Epidemiology of

Gestational Diabetes

Mellitus(GDM) in ZagazigBY

MOHAMMAD G. KHALIFA (MSC.) ASSIST. LECTURER OF INTERNAL MEDICINE ,

DIABETES AND ENDOCRINOLOGY

FACULTY OF MEDICINE , ZAGAZIG UNIVERSITY.(28TH APRIL, 2017)

Introduction…

For many years, Gestational diabetes mellitus (GDM) was defined as any degree of glucose intolerance that was first recognized during pregnancy.

ADA definition: GDM is diabetes that is first diagnosed in the second or third trimester of pregnancy that is not clearly either preexisting type 1 or type 2 diabetes (ADA,2017).

It is usually recognized at 24 to 28 weeks of gestation on the basis of abnormal glucose tolerance testing. Additionally, pregnancy can be complicated by established type 1 or type 2 diabetes. (ADA,2015).

In the 2011 Standards of Care, the ADA for the first time recommended that all pregnant women not known to have prior diabetes undergo a 75-gOGTT at 24–28 weeks of gestation, based on a recommendation of the IADPSG(ADA,2017)

There are limited data regarding the prevalence of GDM worldwide.

One report by the National Institute for Health and Care Excellence (NICE) in the UK suggests that the prevalence of GDM in England and Wales is approximately 3.5% of all pregnancies.(National Collaborating

Centre for Women's and Children's Health, 2015).

The prevalence of GDM varies from 1-

20%, and is rising worldwide, parallel

to the increment in the prevalence of

obesity and type 2 diabetes mellitus

(T2DM). (WHO, 2013).

During normal pregnancy, resistance to insulin action increases. In most pregnancies, pancreatic beta cells are able to compensate for increased insulin demands,and normoglycaemiais maintained.

In contrast, women who develop GDM have deficits in beta-cell response leading to insufficient insulin secretion to compensate for the increased insulin demands (ADA, 2015).

Products of the placenta, including tumor necrosis factor-alpha (TNF-alpha) and human placental lactogen, are thought to play key roles in inducing maternal insulin resistance.

Insulin resistance is most marked in the third trimester , the reason that screening has traditionally been performed at this point(Metzger et al., 2007).

It is well known that the women who are at the

greatest risk of developing GDM are those who

have a history of glucose intolerance or past

gestational diabetes, have delivered a child with

macrosomia or a child who was large for

gestational age, suffer from polycystic ovary

syndrome or have first degree relatives with

diabetes. The prevalence of GDM increases with

age from 25 years old (NICE, 2015).

GDM is associated with maternal and

neonatal adverse outcomes such as :

Gestational hypertension, polyhydramnios, need for cesarean

delivery, maternal trauma from operative delivery ,preterm

labor, fetal macrosomia , shoulder dystocia , preterm delivery

,fetal cardiomyopathy ,Stillbirth, Congenital malformations,

Respiratory distress syndrome and lung immaturity,, Small-

for-gestational-age (SGA), increased risk of developing

diabetes mellitus and obesity ,and hyperbilirubinemia.

Aim and objectives

of the work…

The aim of the work was early diagnosis,

prevention and detection of prevalence of

GDM by universal screening in all non-

diabetic women attending to outpatient

clinics of Zagazig University Hospitals,( in

light of new diagnostic criteria of the

International Association of Diabetes and

Pregnancy Study Groups) (IADPSG).

The main objectives of our study

were to :

determine the prevalence of GDM

and predict the potential risk factors

among the study group.

SUBJECTS

AND

METHODS…

This study was carried out in outpatient clinic of

Internal Medicine Department, and Obstetrics

and gynecology Department in Zagazig University

Hospitals , in the period from December 2014 to

December 2015.

It was a cross sectional study including a total

number of 180 volunteer pregnant subjects.

Inclusion criteria…

Co-operative subjects.

Pregnant females

Gestational age: 24 – 28 weeks.

Non diabetic.

Exclusion criteria…

Pregnant women who were known diabetic.

Drug intake that can cause hyperglycemia

such as corticosteroids.

Methods:

All subjects of the study were subjected to:

A. Full history taking including: Age, previous history of GDM, family history of diabetes in first degree relatives, previous macrosomic baby, polycystic ovary syndrome, Twin pregnancy ,and Drug history.

B. Clinical examination: Full clinical examination.

C. Investigations :

1-oral glucose tolerance test “OGTT”

75-g OGTT will done, with plasma glucose

measurement when patient is fasting and

at 1st and 2nd hour , at 24–28 weeks of

gestation in women not previously

diagnosed with overt diabetes.

The diagnosis of GDM is made when any of

the following plasma glucose values are

met or exceeded:

Fasting: 92 mg/dL (5.1 mmol/L).

1st hour: 180 mg/dL (10.0 mmol/L).

2nd hour : 153 mg/dL (8.5 mmol/L).

2-HbA1c:

HbA1c was done to distinguish

GDM from pre-existing diabetes.

Patients with Hb A1c levels of 6.5% or

higher were considered to have overt

diabetes.

Results

…

Prevalence of GDMVariable

Cases(n=180)

No %

GDM

No

Yes

162

18

90

10

90%

10%

Normal cases Cases with GDM

VariableCases

(n=18)

HbA1c (%)

Mean ± SD

Range

5.23 ± 0.42

4.5 – 6

HbA1c of the GDM group

Comparison between cases with GDM

and normal cases in Demographic data

VariableNo GDM

(n=162)

GDM

(n=18)t P

Age (year)

Mean ± SD

Range

25.48 ± 2.95

19 – 32

25.44 ± 5.38

20 – 37

0.040.97

NS

Age of marriage (year)

Mean ± SD

Range

21.44 ± 1.26

19 – 25

28.5 ± 7.03

19 – 35

11.45 <0.001**

Comparison between cases with GDM and

normal cases as regard Body Mass Index (BMI)

and Glycemic Index (GI) of the diet

VariableNo GDM

(n=162)

GDM

(n=18)t P

BMI (Kg/m2)

Mean ± SD

Range

26.83 ± 1.08

24.1 – 29.8

31.04 ± 2.2

27.7 – 37.7

13.77 <0.001**

Diet

Average GI diet

High GI diet

No % No %

65.55 <0.001**162

5

96.9

3.1

11

7

61.1

38.9

Comparison between cases with GDM

and normal cases in gynecological historyVariable`

No GDM

(n=162)

GDM

(n=18)t / χ2 p

No. of pregnancy

Mean ± SD

Range

1.95 ± 0.83

1 – 4

4.39 ± 1.42

1 – 710.84 <0.001**

History of twins

No

Yes

No % No %

115.7 <0.001**162

0

100

0

6

12

33.3

66.7History of macrosomic baby

No

Yes

162

0

100

0

7

11

38.9

61.1

105.4 <0.001**

History of PCOS

No

Yes

162

0

100

0

7

11

38.9

61.1

105.4 <0.001**

Gestational Age (weeks)

Mean ± SD

Range

26.12 ± 1.87

24 – 28

26.12 ± 1.87

24 – 28

1.620.11

NS

Comparison between cases with GDM and

normal cases in family history of diabetes and

history of GDM

Variable

No GDM

(n=162)

GDM

(n=18) χ2 P

No % No %

Family history of DM

No

Yes

128

33

79

20.4

2

16

11.1

88.9

38.39<0.001**

History of previous GDM

No

Yes

162

0

100

0

7

11

38.9

61.1

105.4 <0.001**

Family History of DM in cases with GDM

89%

11%

Positive family history of DM

Negative family history of DM

History of twins in cases with GDM

66.7 %33.3 %

Cases with GDM with history of…Cases with GDM with no history…

History of PCOs in cases with

GDM

61%

39%

Cases with GDM with history ofPCOs

History of previous GDM in cases with GDM

61.1%

38.9 %

Positive History of previous GDM

Negative history of previous GDM

History of macrosomic baby in cases with

GDM

39%61%

Cases with GDM without history of macrosomic baby

Cases with GDM with history of macrosomic baby

61%

39%

Diet in cases with GDM

Averge GI Diet High GI Diet

Net Results

and

conclusion…

* The prevalence of GDM among all cases included

is10%.

* The risk factors of GDM respectively are : family

history of DM, history of twins, BMI above 30, history

of previous GDM , history of previous macrosomic

baby and history of PCOS which are equal, history of

grand multipara, maternal age above 35 years old,and

lastly history of diet with high glycemic index.

Risk Factors for GDM

89.00%67% 66.00% 61.10% 61.10% 61% 56%

44% 38.90%

0.00%10.00%20.00%30.00%40.00%50.00%60.00%70.00%80.00%90.00%

100.00%

Estimated Risk for GDM %

Discussion

…

The main objectives of our study were to determine the prevalence of GDM

and predict the potential risk factors

among the study group.

Using the new IADPSGs criteria, our

study revealed that the prevalence rate of

GDM is 10% among the study cases.

. Theses results were both in conflict and in agreement with some studies conducted in the arabic countries as Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates.

In general, the prevalence rate observed in this study was related to the universal range varying from 3% to 14% among all pregnancies in different populations as declared by Ben-halima et al. 2012.

The Prevalence rate of our study is also in

agreement with the that of GDM in different

parts of the world that ranged between 1 %

to 14 % in different areas (lowest was less

than 1% in a study conducted in Singapore

and Tanzania as mentioned by

Ben‐Haroush et al. 2004 and highest was

14% in India as explained by Colussi et al.

2015.

Our study rated the following to be the most

important risk factors for GDM respectively:

family history of diabetes ,, history of twins,

body mass index (BMI) above 30 , history of

previous GDM, history of macrosomic baby

above 4.5 kg , history of PCOS, grand parity

( delivery of 5 children or more ), maternal

age above 35 years, and lastly diet with high

glycemic index (GI).

Asregard family history of DM , our study revealed that it is an important risk factor for occurrence of GDM, as 88.9 % of cases with GDM had family history of DM.

This is in agreement with what was explained by Bhat et al. in 2010 who explained that Family history of diabetes was concluded in several cross sectional and prospective studies as a highly significant risk factor for developing GDM.

In 2011 Marcinkevage et al explained that:

family history of diabetes mellitus is widely

recognized as an effective risk factor on the

prevalence of GDM.

Gomez et al in 2011 declared that family history of

DM occurred in 77.7 % of cases included in a

study that was held to determine risk factors of

GDM.

As regard history of twins as a risk factor for

occurrence of GDM , our study revealed that

history of twins occurred in about 67 % of cases

with GDM (12 of 18 cases with GDM) and this is of

statistical significance .

Kjos and Buchanan in 1999 declared that many

studies show that 17 to 67 % of cases with GDM

included had previous history of twin pregnancy.

Obesity as a significant risk factor for GDM

is supported by several studies finding that

overweight or obesity at the start of

pregnancy predispose to GDM .

Our study found that BMI above 30 kg/ m2

is of statistical significance for occurrence

of GDM as about 66 % of cases with GDM

had BMI above 30kg/m2.

Our study results in this point are near to the results of the recent Atlantic DIP 2014 study that reported that over 50% of women who were overweight (BMI 25–29.9 kg/m 2) at the first antenatal visit had excessive gestational weight gain, and developed GDM during subsequent pregnancies as declared by Yessoufou and Moutairou, 2011.

As regard history of previous GDM, macrosomic

baby and history of PCOS, Our study declares

that these factors are found to be associated

with occurrence of GDM, as these three risk

factors occurred in 61% of GDM cases equally.

Our study in this point are near to the results

founded by Marcinkevage and Narayan, 2011

who declared that these factors are widely

recognized as the effective risk factors on the

prevalence of GDM.

It is also in agreement with what explained

by Ashrafi et al. 2014 who explained that

previous reports around the world found

that the following health variables have

been found to be significant risk factors for

GDM: age ≥ 35 years, BMI ≥ 30 kg/m2,

previous GDM, family history of diabetes,

previous macrosomic baby, and history of

PCOs.

Astudy conducted in Yamen in 2016 to detect

prevalence and risk factors for GDM ,revealed

that previous GDM, age ≥ 35 years, family

history of diabetes, and history of PCOS as the

strongest predictors for developing GDM.

Beneret et al. in 2011 said that evidences from

earlier surveys indicated that previous GDM and

age ≥ 35 years are more associated with GDM

than the other risk factors.

Our study show that history of grand

multipara (A woman who has given birth 5 or

more times) is a risk factor for GDM (it

occurred in 55.5 % GDM cases), and this is

consistent with what declared by Roman et

al.in 2007 who assessed the obstetric and

neonatal outcomes in grand multi-parity and

found that grand multi-para had a higher

rate of GDM.

A study conducted in Pakistan to assess

the Socio-demographic risk factors of

GDM shew that, the number of GDM

women with grand multi-parity was 54.4%,

which was significantly higher than the

healthy pregnant women, as mentioned

by Moses et al. in 2011.

Our study in this item revealed that, history of

high GI diet is a risk factor for occurrence of

GDM ( occurred in 38.9% of GDM cases ).

Result of our study in this point is in agreement

with the results of a study held in Lady Hardinge

Medical College in New Delhi to assess the

nutritional risk factors for GDM, which show that

women consuming diet of high GI had high risk

of GDM. (Zhang and Ning, 2011).

Zhang et al. in2006 conducted a hospital

based prospective cohort study in USA to

examine whether dietary Glycemic Index

was related to GDM risk or not . This

study show that dietary Glycemic Index

was positively related to GDM risk.

Finally, our study gives information about the

risks of GDM that can help improve primary

health care measures. However, all pregnant

women should be screened for GDM even they

have the risk factors or not .

Scott et al., 2002 declared that recognizing such

risk factors among pregnant women is important

and should be done by the medical staff in order

to prevent the adverse effects of GDM.

Recommendations…

we recommended the following:All pregnant women should be screened

for GDM at 24 –28 weeks of gestation.

On presence of GDM risk factors,screening should be done at any stage inthe pregnancy .If the initial screening isperformed before 24 weeks of gestationand is negative, rescreen between 24 and28 weeks of gestation.

A 75 g OGTT can be performed (with no prior screening 50 g GCT) as the diagnostic test for GDM using the IADPSG criteria .

Further studies are needed to focus on detection of prevalence, early diagnosis, management of GDM and its risk factors.

Follow up of mothers and their offsprings toprevent occurrence of diabetes mellitus inboth.

THANK YOU