Monitoring daily insulin needs--an important follow-up parameter in late pregnancy in diabetic mothers?

Abstract

Pregnancy is a state of natural insulin resistance, which is due to placental production of human placental lactogen (HPL), an insulin antagonising hormone, leading to a remarkable increase of insulin requirement in pregnant diabetics in the 2nd and 3rd trimester. Aim of the prospective study was the quantification of daily insulin requirement during the last 28 days before delivery in pregnant women suffering from insulin-dependent diabetes mellitus (n = 20) with and without evidence of "placental insufficiency syndrome" employing peripheral rheography as indirect parameter for placental haemoperfusion. All diabetic women included controlled carbohydrate metabolism by means of a functional insulin therapy (FIT; HbA1c in normal range < 5.8%), a multiple injection regime with frequent blood glucose self-control at least from the 2nd trimester of pregnancy. According to the results of peripheral rheography in the 34th gestational week, an impedanceplethysmographic method for quantifying peripheral haemoperfusion, patients were subdivided in a group with (B: n = 8) and without (A: n = 12) indirect evidence of placental dysfunction. Groups did not differ in maternal age, duration of diabetes, maternal weight and week of delivery (A: 39.08 +/- 1.44; B: 39.12 +/- 1.46). Mean weight of neonates was lower in group B (3319 +/- 619 g) compared to group A (3613 +/- 437 g). During a comparable state of near-normoglycaemia in both groups, 7 out of 8 women in group B, but only 1 out of 12 women in group A displayed a significant decrease in daily insulin requirement from day -28 to day -3 before delivery (linear regression; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)