Amniotic fluid glucose at the time of genetic amniocentesis: correlation with duration of pregnancy and birthweight

Biomarkers for Macrosomia Prediction in Pregnancies Affected by Diabetes

Large birthweight, or macrosomia, is one of the commonest complications for pregnancies affected by diabetes. As macrosomia is associated with an increased risk of a number of adverse outcomes for both the mother and offspring, accurate antenatal prediction of fetal macrosomia could be beneficial in guiding appropriate models of care and interventions that may avoid or reduce these associated risks. However, current prediction strategies which include physical examination and ultrasound assessment, are imprecise. Biomarkers are proving useful in various specialties and may offer a new avenue for improved prediction of macrosomia. Prime biomarker candidates in pregnancies with diabetes include maternal glycaemic markers (glucose, 1,5-anhydroglucitol, glycosylated hemoglobin) and hormones proposed implicated in placental nutrient transfer (adiponectin and insulin-like growth factor-1). There is some support for an association of these biomarkers with birthweight and/or macrosomia, although current evidence in this emerging field is still limited. Thus, although biomarkers hold promise, further investigation is needed to elucidate the potential clinical utility of biomarkers for macrosomia prediction for pregnancies affected by diabetes.

Subsequent gestational diabetes mellitus prediction in advanced maternal age using amniotic fluid glucose concentration during second trimester genetic amniocentesis

This prospective study aimed to present the reference range of amniotic fluid glucose (AFglu) among second trimester pregnant women in southern Thailand, to evaluate the possibility of predicting subsequent gestational diabetes mellitus (GDM) using AFglu, and to estimate AFglu cut-off levels for identifying pregnancies at high or low risk for subsequent GDM in singleton pregnancies undergoing genetic amniocentesis due to advanced maternal age. A total of 438 eligible pregnant women were analysed, among whom 58 were subsequently diagnosed as having GDM. The reference range that included the central 95% of AFglu values at 16, 17 and 18 weeks of gestation in women not subsequently developing GDM was determined from a linear regression model. Logistic regression was used to identify predictors of subsequent GDM. Odds ratio of subsequent diagnosed GDM participant increased by 7% for each 1 mg/dl increase in AFglu. Risk of subsequent GDM was also increased in women aged over 36 years and in 17-18 weeks compared to 16 weeks of gestation. Depending on gestational and maternal age, AFglu levels above 51 to 75 mg/dl were at elevated risk of subsequent GDM (likelihood ratio 2.38). We conclude that AFglu tended to decrease with increasing of gestational age. Gestational age and maternal age accompanied with elevated AFglu are predictive factors for subsequent GDM.

Prognostic potential of amniotic fluid analysis at birth on canine neonatal outcomes

Glucose, lactate and cortisol concentrations in amniotic fluid were measured at birth in 95 pups and related to neonatal viability based on Apgar scoring and to neonatal mortality. Neither amniotic parameters nor neonatal mortality were associated with the Apgar score. Stillborn pups showed high lactate (P < 0.001) and cortisol (P < 0.05) but low glucose amniotic concentrations (P < 0.001). No amniotic fluid differences were observed between normal and malformed pups. Amniotic glucose (P < 0.001), lactate (P < 0.05) and cortisol (P < 0.05) concentrations were higher in pups delivered by vaginal parturition than by Caesarean section. Birth weight was higher in live pups than in pups dying within 48 h (P < 0.05). Although these are preliminary results, the analysis of amniotic fluid collected at birth could be a valuable predictor of neonatal outcomes in dogs.

Second trimester amniotic fluid glucose, uric acid, phosphate, potassium, and sodium concentrations in relation to maternal pre-pregnancy BMI and birth weight centiles

OBJECTIVE

To study the evolution profile of amniotic fluid (AF) glucose, uric acid, phosphate, potassium, and sodium, in the second trimester of pregnancy, and explore the possible relations between the concentration of these components and maternal, as well as neonatal characteristics.

METHODS

AF of 52 pregnant women was analyzed using an automatic multichannel analyzer. Maternal age, pre-pregnancy Body Mass Index (BMI), inter-pregnancy intervals, and smoking status were derived from questionnaires. Information on pregnancy and delivery was collected from medical records.

RESULTS

Uric acid increased (r = 0.423, p < 0.01), while phosphate and glucose concentrations decreased during the period of 16-26th week of pregnancy (r = -0.590, p < 0.001 and r = -0.314, p < 0.05, respectively). Maternal pre-pregnancy BMI was significantly correlated with AF uric acid concentration (r = 0.460, p < 0.01) and marginally with AF glucose (r = 0.274, p = 0.052) and sodium (r = 0.254, p = 0.070) levels. Multiple linear regression indicated that mid-trimester AF uric acid and phosphate levels were significantly related to birth weight centiles (R(2)( )= 0.345, p < 0.05).

CONCLUSIONS

Our results suggest that: (a) AF phosphate levels reflect gestational age to a satisfactory extent, (b) maternal pre-pregnancy BMI is significantly correlated with AF uric acid concentration, and (c) in appropriate for gestational age infants, AF phosphate and uric acid levels may serve as potential biomarkers of birth weight centiles. Further studies on AF composition may help to unravel the biochemical pathways underlying fetal development and could offer insight on the potential impact of maternal nutritional management on fetal growth regulation.