Characteristics of the study samples of women with GDM with (CRONOS) and without (GestDiab) SARS-CoV-2 infection
| Characteristic | n | Cohort with SARS-CoV-2 n=409 | Cohort without SARS-CoV-2 n=4598 | P value |
| Maternal basic data and outcomes | ||||
| Maternal age (years) | 409/4598 | 32 (28; 36) | 33 (29; 36) | 0.001 |
| Maternal BMI (kg/m2) | 28.0 (24.2; 33.1) | 27.0 (23.3; 32.0) | 0.006 | |
| Week of gestation of gestational diabetes mellitus diagnosis | 26 (24; 28) | 26 (25; 28) | 0.152 | |
| Insulin therapy, n (%) | 148 (36.2) | 1474 (32.1) | 0.087 | |
| BMI categories according to WHO, n (%) | ||||
| Underweight (<18.5 kg/m²) | 409/4598 | 8 (1.96) | 65 (1.4) | 0.007 |
| Normal weight (18.5–24.9 kg/m²) | 111 (27.1) | 1659 (36.1) | ||
| Preobesity (25.0–29.9 kg/m²) | 131 (32.0) | 1322 (28.8) | ||
| Obesity class I (30.0–34.9 kg/m²) | 89 (21.8) | 852 (18.5) | ||
| Obesity class II (35.0–39.9 kg/m²) | 37 (9.1) | 430 (9.4) | ||
| Obesity class III (≥40 kg/m²) | 33 (8.1) | 270 (5.9) | ||
| Obesity class I, II, III | 159 (38.9) | 1553 (33.8) | 0.037 | |
| Diagnostic venous plasma glucose during OGTT | ||||
| Fasting (mmol/L)† | 5.4±0.5 | 5.3±0.5 | 0.0001 | |
| After 1 hour (mmol/L)† | 9.5±1.7 | 9.6±1.8 | 0.664 | |
| After 2 hours (mmol/L)† | 7.5±1.5 | 7.5±1.5 | 0.778 | |
| Only at fasting, n (%) | 177 (43.3) | 1844 (40.1) | 0.210 | |
| At all 3 time points, n (%) | 45 (11) | 466 (10.1) | 0.579 | |
| Cesarean delivery, n (%) | 408/4390 | 173 (42.4) | 1554 (35.4) | 0.005 |
| Neonatal outcomes | ||||
| Combined (NICU admission, neonatal death, stillbirth), n (%) | 401/3929 | 63 (15.7) | 431 (11.0) | 0.004 |
| Preterm birth <34+0 weeks of pregnancy, n (%) | 409/4598 | 15 (3.7) | 78 (1.7) | 0.005 |
| Preterm birth <37+0 weeks of pregnancy, n (%) | 409/4598 | 43 (10.5) | 342 (7.4) | 0.025 |
| Large for gestational age, n (%) | 368/4395 | 48 (13.0) | 611 (13.9) | 0.647 |
| Small for gestational age, n (%) | 28 (7.6) | 343 (7.8) | 0.893 | |
| Birth weight <2500 g, n (%) | 404/4509 | 31 (7.7) | 200 (4.4) | 0.003 |
| Birth weight >4000 g, n (%) | 53 (13.1) | 543 (12.0) | 0.526 | |
| Birth weight >4500 g, n (%) | 404/4509 | 8 (2.0) | 70 (1.6) | 0.510 |
| Apgar 5 <7, n (%) | 403/2813 | 18 (4.5) | 37 (1.3) | 0.0001 |
| Umbilical arterial cord pH <7.1, n (%) | 398/2573 | 22 (5.5) | 89 (3.5) | 0.043 |
| NICU admission, n (%) | 399/4177 | 58 (14.5) | 423 (10.1) | 0.006 |
| Stillbirth, n (%) | 406/4525 | 5 (1.2) | 8 (0.2) | 0.003 |
| Neonatal death, n (%) | 401/4189 | 2 (0.5) | 0 (0) | 0.008 |
Data are presented as number/total number (percentage) or mean±SD, unless otherwise specified.
P values <0.05 are for comparison between the CRONOS and GestDiab registry based on the χ2 test or Fisher’s exact test (categorical variables) or Student’s t-test (continuous normally distributed variables) or Mann-Whitney U test for normally distributed continuous variables or for continuous non-normally distributed variables, respectively.
The bold p-values indicate statistical significance.
*Median and IQR.
†To convert to mg/dL multiply mmol/L with 18.02.
BMI, body mass index; CRONOS, COVID-19-Related Obstetric and Neonatal Outcome Study; GDM, gestational diabetes mellitus; NICU, neonatal intensive care unit; OGTT, oral glucose tolerance test.