Now showing 1 - 9 of 9
  • Publication
    Maternal Obesity and Neck Circumference
    Obese women are more likely to require general anaesthesia for an obstetric intervention than non-obese. Difficult tracheal intubation and oxygen desaturation is more common in pregnancy. Failed tracheal intubation has been associated with an increase in neck circumference (NC). We studied the relationship between maternal obesity and NC as pregnancy advanced in women attending a standard antenatal clinic. Of the 96 women recruited, 13.5% were obese. The mean NC was 36.8cm (SD 1.9) in the obese women compared with 31.5cm (SD 1.6) in women with a normal BMI (pp<0.001) at 18-22 weeks gestation. In the obese women it increased on average by 1.5cm by 36-40 weeks compared with an increase of 1.6 cm in women with a normal BMI. The antenatal measurement of NC is a simple, inexpensive tool that is potentially useful for screening obese women who may benefit from an antenatal anaesthetic assessment.
  • Publication
    The relationship between gestational weight gain and fetal growth: time to take stock?
    The aim of this article is to review the current evidence on gestational weight gain (GWG). Maternal obesity has emerged as one of the great challenges in modern obstetrics as it is becoming increasingly common and is associated with increased maternal and fetal complications. There has been an upsurge of interest in GWG with an emphasis on the relationship between excessive GWG and increased fetal growth. Recent recommendations from the Institute of Medicine in the USA have revised downwards the weight gain recommendations in pregnancy for obese mothers. We believe that it is time to take stock again about the advice that pregnant women are given about GWG and their lifestyle before, during, and after pregnancy. The epidemiological links between excessive GWG and aberrant fetal growth are weak, particularly in obese women. There is little evidence that intervention studies decrease excessive GWG or improve intrauterine fetal growth. Indeed, there is a potential risk that inappropriate interventions during the course of pregnancy may lead to fetal malnutrition that may have adverse clinical consequences, both in the short- and long-term. It may be more appropriate to shift the focus of attention from monitoring maternal weight to increasing physical activity levels and improving nutritional intakes.
      420Scopus© Citations 15
  • Publication
    A national survey of preanalytical handling of oral glucose tolerance tests in pregnancy
    While the criteria for the diagnosis of gestational diabetes mellitus (GDM) continue to be mired in controversy with a lack of international consensus, many countries and the World Health Organization have adopted the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) recommendations. In addtion, revised stricter recommendations have also been produced and endorsed by the National Academy of Clinical Biochemistry (NACB) for laboratory standards in the analysis of maternal glucose measurements.
      306Scopus© Citations 10
  • Publication
    Comparison of citrate-fluoride-EDTA with fluoride-EDTA additives to stabilize plasma glucose measurements in women being screened during pregnancy with an oral glucose tolerance test: a prospective observational study
    (The American Association for Clinical Chemistry, 2016-06) ; ; ; ; ;
    We recently highlighted the importance of implementing recommended preanalytical standards to avoid missing the diagnosis of gestational diabetes mellitus (GDM)1(1 ).The placement of samples on an ice slurry with separation within 30 min, however, is not always practical.
      264Scopus© Citations 14
  • Publication
    Impact of Implementing Preanalytical Laboratory Standards on the Diagnosis of Gestational Diabetes Mellitus: A Prospective Observational Study
    (American Association for Clinical Chemistry, 2016-02) ; ; ; ; ;
    Background: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes, but risk is reduced with identification and early treatment. Glucose measurements are affected by preanalytical sample handling, such as temperature of storage, phlebotomy–analysis interval, and use of a glycolysis inhibitor. We evaluated glucose concentrations and the incidence of GDM after strict implementation of the American Diabetes Association (ADA) preanalytical guidelines, compared with usual hospital conditions. Methods: Women screened selectively for GDM at 24 –32 weeks’ gestation were recruited at their convenience before a 75-g oral glucose tolerance test. Paired samples were taken: the first sample followed ADA recommendations and was transferred to the laboratory on an iced slurry for immediate separation and analysis (research conditions), and the second sample was not placed on ice and was transferred according to hospital practice (usual conditions). Results: Of samples from 155 women, the mean fasting, 1-h, and 2-h results were 90.0 (12.6) mg/dL [5.0 (0.7) mmol/L], 142.2 (43.2) mg/dL [7.9 (2.4) mmol/L], and 102.6 (32.4) mg/dL [5.7 (1.8) mmol/L], respectively, under research conditions, and 81 (12.6) mg/dL [4.5 (0.7) mmol/L], 133.2 (41.4) mg/dL [7.4 (2.3) mmol/L], and 99 (32.4) mg/dL [5.5 (1.8) mmol/L] under usual conditions (all P 0.0001). GDM was diagnosed in 38.1% (n 59) under research conditions and 14.2% (n 22) under usual conditions (P 0.0001). The phlebotomy–analysis interval for the fasting, 1-h, and 2-h samples was 20 (9), 17 (10), and 17 (9) min under research conditions and 162 (19), 95 (23), and 32 (19) min under usual conditions (all P 0.0001). All cases of GDM were diagnosed on fasting or 1-h samples; the 2-h test diagnosed no additional cases. Conclusions: Implementation of ADA preanalytical glucose sample handling recommendations resulted in higher mean glucose concentrations and 2.7-fold increased detection of GDM compared with usual hospital practices.
      324Scopus© Citations 39
  • Publication
    The interplay between maternal obesity and gestational diabetes mellitus
    There is a strong epidemiological association between maternal obesity and gestational diabetes mellitus (GDM). Since the publication of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study on women with mild hyperglycemia in 2008, new criteria have been introduced in maternity services internationally for the diagnosis of GDM. As a result, the diagnosis of GDM may be made in one-third of obese women (n=68). The aim of this review was to examine the interplay between maternal obesity and GDM in light of the HAPO study and the subsequent revised diagnostic criteria. Obesity and GDM are important obstetric risk factors because they both are potentially modifiable. However, the new international criteria for the diagnosis of GDM have serious resource implications for maternity services provided to the large number of women attending for care in developed countries. Further consideration needs to be given as to whether obese women with mild hyperglycemia need to be referred to a multidisciplinary team antenatally if they do not require insulin treatment.
      566Scopus© Citations 15
  • Publication
    Preanalytic Laboratory Standards (Letters to the Editor)
    (American Association for Clinical Chemistry, 2016-06) ;
    We thank our Canadian colleagues for their interest in our recent article and, in particular, their observations on the need for the 2-h sample with a 75-g OGTT. We note that 25% of their large cohort of 10 773 women had an abnormal 2-h sample using the IADPSG diagnostic criteria and therefore their understandable caution about missing the diagnosis of gestational diabetes mellitus.
  • Publication
    Time And temperature affect glycolysis in blood samples regardless of fluoride-based preservatives: a potential underestimation of diabetes
    Background: The inhibition of glycolysis prior to glucose measurement is an important consideration when interpreting glucose tolerance tests. This is particularly important in gestational diabetes mellitus where prompt diagnosis and treatment is essential. A study was planned to investigate the effect of preservatives and temperature on glycolysis. Methods: Blood samples for glucose were obtained from consented women. Lithium heparin and fluoride-EDTA samples transported rapidly in ice slurry to the laboratory were analysed for glucose concentration and then held either in ice slurry or at room temperature for varying time intervals. Paired fluoride-citrate samples were received at room temperature and held at room temperature, with analysis at similar time intervals. Results: No significant difference was noted between mean glucose concentrations when comparing different sample types received in ice slurry. The mean glucose concentrations decreased significantly for both sets of samples when held at room temperature (0.4mmol/L) and in ice slurry (0.2mmol/L).
      308Scopus© Citations 7
  • Publication
    Maternal Body Mass Index and the prevalence of spontaneous and elective preterm delivery in an Irish obstetric population: a retrospective cohort study
    Objective: To estimate the association between maternal body mass index (BMI) and risk of spontaneous preterm delivery (sPTD) and elective preterm delivery (ePTD) in singleton and multiple pregnancies. Design: Retrospective cohort study. Setting: Electronic records of all deliveries from 2009 through 2013 in a tertiary university hospital were abstracted for demographic and obstetrical information. Participants: A total of 38 528 deliveries were included. Participants with missing data were excluded from the study. BMI was calculated from the measurement of height and weight at the first prenatal visit and categorised. Sonographic confirmation of gestational age was standard. Outcome measures: Primary outcomes, sPTD and ePTD in singleton and multiple pregnancies, were evaluated by multinomial logistic regression analyses, stratified by parity, controlling for confounding variables. Results: Overall rate of PTD was 5.9%, from which 2.7% were sPTD and 3.2% ePTD. The rate of PTD was 50.4% in multiple pregnancies and 5.0% in singleton pregnancies. The risk of sPTD was increased in obese nulliparas (adjusted OR (aOR) 2.8, 95%CI 1.7 to 4.4) and underweight multiparas (aOR 2.2, 95%CI 1.3 to 3.8). The risk of ePTD was increased in underweight nulliparas (aOR 1.8; 95%CI 1.04 to 3.4) and severely obese multiparas (aOR 1.4, 95%CI 1.02 to 3.8). Severe obesity increased the risk of both sPTD (aOR 1.4; 95%CI 1.01 to 2.1) and ePTD (aOR 1.4; 95%CI 1.1 to 1.8) in singleton pregnancies. Obesity did not influence the rate of either sPTD or ePTD in multiple pregnancies. Conclusion: Maternal obesity is an independent risk factor for PTD in singleton pregnancies but not in multiple pregnancies. Obesity and nulliparity increase the risk of sPTD, whereas obesity and multiparity increase the risk of ePTD.
      168Scopus© Citations 18