Infants of diabetic mothers with accelerated fetal growth by ultrasonography: are they all alike?

Anthropometric and Skin Fold Thickness Measurements of Newborns of Gestational Glucose Intolerant Mothers: Does it Indicate Disproportionate Fetal Growth?

AIM OF THE STUDY

Studies have shown that gestational diabetes mellitus (GDM) causes disproportionate growth and increased adiposity in their newborns; however, the effect of gestational glucose intolerance (GGI), i.e., 2 h plasma glucose (PG) between 120 and 139 mg/dl in pregnancy on their newborns growth and adiposity is not well established. The objective of the present study is to evaluate the effect of GGI in pregnancy on anthropometry and adiposity of their newborns at birth in urban South Indian population.

MATERIALS AND METHODS

An observational study was conducted on 119 urban South Indian pregnant women and their newborns. PG levels 2 h after ingestion of 75 g glucose load were determined between 24 and 28 weeks of gestation, and depending on their PG levels, these women were categorized into three different groups, (a) normal glucose tolerance (NGT)-2 h PG < 120 mg/dl, (b) GGI-2 h PG between 120 and 139 mg/dl and (c) GDM-2 h PG > or = 140 mg/dl. GDM mothers were treated with insulin and MNT advised. GGI mothers were advised MNT. These women were followed up till delivery. After delivery, their newborn's anthropometry like weight, length, head circumference (HC), chest circumference (CC), mid-arm circumference, abdominal circumference, bisacromial diameter and subscapular and triceps skin fold thicknesses (SFT) was measured within 72 h of birth. Effect of GGI in pregnancy on newborn's anthropometry and SFT was analyzed and studied in comparison with newborns of other two categories. Further, the newborns were stratified into four groups according to their birth weight and newborns of GGI category were compared with newborns of other two categories of same weight.

RESULTS

The triceps and subscapular skin fold thicknesses which are direct measurements of adiposity were significantly higher in newborns of GGI mothers compared to newborns of GDM and NGT mothers. GGI category newborns showed increased adiposity even when they were compared with newborns of GDM and NGT category of same weight. Also measurements which are likely to increase due to increased adiposity like bisacromial diameter, abdominal circumference, mid-arm circumference were significantly higher in GGI category newborns. On the other hand, measurements which indicate skeletal growth like length, HC, CC were similar in all three category newborns. This confirmed disproportionate growth and increased adiposity in newborns of GGI mothers. It should be noted here that the GDM mothers were on MNT and treated with insulin, the dose of insulin was adjusted so as to mimick Fasting PG and Post Prandial PG levels of NGT mothers.

CONCLUSION

Gestational glucose intolerance during pregnancy does cause disproportionate growth (increased fat body mass but not skeletal mass) and increased adiposity in their newborns. This emphasizes the need for strict glycemic control (2 h of PG level after 75 grams glucose load to < 120 mg/dl and PPPG levels to < 120 mg/dl) during pregnancy. Larger multicentered studies are recommended to confirm this association.

Fetal growth factors and fetal nutrition

Optimal fetal growth is important for a healthy pregnancy outcome and also for lifelong health. Fetal growth is largely regulated by fetal nutrition, and mediated via the maternal and fetal glucose/insulin/insulin-like growth factor axes. Fetal nutrition may reflect maternal nutrition, but abnormalities of placental function can also affect fetal growth, as the placenta plays a key intermediary role in nutritional signalling between mother and fetus. Fetal nutrition also impacts on the development of key fetal endocrine systems such as the glucose-insulin and insulin-like growth factor axes. This is likely to contribute to the link between both fetal growth restriction and fetal overgrowth, and increased risks of obesity and impaired glucose tolerance in later life. This review focuses on the associations between maternal and fetal nutrition, fetal growth and later disease risk, with particular emphasis on the role of insulin-like growth factors and the importance of the periconceptional period.

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.

Activities of cyclooxygenases, and levels of prostaglandins E2 and F2alpha, in fetopathy associated with experimental diabetic gestation

AIM

The present study investigated the cyclooxygenase (COX) pathway to elucidate any changes that may be involved in the mechanism(s) underlying diabetic fetopathy.

METHODS

Diabetes was induced in female rats (n=12) by two successive daily injections of 55 mg/kg streptozotocin, while control animals (n=10) were injected with a buffer solution; hyperglycaemia was confirmed by blood glucose levels greater than 11 mmol/L. The study female rats were made pregnant and, on day 15 of gestation, the rats were sacrificed, and the fetuses, placentas and membranes dissected out of the uterine horns. Following morphological examination, the fetuses, placentas and membranes were homogenized, and used to measure COX activities and prostaglandin (PG) E(2) and PGF(2alpha) levels.

RESULTS

Fetuses from diabetic mothers exhibited significantly (P<0.05) shorter crown-to-rump lengths, lower body weights and heavier placental weights. The activity of COX-1 in the fetuses, placentas and membranes from diabetic mothers represented a small percentage of total COX activity compared with that of COX-2. The presence of a COX-1 inhibitor in the control and diabetic rats was investigated and found to be negative. The activity of COX-2 in malformed fetuses from diabetic mothers was significantly lower (P<0.05) compared with non-malformed fetuses from control and diabetic mothers. The mean level of PGE(2) in fetuses from diabetic mothers was significantly (P<0.05) lower than that in controls. In contrast, the biggest increases in PGF(2alpha) were observed in the malformed diabetic fetuses, placentas and membranes.

CONCLUSION

The increased production of PGF(2alpha) probably proceeds, at least in part, independently of the COX pathway and via the isoprostane route. However, it is unclear whether the relatively high levels of PGF(2alpha) are causally related to, or simply coincidental with, fetal malformation.

Early rapid growth, early birth: accelerated fetal growth and spontaneous late preterm birth

The past two decades in the United States have seen a 24% rise in spontaneous late preterm delivery (34-36 weeks) of unknown etiology. This study tested the hypothesis that fetal growth was identical prior to spontaneous preterm (n = 221, median gestational age at birth 35.6 weeks) and term (n = 3706) birth among pregnancies followed longitudinally in Santiago, Chile. The hypothesis was not supported: Preterm-delivered fetuses were significantly larger than their term-delivered peers by mid-second trimester in estimated fetal weight, head, limb, and abdominal dimensions, and they followed different growth trajectories. Piecewise regression assessed time-specific differences in growth rates at 4-week intervals from 16 weeks. Estimated fetal weight and abdominal circumference growth rates slowed at 20 weeks among the preterm-delivered, only to match and/or exceed their term-delivered peers at 24-28 weeks. After an abrupt growth rate decline at 28 weeks, fetuses delivered preterm did so at greater population-specific sex and age-adjusted birth weight percentiles than their peers from uncomplicated pregnancies (P < 0.01). Growth rates predicted birth timing: one standard score of estimated fetal weight increased the odds ratio for late preterm birth from 2.8 prior to 23 weeks, to 3.6 (95% confidence interval, 1.82-7.11, P < 0.05) between 23 and 27 weeks. After 27 weeks, increasing size was protective (OR: 0.56, 95% confidence interval, 0.38-0.82, P = 0.003). These data document, for the first time, a distinctive fetal growth pattern across gestation preceding spontaneous late preterm birth, identify the importance of mid-gestation for alterations in fetal growth, and add perspective on human fetal biological variability.

The levels of vascular endothelial growth factor-A and placental growth factor-2 in embryopathy associated with experimental diabetic gestation

The objective of this study was to investigate the role of vascular endothelial growth factor-A (VEGF-A) and placental growth factor-2 (PlGF-2) in fetal malformations associated with maternal diabetes. Diabetes was induced in female rats. Diabetic and control female rats were made pregnant. On Day 15 of gestation, rats were sacrificed and embryos and their placentas and membranes were dissected out of the uterine horns. Following morphological examination, embryos and their placentas and membranes were homogenized and used for assayed of VEGF-A and PlGF-2 levels. Embryos of diabetic mothers, exhibited significantly (P < 0.05) shorter crown-to-rump lengths, smaller weights, and heavier placental weights. Experimentally induced maternal diabetes was accompanied by decreased VEGF-A in embryos and associated structures. The levels of PlGF-2 in non-malformed embryos of diabetic gestation and their placentas were significantly (P < 0.05) lower than the average of controls. These results might indicate defective vascularization with a consequent morphological or anatomical anomalies or more subtle biochemical or metabolic changes. In diabetic mothers, a statistically significant (P < 0.05) decrease was noted in the level of VEGF-A in plasma of diabetic rats with a small non-significant decrease in PlGF-2. Like many other diabetic complications, diabetes-induced embryopathies might have vascular origin and correcting the disturbances in these angiogenic factors might help decrease the incidence of malformation in diabetic gestation.

Reproducibility of sonographic assessment of fetal liver length in diabetic pregnancies

OBJECTIVES

Assessing fetal liver size might be useful in monitoring the effectiveness of the treatment of diabetes in pregnancy. We aimed to assess the reproducibility of fetal liver-length measurement in pregnant women with diabetes.

METHODS

From 3 April 2006 to 5 December 2006, we assessed intraobserver and interobserver variation of fetal liver-length measurements on 55 sonograms in 44 pregnant women with diabetes, 34 of whom had gestational diabetes. The mean maternal age was 33 years, the mean maternal weight was 92 kg and the mean body mass index (BMI) was 33.7 kg/m(-2). The effect of covariates BMI, gestational age and maternal age on the reproducibility of fetal liver length was assessed by calculating intraobserver SD ratios. We compared liver length with abdominal circumference and gestational age. Nine of 12 sonographers scanned, on average, six women (range, 3-12) as the first sonographer, and all 12 sonographers scanned, on average, four women (range, 1-10) as the second sonographer. The data were analyzed using a hierarchical linear model.

RESULTS

Measurement of fetal liver length was reproducible. The intraobserver SD was 3.06 (95% CI, 2.68-3.59) mm; the interobserver SD was 2.17 (95% CI, 0.59-4.83) mm; the intraobserver correlation was 0.77 (95% CI, 0.63-0.87), and the interobserver correlation was 0.84 (95% CI, 0.51-0.99). The covariate effects were minimal, the SD for a 1-unit increase in the covariate was 1.06 for gestational age, 0.98 for BMI, and 0.97 for maternal age.

CONCLUSIONS

Measurement of fetal liver length in the diabetic pregnancy is reproducible. It is worthy of further investigation as a parameter for monitoring the effectiveness of treatment of the diabetic pregnancy.

Detection and prevention of macrosomia

It is overly simplistic to try to identify optimal glycemic thresholds, fetal growth characteristics, and methods of detection in the prevention of fetal overgrowth and its attendant morbidities that can be applied to all pregnancies. We can only hope that, as our understanding of the pathophysiology of diabetes in pregnancy grows, we can "fine-tune" our therapy and surveillance to meet the needs of an individual woman who has diabetes and her fetus.

Pregnancy in women with pre-existing diabetes: management issues

Despite significantly increased input from multidisciplinary teams during the antenatal period, pregnancy outcomes for women with type 1 and type 2 diabetes remain substantially worse than that of the general obstetric population. Regarding fetal congenital malformations, these are likely to be preventable only by strategies introduced prior to pregnancy. The relationship between fetal macrosomia and glycaemic control is complex, and reducing the incidence of macrosomia may be possible only by novel management strategies that address the wide fluctuations in blood glucose over a 24-hour period. Irrespective of pregnancy diabetes control, the complication of neonatal hypoglycaemia can largely be avoided by tight control of glucose values during labour and delivery. The continued lack of understanding of the pathophysiology of late fetal death in diabetic pregnancies and the shortcomings of current methods of antenatal fetal surveillance make it likely that infants of diabetic mothers will continue to be delivered preterm, with the attendant implications of neonatal morbidity and cost.

Exposure to maternal diabetes is associated with altered fetal growth patterns: A hypothesis regarding metabolic allocation to growth under hyperglycemic-hypoxemic conditions

The prevalence of diabetes is rising worldwide, including women who grew poorly in early life, presenting intergenerational health problems for their offspring. It is well documented that fetuses exposed to maternal diabetes during pregnancy experience both macrosomia and poor growth outcomes in birth size. Less is known about the in utero growth patterns that precede these risk factor expressions. Fetal growth patterns and the effects of clinical class and glycemic control were investigated in 37 diabetic pregnant women and their fetuses and compared to 29 nondiabetic, nonsmoking maternal/fetal pairs who were participants in a biweekly longitudinal ultrasound study with measurements of the head, limb, and trunk dimensions. White clinical class of the diabetic women was recorded (A2-FR) and glycosylated hemoglobin levels taken at the time of measurement assessed glycemic control (median 6.9%, interquartile range 5.6-9.2%). No significant difference in fetal weight was found by exposure. The exposed sample had greater abdominal circumferences from 21 weeks (P < or = 0.05) and shorter legs, but greater upper arm and thigh circumferences accompanied increasing glycemia in the second trimester. In the third trimester, exposed fetuses had a smaller slope for the occipital frontal diameter (P = 0.00) and were brachycephalic. They experienced a proximal/distal growth gradient in limb proportionality with higher humerus / femur ratios (P = 0.04) and arms relatively long by comparison with legs (P = 0.02). HbA1c levels above 7.5% accompanied shorter femur length for thigh circumference after 30 gestational weeks of age. Significant effects of diabetic clinical class and glycemic control were identified in growth rate timing. These growth patterns suggest that hypoxemic and hyperglycemic signals cross-talk with their target receptors in a developmentally regulated, hierarchical sequence. The increase in fetal fat often documented with diabetic pregnancy may reflect altered growth at the level of cell differentiation and proximate mechanisms controlling body composition. These data suggest that the maternal-fetal interchange circuit, designed to share and capture resources on the fetal side, may not have had a long evolutionary history of overabundance as a selective force, and modern health problems drive postnatal sequelae that become exacerbated by increasing longevity.

Determinants of fetal growth at different periods of pregnancies complicated by gestational diabetes mellitus or impaired glucose tolerance

OBJECTIVE

To determine maternal parameters with the strongest influence on fetal growth in different periods of pregnancies complicated by an abnormal glucose tolerance test (GTT).

RESEARCH DESIGN AND METHODS

Retrospective study of 368 women with gestational diabetes mellitus (GDM; > or = 2 abnormal GTT values, n = 280) and impaired glucose tolerance (IGT; one abnormal value, n = 88) with 869 ultrasound examinations at entry to and during diabetic care. Both groups were managed comparably. Abdominal circumference (AC) > or = 90th percentile defined fetal macrosomia. Maternal historical and clinical parameters, and diagnostic and glycemic values of glucose profiles divided into five categories of 4 weeks of gestational age (GA; <24 weeks, 24 weeks/0 days to 27 weeks/6 days, 28/0-31/6, 32/0-35/6, and 36/0-40/0 [referred to as <24 GA, 24 GA, 28 GA, 32 GA, and 36 GA categories, respectively]) were tested by univariate and multiple logistic regression analysis for their ability to predict an AC > or = 90th percentile at each GA group and large-for-gestational-age (LGA) newborn. Data obtained at entry were also analyzed separately irrespective of the GA.

RESULTS

Maternal weight, glycemia after therapy, rates of fetal macrosomia, and LGA were not significantly different between GDM and IGT; thus, both groups were analyzed together. LGA in a previous pregnancy, (odds ratio [OR] 3.6; 95% CI 1.8-7.3) and prepregnancy obesity (BMI > or = 30 kg/m(2); 2.1; 1.2-3.7) independently predicted AC > or = 90th percentile at entry. When data for each GA category were analyzed, no predictors were found for <24 GA. Independent predictors for each subsequent GA category were as follows: at 24 GA, LGA history (OR 9.8); at 28 GA, LGA history (OR 4.2), and obesity (OR 3.3); at 32 GA, fasting glucose of 32 GA (OR 1.6 per 5-mg/dl increase); at 36 GA, fasting glucose of 32 GA (OR 1.6); and for LGA at birth, LGA history (OR 2.7), and obesity (OR 2.4).

CONCLUSIONS

In the late second and early third trimester, maternal BMI and LGA in a previous pregnancy appear to have the strongest influence on fetal growth, while later in the third trimester coincident with the period of maximum growth described in diabetic pregnancies, maternal glycemia predominates.

A randomized controlled trial using glycemic plus fetal ultrasound parameters versus glycemic parameters to determine insulin therapy in gestational diabetes with fasting hyperglycemia

OBJECTIVE

To compare management based on maternal glycemic criteria with management based on relaxed glycemic criteria and fetal abdominal circumference (AC) measurements in order to select patients for insulin treatment of gestational diabetes mellitus (GDM) with fasting hyperglycemia.

RESEARCH DESIGN AND METHODS

In a pilot study, 98 women with fasting plasma glucose (FPG) concentrations of 105-120 mg/dl were randomized. The standard group received insulin treatment. The experimental group received insulin if the AC, measured monthly, was > or =70th percentile and/or if any venous FPG measurement was >120 mg/dl. Power was projected to detect a 250-g difference in birth weights.

RESULTS

Gestational ages, maternal glycemia, and AC percentiles were similar at randomization. After initiation of protocol, venous FPG (P = 0.003) and capillary blood glucose levels (P = 0.049) were significantly lower in the standard group. Birth weights (3,271 +/- 458 vs. 3,369 +/- 461 g), frequencies of birth weights >90th percentile (6.3 vs 8.3%), and neonatal morbidity (25 vs. 25%) did not differ significantly between the standard and experimental groups, respectively. The cesarean delivery rate was significantly lower (14.6 vs. 33.3%, P = 0.03) in the standard group; this difference was not explained by birth weights. In the experimental group, infants of women who did not receive insulin had lower birth weights than infants of mothers treated with insulin (3,180 +/- 425 vs. 3,482 +/- 451 g, P = 0.03).

CONCLUSIONS

In women with GDM and fasting hyperglycemia, glucose plus fetal AC measurements identified pregnancies at low risk for macrosomia and resulted in the avoidance of insulin therapy in 38% of patients without increasing rates of neonatal morbidity.

Diabetic embryopathy in C57BL/6J mice. Altered fetal sex ratio and impact of the splotch allele

Maternal diabetes (types 1 and 2) induces a broad array of congenital malformations, including neural tube defects (NTDs), in humans. One of the difficulties associated with studying diabetic embryopathy is the rarity of individual malformations. In an attempt to develop a sensitive animal model for maternal diabetes-induced NTDs, the present study uses chemically induced diabetes in an inbred mouse model with or without the splotch (Sp) mutation, a putatively nonfunctional allele of Pax3. Pax3 deficiency has been associated with an increase in NTDs. Female C57BL/6J mice, either with or without the Sp allele, were injected intravenously with alloxan (100 mg/kg), and plasma glucose was measured 3 days later. A wide range of hyperglycemia was induced, and these diabetic mice were bred to C57BL/6J males, some carrying the Sp allele. Gestational-day-18 fetuses were examined for developmental malformations. Fetuses from matings in which either parent carried the Sp allele were genotyped by polymerase chain reaction. Maternal diabetes significantly decreased fetal weight and increased the number of resorptions and malformations, including NTDs. A significant correlation was found between the level of maternal hyperglycemia and the malformation rate. The sex ratio for live fetuses in diabetic litters was significantly skewed toward male fetuses. Matings involving the Sp allele yielded litters with significantly higher percentages of maternal diabetes-induced spina bifida aperta but not exencephaly, and this increase was shown to be associated with the presence of a single copy of the Sp allele in affected fetuses. Thus, Pax3 haploinsufficiency in this murine model of diabetic embryopathy is associated with caudal but not cranial NTDs.

Fetal biometry: clinical, pathological, and technical considerations

Sonographic measurements of fetal ultrasound parameters are the basis for accurate determination of gestational age and detection of fetal growth abnormalities. Selection of the most useful single biometric parameter depends on the timing and purpose of measurement and is influenced by specific limitations. CRL (crown-rump length) is the best parameter for early dating of pregnancy. Biparietal diameter (BPD) maintains the closest correlation with gestational age in the second trimester. In cases of variation in the shape of the skull, head circumference is an effective alternative. Abdominal circumference is the most useful dimension to evaluate fetal growth, and femur length is the best parameter in the evaluation of skeletal dysplasia. Use of multiple predictors improves the accuracy of estimates. An individual approach to each pregnancy is recommended for fetal growth assessment. The various epidemiological factors involved in fetal growth should be considered and specific charts for different communities should be used when possible. The methods of fetal weight estimation with their limitations and potential errors are presented. Clinical application of fetal biometry in abnormal growth is discussed in cases of small- and large-for-gestational-age fetuses, chromosomal aberrations, and skeletal dysplasias.

Estimating fetal weight in the management of macrosomia

The purpose of this review is to examine the evidence that, including estimates of fetal macrosomia in patient care, will decrease adverse perinatal outcomes. A literature search for the years 1980 to 1999 was used. Shoulder dystocia and brachial plexus injuries occur more often in macrosomic than in non-macrosomic neonates. However, 26 to 58 percent of shoulder dystocias and 24 to 44 percent of brachial plexus injuries occur to babies weighing less than 4000 gm. Persistence of impairment is extremely rare. Neither historical nor clinical factors have strong positive predictive values for macrosomia. From 15 to 81 percent of the babies predicted to be macrosomic are confirmed by birth weight. Of babies determined to be macrosomic at birth, only 50 to 100 percent were successfully predicted. Shoulder dystocia and brachial plexus injuries are unpredictable events. Available evidence suggests that planned interventions based on estimates of fetal weight do not reduce the incidence of shoulder dystocia and do not decrease adverse outcomes attributable to fetal macrosomia.

Ultrasound growth parameters in relation to levels of amniotic fluid insulin in women with diabetes type-I

The aim of the study was to investigate the correlation between ultrasound parameters and levels of amniotic fluid insulin (AF-insulin) in pregnancies complicated by insulin-dependent diabetes mellitus (IDDM). In 129 women with IDDM amniocentesis was performed between 28 and 35 weeks of gestation. The levels of AF-insulin were measured by radioimmunoassay (Pharmacia RIA 100) and were correlated with biparietal diameter (BPD), abdominal diameter (AD), abdominal circumference (AC), and femur length (FL). The women were maintained at good glycemic control (fructosamine level: mean +/- S.D.: 236.3 +/- 40 micromol/l) and delivered infants with a mean (+/- S.D.) birth weight of 3477 +/- 640 g. The sensitivity of BPD, AD, AC and FL to detect fetuses with pathological levels of AF-insulin was 50%, 62%, 67% and 49%, respectively. The sensitivities of AD and AC in a selected group (n = 14) with highly pathological levels of AF-insulin (> 20 microU/ml) were both 80%, whereas the specificity was 56% and 46%, respectively. In women with IDDM, fetal biparietal diameter, abdominal diameter, abdominal circumference, and femur length are not reliable markers for the identification of fetal hyperinsulinism. Only cases with highly pathological levels of AF-insulin can be detected by abdominal measurements.

Anthropometric characteristics of full-term infants: effects of varying degrees of "normal" glucose metabolism

Aim of this study was to examine the maternal-neonatal outcome and the neonatal anthropometric characteristics of a full-term mother-infant pairs group with a positive oral glucose challenge test (GCT) without gestational diabetes mellitus (GDM). Our study involved 1615 white women with singleton pregnancies who underwent universal screening for GDM in two periods of pregnancy. This population was divided into three groups according to GCT results: 1) 172 patients with abnormal GCT in both periods; 2) 391 patient with normal GCT in the early period and abnormal GCT in the late period; 3) 1052 patients with normal GCT in both periods (control group). The incidence of LGA (large for gestational age) infants was higher in Group (40.7%) and Group 2 (22.0%) respect to control group (8.3%) (p < 0.00001 and p < 0.0001 respectively) and was significantly different in the two groups (p < 0.0008). Comparison among the three groups of LGA infants showed the following results: male and female newborns of Group I were heavier than those of Group 2 and of the control group, while males and females of the control group had significantly greater length and cranial circumference means. A significant decrease in ponderal index, choracic circumference, weight/length ratio means could be seen as well as a significative increase in cranial/thoracic circumference ratio means from Group I to the control group. These data confirm the involvement of fetal development in terms of weight and anthropometric characteristics in the presence of alterations in maternal glucose metabolism which are not currently classified as gestational diabetes.

Growth promoting peptides in diabetic and non-diabetic pregnancy: interactions with trophoblastic receptors and serum carrier proteins

Infantile macrosomia in diabetic pregnancy (DP) is commonly attributed to fetal hyperinsulinism. However, insulin-like growth factors in the mother and the fetus, their binding proteins and their placental receptors may also play roles in the process of fetal overgrowth. We measured levels of maternal and cord serum IGF-I, IGF-II, C-peptide, IGFBP-1, IGFBP-2 and IGFBP-3 in 8 White Class B insulin dependent DP and 8 non-diabetic pregnancies (NP). These results were correlated with the concentration and affinity of placental trophoblastic membrane receptors (TR) for insulin (IN), IGF-I and IGF-II as well as with infant and placenta weights and maternal body mass indices. Significant respective differences between the diabetic and non-diabetic groups were found in mean infant weight, 4248 +/- 114 vs 3555 +/- 119 g (p < 0.001), placental weight 765 +/- 51 vs 575 +/- 24 g (p < 0.01), maternal body mass index 32.8 +/- 3.8 vs 21.3 +/- 1.2 (p < 0.02), cord serum IGF-I 136.8 +/- 6.6 vs 85.9 +/- 5.7 ng/ml (p < 0.01), cord serum C-peptide 18.7 +/- 3.5 vs 9.0 +/- 1.7 ng/ml (p < 0.025), cord serum IGFBP-1 21.9 +/- 4.7 vs 133.2 +/- 43.2 ng/ml (p < 0.025), cord serum IGFBP-2 672.0 +/- 76 vs 1206 +/- 220 ng/ml (p < 0.05) and cord serum IGFBP-3 11.5 +/- 1.0 vs 5.6 +/- 0.6 ng/ml (p < 0.001). No significant differences were found between DP and NP with respect to cord serum IGF-II, maternal serum IGF-I, IGF-II, C-peptide, IGFBP-1, IGFBP-2 and IGFBP-3, and the concentration and affinity of TR for IN, IGF-I and IGF-II. Analysis of variance revealed an interaction between infant weight and the weight of the placenta (p < 0.01), cord IGF-I (p < 0.02), cord C-peptide (p < 0.01) and cord IGFBP-3 (p < 0.01). Regression analysis revealed significant correlations of cord IGF-I with cord values of IGFBP-2 (r = -0.52, p = 0.04) and IGFBP-3 (r = 0.66, p < 0.005). Maternal serum IGF-I significantly correlated only with maternal IGFBP-3 (r = 0.65, p < 0.01). These results suggest that increased fetal production of insulin and IGF-I may contribute to the development of infantile macrosomia in DP. Concomitant changes in fetal production of IGFBPs, particularly IGFBP-2 and IGFBP-3, may modulate the action of insulin and IGFs. The lack of change in number or binding affinity of placental trophoblastic receptors for insulin, IGF-I and IGF-II tends to exclude a significant regulatory role of these receptors in the production of fetal macrosomia.

Diabetic fetal macrosomia: significance of disproportionate growth

Fetal hyperinsulinism in infants of diabetic mothers (IDMs) produces increased fetal growth leading to macrosomia, which may or may not be proportionate. Disproportionate macrosomia refers to excessive weight characterized by a high weight/length ratio. We tested the hypotheses that (1) macrosomia in IDMs would be characterized by a high ponderal index (defined as weight/length ratio) and (2) infants with macrosomia who have a high ponderal index would have increased neonatal morbidity--specifically, hyperbilirubinemia, hypoglycemia, polycythemia, and acidosis. We studied 170 IDMs and 510 non-IDMs matched 1:3 for gestational age, race, and year of delivery. Forty-five percent of IDMs had macrosomia compared with 8% of control infants (p = 0.001), and 19% of IDMs had disproportionate macrosomia compared with 1% of control infants (p = 0.001). The rates of hyperbilirubinemia (p = 0.02), hypoglycemia (p = 0.01), and acidosis (p = 0.01) were greatest in infants with disproportionate macrosomia and least in nonmacrosomic infants. The incidence of polycythemia was not significantly different between the groups. We suggest that disproportionate macrosomia in the IDM is associated with an increased likelihood of neonatal complications.

Growth and motor development in fetuses of women with type-1 diabetes. I. Early growth patterns

Early embryonic and fetal growth were followed longitudinally in 23 women with type-1 diabetes to investigate whether there was any evidence of early growth delay and, if so, when it originated and when catch-up growth occurred. Weekly crown-rump length (CRL) measurements were taken between 7 and 14 weeks of gestation; the biparietal diameter (BPD) of the fetal head was measured once every 2-4 weeks from 13 to 30 weeks of gestation. Data were compared to those of a control group and to control data published in the literature. The CRL of the fetuses in the diabetic group was generally shorter than that observed normally. Six out of the 23 (26%) fetuses showed true early growth delay (a size smaller than normal by 6 days or more). Growth delay was present from the first recording onwards and must therefore have occurred before the seventh gestational week. Fetal growth (BPD) was found to be normal at around 20 weeks and there was evidence of accelerated growth of the BPD during the second trimester in fetuses that became macrosomic. Early embryonic growth delay was most profound in the women whose periconceptional quality of glucose control was poor, although the relationship with the HbAlc values was not statistically significant. It is concluded that fetuses of women with type-1 diabetes, as a group, have a significantly different growth pattern than control fetuses throughout the first 30 weeks of pregnancy.