HbA1c was measured monthly during pregnancy by
HPLC (Diamat; Bio-Rad Laboratories, Hercules, CA,
USA). The normal range was defined as a HbA1c between
4.0 and 6.0%. The first HbA1c
assessment during pregnancy was carried out between the 7th and 14th week of
gestation. The mid-pregnancy value was obtained between
the 20th and 25th week, and the third measurement
approximately 2 weeks before delivery. The average HbA1c
value of each trimester was used in the analysis.