The clinical management of hyperglycemia in pregnancy complicated by maturity-onset diabetes of the young.
OBJECTIVE
Women with maturity-onset diabetes of the young (MODY) are often first identified and diagnosed with diabetes during pregnancy. Genetics and hyperglycemia play an important role in determining fetal size in MODY pregnancies. The principal objective of the current study is to determine the outcomes and clinical management of hyperglycemia in pregnancies complicated by glucokinase gene (GCK) and hepatocyte nuclear factor (HNF)-1α MODY mutations.


METHODS
A retrospective chart review of 37 women with a GCK/HNF-1α mutation was conducted. Data on variables such as birthweight, mode of delivery, and the treatment of hyperglycemia were available on 89 pregnancies.


RESULTS
The birthweight in unaffected GCK offspring was significantly higher than in the affected GCK offspring (4.8 [4.1-5.2] kg vs 3.2 [3.1-3.7] kg; P = .01). Seven-point home blood glucose monitoring over a 7-day period in each trimester demonstrated higher fasting and postprandial glycemic excursions in the first trimester of GCK pregnancies when compared to HNF-1α pregnancies (fasting 104 [90-115] mg/dL vs 84 [77-88] mg/dL; P = .01 and postprandial 154 [135-196] mg/dL vs 111 [100-131] mg/dL; P = .04) despite insulin treatment. There was a higher percentage of miscarriages in the GCK group when compared to the HNF-1α MODY group (33.3% vs 14%; P = .07), which was similar to the background population. Insulin initiated at an early gestation appeared to lower the incidence of macrosomia in GCK unaffected offspring.


CONCLUSIONS
Hyperglycemia in HNF-1α pregnancies is easily managed with current insulin protocols; in contrast, glycemic excursions are difficult to manage in GCK pregnancies. There was an increased percentage of miscarriages in GCK pregnancies highlighting the importance of a diagnosis of GCK-MODY in women prior to conception and the necessity for preconception care.
Diabetes Day Center, Mater Misericordiae University Hospital, Dublin, Ireland; Rotunda Maternity Hospital, Dublin, Ireland.
Siobhan
S
Bacon
Center for Systems Medicine and Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
Jasmin
J
Schmid
Diabetes Day Center, Mater Misericordiae University Hospital, Dublin, Ireland.
Ailbhe
A
McCarthy
Rotunda Maternity Hospital, Dublin, Ireland.
Jackie
J
Edwards
Rotunda Maternity Hospital, Dublin, Ireland.
Aileen
A
Fleming
Diabetes Day Center, Mater Misericordiae University Hospital, Dublin, Ireland; Coombe Women and Infants University Hospital, Dublin, Ireland.
Brendan
B
Kinsley
National Maternity Hospital, Dublin, Ireland.
Richard
R
Firth
Coombe Women and Infants University Hospital, Dublin, Ireland.
Bridgette
B
Byrne
Diabetes Day Center, Mater Misericordiae University Hospital, Dublin, Ireland; National Maternity Hospital, Dublin, Ireland.
Claire
C
Gavin
Diabetes Day Center, Mater Misericordiae University Hospital, Dublin, Ireland; Rotunda Maternity Hospital, Dublin, Ireland. Electronic address: mbyrne@mater.ie.
Maria M
MM
Byrne
D000022:Abortion, Spontaneous / Q000453:epidemiology; D000293:Adolescent; D015190:Blood Glucose Self-Monitoring; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000235:genetics; D005260:Female; D005941:Glucokinase / Q000235:genetics*; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D011247:Pregnancy; D011254:Pregnancy in Diabetics; D012189:Retrospective Studies; D055815:Young Adult
D051538:Hepatocyte Nuclear Factor 1-alpha; D007004:Hypoglycemic Agents; D007328:Insulin; D005941:Glucokinase
glucokinase gene mutation; hepatocyte nuclear factor-1α; maturity-onset diabetes of the young; pregnancy