Table 1. Participants’ characteristics obtained before, during, and after pregnancy, categorized according to tertiles of neck circumference.
| First tertile (NC ≤ 33.3 cm) | Second tertile (NC 33.4-36.3 cm) | Third tertile (NC ≥ 36.4 cm) | P values | |
|---|---|---|---|---|
| Pregestational data | ||||
| Age (years) | 29.0 ± 6.8 | 31.9 ± 6.6 | 31.0 ± 6.1 | 0.206 |
| White ethnicity – n (%) | 15 (45.5) | 11 (32.4) | 18 (54.5) | 0.184 |
| High education level – n (%) | 11 (33.3) | 6 (17.6) | 9 (37.3) | 0.336 |
| Family history of DM – n (%) | 8 (25.0) | 16 (47.1) | 10 (30.3) | 0.141 |
| Physically active – n (%) | 14 (42.4) | 14 (41.2) | 14 (42.4) | 0.993 |
| Weight (kg) | 70.7 ± 8.6 | 74.0 ± 9.6 | 85.9 ± 10.9ab | <0.001 |
| BMI (kg/m²) | 27.6 ± 2.8 | 28.6 ± 3.0a | 32.7 ± 3.8ab | <0.001 |
| Number of pregnancies – n (%) | 8 (24.2) | 14 (41.2) | 15 (45.5) | 0.168 |
| Gestational data | ||||
| First and second trimesters | ||||
| Weight (kg) | 73.0 ± 9.8 | 78.2 ± 9.8 | 91.5 ± 10.3a,b | <0.001 |
| Systolic blood pressure (mmHg) | 108.7 ± 12.6 | 111.5 ± 11.3 | 114.7 ± 11.3 | 0.194 |
| Diastolic blood pressure (mmHg) | 67.4 ± 10.2 | 67.8 ± 9.6 | 71.4 ± 10.3 | 0.307 |
| Third trimester | ||||
| Weight (kg) | 77.7 ± 8.4 | 82.0 ± 10.0 | 92.0 ± 11.5ab | <0.001 |
| Systolic blood pressure (mmHg) | 108.4 ± 11.1 | 113.0 ± 10.3 | 119.8 ± 11.7a | <0.001 |
| Diastolic blood pressure (mmHg) | 66.2 ± 8.3 | 71.9 ± 9.5 | 74.9 ± 11.0a | 0.002 |
| Gestational weight gain (kg) | 9.6 ± 6.1 | 10.5 ± 5.6 | 9.5 ± 6.3 | 0.774 |
| Gestational age of delivery (weeks) | 38.6 ± 1.6 | 38.8 ± 1.1 | 38.4 ± 1.1 | 0.508 |
| Birth weight (kg) | 3.2 ± 0.6 | 3.2 ± 0.4 | 3.3 ± 0.4 | 0.640 |
| Birth weight according to gestational age – n (%) | ||||
| Small for gestational age | 3 (9.1) | 1 (3) | 3 (0.4) | 0.306 |
| Adequate for gestational age | 25 (75.8) | 28 (84.8) | 20 (62.5) | |
| Large for gestational age | 5 (12.2) | 4 (12.1) | 9 (28.1) | |
| GDM – n (%) | 9 (27.3) | 18 (52.9) | 23 (69.7) | 0.002 |
| Insulin use during pregnancy – n (%) | 4 (12.1) | 9 (27.3) | 16 (50) | 0.003 |
| Postpartum data | ||||
| Physically active – n (%) | 0 (0.0) | 2 (5.9) | 6 (6.3) | 0.352 |
| Weight (kg) | 71.4 ± 9.3 | 75.3 ± 11.6 | 85.6 ± 11.5a,b | <0.001 |
| BMI (kg/m²) | 27.4 ± 3.1 | 29.4 ± 3.7 | 32.1 ± 3.6a,b | <0.001 |
| Neck circumference (cm) | 33.16 ± 1.32 | 34.8 ± 2.0a | 37.4 ± 2.6a,b | <0.001 |
| Systolic blood pressure (mmHg) | 110.6 ± 9.6 | 117.2 ± 8.7a | 115.50 ± 9.50 | 0.013 |
| Diastolic blood pressure (mmHg) | 70.7 ± 6.9 | 75.4 ± 7.5a | 74.5 ± 5.9 | 0.016 |
| Total cholesterol (mg/dL) | 194.7 ± 38.2 | 190.5 ± 49.5 | 194.4 ± 40.0 | 0.904 |
| LDL cholesterol (mg/dL) | 116.6 ± 34.3 | 113.1 ± 43.0 | 117.4 ± 35.2 | 0.887 |
| HDL cholesterol (mg/dL) | 56.5 ± 12.0 | 56.2 ± 9.1 | 52.2 ± 12.0 | 0.230 |
| Triglycerides (mg/dL) | 109.4 ± 68.6 | 93.5 ± 47.8 | 124.0 ± 43.1b | 0.018 |
| Fasting plasma glucose (mg/dL) | 90.6 ± 8.6 | 90.2 ± 10.2 | 95.3 ± 14.1 | 0.131 |
| 2-hour plasma glucose (mg/dL) | 105.8 ± 34.8 | 99.6 ± 19.6 | 119.8 ± 42.0 | 0.050 |
| HbA1c (%) | 5.3 ± 0.2 | 5.4 ± 0.3 | 5.6 ± 0.4a, b | 0.006 |
| Fasting insulin (µIU/mL) | 9.5 ± 4.9 | 11.1 ± 5.8 | 13.2 ± 6.6a | 0.041 |
| 2-hour insulin (µIU/mL) | 42.4 ± 39.7 | 44.4 ± 29.0 | 57.2 ± 39.6 | 0.230 |
| HOMA-IR | 2.1 ± 1.2 | 2.5 ± 1.3 | 3.1 ± 1.7a | 0.035 |
| TyG index | 4.5 ± 0.3 | 4.5 ± 0.2 | 4.6 ± 0.2b | 0.010 |
| Prediabetes – n (%) | 7 (23.3) | 7 (21.2) | 9 (28.1) | 0.802 |
The values are shown as mean ± standard deviations or n (%). Analysis of variance (ANOVA) was used for continuous variables, and the chi-square test was used for categorical variables. Variables without normal distribution were log transformed. Bonferroni correction was applied if p < 0.05.
,versus first tertile.
,versus second tertile. A high education level was defined by at least 14 years of schooling. Physical activity levels were deemed to be of moderate intensity when lasting ≥ 75 minutes/week and high intensity when lasting ≥ 150 minutes/week. Abbreviations: BMI, body mass index; DM, diabetes mellitus; GDM, gestational diabetes; HbA1c, glycated hemoglobin; HDL, high-density lipoprotein; HOMA-IR, homeostatic model of insulin resistance; LDL, low-density lipoprotein; NC, neck circumference; TyG index, triglyceride-glucose index. The HOMA-IR index was calculated using the formula (fasting insulin in µIU/mL x fasting glucose in mmol/L) / 22.5 and the TyG index was calculated as log (fasting triglycerides in mg/dL X fasting glucose in mg/dL) / 2.