Introduction

Gestational diabetes mellitus (GDM) is the most frequently encountered endocrine disorder in pregnancy and is associated with adverse outcomes if remains undiagnosed or untreated. It is defined as glucose intolerance of variable severity with onset or first recognized during the present pregnancy. The prevalence of GDM is 9.7% according to the WHO criteria and 12.9% according to the ADA (American Diabetic Association) criteria in Bangladesh. South Asians are more prone to have diabetes at an earlier age and thus more vulnerable to GDM [1].

GDM is associated with macrosomia, which may subsequently lead to shoulder dystocia and birth trauma in addition to an increase in the rate of Caesarean sections. Globally, researchers are concerned about an increase in the prevalence of gestational diabetes mellitus (GDM) [2]. Middle Eastern countries range from 13.9% in Qatar to 7% in Iran in comparison to the United States, where the prevalence ranges from 3.47% to 7.15% [3]. GDM is associated with adverse fetal and maternal outcomes. Adverse fetal outcomes include congenital anomalies, trauma during birth, macrosomia and perinatal mortality. Adverse maternal outcomes include increased rates of caesarean section and increased lifetime risk of developing type 2 diabetes. Pre-eclampsia is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine [4].

When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease, there may be red blood cell breakdown, a low blood platelet count, impaired liver function, kidney dysfunction, swelling, shortness of breath due to fluid in the lungs, or visual disturbances. Pre-eclampsia increases the risk of undesirable outcomes for both the mother and the fetus. If left untreated, it may result in seizures at which point it is known as eclampsia [5,6]. Risk factors for pre-eclampsia include obesity, prior hypertension, older age, and diabetes mellitus. It is also more frequent in a woman's first pregnancy and if she is carrying twins. It takes place only in the presence of the placenta even without the fetus (hydatidiform mole), and typically improves postpartum. Hypoperfusion and ischemic conditions show the abnormal placenta.

Although the identification of underlying risk factors for preeclampsia is different some identified risk factors are documented like nulliparity, family history, preeclampsia in previous pregnancy, multiple gestation, pregestational diabetes mellitus, chronic hypertension, chronic renal disease and some autoimmune diseases. The development of GDM originates from insulin resistance, and that of preeclampsia is related to abnormal placentation leading to reduced placental perfusion. Dyslipidemia plays a significant role in the pathogenesis of both diseases [12].

Preeclampsia and GDM share similar risk factors, such as obesity-related dyslipidemia [13]. Common risk factors that may contribute to the increase of gestational diabetes, are maternal age >35 years, BMI >30kg/m2, prior history of GDM, previous macrosomic baby (weight >4.5kg), prior history of unexplained stillbirth, family history of diabetes (1st degree), and PCOS [14].

Materials and Methods

Study design: Cross-sectional analytical study.

Place of study: This study was carried out in the Department of Obstetrics and Gynaecology, Bangladesh Institute of Research & Rehabilitation for Diabetes, Endocrine & Metabolic Disorders (BIRDEM), General Hospital, Dhaka, Bangladesh.

Study population: Pregnant women between 25-40 years of age attending the antenatal clinic in the Department of Obstetrics and Gynaecology, BIRDEM General Hospital, in their third trimester of pregnancy, were included in this study.

GDM with preeclampsia (Group-I): GDM with preeclampsia in their third trimester admitted for pregnancy termination under the Department of Obstetrics and Gynecology, BIRDEM was recruited as group I.

GDM without preeclampsia (Group II): GDM without preeclampsia in their third trimester, admitted for pregnancy termination under the Department of Obstetrics and Gynecology, BIRDEM was recruited as group II.

Period of study: One year from IRB (Institutional Review Board) approval date 26-12-2021.

Sample size determination:The sample size was determined by the following formula.

A thorough clinical examination was done on all the subjects. After delivery simultaneously, data was collected for maternal outcome and fetal outcome. For every subject separate data collection sheet was prepared.

Data was collected from the patients on variables of interest using the structured design by interview, observation, clinical examination, haematological investigations and from history sheet of patients.

Blood collection: Maternal blood samples were drawn from the antecubital vein (in an arm without intravenous infusion ongoing). 5 millilitres of blood was drawn with proper aseptic precautions. The blood sample was transferred into a clean, dry test tube and taken to the laboratory.

Blood pressure (BP): As a baseline clinical examination, after 10 minutes of rest, BP was measured on the right arm at the level of the heart in a sitting posture/lateral decubitus with an average-sized cuff following all standard procedures. Blood pressure was measured again after 4-6 hours interval and the average was used for the analysis.

Safety precaution: Universal precaution was obtained. Gloves, lab coats, and safety glasses were worn when handling all human blood products. Disposable plastic, glass, paper and gloves that contact with blood were placed in a biohazard bag. Non-disposable material at the end of the working day was disinfected. Washing hands thoroughly was done after the removal of personal protective devices used in handling specimens and kit reagents.

Data Analysis:Statistical analyses were carried out by using the Statistical Package for Social Sciences version 22.0 for Windows (SPSS Inc., Chicago, Illinois, USA). Continuous variables were expressed as mean ±standard deviation and categorical variables as frequencies and percentages n (%). The chi-square test was used to analyze the categorical variables and shown in the cross-tabulation. The mean difference between groups was analyzed by unpaired t-test for continuous variables. P values <0.05 are considered as statistically significant.

Results

A total of 150 pregnant women were included in this study and then they were divided into two groups.

^{A c} hi-square test was done to measure the level of significance.
^c Unpaired t-test was done to measure the level of significance.
ns = not significant.

The majority, 62.7% of the respondents in group II had regular menstrual cycles and only, 37.3% had irregular menstrual cycles. The majority, 69.3% of group I was multigravida and only, 30.7% were primigravid. The mean gestational age was in both group I (35.55 ± 1.74) week and group II (36.05 ± 1.77) week. There were no significant differences between the two groups regarding the variable (p>0.05) (Table 2).

Table 3: Distribution of the respondents according to personal history by group (GDM with preeclampsia = 75, GDM without preeclampsia= 75)

^{A c}hi-square test was done to measure the level of significance.
^b Fisher's exact test was done to measure the level of significance.
ns = not significant.

No significant difference was observed in terms of weight gain and smoking between the two groups (p≥0.05) (table 3).

Table 4: Distribution of the respondents according to BMI by group (GDM with preeclampsia = 75, GDM without preeclampsia= 75)

^aChi square test was done to measure the level of significance.
^cUnpaired t-test was done to measure the level of significance.
ns = not significant. Table 4 denotes that the mean BMI in both groups I (31.87± 5.93) and II (31.16 ± 4.72) and the finding was statistically non-significant (p≥0.05).

^{A c}hi-square test was done to measure the level of significance.

Table 8: Distribution of the respondents according to maternal complication by group (GDM with preeclampsia = 75, GDM without preeclampsia-75)

Table 9: Distribution of the respondents according to perinatal complication by group (GDM with preeclampsia - 75, GDM without preeclampsia= 75)

^{A c}hi-square test was done to measure the level of significance.
^b Fisher's exact test was done to measure the level of significance.
^c Unpaired t-test was done to measure the level of significance.

The mean gestational age was almost similar in both group I (35.55 ± 1.74) week and group II (36.05 ± 1.77) week. All these findings were not statistically significant (p≥0.05). A study revealed that PE is most commonly developed in primiparas (p<0.05). The majority, 66.7% among the respondents of group I did not have anemia, 30.7% had mild and only 2.7% had moderate anemia. Similarly, the majority, 86.7% among the respondents of group II did not have anemia, 12.0% had mild and only 1.3% had moderate anemia. All these findings were statistically significant (P<0.05). A study reported anaemia, and edema, 56.7% in the second half of gestation in pregnancy complicated with preeclampsia [17]. A significant difference was observed in regards to mode of delivery where all (100.0%) among group I and in group II most of the respondents, 90.7% had LSCS and only, 9.3% in group II had NVD (p=.013). A similar study reported that 82% of patients were delivered by Caesarean section in GDM with pre-eclampsia and 72% of patients were delivered by Caesarean section in GDM without pre-eclampsia group [18]. Another study stated that in GDM with pre-eclampsia, 80% and in GDM without pre-eclampsia, 66.7% were delivered by LUCS Jesmin et al., [19] which supports the finding of this study. In the present study, in group I 5.3% and none of group II had absent fetal movement which was statistically significant (p<0.04).). In group I majority had oligohydramnios, 16.0%, followed by polyhydramnios, 4.2% and PPH, 1.3%. A similar study reported that oligohydramnios were higher in GDM with preeclampsia compared to that in GDM without preeclampsia [18]. In this study in group I majority (64.0%) had preterm delivery and in group II 41.3% had preterm delivery. In group I, 5.3% and none of group II had IUD which was statistically significant (p<0.05). In a similar study preterm delivery (<37 weeks of gestation) was higher among GDM with preeclampsia group, 55% compared to GDM without preeclampsia, 32% group. Term delivery was 45% vs 68% between the two groups. The distribution was highly significant (p<0.001) [18].

Conclusions

Gestational diabetes mellitus and preeclampsia are prevalent in mothers attending antenatal clinics and are associated with an increased risk of pregnancy and delivery complications.