What is the significance of macrosomia?

Interactive effects and relative contribution of prepregnancy overweight and obesity, excessive gestational weight gain and gestational diabetes mellitus to macrosomia: A retrospective cohort in Fujian, China

AIM

To conduct a retrospective cohort study to investigate the association between prepregnancy overweight and obesity, excessive gestational weight gain (GWG), gestational diabetes mellitus (GDM) and macrosomia, both individually and in combination.

METHODS

Binary logistic regression was used to analyse the effects of overweight and obesity, excessive GWG and GDM on macrosomia, both separately and in combination. The interaction effects between prepregnancy overweight and obesity, excessive GWG and GDM were tested. The population attributable fraction (PAF) was calculated separately when interaction terms were significant.

RESULTS

When analysed separately, prepregnancy overweight and obesity, excessive GWG and GDM increased the risk of macrosomia significantly. The pairwise interactions of each pair of risk factors or all three risk factors on macrosomia appear to be greater than any of them individually. Prepregnancy overweight and obesity contributed the least (5.69%) to macrosomia, while GDM contributed the most (8.5%). The PAF values for prepregnancy overweight and obesity/GDM, excessive GWG/GDM, and prepregnancy overweight and obesity/excessive GWG were 13.6%, 16.25% and 14.45%, respectively, and the total PAF for all three risk factors was 22.63%.

CONCLUSIONS

Prepregnancy overweight and obesity, excessive GWG and GDM were associated with newborn macrosomia.

Association of Triglyceride-Glucose Index with Risk of Large for Gestational Age: A Prospective Cohort Study

Background

To evaluate the association of the baseline triglyceride-glucose (TyG) index in the first trimester of pregnancy with the risk of large for gestational age (LGA) in Southeast Chinese pregnant women.

Methods

A prospective birth cohort study recruiting 12,108 pregnant women at their first prenatal visit before 13 gestation weeks was conducted in 2019-2022. Baseline characteristics were collected from medical records or using questionnaires and blood samples were collected in the first trimester. The TyG index was obtained through the formula: ln[triglyceride (mg/dl)×fasting plasma glucose (mg/dl)/2]. The binary logistic regression model was performed to calculate the odds ratio (OR) and 95% confidence intervals (CI) to reveal the relationship between TyG index and LGA. Receiver-operating characteristic curve analysis was conducted to evaluate the ability of the TyG index to predict the risks of LGA.

Results

The overall incidence of LGA in the current study was 11.4% and the incidence of LGA increased with the baseline TyG index increasing. The risk of LGA was 2.05 (1.64, 2.57) for per unit increase in baseline TyG index. The increasing trend was found across the TyG index quartiles and the highest TyG quartiles raised the risk of LGA to 1.86 (95% CI: 1.51, 2.27) compared to the bottom TyG quartiles after full adjustment. The risk of LGA remained positive after stratification analysis. The AUC was 0.584 (95% CI: 0.569~0.600) in the entire subject, and the threshold was 8.34, with a sensitivity of 0.74 and specificity of 0.38.

Conclusion

The findings suggested that a higher TyG index in the first trimester was independently associated with higher risk of LGA and high TyG index in the first trimester may play as a early predictor for LGA.

Secular Trends of Birth Weight in Twins and Singletons in South Korea from 2000 to 2020

Whether the decline of birth weight (BW) reported in developed countries in the early 2000s is ongoing remains unknown. Furthermore, despite recent sharp increases in twin births, comparing secular trends of BW between singletons and twins is difficult, as studies have rarely examined secular trends of BW in twins and singletons simultaneously. Therefore, this study aimed to investigate the most recent 20-year trends (2000-2020) of BW in twins and singletons in South Korea. Annual natality files from 2000 to 2020 obtained from the Korean Statistical Information Service were analyzed. A yearly decrease of BW was 3 g among singletons and 5 to 6 g in twins from 2000 to 2020, indicating a widening gap of BW between twins and singletons with increasing years. Gestational age (GA) also decreased in twins and singletons with yearly decreases of 0.28 days in singletons and 0.41 days in twins. Whereas BW decreased in term (GA ≥ 37 weeks), and very preterm groups (28 weeks ≤ GA < 32 weeks) from 2000 to 2020 in twins and singletons, it increased in moderate to late preterm (32 weeks ≤ GA < 37 weeks) groups, indicating a non-linear relationship between BW and GA. The prevalence of macrosomia (BW > 4000 g) in singletons decreased from 2000 to 2020, whereas low birth weight (LBW; BW < 2500 g) increased in twins and singletons. LBW is associated with adverse health outcomes. Effective public health strategies aiming at reduction in the incidence of LBW in the population should be developed.

Air pollution exposure and the risk of macrosomia: Identifying specific susceptible months

Birth weight is an important indicator of future growth and development for newborns. Few studies investigated the potential effects of air pollutants on macrosomia and their susceptible windows. We included 38,971 singleton full-term births from Beijing HaiDian Maternal and Child Health Hospital between 2014 and 2018, and assessed the associations of air pollutants exposure during preconception and pregnancy with macrosomia as well as the corresponding susceptible windows. The concentrations of air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃) for participants were calculated by the data from the nearest monitoring stations. Distributed lag models (DLM) incorporating logistic regression models were used to estimate the associations between air pollutants exposure during the 3 months before conception and pregnancy period and the risk of macrosomia, identifying susceptible windows of air pollutants. Weighted quantile sum (WQS) regression was applied to estimate the joint effect of air pollutants. A 10 μg/m³ increase in PM_2.5 exposure from 3rd to 8th gestational month was positively associated with the risk of macrosomia, with the strongest effect in the 6th month (OR = 1.010, 95 % CI: 1.002-1.019). For a 10 μg/m³ increase in SO₂, the windows of significant exposure were from the 1st preconception month to the 3rd gestational month, with the strongest effect in the 2nd month (OR = 1.030, 95 % CI: 1.010-1.049). We also observed the significant positive associations were in the 5th-8th gestational months for PM₁₀, the 8th-9th gestational months for NO₂ and the 3rd-7th gestational months for CO respectively. WQS regression also indicated a positive association between co-exposure to air pollutants and macrosomia. Our results suggest air pollution exposure is associated with increased risk of macrosomia. The windows of exposure for susceptibility to the risk of macrosomia vary between air pollutants. The susceptible exposure windows were middle and late pregnancy for PM, CO and NO₂, while for SO₂, early pregnancy is the window of vulnerability. Our findings provide the evidence that air pollution exposure is an independent risk factor for macrosomia and a basis for targeted environment policy.

Large for gestational age and macrosomia in pregnancies without gestational diabetes mellitus

Objective: This study aims to estimate the prevalence and risk factors of macrosomia and LGA (large for gestational age) in non-GDM (gestational diabetes mellitus) pregnant women in Fuyang, Anhui Province of China.Methods: A large population-based cohort study was conducted among non-GDM pregnant women aged 18-45 years. Maternal sociodemographic data prior to pregnancy were collected using interviewer-administered standardized questionnaire. Maternal obstetrical delivery records and newborn hospital records were extracted from antenatal care booklets and hospital discharge abstracts. Logistic regression analysis was used to identify the predictors of macrosomia and LGA.Results: The incidence of macrosomia and LGA was 9.2 and 15.9%, respectively. Mothers ≥35 years of age (aOR 2.75, 95% CI 1.98, 3.80), male neonates (aOR 1.68, 95% CI 1.51, 1.89), overweight and obese (aOR 1.61, 95% CI 1.34, 1.92 and aOR 3.05, 95% CI 2.05, 4.56, respectively) were associated with increased risk of macrosomia. Compared with the less educated mothers, the educated mothers were more likely to have increased risk of macrosomia. IFA (iron and folic acid) supplements intake during pregnancy was more likely to deliver macrosomia or LGA (aOR1.32, 95% CI 1.08, 1.49 and aOR1.42, 95% CI 1.24, 1.61, respectively) as compared with no IFA supplements intake. SCr (serum creatinine concentration) >80 µmol/L was related to decreased risk of macrosomia (aOR 0.73, 95% CI 0.61, 0.86) and LGA (aOR 0.67, 95% CI 0.59, 0.77) as compared with normal range (44-80 µmol/L).Conclusions: There was a high prevalence of macrosomia and LGA in non-GDM pregnant women in China. Healthcare educations and reasonable body weight are necessary for pregnant women to prevent macrosomia and LGA. Pregnant women should be checked regularly and have the first prenatal visit as soon as possible.

Correlation of placental microbiota with fetal macrosomia and clinical characteristics in mothers and newborns

Substantial studies indicated that fetal macrosomia was associated with detrimental pregnancy outcomes, and increased susceptibility to metabolic diseases in later life. However, investigations into the association between placental microbiota and fetal macrosomia are limited. We aimed to profile the placental microbiota of fetal macrosomia and study whether they relate to clinical characteristics. Placenta samples were collected from fetal macrosomias and newborns with normal birth weight. The clinical characteristics, umbilical cord blood parameters were measured, and placental microbiota were sequenced and further analysed. The clinical characteristics of infants and mothers and umbilical cord blood parameters were significantly different between macrosomias and controls. The relative abundance of microbiota sequences revealed that microbial structures of the placenta differed significantly between macrosomia and controls. Regression analysis showed a cluster of key operational taxonomic unit (OTUs), phyla and genera were significantly correlated with body length, ponderal index and placenta weight, body weight increase during pregnancy of mothers, and cord blood IGF-1 and leptin concentrations. In conclusion, our study for the first time explored the relationship between placental microbiota profile and fetal macrosomia. It is novel in showing that a distinct placental microbiota profile is present in fetal macrosomia, and is associated with clinical characteristics of mothers and newborns.

Influence of pre-pregnancy obesity on the development of macrosomia and large for gestational age in women with or without gestational diabetes mellitus in Chinese population

OBJECTIVE

To determine the effects of gestational diabetes mellitus (GDM) and pre-pregnancy obesity on macrosomia and large for gestational age (LGA).

STUDY DESIGN

We conducted a prospective cohort study of 587 GDM women and 478 non-GDM women from 2012 to 2013. We collected their data of the pre-pregnancy weight, sociodemographic data, medical histories, clinical treatment, and followed-up the outcomes of delivery including birth weight. Multiple logistic regression models were used to test associations between pre-pregnant obesity and macrosomia/LGA and between GDM and macrosomia/LGA.

RESULT

Of 1065 women we studied, obese women had 4.17 times and 2.27 times increased risk of developing macrosomia (95% CI: 2.52 to 6.91) and LGA (95% CI: 1.60 to 3.21), respectively, than non-obese women after adjustment for maternal age, gestational weeks and GDM. We did not find GDM is a risk factor for macrosomia or LGA after GDM treatment.

CONCLUSION

Pre-pregnancy obesity accounts for a high prevalence of macrosomia. Interventions that focus on pre-pregnancy obesity have the potential to reach far more women at risk of macrosomia.

Comparison of neonatal outcomes in macrosomic infants of diabetic and non-diabetic mothers

OBJECTIVE

To compare the neonatal outcomes in macrosomic term infants of diabetic mothers and non-diabetic mothers.

METHODS

This is a retrospective survey of all live-born term singletons with a birth weight ≥4000 g, admitted at Tianjin Medical University General Hospital between 2010 and 2013. Data collected for the mothers included age, parity, gestational age, method of glycemic control and mode of delivery. Data for the infants included sex, birth weight, birth length, duration of hospital stay and laboratory tests. Outcomes were compared between infants of diabetic mothers (IDMs) and infants of non-diabetic mothers (Non-IDMs). All data were analyzed using Statistical Package for Social Sciences (SPSS) 17.0.

RESULTS

One hundred and eleven infant-mother pairs met the inclusion criteria. Fifty-seven were IDMs while 54 were non-IDMs. Seven (12.28%) of the IDMs were delivered vaginally while 50 (87.72%) were delivered via Caesarian section (CS). Seventeen (31.48%) of the non-IDMs were delivered vaginally while 37 (68.51%) were delivered by CS. Respiratory distress was the most common morbidity affecting 52.6% of the IDMs and 40.7% of the non-IDMs. Hyperbilirubinemia was observed in 49.1% of the IDMs and 14.8% of the non-IDMs. Hypoglycemia affected 38.6% of the IDMs and 7.4% of the non-IDMs. Cardiac enzymes were higher in IDMs than in non-IDMs. On average, IDMs had a longer duration of hospital stay.

CONCLUSION

Macrosomic IDMs in comparison to macrosomic non-IDMs are at an increased risk for adverse neonatal outcomes.

Differential expression of circulating miRNAs in maternal plasma in pregnancies with fetal macrosomia

Macrosomia is associated with problems at birth and has life-long health implications for the infant. The aim of this study was to profile the plasma microRNAs (miRNAs or miRs) and evaluate the potential of circulating miRNAs to predict fetal macrosomia. The expression levels of miRNAs in plasma samples obtained from pregnant women with fetal macrosomia and from women with normal pregnancies (controls) were analyzed using TaqMan Low-Density Arrays (TLDAs) followed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) validation and analysis. The TLDA data revealed that 143 miRNAs were differentially expressed in the plasma samples from pregnant women with fetal macrosomia compared with the controls (43 upregulated and 100 downregulated miRNAs). Twelve of these miRNAs were selected for RT-qPCR analysis. Receiver operational characteristic (ROC) curve analysis indicated that several miRNAs (e.g., miR-141-3p and miR-200c-3p) were clearly distinguished between pregnancies with fetal macrosomia and other types of abnormal pregnancy and healthy pregnancies with high sensitivity and specificity (AUC >0.9). The expression of miRNA clusters also showed a similar trend in pregnancies with fetal macrosomia. This study provides a platform for profiling circulating miRNAs in maternal plasma. Our data also suggest that altered levels of maternal plasma miRNAs have great potential to serve as non-invasive biomarkers and as a mechanistic indicator of abnormal pregnancies.

Prevalence of macrosomia and its risk factors in china: a multicentre survey based on birth data involving 101,723 singleton term infants

BACKGROUND

Macrosomia, defined as a birthweight at least 4000 g, is a public health problem because of its adverse influences on maternal and neonatal outcomes. Studies show that there is an increasing prevalence of macrosomia births in developing countries. However, information on the epidemiology of macrosomia is limited in China. This study aimed to determine the prevalence and geographic variability of macrosomia in China and risk factors that can be targeted for intervention.

METHODS

A hospital-based, cross-sectional survey was conducted in 14 provinces in China, covering a wide range of geographic areas. The medical records of 101,723 singleton term infants born in 39 hospitals during 2011 were reviewed. Multiple logistic regression analysis was used to examine the associations between demographic characteristics and the risk of macrosomia.

RESULTS

The total prevalence of macrosomia was 7.3%. The prevalence varied between provinces, ranging from 4.1% to 13.4%. The prevalence of macrosomia in northern China (8.5%) was significantly higher than that in southern China (5.6%). Logistic regression analyses showed that risk of macrosomia was positively associated with maternal age, pre-pregnant body mass index (BMI), gravidity, parity, maternal height, gestational weight gain (GWG), gestational diabetes mellitus (GDM), and male fetal sex. Maternal BMI, gestational week, and GWG were the three risk factors most strongly associated with macrosomia.

CONCLUSIONS

The prevalence of macrosomia varied dramatically between different areas of China. High pre-pregnancy BMI and GWG represent main modifiable risk factors for macrosomia and need more attention from health care providers.

HbA1c levels in patients with gestational diabetes mellitus: Relationship with pre-pregnancy BMI and pregnancy outcome

BACKGROUND/AIMS

The use of glycated hemoglobin (HbA1c) measurement in gestational diabetes mellitus (GDM) is controversial. Aim of the present study was to determine HbA1c levels in a series of GDM patients, in order to verify the possible contribution of HbA1c to GDM management.

MATERIALS/SUBJECTS AND METHODS

The study included 148 caucasian GDM patients. GDM screening was performed between the 24th and the 28th week of gestation by a two-step procedure, according to the 4th and 5th International Workshop Conference on Gestational Diabetes Mellitus recommendations. Exclusion criteria were: preexisting diabetes, corticosteroid therapy, history of asthma or hypertension, known fetal anomaly, history of previous stillbirth, preterm delivery considered to be likely for either maternal disease or fetal conditions. HBA1c was determined by a standard HPLC technique.

RESULTS

At GDM diagnosis, all HbA1c levels were ≤ 6% and the greatest frequency (71/148; 48.0%) of HbA1c values resulted in the range 5.0-5.3%. This frequency increased to 54% before delivery. A significant correlation between HbA1c values at GDM diagnosis and individual BMI prior to conception was observed. The proportion of pregnancies presenting negative outcomes increased progressively with increasing HbA1c levels, from 6.2% (1/16) for HbA1c levels <5% to 18.3% (13/71) for HbA1c 5.0-5.3%, to 37.8% (17/45) in patients with HBA1c levels 5.4-5.6%, to 56.2% (9/16) for HbA1c levels >5.6%. ROC analysis showed that HbA1c at diagnosis and before delivery resulted a good predictor of adverse pregnancy outcome.

CONCLUSIONS

The present results indicate that HbA1c levels could be of help in predicting adverse pregnancy events.

Measurement of fetal fat in utero in normal and diabetic pregnancies using magnetic resonance imaging

OBJECTIVES

To assess the reliability of magnetic resonance imaging (MRI) to measure fetal fat volume in utero, and to study fetal growth in women with and without diabetes in view of the increased prevalence of macrosomia in the former.

METHODS

We studied 26 pregnant women, 14 with pre-gestational diabetes and 12 non-diabetic controls. Fetal assessment took place at 24 weeks' gestation and again at 34 weeks by standard ultrasound biometry followed by MRI at 1.5 T. Fetal fat volume was determined from T1-weighted water-suppressed images using a semi-automated approach based on pixel intensity and taking into account partial volume effects. Fetal volume was also determined from the MRI images. Fetal weight was calculated using published fat and lean tissue densities.

RESULTS

There was little fetal fat at 24 weeks' gestation, but at 34 weeks the fetal fat content was considerably higher in the women with diabetes, with a mean fat content of 1090 ± 417 cm(3) compared with 541 ± 348 cm(3) in the controls (P = 0.006). Measurements of fetal fat volume showed low intra- and interobserver variability at 34 weeks, with intraclass correlation coefficients consistently above 0.99. Birth-weight centile correlated with fetal fat volume (R(2)  = 0.496, P < 0.001), percentage of fetal fat (R(2)  = 0.362, P = 0.008) and calculated fetal weight (R(2)  = 0.492, P < 0.001) at 34 weeks.

CONCLUSIONS

MRI appears to be a promising tool for the determination of fetal fat, body composition and weight in utero during the third trimester of pregnancy.

The feto-placental endothelium in pregnancy pathologies

This review aims to provide a comprehensive summary of the aspects of endothelial and vascular dysfunction in the feto-placental vasculature occurring in pregnancy pathologies. This endothelium is continuous with the fetal circulation. Its function and potential dysfunction in pathologies will have a profound impact on fetal development. Gestational diabetes mellitus represents one of these pathologies, in which its associated metabolic derangements will alter feto-placental endothelial functions. These, in turn, may result in functional changes of the placenta, which may entail impaired fetal development. By contrast, changes in the feto-placental vasculature observed in cases of fetal growth restriction and preeclampsia may be causative (fetal growth restriction) or secondary (preeclampsia) for the pathology.

The effect of customized growth charts on the identification of large for gestational age newborns

OBJECTIVE

To determine the effect of using customized vs. standard population birthweight curves to define large for gestational age (LGA) infants.

METHODS

We analyzed data obtained from 2,097 singleton pregnancies using three different methods of classifying newborn birthweight: standard population curves, British or Spanish customized curves. We recorded maternal characteristics, proportion of LGA newborns when using each method, percentage of LGA according to one method but not for the others, and concordance between the different methods.

RESULTS

The proportion of LGA newborns according to Spanish customized curves was significantly lower than that calculated using either standard general population birthweight curves or British curves (p < 0.001). A third (33.9%) of the infants classified as LGA according to the general population method were adequate for gestational age (AGA) when the Spanish customized curves were used, and 18.5% of non-LGA were LGA according to customized curves (p < 0.001). Concordance between the different models high, but on excluding AGA the concordance coefficient was low (Cohen's κ <0.4).

CONCLUSIONS

The use of customized curves allows differentiation between constitutional LGA and cases of fetal overgrowth, leading to a decrease in the rate of both false-positives and negatives as well as the overall proportion of LGA babies.

Risk factors and long-term health consequences of macrosomia: a prospective study in Jiangsu Province, China

We sought to determine risk factors associated with fetal macrosomia and to explore the long-term consequence of infant macrosomia at the age of 7 years. A prospective population based cohort study was designed to examine the associations between maternal and perinatal characteristics and the risk of macrosomia. A nested case-control study was conducted to explore the long-term health consequence of infant macrosomia. The mean maternal age of the macrosomia group was 24.74±3.32 years, which is slightly older than that in the control group (24.35±3.14 years, P = 0.000). The mean maternal body mass index (BMI) at early pregnancy was 22.75±2.81 kg/m², which was also higher than that in the control group (21.76±2.59 kg/m², P = 0.000). About 64.6% of macrosomic neonates were males, compared with 51.0% in the control group (P = 0.000). Compared with women with normal weight (BMI: 18.5-23.9 kg/m²), women who were overweight (BMI: 24-27.9 kg/m²) or obese (BMI≥28 kg/m²), respectively, had a 1.69-fold (P = 0.000) and a 1.49-fold (P = 0.000) increased risks of having a neonate with macrosomia, while light weight (BMI<18.5 kg/m²) women had an approximately 50% reduction of the risk. Furthermore, macrosomia infant had a 1.52-fold and 1.50-fold risk, respectively, of developing overweight or obesity at the age of 7 years (P = 0.001 and P = 0.000). Older maternal age, higher maternal BMI at early pregnancy and male gender were independent risk factors of macrosomia. Macrosomic infant was associated with an increased predisposition to develop overweight or obesity at the beginning of their childhood.

Secular trends of macrosomia in southeast China, 1994-2005

Background

The rate of macrosomia (birth weight≥4, 000 g) increased over the past four decades in many parts of the world. Macrosomia is associated not only with higher risks of maternal and neonatal complications but also with health risks in adulthood. We examined trends in neonatal macrosomia and large-for-gestational-age (LGA) births among singleton, live, term and postterm births (≥37 complete weeks' gestation) in southeast China from 1994 to 2005 and explored possible causes of the temporal trends.

Methods

Data from Perinatal Health Care Surveillance System in 12 cities and counties in southeast China were analyzed for trends in birth weight, neonatal macrosomia and LGA from 1994 to 2005. A total of 594, 472 singleton live births were included. We conducted multiple logistic regression analyses to relate these trends to changes in maternal and pregnancy characteristics.

Results

The rate of macrosomia rose from 6.00% in 1994 to 8.49% in 2000 and then levelled off to 7.83% in 2005. Similar trends were observed in mean birth weight. The incidence of LGA births increased continuously from 13.72% in 1994 to 18.08% in 2000, but the LGA rate remained relatively stable from 2002 to 2005. There was a decrease in gestational age and a significant increase in frequency of prelabor caesarean delivery from 1994 to 2005. In an adjusted multivariable model, the increase in LGA rate from 1994 to 2000 was associated with increasing net gestational weight gain, maternal age, maternal height and maternal education. But they didn't fully explain the increase. The trends of 2002-2005 LGA declined after adjusted for maternal and neonatal characteristics.

Conclusions

In southeast China, the incidence of macrosomia increased from 1994 to 2000 was mainly related to increasing net gestational weight gain. The incidence of macrosomia has levelled off in recent years partly due to increasing use of prelabor caesarean delivery and earlier delivery and partly due to moderation of gestational weight gain.

Variation in Excessive Fetal Growth across Levels of Prenatal Care among Women with Gestational Diabetes

OBJECTIVE

Examine the association between prenatal care and excessive fetal growth outcomes among mothers with gestational diabetes mellitus (GDM).

METHODS

We conducted a retrospective analysis of 2004-2007 singleton live births to South Carolina women, limited to those for whom both birth certificate and hospital discharge data were available (N = 179 957). Gestational diabetes mellitus was identified from birth certificate and/or hospital discharge claims. Measures of excessive fetal growth were large for gestational age (90th and 95th percentiles) and macrosomia (birth weight > 4500 g). The Adequacy of Prenatal Care Utilization index was used to measure prenatal care.

RESULTS

Gestational diabetes mellitus was recorded for 6.9% of women in the study population. Women with GDM were more likely than other women to have an infant with excessive fetal growth, regardless of the level of prenatal care; however, there was a significant interaction between GDM status and levels of prenatal care. All women with GDM had increased odds for large infant outcomes. However, those receiving inadequate prenatal care were markedly more likely to experience excessive fetal growth outcomes (odds ratio = 1.38, confidence interval = 1.15-1.66) than women also with GDM and intermediate/adequate prenatal care. Similar patterns were noted for large for gestational age (95th) and macrosomia (total birth weight ≥ 4500 g).

CONCLUSIONS

Observed associations suggest a link between inadequate prenatal care and a higher risk for excessive fetal growth among women with GDM. Further research is needed to clarify the nature of the association and suggest ways to get high-risk women into care sooner.

Birth weight for gestational age centiles for Italian neonates

OBJECTIVE

To provide centiles for birth weight (BW) according to gestational age (GA) and sex for infants born in Italy.

METHODS

We used records of the whole neonatal population of Tuscany, a region in Italy, from July 1991 to June 2002 as resulting from the database of the cystic fibrosis neonatal screening program (n=290129). We excluded as unlikely for GA those BW that were more than two interquartile ranges above the 75th centile or below the 25th centile for each GA and gender group.

RESULTS

We present the 3rd, 10th, 25th, 50th, 75th, 90th and 97th centiles of BW for GA from the 24th to 43rd week of gestation for male and female Italian neonates, as both tables and smoothed curves.

CONCLUSIONS

The large size of the examined population allows us to provide up-to-date, reliable BW for GA centiles for Italian newborns, especially for lower GAs.

Fetal macrosomia and pregnancy outcomes

BACKGROUND

Pregnancies with a macrosomic fetus comprise a subgroup of high-risk pregnancies. There is uncertainty in the clinical management and outcomes of such pregnancies.

AIM

We sought to examine clinical management and maternal and fetal outcomes in pregnancies with macrosomic infants at Royal Brisbane and Women's Hospital (RBWH).

METHODS

Data from 276 macrosomic births (weighing > or = 4500 g) and 294 controls (weighing 3250-3750 g) delivered during 2002-2004 at RBWH were collected from the hospital database. Univariate and logistic regression analyses were performed for maternal risk factors and maternal and neonatal outcomes that were associated with fetal macrosomia.

RESULTS

Macrosomia was more than two times likely in women with body mass index (BMI) of > 30 kg/m(2) (odds ratio (OR) 2.41, 95% confidence interval (CI) 1.26-4.61) and in male infant sex (OR 2.05, 95% CI 1.35-3.12), and four times more likely in gestation of > 40 weeks (OR 3.93, 95% CI 1.99-7.74). Maternal smoking reduced the risk of fetal macrosomia (OR 0.27, 95% CI 0.14-0.51). Macrosomia was associated with nearly two times higher risk of emergency caesarean section (OR 1.75, 95% CI 1.02-2.97) and maternal hospital stay of > 3 days (OR 1.66, 95% CI 1.11-2.50), and four times higher risk of shoulder dystocia (OR 4.08, 95% CI 1.62-10.29). Macrosomic infants were twice as likely to have resuscitation (OR 2.21, 95% CI 1.46-3.34) and intensive care nursery admission (OR 1.89, 95% CI 1.03-3.46).

CONCLUSION

Macrosomia was associated with an increased risk of adverse maternal and neonatal health outcomes. Optimal management strategies of macrosomic pregnancies need evaluation.

Recurrence of fetal macrosomia in non-diabetic pregnancies

Fetal macrosomia (birth weight >/=4,500 g) is known to increase a number of adverse maternal and perinatal outcomes. Although there is a clear association between maternal diabetes mellitus and fetal macrosomia, the majority of macrosomic infants are born to non-diabetic mothers. We wished to determine the recurrence rate of macrosomia in non-diabetic pregnancy and to see if a history of multiple prior macrosomic infants confers additional risk. A retrospective analysis of 14,461 term, singleton, infants born to non-diabetic mothers in 1997 and 1998 was performed, using a computerised hospital database. Among 14,461 term pregnancies, 529 infants (3.7%) were macrosomic, and the incidence was significantly higher in parous women (4.6%) compared with nulliparas (2.4%, p < 0.0001). Over the next 5 years, 164 of these women returned for another delivery. Women with a history of one macrosomic infant are at significantly increased risk of another macrosomic infant in a subsequent pregnancy (OR 15.8, 95% CI 11.45 - 21.91, p < 0.0001). For women with two or more macrosomic infants, the risk is even greater (OR 47.4, 95% CI 19.9 - 112.89, p < 0.0001). Macrosomia was associated with increased rates of instrumental delivery and anal sphincter injury regardless of parity, and additionally with increased rates of caesarean delivery and shoulder dystocia among nulliparas. Overall, 88% of women who laboured with a macrosomic infant achieved vaginal delivery.

Neonatal diabetes mellitus

An explosion of work over the last decade has produced insight into the multiple hereditary causes of a nonimmunological form of diabetes diagnosed most frequently within the first 6 months of life. These studies are providing increased understanding of genes involved in the entire chain of steps that control glucose homeostasis. Neonatal diabetes is now understood to arise from mutations in genes that play critical roles in the development of the pancreas, of beta-cell apoptosis and insulin processing, as well as the regulation of insulin release. For the basic researcher, this work is providing novel tools to explore fundamental molecular and cellular processes. For the clinician, these studies underscore the need to identify the genetic cause underlying each case. It is increasingly clear that the prognosis, therapeutic approach, and genetic counseling a physician provides must be tailored to a specific gene in order to provide the best medical care.

Tracing the origins of “fetal origins” of adult diseases: Programming by oxidative stress?

Too small size at birth (due to poor fetal growth and/or preterm delivery) has been associated with substantially elevated risks of the metabolic syndrome (dislipidemia, insulin resistance, hypertension), type 2 diabetes and cardiovascular disease in adulthood. The mechanisms of such "fetal origins" or "programming" of disease phenomenon remain unresolved. Too large size at birth seems also associated with an increased risk. Many known or suspected causes of or conditions associated with adverse (poor or excessive) fetal growth or preterm birth have been associated with oxidative stress. Plausibly, oxidative stress may be a common link underlying the superficial "programming" associations between adverse fetal growth or preterm birth and elevated risks of certain chronic diseases. The mechanisms of oxidative stress programming may be through directly modulating gene expression or indirectly through the effects of certain oxidized molecules. Experimental investigations have well demonstrated the role of redox balance in modulating gene expression, and recent studies indicate that both the insulin functional axis and blood pressure could be sensitive targets to oxidative stress programming. Adverse programming may occur without affecting fetal growth, but more frequently among low birth weight infants merely because they more frequently experienced known or unknown conditions with oxidative insults. As oxidative stress levels are easily modifiable during pregnancy and early postnatal periods (which are plausible critical windows), the hypothesis, if proved valid, will suggest new measures that could be very helpful on fighting the increasing epidemic of the metabolic syndrome, type 2 diabetes and cardiovascular disease. Currently, there are several ongoing large randomized trials of antioxidant supplementation to counter oxidative stress during pregnancy for the prevention of preeclampsia. It would be invaluable if long-term follow-ups of infants born to women in such trials could be realized to test the oxidative stress programming hypothesis in such experimental trial settings.

Glucose concentration and AMP-dependent kinase activation regulate expression of insulin receptor family members in rat islets and INS-1E beta cells

AIMS/HYPOTHESIS

Glucose and the peptide growth factors insulin, IGF-I and IGF-II strongly regulate beta cell mass. Furthermore, beta cell expression of IGF-I receptor (Igf1r) and insulin receptor (Insr) is mandatory for several steps of insulin secretion.

MATERIALS AND METHODS

We hypothesised that glucose concentration might regulate expression of Igf1r, Insr and insulin receptor-related receptor (Insrr) in islets and beta cells. Moreover, since the ratio of ATP:ADP is the most important intracellular mechanism involved in insulin secretion, and since depletion of ATP leads to AMP accumulation, we evaluated the role of AMP-activated protein kinase (AMPK) in glucose-dependent receptor regulation.

RESULTS

In rat islets, high glucose exposure (25 mmol/l) increased gene expression of Igf1r, Insr and Insrr but also of the metabolic glycolysis gene liver-type pyruvate kinase (Pklr) compared with intermediate (6.2 mmol/l) or low glucose concentration (1.6 mmol/l) after 24 h. In rat INS-1E beta cells, only Pklr expression was suppressed by low glucose as in islets, while Insr and Insrr were suppressed by high and increased by low glucose levels. Igf1r expression was suppressed by both high- and low- glucose concentration. Activation of AMPK by 5-amino-imidazolecarboxamide riboside (AICAR, 0.5 mmol/l) suppressed Pklr expression, but strongly stimulated gene expression of Igf1r, Insr and Insrr. Protein expression of IR and IGF-IR reflected glucose and AICAR-regulated mRNA expression of both receptors in INS-1E cells.

CONCLUSIONS/INTERPRETATION

We conclude that glucose directly interacts with islet and beta cell expression of growth factor receptors that are mandatory for both beta cell growth and insulin secretion. Stimulation of Igf1r and Insr gene expression by the AMPK-activator AICAR might indicate involvement of AMPK in the regulation of Igf1r, Insr and Insrr expression in beta cells.

Hypoglycemia during the 100-g oral glucose tolerance test: incidence and perinatal significance

OBJECTIVE

To estimate and report the incidence and perinatal significance of hypoglycemia during the 100-g oral glucose tolerance test in pregnant women.

METHODS

Over a 3-year period, we analyzed the incidence and perinatal outcome of pregnant women who experienced hypoglycemia, defined as a plasma glucose level of 50 mg/dL or less while undergoing the 100-g oral glucose tolerance test. The study group included women who delivered singletons at term. Women who underwent the 100-g oral glucose tolerance test during the same period and had no hypoglycemia served as the control group.

RESULTS

A total of 805 women were included in the study, which comprised 51 women (6.3%) who experienced hypoglycemia during the test and 754 women in the control group. Gestational diabetes mellitus was diagnosed in 5/51 (9.8%) women in the study group, compared with 216/754 (28.6%) women in the control group (P < .03), and the neonates born to these women had significantly lower birth weights.

CONCLUSION

The incidence of reactive hypoglycemia during the 100-g oral glucose tolerance test in our population is 6.3%. Women who experience hypoglycemia during the test have a significantly lower incidence of gestational diabetes and neonatal birth weights.

Obstetric outcome of excessively overgrown fetuses (> or = 5000 g): a case-control study

AIMS

To compare the obstetric outcome of excessively- and appropriately-grown fetuses.

METHODS

Medical records of mothers who delivered excessively overgrown fetuses, defined as birthweight > or = 5000 g, in our hospital between 1996 and 2000 (n = 47, study group), and a control group who delivered fetuses with normal birthweight (n = 47) were reviewed.

RESULTS

Incidence of excessively overgrown fetuses was 0.24% and 68% were boys. Mothers in this group were significantly older, overweight and multiparous (p < 0.0001) and had gestational diabetes mellitus (p < 0.0001) and prolonged pregnancies (p = 0.04). A previous big baby was also significant (p < 0.0001) and the commonest risk factor. There were no obvious risk factors in nine (19.1%) cases. More than half (n = 28, 59.5%) of these babies were delivered vaginally without clinical suspicion of excessive fetal size. Duration of second stage of labor and incidence of maternal trauma were similar in both groups. Cesarean delivery (p = 0.0003), postpartum hemorrhage (p = 0.004), birth asphyxia (p = 0.007), shoulder dystocia (p < 0.0001) and fetal trauma (p = 0.03) were significantly more frequent in the study group.

CONCLUSIONS

Excessively overgrown fetuses are associated with the same risk factors as fetal macrosomia and should be delivered by cesarean if diagnosed antenatally because of increased maternal and perinatal morbidity during vaginal delivery.

Secular trends in neonatal macrosomia in Berlin: influences of potential determinants

To investigate the trend in the prevalence of neonatal macrosomia and to evaluate the influences of potential determinants, key features of 206 308 hospital deliveries (97% of all) in Berlin in the years 1993-99, collected by the Berlin Medical Board, were analysed using SPSS 10.0. After exclusion of multiple births and preterm infants, there was a significant increase over 7 years (P < 0.01) in the prevalence of birthweights >or= 4000 g, maternal age >or= 30 years, height of >or= 165 cm, prepregnancy BMI (body mass index) >or= 26 kg/m2 and pregnancy weight gain> 16 kg, but no substantial trend in the prevalence of recognised diabetes or maternal smoking. The adjusted model (OR [95% CI]) for delivering a newborn >or= 4000 g was statistically significant for post-term delivery (2.56 [2.39, 2.75]), women aged >or= 30 years (1.06 [1.02-1.11]), >or= 165 cm tall (1.94 [1.87,2.01]), multiparae (1.98 [1.91, 2.05]), not smoking in pregnancy (2.03 [1.93, 2.14]), prepregnancy BMI >or= 26 compared with < 20 (4.01 [3.77, 4.26]), pregnancy weight gain >or= 16 kg compared with < 10 kg (3.37.[3.22, 3.53]) and for recognised diabetes (1.85.[1.69, 2.04]). It is speculated that this increase in the prevalence of neonatal macrosomia may contribute to the secular trend of overweight and obesity under affluent living conditions.

Suspected big baby: a difficult clinical problem in obstetrics

BACKGROUND

Large for gestational age fetuses, also called macrosomic fetuses, represent a continuing challenge in obstetrics.

METHODS

We review various problems with large for gestational age fetuses. We have performed a literature search, mainly through the database PubMed (includes the Medline database). The clinical problem is discussed from the primary care provider's, the patient's and the obstetrician's point of view.

RESULTS

Macrosomia is arbitrarily defined as having a fetal weight of above the 90th percentile, a birth weight of above 4000 g or 4500 g, or a birth weight of over +2 standard deviation of the mean birth weight by gestational age. The diagnosis of macrosomia is difficult, both by palpation and symphysis fundus measurement; even with sophisticated sonographic measures. The combination of biparietal diameter, femur length and abdominal circumference appears to be no better than abdominal circumference alone.

INTERPRETATION

Based on the literature, labor should not be induced in nondiabetic pregnancies. The best policy is to await spontaneous birth or to induce labor after 42 weeks completion. A great number of cesarean sections have to be performed to avoid a single case of plexus brachialis paresis resulting from a difficult shoulder delivery. Cesarean section should not be considered in nondiabetic pregnancies unless the estimated fetal weight is above 5000 g. In pregnancies complicated by diabetes mellitus there are reasons for selective induction of labor if macrosomia is suspected and for cesarean section if the calculated birth weight is above 4000 g. Each department should have a strategy to handle such a situation because the problem with the difficult shoulder delivery cannot be completely avoided. Different procedures of managing difficult shoulder delivery are described.

Effects of diabetic pregnancy on the fetus and newborn

Diabetes in pregnancy is unique because of the diversity of problems that can affect the embryo/fetus beginning with conception. Considerable effort has been devoted to understanding the basic developmental biology from observing young embryos in vitro or in vivo. Maternal glucose control has been identified as an important event. The preponderance of evidence indicates that rigid glucose control will minimize the incidence of anomalies incurred before 9 weeks of pregnancy. Later events are related to fetal hyperinsulinemia. These include fetal macrosomia, respiratory distress syndrome, neonatal hypoglycemia, neonatal hypocalcemia, and neonatal hypomagnesemia. Control of maternal metabolism can have a significant impact on each of the above. Finally, the long-term effects of maternal diabetes are as diverse as the pathogenetic events during pregnancy. Surprisingly, there is a significant transmission rate of 2% of type I diabetes if the mother has insulin-dependent diabetic mother, whereas the rate is 6% for the father. The Diabetes in Early Pregnancy Study showed that good maternal control was associated with normal neurodevelopmental outcome.