements in the management of pregnan cy in diabetic women are needed if target of die St Vincent declaratio n of 1989 is to be met.