Table 1—

Study and participant characteristics and methods used to measure GHb

Study and participant characteristics
GHb
Year (reference)DesignStudy setting; periodNo. with type 1/type 2 diabetesMean ± SD maternal age (years)Definition of periconception periodAssay usedGHb measureMean ± SD for nondiabetic, nonpregnant control subjects (%)
1987 (6)Prospective cohortSingle U.S. medical center; 1979–198463/2025.6 ± NA<15 weeks’ gestationSpectrophotmetric absorptionA1C5.1 ± 1.1
1988 (7)Prospective cohortU.S. university; 1978–1986134/025.0 ± NARecruited during first trimester of pregnancy1978–1980: high-performance liquid chromatography; 1981–1986: column chromatographyHbA1NA*
1989 (8,9)Prospective cohortLarge U.S. diabetes center; 1984–1992599/029.1 ± NA≤12 weeks’ gestationElectrophoresisA1C5.9 ± 0.57
1989 (13)Prospective cohortSingle U.S. hospital; 1980–198587/0NA<16 weeks’ gestationIon exchange chromatographyHbA1a + b+c6.0 ± 1.0
2000 (14)Prospective cohortFinnish university hospital; 1988–1997663/0NA5–10 weeks’ gestationHigh-performance liquid chromatographyA1C4.9 (0.32)
1991 (15)Prospective cohortCalifornia, U.S. database; 1982–198884/029.7 ± 4.4Participation prior to conceptionHigh-pressure column chromatographyA1C6.2 ± 0.7
1988 (16)Prospective cohortU.S.327/027.8 ± 4.0Before conception and up to 21 days after conceptionThiobarbituric acid colorimetric methodNANA
  • *

    * Not provided, but the number of SD was given in paper.

  • SD estimated from the reported range of values.