Table 1.
Baseline characteristics of participants according to pregnancy status
|
Pregnant |
Planning pregnancy |
||||
|---|---|---|---|---|---|
| CGM (n=108)* | Control (n=107) | CGM (n=53) | Control (n=57) | ||
| Age (years) | 31·4 (4·5) | 31·5 (4·9) | 33·5 (3·5) | 32·4 (3·6) | |
| European origin | 94 (87%) | 90 (84%) | 44 (83%) | 51 (89%) | |
| Gestational age (weeks) | 10·5 (2·2) | 11·0 (2·0) | ·· | ·· | |
| Primiparous | 44/107 (41%) | 40 (37%) | ·· | ·· | |
| Body-mass index (kg/m2)† | 26·1 (5·1) | 25·3 (3·8) | 26·4 (4·2) | 26·6 (4·9) | |
| Normal (<25 kg/m2) | 53/107 (50%) | 56 (52%) | 23 (43%) | 23 (40%) | |
| Overweight (25–30 kg/m2) | 33/107 (31%) | 38 (36%) | 23 (43%) | 21 (37%) | |
| Obese (≥30 kg/m2) | 21/107 (20%) | 13 (12%) | 7 (13%) | 12 (21%) | |
| Duration of diabetes (years) | 17·0 (6·0–28·0) | 16·0 (6·6–26·4) | 18·0 (6·2–30·0) | 19·0 (9·0–28·0) | |
| HbA1c at enrolment‡ | |||||
| Percentage | 7·43 (0·70) | 7·37 (0·77) | 7·91 (0·69) | 7·85 (0·67) | |
| mmol/mol | 58 (7·3) | 57 (8·4) | 63 (7·5) | 62 (7·3) | |
| HbA1c at randomisation§ | |||||
| Percentage | 6·83 (0·67) | 6·95 (0·66) | 7·57% (0·77) | 7·57 (0·58) | |
| mmol/mol | 51 (7·3) | 52 (7·2) | 59 (8·4) | 59 (6·3) | |
| Smoking | 13/107 (12%) | 23 (21%) | 3 (6%) | 6 (11%) | |
| Post-secondary education | 88 (81%) | 77 (72%) | 46 (87%) | 47 (82%) | |
| Pre-conception folic acid | 54/107 (50%) | 55 (51%) | 29 (55%) | 27 (47%) | |
| Pre-conception multivitamin | 35/107 (33%) | 26 (24%) | 18 (34%) | 19 (33%) | |
| Insulin pump | 50 (46%) | 48 (45%) | 39 (74%) | 42 (74%) | |
| Automated insulin delivery option¶ | 19/103 (18%) | 6/104 (6%) | 6/52 (11%) | 1 (2%) | |
| Insulin injections | 58 (54%) | 59 (55%) | 14 (26%) | 15 (26%) | |
| Total insulin dose (U/kg per day) | 0·69 (0·25) | 0·76 (0·31) | 0·61 (0·19) | 0·61 (0·16) | |
| Diabetes complications|| | 27 (25%) | 30 (28%) | 18 (34%) | 23 (40%) | |
| Retinopathy | 22 | 29 | 16 | 19 | |
| Nephropathy | 6 | 2 | 3 | 3 | |
| Neuropathy | 3 | 4 | 2 | 4 | |
| Hypertension | 4 (4%) | 10 (9%) | 11 (21%) | 7 (12%) | |
| Systolic blood pressure (mm Hg) | 116·0 (14·0) | 116·0 (13·6) | 118·8 (13·8) | 116·2 (12·0) | |
| Diastolic blood pressure (mm Hg) | 69·1 (8·8) | 70·0 (8·6) | 73·7 (8·4) | 71·7 (8·1) | |
| Severe hypoglycaemia in past year** | 13/107 (12%) | 7 (7%) | 3 (6%) | 7 (12%) | |
| Severe hypoglycaemia during early pregnancy (pre-randomisation) | 7/107 (7%) | 4 (4%) | ·· | ·· | |
| Hypoglycaemia awareness symptoms | |||||
| Always aware | 74/107 (69%) | 76 (71%) | 42 (79) | 48 (84%) | |
| Sometimes | 30/107 (28%) | 28 (26%) | 10 (19%) | 8 (14%) | |
| Never aware | 3/107 (3%) | 3 (3%) | 1 (2%) | 1 (2%) | |
Data are mean (SD), n (%), or n/N (%) where data are missing, except for duration of diabetes, which is median (tenth to 90th percentile). Data were collected at enrolment or randomisation (2 weeks after enrolment). CGM=continuous glucose monitoring. HbA1c= glycated haemoglobin.
One CGM participant withdrew immediately after randomisation and before baseline assessments, leaving 107 in both planning-pregnancy groups.
One underweight control participant (body-mass index <18·5 kg/m2) was planning pregnancy.
Locally assessed.
Centrally assessed. Randomisation HbA1c levels were unavailable for nine CGM participants (six lost or not collected, two withdrawals, and one pregnancy loss) and 11 control participants (nine lost or not collected, one withdrawal, and one pregnancy loss) in early pregnancy and for seven CGM participants (four lost or not collected, two withdrawals, and one pregnant) and five control participants (five lost or not collected) planning pregnancy. All participants had HbA1c levels (local lab) at enrolment.
25 pregnant participants and seven participants planning pregnancy used pumps with low glucose suspend features. Data regarding the use or frequency of insulin suspension is not available.
Diabetes complications are not mutually exclusive.
Severe hypoglycaemia was defined as an episode requiring third-party assistance.