Using fasting plasma glucose concentrations to screen for gestational diabetes mellitus: prospective population based study
BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7213.812 (Published 25 September 1999) Cite this as: BMJ 1999;319:812
All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Perucchini et al have stated in their article (1) that fasting blood
sugar (FBS) over 4.8 mmol/l is a good single step screening test to
identify patients with gestational diabetes mellitus (GDM).
In a
prospective observational study conducted at Ibra Hospital in the
Sultanate of Oman, 563 antenatal cases were screened for GDM by oral
glucose tolerance test using 0 and 2hr-post 75 gram glucose protocol.
Whole blood capillary glucose was measured using a glucometer. Fasting
more than 5 mmol/L and post glucose 6.7 (equivalent to plasma glucose-
7.8mmol/L) was taken as diagnostic of GDM (2). The prevalence of GDM was
21.31 % ( 95 % confidence limits 18.31% to 24.31%).
It was interesting to
note that out of 120 patients who exhibited GDM, only 6 had high FBS (
mean- 7.6 ,SD- 2.26 mmol/L ). On the other hand 114 patients had GDM by
the criterion of 2 hr post 75 gram glucose ( Mean 8.66, SD 1.72).Control group of non diabetic pregnancy (NDP) had FBS of average
3.76 (SD 0.58) and post glucose blood sugar (PGBS) of mean 4.94 (SD 1.03).
In view of the above results we feel that, at least in ethnic groups
where diabetes prevalence is high (3) PGBS may be more important than FBS
in diagnosing or excluding GDM.
Time at which screening for GDM should be done is usually advocated
as 28 wks of pregnancy. We did GTT screening for our patients at first
contact during antenatal visits. When it was normal the test was repeated
4-6 weeks apart at two additional occasions such that the last GTT
coincided with 28 wks pregnancy. Most of the GDM cases were diagnosed at
the first testing (i.e. 87.5%) and 2nd and 3rd GTT added additional
information only in a minority of cases i.e. 10% and 2.5% respectively.
The highest yield of GDM was in 3rd month of pregnancy (25.8%) and almost
all cases (over 80 %) were diagnosed much before 28 th week of pregnancy
.
We therefore feel that the screening for GDM in countries with high
prevalence of diabetes should take place much before 28 wk of pregnancy,
preferably at the first contact with the patients. Most of the GDM cases
exhibited normal glucose tolerance when tested at 40 days postpartum.
References:
1 Perucchini D , Fischer U, Spinas G A, Huch R, Huch A, Lehmann R. Using
fasting plasma glucose concentrations to screen for gestational diabetes
mellitus: prospective population based study . . BMJ 1999;319:812-815 ( 25
September )
2 Diabetes in Pregnancy.Antenatal care manual.Third Edition 1996.Published
by the Department of Family and Community Health,Ministry of Health
,Sultanate of Oman
3. Asfour MG, Lambourne A, Soliman A, Al-Behlani S, Al-Asfoor D, Bold A,
Mahtab H, King H High prevalence of diabetes mellitus and impaired glucose
tolerance in the Sultanate of Oman: results of the 1991 national survey.
Diabet Med 1995 (12):1122-5
Dr Umesh Kumar Dashora, MRCP, Regional Diabetologist
Dr Vandana Dashora, MS, Medical Officer, Gynaecology and Obstetrics
Dr John Idicula, MS, Medical Superintendent,
Ibri Regional Referral Hospital, POB 46 PC 516
Sultanate of Oman.Ph 968 491905 Fax:968 491915
Dr MG Asfour, Head, National Diabetes Center,Muscat- WHO
collaborating center
E-mail: dashora@hotmail.com
Acknowledgement: We are thankful to Mr Ali Abdulla Habsi ,the
Director General of North Sherqia region for his kind support for the
study.
Competing interests: No competing interests
High prevalence countries for diabetes mellitus should make it mandatory to screen all women for gestational diabetes
In high prevalence regions for diabetes such as India, the screening
for gestational diabetes should be mandatory to all women in antenatal
care during pregnancy. It will not only screen all women for GDM and help
in preventing adverse maternal outcome ( Preeclampsia, shoulder dystocia,
miscarriage and preterm labour) and perinatal outcome (congenital
malformation, macrosomia, birth injury, perinatal mortality); but it will
also help in screening women and allowing them to have an early warning
signal for developing the future diabetes mellitus. Those who are positive
for gestational diabetes should be on surveillance for developing diabetes
and should also be given counselling for lifestyle changes and keep the
diabetes on bay.
Competing interests: No competing interests