Poor pregnancy outcome in women with type 1 diabetes is predicted by elevated HbA_1c and spikes of high glucose values in the third trimester

Figures & data

Table 1. Predictors of poor outcome in late pregnancy given a successful outcome in early pregnancy.

Predictor	Successful outcome (n = 181)	Poor outcome (n = 78)	Odds ratio (CI), model 1	p Value, model 1	p Value, model 2
Base model
BMI (mean, SD), kg/m^2	24.7 (3.9)	24.7 (3.5)	0.99 (0.92,1.07)	0.765	0.707
Age (mean, SD), years	28.9 (4.7)	29.1 (4.8)	1.01 (0.95,1.08)	0.791	0.842
Smoker, yes	13 (7%)	8 (10%)	1.66 (0.64,4.30)	0.297	0.724
Duration of diabetes (mean, SD), years	11.8 (6.9)	12.5 (8.5)	1.01 (0.97,1.06)	0.525	0.830
Parity
0	84 (46%)	42 (54%)	0.72 (0.41,1.24)	0.236	0.252
1 or more	97 (54%)	36 (46%)
Predictors
Systolic BP (mean, SD), mmHg	114.0 (10.0)	114.0 (12.0)	1.00 (0.98,1.03)	0.720	NA
Diastolic BP (mean, SD), mmHg	70.2 (8.7)	69.8 (8.4)	1.00 (0.97,1.03)	0.884	NA
Insulin analogue treatment, yes	97 (54%)	35 (45%)	0.69 (0.40,1.19)	0.184	NA
Presence of albuminuria, yes	6 (3%)	9 (12%)	4.11 (1.36,12.43)	0.012	0.007
Presence of retinopathy, yes	18 (10%)	8 (10%)	0.99 (0.40,2.47)	0.990	NA
PG > 11 mmol/L [>198 mg/dL], yes	34 (19%)	26 (34%)	2.12 (1.14,3.92)	0.017	0.092
PG outside range (mean, SD), %	44.5 (23)	51.6 (23)	1.01 (1.00,1.02)	0.045	NA
HbA1c (mean, SD), %	6.0 (0.6)	6.2 (0.7)	1.68 (1.08,2.61)	0.022	0.058

Statistics are mean (standard deviation [SD]) for continuous predictors and frequency (percentage) for categorical predictors. All values apart from plasma glucose (PG) > 11 mmol/L (>198 mg/dL), %PG in range and HbA_1c (%) are taken from baseline or screening for subjects pregnant at randomisation and from start of pregnancy visit for subjects not pregnant at randomisation.

%PG outside of range indicates those PG values falling below 3.9 mmol/L (70 mg/dL) or above 7.0 mmol/L (126 mg/dL). PG and HbA_1c values were taken from the third-trimester study visit. If the third-trimester study visit value was missing, the second-trimester study visit value was used.

p Value model 1: logistic regression adjusting for BMI, age, smoking, duration of diabetes and parity.

p Value model 2: model 1 + predictors with a p value from model 1 < 10%.

BP, blood pressure; CI, confidence interval; NA, not included in model.

Table 2. Predictors of preterm delivery in late pregnancy.

Predictor	Delivery at term (n = 194)	Preterm delivery (n = 63)	Odds ratio (CI) model 1	p Value model 1	p Value model 2
Base model
BMI (mean, SD), kg/m^2	24.7 (3.8)	24.7 (3.7)	0.99 (0.91,1.07)	0.748	0.774
Age (mean, SD), years	28.8 (4.6)	29.3 (4.9)	1.02 (0.95,1.09)	0.620	0.670
Smoker, yes	13 (7%)	8 (13%)	2.35 (0.89,6.18)	0.083	0.328
Duration of diabetes (mean, SD), years	11.7 (6.9)	12.8 (8.8)	1.02 (0.98,1.07)	0.377	0.646
Parity
0	90 (46%)	34 (54%)	0.69 (0.38,1.24)	0.215	0.284
1 or more	104 (54%)	29 (46%)
Predictors
Systolic BP (mean, SD), mmHg	114.0 (10.0)	113.0 (12.0)	0.99 (0.96,1.02)	0.574	NA
Diastolic BP (mean, SD), mmHg	70.3 (8.6)	69.2 (8.5)	0.99 (0.95,1.02)	0.529	NA
Insulin analogue, yes	103 (53%)	28 (44%)	0.70 (0.39,1.25)	0.224	NA
Presence of albuminuria, yes	8 (4%)	7 (11%)	2.98 (0.99,8.94)	0.051	0.036
Presence of retinopathy, yes	19 (10%)	7 (11%)	1.08 (0.42,2.82)	0.868	NA
PG > 11 mmol/L [>198 mg/dL], yes	38 (20%)	21 (34%)	2.00 (1.04,3.84)	0.038	0.204
%PG outside range (mean, SD)	44.4 (23)	53.4 (23)	1.02 (1.00,1.03)	0.024	NA
HbA1c (mean, SD), %	6.0 (0.6)	6.3 (0.7)	1.75 (1.08,2.82)	0.023	0.045

Statistics are mean (standard deviation [SD]) for continuous predictors and frequency (percentage) for categorical predictors. All values apart from plasma glucose (PG) > 11 mmol/L (>198 mg/dL), %PG in range and HbA_1c (%) are taken from baseline or screening for subjects pregnant at randomisation and from start of pregnancy visit for subjects not pregnant at randomisation.

%PG outside of range indicates those PG values falling below 3.9 mmol/L (70 mg/dL) or above 7.0 mmol/L (126 mg/dL). HbA_1c values were taken from the third trimester study visit. If the third-trimester study visit value was missing, the second-trimester study visit value was used.

p Value model 1: logistic regression adjusting for BMI, age, smoking, duration of diabetes and parity.

p Value model 2: model 1 + predictors with a p value from model 1 < 10%.

CI, confidence interval; NA, not included in model.

Table 3. Predictors of LGA/macrosomia in late pregnancy.

Predictor	No (n = 169)	Yes (n = 88)	Odds ratio (CI) model 1	p Value model 1	p Value model 2
Base model
BMI (mean, SD), kg/m^2	24.8 (3.7)	24.5 (3.8)	0.98 (0.91,1.05)	0.587	0.615
Age (mean, SD), years	28.9 (4.7)	28.9 (4.6)	0.99 (0.93,1.05)	0.687	0.496
Smoker, yes	16 (9%)	5 (6%)	0.55 (0.19,1.60)	0.274	0.392
Duration of diabetes (mean, SD), years	12.1 (7.1)	11.8 (8.1)	1.00 (0.96,1.04)	0.993	0.756
Parity
0	87 (51%)	37 (42%)	1.55 (0.90,2.65)	0.113	0.099
1 or more	82 (49%)	51 (58%)
Predictors
Systolic BP (mean, SD), mmHg	114.0 (10.0)	113.0 (12.0)	0.99 (0.97,1.02)	0.530	NA
Diastolic BP (mean, SD), mmHg	70.4 (8.7)	69.3 (8.2)	0.98 (0.95,1.01)	0.282	NA
Insulin analogue, yes	91 (54%)	40 (45%)	0.72 (0.42,1.21)	0.216	NA
Presence of albuminuria, yes	12 (7%)	3 (3%)	0.48 (0.13,1.80)	0.278	NA
Presence of retinopathy, yes	19 (11%)	7 (8%)	0.63 (0.25,1.62)	0.341	NA
PG > 11 mmol/L [>198 mg/dL], yes	29 (17%)	30 (35%)	2.72 (1.47,5.06)	0.002	0.027
%PG outside range (mean, SD)	43.9 (23)	51.9 (23)	1.02 (1.01,1.03)	0.004	NA
HbA1c (mean, SD), %	6.0 (0.6)	6.3 (0.6)	2.73 (1.72,4.33)	0.000	0.001

Statistics are mean (standard deviation [SD]) for continuous predictors and frequency (percentage) for categorical predictors. All values apart from plasma glucose (PG) > 11 mmol/L (>198 mg/dL), %PG in range and HbA_1c (%) are taken from baseline or screening for subjects pregnant at randomisation and from start of pregnancy visit for subjects not pregnant at randomisation.

%PG outside of range indicates those plasma glucose values falling below 3.9 mmol/L (70 mg/dL) or above 7.0 mmol/L (126 mg/dL). PG and HbA_1c values were taken from the third-trimester study visit. If the third-trimester study visit value was missing, the second-trimester study visit value was used.

p Value model 1: logistic regression adjusting for BMI, age, smoking, duration of diabetes and parity.

p Value model 2: model 1 + predictors with a p value from model 1 < 10%.

CI, confidence interval; NA, not included in model.