Fetal growth in women managed with insulin pump therapy compared to conventional insulin.
OBJECTIVE
Fetal hyperinsulinaemia secondary to maternal hyperglycaemia is considered to be the driving force behind excessive fetal growth. We hypothesised that insulin pump therapy (continuous subcutaneous insulin infusion, CSII) would improve maternal glycaemic control and normalise fetal growth parameters. To this end, this study compares maternal glycaemic control and fetal growth of women receiving insulin pump therapy with those receiving conventional insulin therapy.


METHODS
Prospective non-randomised study of 42 women with pre-existing diabetes attending a joint obstetric diabetic clinic. Each woman was offered the choice of commencing insulin pump therapy or remaining on a conventional insulin regime. Estimated fetal weight and fetal growth velocity were calculated from routinely collected third trimester ultrasound biometry and expressed as standard deviation (Z) scores.


RESULTS
Eighteen women commenced insulin pump therapy. There was no difference in pre-conception glycosylated haemoglobin A1c concentrations (HbA1c) between pump and conventional therapy groups (mean HbA1c 7.62 versus 8.01; p=0.49) or third trimester glycaemic control (mean HbA1c 6.63 versus 6.44; p=0.51). Women using pump therapy had similar mean growth velocity Z scores (1.5 versus 1.36; p=0.83), similar mean estimated fetal weight Z scores prior to delivery (2.80 versus 2.16; p=0.16) and similar mean birthweight Z scores (2.09 versus 2.00; p=0.86) compared to women using conventional insulin therapy.


CONCLUSIONS
This small, non-randomised study suggests that the use of insulin pump therapy offers no benefit in terms of normalising fetal growth velocity, fetal size, birthweight or improving maternal glycaemic control compared to conventional insulin therapy.
Kernaghan
Dawn
D
The Princess Royal Maternity Hospital, 16 Alexandra Parade, Glasgow, G31 2ER, UK. dawn.kernaghan@btinternet.com
Farrell
Tom
T
Hammond
Peter
P
Owen
Philip
P
D000328:Adult; D001724:Birth Weight / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D005260:Female; D047109:Fetal Development / Q000187:drug effects / Q000502:physiology*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D007279:Injections, Subcutaneous; D007328:Insulin / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D007332:Insulin Infusion Systems; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood / Q000188:drug therapy*; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin