Factors affecting fetal weight distribution in women with type I diabetes

Novel metabolic marker Afamin: A predictive factor for Large-for-Gestational-Age (LGA) fetus estimation in pregnancies with gestational diabetes mellitus?

OBJECTIVE

Gestational diabetes mellitus (GDM) affects both maternal and fetal/infant outcomes during and after pregnancy. The reason for the high incidence of large-for-gestational-age (LGA) infants in GDM patients despite close monitorization of glucose levels with early detection of the disease remains unclear to date. Our study aims to investigate the levels of the third-trimester novel marker afamin in GDM versus non-GDM pregnancies in terms of glycemic control status and their utility in the prediction of LGA fetuses.

MATERIAL AND METHODS

This prospective case-control study analysis involved 49 pregnant women with GDM diagnosed using the 75-g oral glucose tolerance test (75-g OGTT) and 40 randomly selected women with a similar body mass index (BMI) and gestational age (GA). Blood samples were collected in the third trimester of pregnancy. The afamin level was determined using a human afamin ELISA kit according to the manufacturer's procedure.

RESULTS

There was no significant difference found in BMI or GA of patients. Third-trimester afamin levels were 93.91 mg/L and 83.87 mg/L in the GDM and non-GDM groups, respectively (p=0.625). Afamin values of patients were not correlated with age, BMI, GA, HgA1c, 75-g OGTT fasting and 75-g OGTT 1-hour, or 75-g OGTT 2-hour values (p>0.05). GDM patients with LGA fetuses had significantly higher afamin values than patients with appropriate-for-gestational-age (AGA) fetuses (120.8 mg/L versus 91.26 mg/L, respectively). Between GDM patients with either LGA or AGA fetuses, there was no statistically significant difference found for age, BMI, GAs, insulin dose, 75-g OGTT results, or HgA1c values.

CONCLUSION

Our findings conclude that novel marker afamin levels could predict the risk of LGA infants independently of glycemic control status and provide insight into the pathogenesis of LGA fetuses, thus helping to reduce the risk of associated complications.

No association between early maternal HbA1c and offspring birthweight among women without pre-existing diabetes in Greenland

Studies of the association between maternal blood glucose measured by glycated haemoglobin (HbA1c) during pregnancy and the offspring’s birthweight have been heterogeneous. The aim of this study was to examine the association between maternal HbA1c level before gestational week 20 and the offspring’s birthweight among predominantly indigenous women in Greenland. A retrospective cohort study including all women (n = 503) and their offspring delivered from September 2015 to September 2016 at Queen Ingrid’s Hospital in Nuuk was conducted. Data were obtained from the electronic medical record. Linear regression models were used to analyse the effect of maternal HbA1c on the offspring’s birthweight with adjustment and stratification for relevant confounders and effect modifiers. Birthweight increased with 3.3 g per mmol/mol increase in HbA1c. Yet, no significant association between maternal HbA1c and the offspring’s birthweight was found after adjustment for maternal age, ethnicity, residence, smoking, and parity (β = 0.058, p = 0.711). Among obese women, a borderline significant positive association (β = 0.657, p = 0.059) was found. For term newborns, this corresponded to an increase in birthweight of 31 g per mmol/mol increase in HbA1c. Based on the current study, the use of HbA1c during pregnancy to detect the risk of delivering a newborn with macrosomia is not recommended in Greenland.

Abbreviation: HbA1c: glycosylated haemoglobin; GA: gestational age; SD: standard deviation; CI: confidence interval.

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.

Maternal 75-g OGTT glucose levels as predictive factors for large-for-gestational age newborns in women with gestational diabetes mellitus

OBJECTIVE

Our goal was to investigate which glucose measurement from the 75-g oral glucose tolerance test (OGTT) has more capability of predicting large for-gestational-age (LGA) newborns of mothers with gestational diabetes mellitus (GDM).

SUBJECTS AND METHODS

The study group consisted of 118 consecutively pregnant women with singleton pregnancy, patients of Outpatients Department of the Endocrinology, Diabetes, and Metabolic Disorders Clinic. All were prospectively screened for GDM between 24th and 28th week of pregnancy and followed to delivery. Outcome measures included: patients' ages, pre-pregnancy BMI, BMI before delivery, FPG, 1 and 2 hour OGTT glucose values, haemoglobin A1c at third trimester, gestational week of delivery, mode of delivery and baby birth weight.

RESULTS

From 118 pregnancies, 78 (66.1%) women were with GDM, and 40 (33.9%) without GDM. There were statistically significant differences (30.7 versus 5.0%, p < 0.01) between LGA newborns from GDM and control group, respectively. Gestation week of delivery and fasting glucose levels were independent predictors for LGA (Beta = 0.58 and Beta = 0.37 respectively, p < 0.01). Areas under the receiver operator characteristic curve (AUC) were compared for the prediction of LGA (0.782 (0.685-0.861) for fasting, 0.719 (0.607-0.815) for 1-hour and 0.51 (0.392-0.626) for 2-hour OGTT plasma glucose levels).

CONCLUSION

Fasting and 1-hour plasma glucose levels from OGTT may predict LGA babies in GDM pregnancies.

Diagnosis and Management of IUGR in Pregnancy Complicated by Type 1 Diabetes Mellitus

This review discusses available literature on the diagnosis and management of intrauterine growth restriction (IUGR) in women with type 1 diabetes. IUGR is diagnosed when ultrasound-estimated fetal weight is below the 10th percentile for gestational age. IUGR diagnosis implies a pathologic process behind low fetal weight. IUGR in pregnancy complicated by type 1 diabetes is usually caused by placental dysfunction related to maternal vasculopathy. Prevention of IUGR should ideally start before pregnancy. Strict glycemic control and intensive treatment of nephropathy and hypertension are essential. Low-dose aspirin initiated before 16 gestational weeks can also reduce IUGR risk in women with vasculopathy. Umbilical and uterine artery Doppler studies can guide diagnosis and surveillance of fetuses with IUGR. Decisions regarding the timing of delivery should be based on assessment of umbilical artery Doppler. The risk of prematurity and impaired fetal lung maturation should always be considered, especially in fetuses younger than 32 weeks.

Glucose variability in diabetic pregnancy

BACKGROUND

Fetal overgrowth is the most important complication of gestational (GDM) and pregestational diabetes mellitus.

METHODS

We correlated maternal glucose profiles, as detected by continuous glucose monitoring (CGM), with fetal growth parameters for 80 pregnant women (32 with type 1 diabetes, 31 with GDM, and 17 healthy controls). Glucose profiles were monitored in the first, second, and third trimesters of pregnancy for type 1 diabetes women and in the second and third trimesters for GDM women and controls. To analyze glycemic variability, we considered the mean amplitude of glycemic excursion, mean glycemia, the continuous overlapping net glycemic action (CONGA), the SD, the High Blood Glucose Index (HBGI), the Low Blood Glucose Index, and the interquartile range (IQR).

RESULTS

Mean age was the same for the three groups. Prepregnancy body mass index was higher for the women with diabetes (GDM and type 1) than for controls. The newborn's mean birth weight and ponderal index were higher, although not significantly so, for the women with diabetes than for controls. For the type 1 diabetes patients, ponderal index correlated with the HBGI in the first trimester, CONGA1 and IQR in the second, and mean glycemia and SD in the third. For GDM patients, ponderal index correlated with mean glycemia and the HBGI in the second trimester.

CONCLUSIONS

Fetal exposure to glycemic variability and hyperglycemia seems to be important in determining fetal overgrowth in pregnant women with diabetes. Optimal glucose control and less glucose variability are needed as early as possible in both type 1 diabetes and GDM patients to ensure normal fetal growth.

Antepartum A1C, maternal diabetes outcomes, and selected offspring outcomes: an epidemiological review

Between 1989 and 2004, the prevalence of gestational diabetes mellitus (GDM) in the United States increased by 122%. Glycated haemoglobin, as measured by haemoglobin A1C (A1C), can potentially identify pregnant women at high risk for adverse outcomes associated with GDM including macrosomia and post-partum glucose intolerance. Our objective was to systematically review the literature with respect to A1C levels during pregnancy and associated maternal and offspring outcomes. We used MEDLINE to identify relevant publications from 1975 to 2009. We included articles if they met the following criteria: original full text articles in English; primary exposure of antepartum A1C; women with GDM at baseline or who developed GDM during the study; primary outcome of GDM, insulin use, post-partum abnormal glucose or type 2 diabetes (T2DM), birthweight, macrosomia or large for gestational age. Case series and case reports were excluded. Twenty studies met our criteria. A1C at GDM diagnosis was positively associated with post-partum abnormal glucose. Women with post-partum T2DM or impaired glucose tolerance had mean A1C at GDM diagnosis higher than those with normal post-partum glucose (P ≤ 0.002) and a 1% increase in A1C at GDM diagnosis was associated with 2.36 times higher odds of post-partum abnormal glucose 6 weeks after delivery [95% confidence interval 1.19, 4.68]. The association of A1C and birthweight varied substantially between studies, with correlation coefficients ranging from 0.11 to 0.51. A1C, a less burdensome and costly measure than an oral glucose tolerance test, appears to be an attractive measure for identifying women at high risk of adverse outcomes associated with GDM.

Birth size distribution in 3,705 infants born to mothers with type 1 diabetes: a population-based study

OBJECTIVE

To characterize birth size distribution in infants born to mothers with type 1 diabetes. In particular, the relationship between birth weight (BW) and length (BL) was studied because it may provide information on different causal pathways of fetal macrosomia commonly seen in diabetic pregnancies.

RESEARCH DESIGN AND METHODS

This was a population-based cohort study of 3,705 infants of type 1 diabetic mothers (1,876 boys), with a gestational age of 28-43 weeks, born in Sweden between 1998 and 2007. BW and BL were retrieved from the Medical Birth Registry and expressed as SD scores (SDS). Ponderal index (PI) was calculated as BW in g/length in cm³. A BW >90th and a PI ≤ 90th percentile was defined as proportionate large-for-gestational age (LGA), whereas if both BW and PI > 90th percentile, the infant was categorized as disproportionately large. Values are mean (SD).

RESULTS

The BW distribution for offspring of type 1 diabetic mothers was bell-shaped, significantly broader, and markedly shifted to the right (BWSDS: 1.27 [1.48]) of the reference. Of the infants born to diabetic mothers, 47% were LGA, and among them, 46% were disproportionately large compared with 35% in nondiabetic LGA infants (P < 0.001). Female offspring of type 1 diabetic mothers had significantly higher BWSDS than males (1.34 vs. 1.20, P < 0.01), and preterm infants had higher BWSDS than term infants (1.41 vs. 1.23, P < 0.01)

CONCLUSIONS

Fetal macrosomia in type 1 diabetic pregnancies is due to a right-shift and broadening of the entire BW distribution. The large number of disproportionate LGA infants born to type 1 diabetic mothers suggests an underlying metabolic problem. Fetal macrosomia was more pronounced in preterm and female offspring of type 1 diabetic mothers.

Prediction of macrosomia at birth in type-1 and 2 diabetic pregnancies with biomarkers of early placentation

OBJECTIVE

To evaluate the value of first trimester placental biomarkers (fβ-hCG, PAPP-A, ADAM12, PP13 and PlGF) and fetal nuchal translucency (NT) in the prediction of macrosomia at birth in pregestational type-1 and type-2 diabetes (PGDM).

DESIGN

Nested case-control study.

SETTING

Routine first-trimester combined test.

POPULATION

A total of 178 PGDM and 186 control pregnancies.

METHODS

ADAM12, PP13 and PlGF concentrations were measured in stored first-trimester serum, previously tested for fβ-hCG and PAPP-A. All concentrations were expressed as multiples of the median (MoM). Where applicable, the median MoMs of PGDM and control pregnancies were compared in relation to birthweight centiles (≤90th centile, non-macrosomic, versus >90th centile, macrosomic). Model-predicted detection rates for fixed false-positive rates were obtained for statistically significant markers, separately and in combination.

MAIN OUTCOME MEASURES

Prediction of macrosomia in diabetic pregnancies.

RESULTS

In the PGDM group, median ADAM12 MoM (0.88; P = 0.007) was lower than in the controls. Subgroup analyses showed that median MoMs of PAPP-A (0.65), ADAM12 (0.85), PP13 (0.81) and PlGF (0.91) were only reduced in the PGDM non-macrosomic birthweight subgroup (n = 93) compared with other weight subgroups. In the PGDM macrosomic birthweight subgroup (n = 69), MoMs of all markers were comparable with the control birthweight subgroups. The screening performance for macrosomia at birth in the PGDM group provided a detection rate of 30% for a 5% false-positive rate (FPR) and 43% for a 10% FPR.

CONCLUSIONS

Macrosomia at birth in PGDM pregnancies may be predicted by normal levels of PAPP-A, ADAM12, PP13 and PlGF already in the first trimester of pregnancy. Fetal birthweight in PGDM offspring is partially determined by placental development during the first trimester of pregnancy. The present increase in fetal macrosomia may be related to better early glycemic control and placentation.

Fetal growth trajectories in Type-1 diabetic pregnancy

OBJECTIVE

To describe the individual intrauterine growth patterns of fetuses of insulin-dependent (Type-1) diabetic women and to examine determinants of overgrowth (macrosomia) and its timing.

METHODS

This retrospective longitudinal study examined the developmental trajectories of fetal abdominal circumference (AC) and biparietal diameter in 76 Type-1 diabetic women with singleton pregnancies. Latent class analysis was used to identify subgroups of patients with a shared fetal AC growth trajectory. Subsequently, maternal factors, including glycemic control as assessed by glycosylated hemoglobin (HbA1c), were examined to see whether they had any effect on fetal growth.

RESULTS

Four subgroups with different AC growth patterns were identified. Differences in birth weight between the distinct subgroups were related to the shape of the AC growth velocity curve over gestation. Acceleration of AC growth commencing before or after 25 weeks' gestation was associated with the birth of a heavy or large-for-dates baby in 94 and 56% of cases, respectively. Poor glycemic control (HbA1c > 7.0%) during the periconception period or before 12 weeks' gestation was a modest predictor of midtrimester growth in AC. Other diabetes-related factors, fetal sex, parity, or maternal weight/obesity were unrelated to the fetal growth pattern.

CONCLUSION

The findings suggest that an individual fetus's growth trajectory is set early in gestation and that the contemporaneous degree of maternal glycemia plays a role in determining birth weight.

Placental structure in type 1 diabetes: relation to fetal insulin, leptin, and IGF-I

OBJECTIVE

Alteration of placental structure may influence fetal overgrowth and complications of maternal diabetes. We examined the placenta in a cohort of offspring of mothers with type 1 diabetes (OT1DM) to assess structural changes and determine whether these were related to maternal A1C, fetal hematocrit, fetal hormonal, or metabolic axes.

RESEARCH DESIGN AND METHODS

Placental samples were analyzed using stereological techniques to quantify volumes and surface areas of key placental components in 88 OT1DM and 39 control subjects, and results related to maternal A1C and umbilical cord analytes (insulin, leptin, adiponectin, IGF-I, hematocrit, lipids, C-reactive protein, and interleukin-6).

RESULTS

Intervillous space volume was increased in OT1DM (OT1DM 250 + or - 81 cm(3) vs. control 217 + or - 65 cm(3); P = 0.02) with anisomorphic growth of villi (P = 0.025). The placentas showed a trend to increased weight (OT1DM 690 + or - 19 g; control 641 + or - 22 g; P = 0.08), but villous, nonparenchymal, trophoblast, and capillary volumes did not differ. Villous surface area, capillary surface area, membrane thickness, and calculated morphometric diffusing capacity were also similar in type 1 diabetic and control subjects. A1C at 26-34 weeks associated with birth weight (r = 0.27, P = 0.03), placental weight (r = 0.41, P = 0.0009), and intervillous space volume (r = 0.38, P = 0.0024). In multivariate analysis of cord parameters in OT1DM, fetal IGF-I emerged as a significant correlate of most components (intervillous space, villous, trophoblast, and capillary volumes, all P < 0.01). By contrast, fetal insulin was only independently associated with capillary surface area (positive, r(2) = 6.7%; P = 0.02).

CONCLUSIONS

There are minimal placental structural differences between OT1DM and control subjects. Fetal IGF-I but not fetal insulin emerges as a key correlate of placental substructural volumes, thereby facilitating feedback to the placenta regarding fetal metabolic demand.

Erythrocytosis in offspring of mothers with Type 1 diabetes--are factors other than insulin critical determinants?

AIM

Maternal diabetes is associated with polycythaemia and thrombocytopaenia in the offspring; however, the relationship with fetal hormones is unknown. We assessed the association of maternal glycaemic control, birthweight and fetal hormones with haematological indices in pregnancies complicated by maternal diabetes.

METHODS

Prospective study using cord blood samples from 89 offspring of mothers with Type 1 diabetes (OT1DM) and 34 control offspring. Full blood count, insulin, leptin, adiponectin, cortisol, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3, intercellular adhesion molecule 1 and C-reactive protein were measured in the umbilical vein at birth.

RESULTS

Haematocrit was higher in OT1DM (OT1DM 0.55 +/- 0.17%, control offspring 0.51 +/- 0.06%; P = 0.02). The difference in platelets count was not statistically significant [OT1DM 214 x 10(9)/l (173-259); control offspring 253 x 10(9)/l (180-310), P = 0.06]. Maternal glycated haemoglobin (HbA(1c)) showed a moderate positive correlation with fetal haematocrit (r = 0.30, P = 0.02). Cord platelet counts were negatively associated with birthweight in OT1DM (r = -0.27, P = 0.01). In multivariate models, cord insulin was not associated with haematocrit, but cord leptin was negatively associated with platelets in control offspring (P < 0.001) and OT1DM (P = 0.046), with additional contributions from male sex (P = 0.08) in OT1DM, and IGF-1 (P = 0.04) and insulin (P = 0.04) in control offspring.

CONCLUSIONS

Fetal haematocrit is increased in response to diabetes in pregnancy and is related to maternal glycaemic control. Fetal hyperinsulinism, hyperleptinaemia or macrosomia, although readily demonstrable in this cohort, do not emerge as determinants of raised fetal haematocrit in OT1DM. Both increased birthweight and fetal leptin are negatively associated with platelet count.

Intrauterine growth rate in pregnancies complicated by type 1, type 2 and gestational diabetes

Fetal macrosomia is a feature of all subtypes of maternal diabetes. The intrauterine time course of development of macrosomia in type 1, type 2 and gestational diabetes (GDM) could identify the times of more rapid growth, which differ as a result of different influences in subtypes of diabetes. Higher maternal weight in type 2 and GDM may be expected to contribute to macrosomia and the blood glucose control will exert an additional influence. Information was collected prospectively on 217 pregnancies in insulin-treated women at a single centre over a six-year period. All women were managed by a single team of obstetricians and diabetologists at a Joint Obstetric Medical Clinic. The rate of increase in abdominal circumference from 28 weeks was identical in each subtype of diabetes and there were no differences between subtypes at the earliest gestation assessed. Use of customized growth centiles showed rates of macrosomia to be similar in type 1, type 2 and GDM (43.0%, 50.0% and 41.8%, respectively). The intrauterine time course to macrosomia is similar in type 1, type 2 and GDM. The relationship of macrosomia to extent of elevation of mean blood glucose control is weak, implying a low threshold for maximal effect on the rate of fetal growth.

TYPE 1 DIABETES IN PREGNANCY; INFLUENCES ON MOTHER AND FETUS

Type 1 diabetes complicates around 1 in 200 to 300 pregnancies in the United Kingdom. Historically maternal type 1 diabetes carried very high risks for mother and child. Introduction of insulin led to an immediate, marked decline in the previously very high rates of maternal mortality; in contrast an improvement in perinatal outcomes occurred more slowly but was nevertheless dramatic. This is strikingly demonstrated by the temporal decline in perinatal mortality in offspring of mothers with type 1 diabetes which was virtually universal before use of insulin in the 1920's, likely remained in excess of 20% even in the 1960's and fell to under 4% by the 1990's. The reasons for this more gradual improvement in perinatal outcomes cannot be defined with precision but will have been influenced by improved glycaemic management with use of intensive, multiple dose insulin treatment and home glucose monitoring; improvements in obstetric and neonatal management, and better management of complications of diabetes before and during pregnancy. In 1989 the St Vincent declaration proposed that pregnancy outcomes in women with type 1 diabetes should approximate those of the non-diabetic population. While the long term improvements in fetal outcomes have been dramatic, contemporary surveys confirm a persistent doubling or more of rates of congenital anomaly and a three to four fold increase in perinatal mortality in the UK and other European countries which will require further clinical innovation to overcome.

Prediabetes and the big baby

The concept of prediabetes has come to the fore again with the worldwide epidemic of Type 2 diabetes. The careful observations of W. P. U. Jackson and his colleagues in Cape Town, South Africa 50 years ago still deserve attention. Maternal hyperglycaemia cannot be the only cause of fetal macrosomia, and the pathophysiological reason for the unexplained stillbirth in late diabetic pregnancy still eludes us. The biochemical concepts of 'facilitated anabolism' and 'accelerated starvation' were developed by Freinkel as explanations of the protective mechanisms for the baby during the stresses of pregnancy. Some of these nutritional stresses may also occur in the particular form of early childhood malnutrition known in Africa as kwashiorkor, where subcutaneous fat deposition, carbohydrate intolerance, islet hyperplasia and sudden death may follow a period of excess carbohydrate and deficient protein intake. Different feeding practices in different parts of the world make comparisons uncertain, but there is evidence for insulin resistance in both the macrosomic fetus of the hyperglycaemic mother and in the child with established kwashiorkor. These adaptive changes in early development may play both a physiological and a pathological role. Worldwide studies of hyperglycaemia in pregnancy are gradually establishing acceptable diagnostic criteria, appropriate screening procedures and an evidence base for treatment. Nevertheless the challenge of prediabetes and the big baby is still with us--in Jackson's words--'diabetes mellitus is a fascinating condition-the more we know about it the less we understand it'.

Inflammation and endothelial activation is evident at birth in offspring of mothers with type 1 diabetes

OBJECTIVE

Offspring of mothers with diabetes are at risk of obesity and glucose intolerance in later life. In adults, markers of subclinical inflammation (C-reactive protein [CRP] and interleukin [IL]-6) and endothelial activation (intracellular adhesion molecule [ICAM]-1) are associated with obesity and higher risk for incident type 2 diabetes. We examined whether these biomarkers were elevated at birth in offspring of type 1 diabetic mothers (OT1DM).

RESEARCH DESIGN AND METHODS

Umbilical cord plasma CRP, IL-6, and ICAM-1 were measured in 139 OT1DM and 48 control offspring, with analysis relative to fetal lipids and hormonal axes.

RESULTS

OT1DM had higher median (interquartile range) CRP (OT1DM 0.17 mg/l [0.13-0.22] vs. control subjects 0.14 mg/l [0.12-0.17], P < 0.001) and ICAM-1 (OT1DM 180 ng/ml [151-202] vs. control subjects 166 ng/ml [145-187], P = 0.047). IL-6 was not different after necessary adjustment for mode of delivery. Birth weight was unrelated to inflammatory indexes; however, leptin was correlated with CRP (control subjects r = 0.33, P = 0.02; OT1DM r = 0.41, P < 0.001) and with IL-6 (r = 0.23, P < 0.01) and ICAM-1 (r = 0.29, P < 0.001) in OT1DM. In OT1DM, CRP correlated with maternal glycemic control (A1C at 35-40 weeks; r = 0.28, P = 0.01). In multivariate analysis, leptin was a determinant of CRP (P < 0.001), ICAM-1 (P = 0.003), and IL-6 (P = 0.02) in OT1DM. Inflammatory measures demonstrated positive relationships with triglycerides in OT1DM (CRP, IL-6, and ICAM-1 P < 0.05) and control subjects (ICAM-1 P = 0.001).

CONCLUSIONS

Inflammatory markers are increased in OT1DM and are related to measures of fetal adiposity, particularly leptin, and maternal glycemia. Subclinical inflammation is a novel component of the diabetic intrauterine environment and should be considered a potential etiological mechanism for in utero programming of disease.

Fetal growth is increased by maternal type 1 diabetes and HLA DR4-related gene interactions

AIMS/HYPOTHESIS

Intrauterine growth in non-diabetic pregnancies is reported to be influenced by type 1 diabetes susceptibility genes. In particular, the high-risk HLA DR4_DQB1*0302 haplotype is associated with increased birthweight. The aim of this study was to determine whether HLA DR4 was associated with increased birthweight in a maternal diabetes environment and whether effects persisted during early childhood.

SUBJECTS AND METHODS

Birthweight and gestational age were obtained in singleton births from mothers with type 1 diabetes (n = 1161) or whose fathers or siblings have type 1 diabetes (n = 872). Weight and height at ages 2 and 5 years were obtained from paediatric records. Data were adjusted for (gestational) age and sex and expressed as percentiles of German reference data. HLA DR typing was obtained for all children and 1090 children also had insulin gene (INS) variable number of tandem repeats (VNTR) typing.

RESULTS

Maternal type 1 diabetes was associated with increased birthweight, gestational age and birthweight percentiles (all p < 0.0001). In children of mothers with type 1 diabetes, birthweight percentile was further related to maternal HbA(1c) during pregnancy (r = 0.26; p < 0.0001) and was independently increased if children had HLA DR4 alleles (76th vs 64th percentile; p < 0.0001). HLA DR4 was not associated with birthweight in children of non-diabetic mothers. Birthweight was not associated with INS VNTR genotypes. High birthweight, but not HLA DR4 was associated with increased weight and BMI at ages 2 and 5 years (p < 0.0001).

CONCLUSIONS/INTERPRETATION

Our findings are consistent with the hypothesis that a diabetic intrauterine environment interacts with gene(s) marked by the type 1 diabetes susceptibility HLA DR4 alleles to increase fetal growth.

Maternal glycated haemoglobin, pre-gestational weight, pregnancy weight gain and risk of large-for-gestational-age babies: a Danish cohort study of 209 singleton Type 1 diabetic pregnancies

AIMS

To examine the association between maternal glycated haemoglobin in the second half of diabetic pregnancies and the relative risk of delivering large-for-gestational-age (LGA) babies, controlling for maternal body mass index (BMI) before pregnancy, weight gain, age, White class and smoking habits.

METHODS

We identified all pregnant diabetic women in North Jutland County, Denmark from 1985 to 2003. Data on HbA(1c) values from the 20th gestational week to term were collected from medical records and the babies were classified as large, normal or small for gestational age. The association between glycated haemoglobin (HbA(1c)) and relative risk of delivering an LGA baby was quantified based on logistic regression models and stratified analysis controlling for the five covariates.

RESULTS

We included 209 singleton pregnancies with assessable HbA(1c) values of which 59%[95% confidence interval (CI) 52-65%] terminated with an LGA baby. Increasing levels of HbA(1c), BMI and weight gain were all associated with increasing risk of delivering an LGA baby. Analyses stratified according to maternal BMI showed that the association between HbA(1c) and risk of delivering an LGA baby was restricted to pregnancies with pre-pregnancy BMI > 23 kg/m(2). We found no association between HbA(1c) and risk of delivering an LGA baby in pregnancies with lower BMI.

CONCLUSION

The positive association between glycated haemoglobin and birth of an LGA baby seems to be restricted to women with BMI > 23 kg/m(2).

Type 1 diabetes and pregnancy: trends in birth weight over 40 years at a single clinic

OBJECTIVE

To examine changes in perinatal mortality and birth weight of babies born to mothers with pregestational type 1 diabetes over 40 years in a single teaching hospital clinic.

METHODS

This was a retrospective survey of cases from the combined diabetes and obstetrics antenatal clinic at the Royal Infirmary of Edinburgh and Simpson Memorial Maternity Pavilion, Edinburgh, Scotland. Birth weight, standardized birth weight, and perinatal mortality were obtained from 643 singleton babies born after 28 weeks of gestation to mothers with pregestational type 1 diabetes between 1960 and 1999.

RESULTS

There was a dramatic improvement in perinatal mortality rate, falling from 225 (per 1,000 total births after 28 weeks of gestation) in the 1960s to 102 in the 1970s, 21 in the 1980s, and 10 in the 1990s (P < .001 for effect of birth year). In contrast, standardized birth weight (adjusted for sex, gestational age, and parity), which was significantly higher than the background population (+1.41 standard deviations above the population norm, P < .001) showed no significant change over time.

CONCLUSION

Changes in diabetic management and obstetric practice over the 40 years of our survey have resulted in enormous improvements in the outlook for offspring of mothers with diabetes. Somewhat surprisingly this has not been associated with a reduction in overgrowth of the fetus.

LEVEL OF EVIDENCE

II-2.

What proportion of birth weight is attributable to maternal glucose among infants of diabetic women?

OBJECTIVE

This study was undertaken to determine the proportion of birth weight attributable to glucose concentrations of diabetic mothers.

STUDY DESIGN

Data of diabetic women who used insulin were eligible for analysis if the women had been treated during pregnancy for at least 12 weeks, and had recorded at least 50% of 4 daily glucose checks (fasting and 1-hour postprandial) until the last office visit before delivery. The independent association between maternal glucose values and demographics and birth weight percentiles for gestational age and gender were analyzed by multiple regression methods.

RESULTS

Data of 90 diabetic women were analyzed. Only third-trimester glucose concentrations were associated with birth weight. Prepregnancy body mass index was also selected in the models, including second- and/or third-trimester glucose. Together, these variables explained 18% of the variance in birth weight percentiles.

CONCLUSION

Maternal glycemia during third-trimester and prepregnancy body mass index are independent predictors of birth weight in pregnancies complicated by insulin-requiring gestational or type 2 diabetes.

Sibling birthweight as a predictor of macrosomia in women with type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to establish the value of maternal HbA1c levels and older sibling birthweight as predictors of birthweight and macrosomia in the offspring of women with type 1 diabetes.

SUBJECTS AND METHODS

A total of 214 pregnancies of 107 women with type 1 diabetes were studied. Regression analysis was performed to test the predictive value of the birthweight of the first-born infant, HbA(1)c levels, maternal BMI, maternal age and time between subsequent births on the birthweight of the second-born infant. Birthweights were corrected for sex and gestational age. The percentages of first- and second-born infants with macrosomia (weight >90th centile) were calculated and compared.

RESULTS

Only the birthweight of earlier born infants was significantly related to that of second-born infants (p<0.001) and 40-50% of the variation in the birthweight of second-born infants could be explained by the birthweight of the first-born infants. About 85% of the mothers who gave birth to a macrosomic infant had a macrosomic infant in a subsequent pregnancy.

CONCLUSIONS/INTERPRETATION

Although it is clear that glycaemic control contributes to birthweight in women with type 1 diabetes, the birthweight of an earlier born infant appears to be a much better predictor of the birthweight of a subsequent infant than HbA1c levels during pregnancy. It may, therefore, be used to identify patients at risk of giving birth to a macrosomic infant. Daily home monitoring of glucose levels, rather than HbA1c levels, should be used for assessment of maternal glycaemia during pregnancy.

The relation of insulin, leptin and IGF-1 to birthweight in offspring of women with type 1 diabetes

OBJECTIVE

Maternal diabetes is associated with excess foetal growth. We have assessed the influence of maternal diabetes on hormones associated with foetal growth and the relationship of these hormones to birthweight.

DESIGN

Case-control study.

PATIENTS

Singleton offspring of mothers with type 1 diabetes (ODM, n = 140) and control mothers (Control, n = 49).

MEASUREMENTS

Birthweight, cord blood insulin, proinsulin, 32-33 split proinsulin, leptin, IGF-1, IGFBP-3, cortisol.

RESULTS

Maternal diabetes was associated with higher birthweight (ODM 3.80 +/- 0.69 kg; Control; 3.56 +/- 0.52 kg, P = 0.02) and marked increases in insulin (median [interquartile range]: ODM 110 [60-217] pmol/l; Control 22 [15-37] pmol/l; P < 0.0001) and leptin (ODM 32 [15-60] ng/ml; Control 9 [4-17] ng/ml; P < 0.0001) but no absolute difference in IGF-1 (ODM 7.9 [6.2-9.8] nmol/l, Control 7.5 [6.2-9.8] nmol/l, P = 0.24) or its principle binding protein IGFBP-3 (ODM 1.63 +/- 0.38 micro g/ml, Control 1.63 +/- 0.28 micro g/ml; P = 0.12). Individually, insulin, insulin propeptides, leptin, IGF-1 and IGFBP-3 were significantly (P < 0.05) correlated with birthweight (in ODM and Control). IGF-1 and leptin were positively related to birthweight independently of each other and insulin in both ODM and Control. By contrast, insulin showed independent relationships to birthweight in ODM (P < 0.0001) but not in Control (P = 0.4).

CONCLUSIONS

Maternal diabetes is associated with marked elevation of insulin and leptin in cord blood of their offspring. Hormonal correlates of birthweight differ between ODM and Control with an independent relationship of insulin to birthweight observed only in ODM.

Adiponectin is present in cord blood but is unrelated to birth weight

OBJECTIVE

In adults, adiponectin is reduced in association with excess adiposity, type 2 diabetes, and hyperinsulinemia. We assessed whether adiponectin was 1) present in the fetal circulation, 2) altered in the fetal circulation in the presence of maternal diabetes, and 3) had relations to fetal cord blood insulin or adiposity.

RESEARCH DESIGN AND METHODS

We assessed adiponectin in cord blood in a large cohort of singleton offspring of diabetic mothers (ODM; n = 134) and control mothers (n = 45).

RESULTS

Adiponectin was present in cord blood and, in ODM, was higher in those delivered at later gestational ages (Spearman r = 0.18, P = 0.03). Adiponectin was slightly lower in ODM than control subjects (ODM 19.7 +/- 6.1 vs. control 21.8 +/- 5.3 micro g/ml; P = 0.04), although this difference could potentially reflect different gestational ages in the two groups (ODM 37.6 +/- 1.5 and control 40.1 +/- 1.1 weeks). In contrast to adults, adiponectin levels in the fetus were unrelated to the degree of adiposity, blood insulin, or leptin in either control subjects or ODM.

CONCLUSIONS

Adiponectin is present in cord blood but does not show expected physiological relations with adiposity as observed in adults.

The relationship between birth weight and maternal glycated haemoglobin (HbA1c) concentration in pregnancies complicated by Type 1 diabetes

AIM

To examine the relationships between maternal HbA1c concentration at different time points and birth weight in pregnancies complicated by pre-existing Type 1 diabetes.

METHODS

A comprehensive audit dataset was collected prospectively on all deliveries in Scotland to women with pre-existing Type 1 diabetes occurring between 1 April 1998 and 31 March 1999. Data items included HbA1c concentrations prior to conception and in each of the three trimesters of pregnancy, and birth weight. Relationships between standardized birth weight and HbA1c concentrations at each of the four time points were examined using correlation analysis.

RESULTS

Standardized birth weight (Z scores) could be calculated for 203 of 208 singleton liveborn infants. HbA1c concentrations, standardized to correct for assay differences among hospitals, at different time points were available for between 134 (pre-pregnancy) and 192 (third trimester) cases. Standardized birth weight, relative to a reference population, showed a unimodal distribution, shifted to the right (mean, +1.57 sd). There was a significant negative correlation between pre-pregnancy HbA1c and birth weight (Spearman's R, -0.208; P = 0.016). There were no statistically significant correlations for other time points.

CONCLUSIONS

Standardized birth weight scores of the infants of diabetic mothers are higher than those of a reference population. There is no simple relationship between maternal glycaemic status and birth weight, but there appears to be a paradoxical inverse relationship between pre-pregnancy glycaemic control and standardized birth weight.