Q.32 and Q.33What information and follow-up should be offered to women with gestational diabetes after birth? What information and follow up should be offered to women with type 1 and type 2 diabetes after birth?

These two clinical questions were addressed together.

Comparative studies
Bibliographic InformationStudy Type & Evidence LevelNumber of PatientsPatient CharacteristicsIntervention & ComparisonFollow-up & Outcome MeasuresEffect SizeStudy SummaryReviewer Comments
Kim C;Newton KM;Knopp RH;

2002 Oct

394
Study Type: Systematic review - meta-analysis

Evidence level: 2+
28 studies includedInclusion criteria: GDM and incidence of type 2 diabetes

Country: Various
Epidemiological risk factors for developing type 2 diabetes after having GDMFollow-up period: Various

Outcome Measures:
The included studies report rates of type 2 conversion from 2.6% to 70% over periods from 6-weeks to 28 years. The epidemiological data showed that the incidence of type 2 diabetes increased most rapidly in the first 5 years after pregnancy. The results of fasting glucose levels from oral glucose tolerance test administered during pregnancy were predictive of developing type 2 diabetes after pregnancy. There was no clear pattern for risks factors such as BMI, maternal age, previous history of GDM, family history of diabetes, or parity. The review highlighted that included studied varied in ethnicity, length of follow-up, and criteria for gestational diabetes and type 2 diabetes, which made comparison and generalisation of results difficult.
Tuomilehto et al

2001

405
Study Type: RCT

Evidence level: 1+
522 randomised. 265 to intervention group and 257 to control group.

Country: Finland
Intervention = detailed education and targets for lifestyle change; one-to- one support sessions

control = general information on diet
Follow-up period: Up to 6 years

Outcome Measures: Diabetes status; weight change; plasma glucose change; serum insulin change; serum lipids change; blood pressure change
Diabetes status:
Intervention group = 32 per 1000 person years
Control group = 78 per 1000 person years
Diabetes prevention program research group

2002

404
Study Type: RCT

Evidence level: 1+
3234 randomised. 1082 = placebo, 1073 = metformin, 1079 = lifestyleEntry criteria: Men and women; aged =.25 years; BMI => 24; plasma glucose concentration of 5.3 to 6.9 mmol/l in fasting state; and 7.8 tio 11.0 mmol/l after 2 hour 75 g OGTT

Baseline characteristics (n = 3234):
Female = 67.7%
Family history of diabetes = 69.4%
Age = 50.6
History of GDM = 16.1% of women
BMI = 34.0

Country: USA
Placebo and standard lifestyle recommendations;

metformin and standard lifestyle recommendations;

Intensive lifestyle intervention (24 week programme, including one-to-one counselling)
Follow-up period: Up to 4 years

Outcome Measures: Incidence of diabetes; change in weight; change in physical activity
Incidence of diabetes(per100 person years)
Placebo = 11.0
Metformin = 7.8
Lifestyle = 4.8

all statistically different (P < 0.05)
Gillies CL, Abrahams
KR et al.

2007

407
Study Type: Systematic review - meta-analysis

Evidence level: 1+
21 RCTs met the inclusion criteria out of which 17 trials with 8084 people with impaired glucose tolerance gave enough results for analysisRandomized controlled trials

Country:
Intervention: Interventions to delay or prevent type 2 diabetes in individuals with impaired glucose tolerance.

Comparison:
Follow-up period:

Outcome Measures: Development of type 2 diabetes and related adverse events
Meta-analyses showed: Pooled hazard ratios 0.51, 95% CI 0.44 to 0.60 for lifestyle interventions vs standard advice, 0.70, 95% CI 0.62 to 0.79 for oral diabetes drugs vs control, 0.44, 95% CI 0.28 to 0.69 for orlistat vs control, and 0.32, 95% CI 0.03 to 3.07 for the herbal remedy jiangtang bushen recipe vs standard diabetes advice. These correspond to numbers needed to treat for benefit (NNT) and harm (NNH) of 6.4 for lifestyle (95% credible interval, NNT 5.0 to 8.4), 10.8 for oral diabetes drugs (NNT 8.1 to NNT 15.0), 5.4 for orlistat (NNT 4.1 to NNT 7.6), and 4.0 for jiangtang bushen (NNH 16.9 to NNT 24.8).In people with impaired glucose tolerance lifestyle and pharmacological interventions reduce the rate of progression to type 2 diabetes.
Lifestyle interventions seem to be at least as effective as drug treatment.
No separate analyses for women and men were reported in this study
Diagnostic studies
Bibliographic InformationStudy type & Evidence levelNumber of patients & prevalencePopulation CharacteristicsType of test and Reference standardSensitivity, Specificity, PPV and NPVStudy SummaryReviewer comment
Holt RI;Goddard JR;Clarke P;Coleman MA;
2003 Jul 408
Study type:
Diagnostic
Diagnostic
Evidence level: III
152Women with WHO defined GDM

Country: UK
Fasting plasma glucose test versus 75 g OGTT for identifying diabetesUsing a cut-off for fasting plasma glucose of 6.0 mmol/l, the specificity was 100% and specificity was 94% for identifying those who have diabetes compared to OGTT.
Tan YY;Yeo SH;Liauw PC;
1996 Aug 409
Study type:
Diagnostic
Diagnostic
Evidence level: III
298Women with WHO defined GDM

Country: Singapore
Test: 75 g OGTT testing antenatal versus 75 g OGTT testing postnatal to detect postnatal diabetesThe results showed that at a cut-off of 4.5 mmol/l the sensitivity was 73.9% and specificity was 70.3%.

For a 2-hour OGTT the cut-off was 10.5 mmol/l with a sensitivity of 55.1% and a specificity of 84.7.
Non-comparative studies
Bibliographic InformationStudy Type & Evidence LevelAim of StudyNumber of Patients & Patient CharacteristicsPopulation CharacteristicsOutcome measuresResults & CommentsStudy SummaryReviewer Comment
Aberg AE;Jonsson EK;Eskilsson I;Landin- Olsson M;Frid AH;

2002 Jan

400
Study Type: Other Epidemiological comparative cohorts

Evidence Level: 2+
Examine following risk factors: BMI, weight increase, estimated foetal weight and birth weight, 2 hour OGTT value and HbA1c at diagnosis, use of insulin during pregnancy468, 315 cases, 153 controlsWomen with or without European Association for the Study of Diabetes criteria for classification

Country: Sweden
Incidence of diabetesAt 1 year follow up 50 of 229 (22%) cases and 1 of 60 (1.6%) controls had developed type 2 diabetes (P < 0.001). Further results were that 24 of 90 insulin users against 23 of 132 (17%) non- insulin users had 2 hour OGTT value of 7.8 to 11.0 ml and 18 of 90 (20%) and 3 of 132 (2%) had >11.0 mmo/l, respectively. The study found 2 hour OGTT value and HbA1c st diagnosis were associated with diabetes at 1 year, but BMI, weight increase, estimated foetal weight and birth weight were not associated with developing diabetes. Multiple regression analysis found on OGTT test during pregnancy was predictive.
Jarvela IY;Juutinen J;Koskela P;Hartikainen AL;Kulmala P;Knip M;Tapanainen JS;

2006 Mar

401
Study Type: Other Epidemiological comparative cohorts

Evidence Level: 2+
Examine following risk factors: age, use of insulin treatment, positive ICA, positive GAD Antibodies and being positive for more than one antibody435 with and 435 without GDMWomen with Finnish Diabetes Association classification for GDM

Country: Finland
Incidence of developing diabetesThe study found that 43 of 435 in the case group had developed diabetes (either type 1 or type 2) whereas none of the control group had developed diabetes. Women treated with insulin during pregnancy were more likely (P < 0.0001) than those not. The women in the control group were significantly younger (27.2 versus 34.0, P < 0.001). Regression analysis showed that age, use of insulin treatment, positive ICA, positive GADA and being positive for more than one antibody were all predictive of developing diabetes.
Lauenborg J;Hansen T;Jensen DM;Vestergaard H;Molsted-Pedersen L;Hornnes P;Locht H;Pedersen O;Damm P;

2004 May

395
Study Type: Other Epidemiological cohorts

Evidence Level: 2−
Examine following risk factors: BMI, ethnic origin, pre-existing diabetes481. 330 in new cohort (1987 to 1996). 151 in old cohort (1978 to 1985)Women with WHO defined GDM.

Country: Denmark
Incidence of diabetesThe study found that overall 192 (40.0%) diabetes (type 1 or type 2) and 130 (27.0%) had impaired glucose tolerance/impaired fasting glucose. Comparing the cohorts, 40.9% in the new cohort had diabetes (type 1 or type 2) compared to 18.3% in the old cohort. Multiple regression analysis showed that membership of the new cohort, being overweight pre-pregnancy (BMI => 25 kg/m^2) and IGT postpartum were identified as statistical significant risk factors in developing diabetes (P < 0.05).
Lee CP;Wong HS;Chan FY;Pun TC;To WK;Lam YH;Baldwin S;Wong VCW;

1994

398
Study Type: Other Epidemiological

Evidence Level: 3
Examine following risk factors: Age, BMI, family history of diabetes, baby greater 4 kg193Women with WHO defined GDM

Country: Hong Kong
Incidence of diabetesThe study found that 56 of 193 (29.0%) women with GDM had impaired glucose tolerance (n = 38) or diabetes (n = 18) by 6 years follow-up compared to 8 (5 and 3, respectively) of 58 (13.8%) in women without GDM. The study found that age, BMI, abnormal OGTT at 6 weeks postpartum, diabetes in first degree relative, macrosomia, recurrent GDM and use of oral contraceptives were not predictive of later developing diabetes.
Lobner K;Knopff A;Baumgarten A;Mollenhauer U;Marienfeld S;Garrido- Franco M;Bonifacio E;Ziegler A;

2006

396
Study Type: OtherEpidemiological

Evidence Level: 3
Examine following risk factors: first-degree relative with diabetes, age, duration of pregnancy, birth weight of child and number of previous pregnancies, insulin during pregnancy, BMI >30 and serum CRP at 9 months in 2 to 4th quartiles302Women with ADA defined GDM

Country: Germany
Association between risk factors and incidence of diabetes;The study found that insulin during pregnancy, BMI >30 and serum CRP at 9 months in 2 to 4th quartiles were statistically significant predictors of developing diabetes. The study found that first-degree relative with diabetes, age, duration of pregnancy, birth weight of child and number of previous pregnancies was not predictive of subsequent diabetes. The study recommended that prospective diabetes assessment and intervention should be considered in women with GDM who are autoantibody positive, require insulin treatment during pregnancy or who are obese.
Pettitt DJ;Narayan KM;Hanson RL;Knowler WC;

1996 Nov

402
Study Type: Other Comparative cohort

Evidence Level: 2−
Examine following risk factors: Pregnant or not317Women with impaired glucose tolerance test results

Country: USA
Incidence of diabetesThe study found that 114 of 244 (46%) of non-pregnant women and 17 of 73 (23%) pregnant women within the 10 year follow-up period. Using multiple regression analysis the study found that 2 hour plasma glucose, parity and not being pregnant were all statistically significant risk factors in developing diabetes.
Wein P;Beischer NA;Sheedy MT;

1997 Nov

397
Study Type: Other Epidemiological

Evidence Level: 3
Examine following risk factors: BMI, antenatal GTT results, insulin during pregnancy, severity of GD and ethnic origin, age, macrosomic infants and booking status (private or not)2957Women with WHO defined GDM

Country: New Zealand
Incidence of diabetesThe study found that BMI, antenatal GTT results, insulin during pregnancy, severity of GD and ethnic origin were all predictive of women developing diabetes. However, age, macrosomic infants and booking status (private or not) were not predictive of future diabetes. Multivariate analysis found that severity of GD, Asian origin, 1-hour plasma glucose were predictive of developing diabetes, but tat insulin during pregnancy, BMI and foetal macrosomia were not.
Linne et al

399
Study Type: Other Epidemiological case-control study

Evidence Level: 2−
Examine following risk factors: weight, BMI, fasting blood sugar and HBA1c70. 28 women with GDM and 52 controlsWomen with and without GDM

Country: Sweden
Incidence of diabetes.The study found that 10 of 28 (35%) women with GDM had developed type 2 diabetes but none of 52 controls had developed diabetes (P < 0.001). The study found that weight, BMI, fasting blood sugar and HBA1c (P < 0.05) were all significant predictors of women with GDM developing diabetes compared to women with GDM that did not develop diabetes
Bibliographic InformationStudy Type & Evidence LevelNumber of PatientsPatient CharacteristicsIntervention & ComparisonFollow-up & Outcome MeasuresEffect SizeStudy SummaryReviewer Comments
Smith BJ;Cheung NW;Bauman AE;Zehle K;McLean M;

2005

406
Study Type: Cross- sectional

Evidence level: 3
226Inclusion criteria: Women who had attended diabetes clinics for the treatment of GDM, had given birth 6–24 months earlier and were able to speak English
Exclusion criteria: Women who had given birth within 6 months

Country: Australia
Intervention: Survey by telephone

Comparison:
Follow-up period:

Outcome Measures: Physical activity behaviours, self- efficacy, social support, and barriers to participation.
Mean age of women was 33.4 years. 26.5% were classified as sedentary, and only 33.6% reported sufficient physical activity as recommended by health authorities. Walking was the most popular physical activity, and most women reported no other moderate- or vigorous-intensity activity. Most common barriers to physical activity were lack of assistance with child care (49.1%) and insufficient time (37.6%). The type of social support most often reported was verbal encouragement (39.1%). Self- efficacy for physical activity was lowest when women were under time pressure or tired. Sufficient physical activity was associated with high social support (OR 2.5, 95% CI 1.21– 3.79) and high self-efficacy (OR 2.09, CI 1.06–3.20)There was low prevalence of physical activity and it was strongly related to social support and self-efficacy

From: Evidence tables

Cover of Diabetes in Pregnancy
Diabetes in Pregnancy: Management of Diabetes and Its Complications from Preconception to the Postnatal Period.
NICE Clinical Guidelines, No. 63.
National Collaborating Centre for Women's and Children's Health (UK).
London: RCOG Press; 2008 Mar.
Copyright © 2008, National Collaborating Centre for Women’s and Children’s Health.

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