Characteristics of the Patients
From 1 January 2016 to 31 December 2018, a total of 642 pregnant women were identified with gestational diabetes mellitus (GDM) at King Abdulaziz Medical City and used as study samples for this particular study. More than half of the patients (65.8%) were below 35 years old and only 34.2% were above age 35. Almost all of these patients (98.8%) were Saudi nationals and the remaining participants (1.2%) were non-Saudi nationals (Table 1).
Out of the 642 pregnant women with GDM, only 32.9% have reported comorbidity. The most commonly observed comorbidity among the pregnant women were hypothyroidism (36), CVD (7), asthma (7), depression (5), BA (3), HTN (3), APAS (3), epilepsy (3), seizure (2), Hodgkin lymphoma (2). Aside from this, comorbidity such as PCOS, autoimmune hepatitis, dyslipidemia, hyperthyroidism, nephrectomy, post thyroidectomy, SCA, single kidney and thyrotoxicosis were observed (Table 2).
Family History and Sugar Scores of Patients
To check if the patients had inherited condition of diabetes, the family history on DM, GDM and other disease were investigated. As shown on Table 3 below, out of the 642 patients, a total of 214 had family history of DM while 211 had indicated none. However, there were 217 patients that have missing information on their family history of this disease. No history of GDM was observed to 424 patients and 218 had missing information on the records that was investigated. Other diseases/disorders such as HTN, hydrocephaly, sickle cell disease and thromboembolic disorder were also reported in the records of 96 patients that were investigated. Among the 96, majority had HTN (92), two (2) had sickle cell disease, and both hydrocephaly and thromboembolic disorder had one (1).
Sugar score of patients was also checked on the medical files retrieved. Records revealed that oral glucose tolerance test (OGTT) was done for diagnosing both GDM and Type 2 diabetes. OGTT in diagnosing GDM was done in various timing. At 0 hour, there were 546 patients that had the test with mean sugar score of 5.11 (SD 0.8 min 3.60 max 12.40). The highest sugar score mean was observed at 1 hour and 2 hours after consuming glucose which was 11.16 (SD 1.4 min 6.60 max 18.50) and 10.50 (SD 3.9 min 3.10 max 17.10), respectively. A total of 545 patients had the test 1 hour while 544 had it after 2 hours of glucose consumption. After 3 hours of glucose consumption, there were 542 patients that had the test this way and have a mean sugar score of 7.95 (SD 1.8 min 3.19 max 17.10). On the other hand OGTT as screening for and diagnosing Type 2 diabetes was done in two different timing (0 hour and 2 hours) and glucose dose (75 g and 100 g). A total of 121 patients had the test at 0 hour with mean sugar score of 5.35 (SD 0.7 min 3.4 max 9.5). After 2 hours period, the mean sugar score of the 123 patients that had this test was 6.82 (SD 2.1 min 3.0 max 16.50) (Table 4).
Screening Predictors and GDM Management
To identify predictors that would be used as basis on who among the patients should be returning for a screening test for type 2 diabetes weight, height, and parity, number of pregnancies with GDM, BMI and mode of delivery were investigated. The patients that was investigated in this study have a mean weight and height of 76.96 kg (SD 16.2, min 37.9 kg max 163 kg) and 2.74 m (SD 13.4, min 0.55 m max 155 m), respectively. Meanwhile, the mean parity observed was 3.37 (SD 2.1 min 0 max 10).
Out of the 642 patients, a total of 586 had pregnancy with GDM and having a mean of 1.35 (SD 0.7 min 1 max 5). BMI of the patients were categorized into four (4) as normal, underweight, overweight, and obese. Majority of the patients in this study were beyond on their BMI while only 10.9% fall within the normal range. There were 56.9% of the participants who were obese, 31.1% were overweight while the remaining 1.1% were underweight. The mode of delivery for 376 (59.1%) was SVD while the 260 (40.9%) was C/S. However, six (6) patients had no indication of neither SVD or C/S mode of delivery. In terms on the information regarding the type GDM management during pregnancy, majority of the patients (91.4%) were following good lifestyle practices (diet and exercise) while 7.4% of them had administered insulin and only 1.3% had metformin (Table 5).
Prevalence of Postpartum Diabetes and Screening History of Patients
Based on the patients files investigated, out of the 642, 18 (3.9%) patients had developed type 2 diabetes and 116 (25.2%) did not have the disease during the study period covered. However, 386 (70.9%) of the patients had no indication whether they had the disease or not. Also, the records reviewed did not indicate any information (missing) regarding the development of T2DM to the 182 patients.
Additionally, whether the patients had T2DM or none, the data of patients underwent a particular screening for type 2 diabetes was checked. Investigators of this study found that only 128 (20%) was actually screened. The vast majority (511 or 80%) was not screened and 3 had missing information. Among the 128 patients who had screening, more than half (57.6%) reportedly screened less than 6 weeks after giving birth while 42.4% were screened more than 6 weeks after delivery. Only 3 of these patients had missing information again. Interestingly, out of the 511 patients that weren’t screened, 335 (65.6%) had the test ordered but they did not comply and in only 176 (34.4%) the test was not ordered for them by the physician to do the screening (Table 6).
Predictors for the Development of Type 2 Diabetes (T2DM)
In order to identify predictors for development of T2DM, the difference between the patients that had T2DM from those doesn’t have were subjected to statistical analysis against predictors like parity, number of pregnancies with GDM, age, BMI, mode of delivery and screening for T2DM of the patients. For this study, statistical analysis showed that predictors such as parity (p-value 0.043) and mode of delivery (p-value 0.023) are significantly different at <0.05 level of confidence (Table 7). This result reveals further that parity and mode of delivery were correlated to the development of T2DM on the patients being investigated.
Predictors of Screening for Type 2 Diabetes Mellitus (T2DM)
To determine the factors that patients would likely to get involved to screening for T2DM, information on parity, the history of having pregnancies with GDM, age, BMI and mode of delivery were investigated. As shown on Table 8, statistical analysis showed that significant difference was only observed on the mode of delivery with p-value of 0.014 at <0.05 level of confidence (Table 8). Again, this result reveals further that mode of delivery were correlated for patients to get screening for T2DM.
Predictors for the Management of GDM during Pregnancy
To identify the factors that determines the type of management mostly practiced by pregnant patients with GDM, information on the mode of delivery, whether screened for type 2 diabetes or not and if the patients developed T2DM were examined. The statistical analysis conducted showed that again, mode of delivery are significantly different having a p-value of 0.015 at <0.05 level of confidence (Table 9). This also implies that the mode of delivery determines the types of management of GDM during pregnancy.
Mode of Delivery as a Predictor
As mode of delivery was the most frequently identified predictor in this study, a closer examination of its relationship to the development of T2DM, screening for postpartum diabetes incidences and the type of management of GDM during pregnancy was done.
Figure 1 showed the differences between patients with SVD or C/S mode of delivery that had development of postpartum diabetes, patients that was screened for T2DM and the type of GDM management employed during the pregnancy period of the patients. Figure 1A showed that patients who had SVD mode of delivery were more likely to develop type 2 diabetes as compared to those that have C/S. Whereas, Figure 1B showed that patients who had C/S mode of delivery were more likely to get screened for type 2 diabetes than those patients who had SVD mode of delivery. On the other hand, Figure 1C showed that patients who had SVD mode of delivery were more likely to practice good lifestyle (diet and exercise) as a way to manage GDM during pregnancy while patients who had C/S mode of delivery were more likely to practice insulin treatment.