The large fetus

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.

Mid-Trimester Fetal Anterior Abdominal Wall Subcutaneous Tissue Thickness: An Early Ultrasonographic Predictor of Gestational Diabetes Mellitus

Background This study aimed to determine whether mid-trimester fetal anterior abdominal wall subcutaneous tissue thickness (FASTT) is an early sonographic predictor of gestational diabetes mellitus (GDM), as well as to study its correlation with maternal glycemic values on GDM screening at 24-28 weeks. Methodology We conducted a prospective, case-control study. FASTT was assessed at anomaly scan in 896 uncomplicated singleton pregnancies. The 75-gram oral glucose tolerance test (OGTT) was done for all included patients at 24-28 weeks. Women diagnosed with GDM were taken as cases and appropriately matched in equal numbers as controls. Statistical analysis was done using SPSS version 20 (IBM Corp., Armonk, NY, USA). Independent-samples t-test, chi-square test, receiver operating characteristic curve, and Pearson's correlation coefficient (r) were performed wherever applicable. Results A total of 93 cases and 94 controls were included. Fetuses of women with GDM had significantly higher mean FASTT at 20 weeks (1.605 ± 0.328 mm vs. 1.222 ± 0.121 mm; p < 0.001). The FASTT cut-off obtained was 1.35 mm (sensitivity = 79.6%, specificity = 87.2%, positive predictive value = 86%, negative predictive value = 81.2%). There was a moderate positive correlation between fasting blood sugar (FBS) and two-hour OGTT values and FASTT (r = 0.332, p < 0.001 and r = 0.399, p < 0.001, respectively). FASTT >1.35 mm had an independent predictive value for GDM and was associated with a 19.608-fold increased risk of GDM. Conclusions FASTT values greater than 1.35 mm at 20 weeks are associated with a significantly increased risk of GDM. In addition, FASTT correlates with FBS and two-hour OGTT at 24-28 weeks and is a simple predictor of GDM at 18-20 weeks.

Facteurs de risque et pronostic materno-fœtal de la macrosomie fœtale: étude comparative a propos de 820 cas

L’accouchement d’un fœtus macrosome est une situation relativement fréquente. Il s’agit d’un accouchement à haut risque aussi bien maternel que fœtal. Les principales complications maternelles étaient représentées par l’augmentation du taux de césarienne, d’hémorragie de la délivrance et des déchirures traumatiques cervico-vaginales. La principale complication fœtale était la dystocie des épaules exposant aux élongations du plexus brachial. L’objectif était d’identifier les facteurs de risque et les complications materno-fœtales liées à la macrosomie fœtale. Une étude rétrospective comparative effectuée au service universitaire de maternité de Kairouan durant l’année 2010. Au cours de cette étude, nous comparons un groupe de 820 cas de macrosomes à un groupe de 800 cas de témoins nés au cours de la même période. Au cours de la période d’étude, nous avons colligé 820 cas de macrosomies sur un total de 7495 naissances soit une incidence de 10.94%. Plusieurs facteurs favorisants la macrosomie fœtale étaient mis en évidence: un âge maternel >35 ans était présent dans 28.5% des cas; L’obésité maternelle était trouvée dans 45% des cas; Les antécédents de macrosomie étaient notés dans 28,8% des cas; Le terme prolongé > 41 semaines d’aménorrhée était noté dans 35.6% des cas; La multiparité était trouvée dans 47% des cas. Les complications maternelles étaient essentiellement l’hémorragie de la délivrance: 71 cas et les traumatismes génitaux: 24 cas. Les complications périnatales étaient dominées par la dystocie des épaules, 27 cas soit 3.3%. Les complications postnatales traumatiques étaient retrouvées dans 11.6%.

Prediction of large-for-gestational-age neonates: screening by maternal factors and biomarkers in the three trimesters of pregnancy

OBJECTIVE

To develop a model based on maternal characteristics and medical history (maternal factors) for the prediction of delivery of large-for-gestational-age (LGA) neonates, and to examine the potential value of first-, second- and third-trimester fetal biometry and biomarkers in improving such a model.

METHODS

This was a screening study in 76 300, 54 999, 25 727 and 6181 singleton pregnancies at 11-13, 19-24, 30-34 and 35-37 weeks' gestation, respectively. The a-priori risk for LGA with birth weight > 95(th) percentile (LGA > 95(th) ) was calculated using multivariable logistic regression analysis to determine which of the maternal factors had a significant contribution. Regression analysis was then used to determine whether screening by a combination of maternal factors, fetal biometry and various biophysical and biochemical markers had significant contribution in predicting delivery of LGA neonates.

RESULTS

The likelihood of LGA > 95(th) increased with increasing maternal weight and height and was lower in women of Afro-Caribbean and South Asian racial origins, in cigarette smokers and in nulliparous women. The risk was higher in women with pre-existing diabetes mellitus Type I and lower in those with chronic hypertension. In parous women, the risk increased with birth-weight Z-score in previous pregnancy and prior history of gestational diabetes and decreased with interpregnancy interval. Screening by maternal factors at 11-13 weeks predicted 32%, 44% and 60% of LGA > 95(th) at false-positive rates (FPRs) of 5%, 10% and 20%, respectively. With the addition of fetal biometry, the detection rates improved to 37%, 51% and 68% at 19-24 weeks, 50%, 65% and 81% at 30-34 weeks and 60%, 73% and 85% at 35-37 weeks at FPRs of 5%, 10% and 20%, respectively. The addition of biomarkers did not improve the detection rates achieved when screening by a combination of maternal factors and fetal biometry.

CONCLUSION

Combined screening by maternal factors and fetal biometry can predict a high proportion of pregnancies that will deliver LGA neonates. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Macrosomia in 23 developing countries: an analysis of a multicountry, facility-based, cross-sectional survey

BACKGROUND

Macrosomia is a risk factor for adverse delivery outcomes. We investigated the prevalence, risk factors, and delivery outcomes of babies with macrosomia in 23 developing countries in Africa, Asia, and Latin America.

METHODS

We analysed data from WHO's Global Survey on Maternal and Perinatal Health, which was a facility-based cross-sectional study that obtained data for women giving birth in 373 health facilities in 24 countries in Africa and Latin America in 2004-05, and in Asia in 2007-08. Facilities were selected by stratified multistage cluster sampling and women were recruited at admission for delivery. We extracted data from the medical records with a standardised questionnaire. We used logistic regression with random effects to assess the risk factors for macrosomia and the risks for caesarean section and adverse maternal and perinatal outcomes (assessed by a composite score) in babies with the disorder.

FINDINGS

Of 290,610 deliveries, we analysed data for 276,436 singleton livebirths or fresh stillbirths. Higher maternal age (20-34 years), height, parity, body-mass index, and presence of diabetes, post-term pregnancy, and male fetal sex were associated with a significantly increased risk of macrosomia. Macrosomia was associated with an increased risk of caesarean section because of obstructed labour and post-term pregnancy in all regions. Additionally, macrosomia was associated with an increased risk of adverse maternal birth outcomes in all regions, and of adverse perinatal outcomes only in Africa.

INTERPRETATION

Increasing prevalence of diabetes and obesity in women of reproductive age in developing countries could be associated with a parallel increase in macrosomic births. The effect and feasibility of control of diabetes and preconception weight on macrosomia should be investigated in these settings. Furthermore, increased institutional delivery in countries where rates are low could be crucial to reduce macrosomia-associated morbidity and mortality.

FUNDING

None.

Impact of maternal characteristics on fetal growth in the third trimester: a population-based study

OBJECTIVES

To investigate the association between maternal characteristics and fetal growth during the third trimester of pregnancy.

METHODS

Using a population-based perinatal register, 48809 term singleton pregnancies were identified for which a routine ultrasound examination in the third trimester had been performed between 1995 and 2009. Fetal and infant weight were expressed as gestational age-specific standard deviation scores (z-scores) using a Swedish ultrasound-based reference curve. The growth of each fetus was assessed using the difference between the birth-weight z-score and the fetal-weight z-score estimated at the ultrasound examination, adjusted for gestational age, and divided by the time elapsed between the ultrasound examination and delivery. Analyses were performed using multivariable linear and polynomial regression analyses.

RESULTS

Positive associations were found between maternal body mass index (BMI), height, pre-existing diabetes mellitus, female fetal gender and fetal growth, whereas maternal smoking had a negative association. In the univariate analyses, primiparity and parity with four or more previous children were significantly associated with reduced fetal growth, but in the multivariable analysis, no association between parity and fetal growth could be detected. Both univariate and multivariable analyses revealed a significant inverse U-shaped association between maternal age and fetal growth.

CONCLUSIONS

Third-trimester fetal growth was positively associated with increasing maternal BMI, height and pre-existing diabetes mellitus, and negatively associated with maternal smoking.

First-trimester prediction of macrosomia

OBJECTIVE

To determine if combinations of maternal characteristics and measurements of parameters used in screening for aneuploidies at 11-13 weeks provide significant prediction of macrosomia.

METHOD

Maternal characteristics, fetal nuchal translucency (NT), free β-human chorionic gonadotrophin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A) were recorded at 11(+0)-13(+6) weeks in 36,743 singleton pregnancies. Regression analysis was used to determine if in predicting macrosomia significant contributions are provided by maternal factors, fetal NT, free β-hCG and PAPP-A.

RESULTS

The risk for macrosomia increased with maternal weight and height and was higher in parous women with previous delivery of a macrosomic baby and in those with diabetes mellitus; the risk was lower in women of African and South Asian racial origins, in cigarette smokers and in those with chronic hypertension. In the macrosomic group compared to the unaffected group there were higher Δ-NT (0.167 vs. 0.116 mm), free β-hCG (1.010 vs. 0.964 MoM) and PAPP-A (1.103 vs. 1.003 MoM). Prediction of macrosomia provided by maternal factors was significantly improved by fetal NT, free β-hCG and PAPP-A (34.4 vs. 33.1% at a false-positive rate of 10%).

CONCLUSION

Prediction of macrosomia is provided in the first trimester of pregnancy by a combination of maternal characteristics and measurements of parameters used in screening for aneuploidies.

Ghrelin, leptin, IGF-1, IGFBP-3, and insulin concentrations at birth: is there a relationship with fetal growth and neonatal anthropometry?

BACKGROUND

Insulin, growth hormone (GH), and growth factors (insulin-like growth factors [IGFs] and their binding proteins [IGFBPs]) are known to influence fetal growth and also the synthesis/secretion of the recently discovered hormones leptin and ghrelin.

METHODS

In 153 delivering mothers and their offspring at birth, we prospectively investigated the association between mothers' and babies' serum concentrations of ghrelin, leptin, insulin, IGF-1, and IGFBP-3 and neonatal anthropometric characteristics and the growth of the fetus. We also tried to put babies' serum glucose and GH measurements in this context.

RESULTS

Birth weight (BW), birth length, head circumference, and ponderal index (PI) were positively associated with cord IGF-1, IGFBP-3, and leptin and negatively associated with GH. BW was independently associated with maternal stature and prepartum weight, birth length with maternal stature, PI with maternal insulin and prepartum weight, and head circumference with maternal ghrelin. Compared with preterm infants whose development was appropriate for gestational age (AGA), preterm growth-restricted babies displayed alteration in GH-IGF axis (increased GH and low IGF-1 and IGFBP-3 concentrations), low leptin and glucose concentrations, and increased ghrelin concentrations. In large-for-gestational-age (LGA) babies, leptin, IGFBP-3, insulin, and glucose concentrations were significantly higher in asymmetric LGA newborns than in symmetric LGA and AGA newborns.

CONCLUSIONS

We found relationships between metabolic factors, fetal growth, and anthropometry. Intrauterine growth restriction involved alteration in the fetal GH-IGF axis, with relatively low leptin and glucose concentrations and increased ghrelin concentrations. Leptin, insulin, and IGFBP-3 delineated subtypes of fetal overgrowth.

Mode of delivery and the survival of macrosomic infants in the United States, 1995-1999

BACKGROUND

Although increases in perinatal mortality risk associated with fetal macrosomia are well documented, the optimal route of delivery for fetuses with suspected macrosomia remains controversial. The objective of this investigation was to assess the risk of neonatal death among macrosomic infants delivered vaginally compared with those delivered by cesarean section.

METHODS

Data were derived from the U.S. 1995-1999 Linked Live Birth-Infant Death Cohort files and term (37-44 wk), single live births to United States resident mothers selected. A proportional hazards model was used to analyze the risk of neonatal death associated with cesarean delivery among 3 categories of macrosomic infants (infants weighing 4,000-4,499 g; 4,500-4,999 g; and 5,000+ g).

RESULTS

After controlling for maternal characteristics and complications, the adjusted hazard ratio for neonatal death associated with cesarean delivery among the 3 categories of macrosomic infants was 1.40, 1.30, and 0.85.

CONCLUSIONS

Although cesarean delivery may reduce the risk of death for the heaviest infants (5,000+ g), the relative benefit of this intervention for macrosomic infants weighing 4,000-4,999 g remains debatable. Thus, policies in support of prophylactic cesarean delivery for suspected fetal macrosomia may need to be reevaluated.

High birthweight and shoulder dystocia: the strongest risk factors for obstetrical brachial plexus palsy in a Swedish population-based study

BACKGROUND

Obstetrical brachial plexus palsy (OBPP) is a serious form of neonatal morbidity.

OBJECTIVE

The aim of this work was to study the incidence of OBPP and to analyze its risk factors.

METHODS

This is a population-based retrospective case-control study. All deliveries recorded in the Swedish Medical Birth Registry between 1987 and 1997 (n = 1 213 987) were investigated. Cases (n = 2399) with OBPP were compared to all other cases.

RESULTS

The incidence of OBPP increased from 0.17 in 1987 to 0.27% in 1997 (p = 0.002). During the same time period, the mean birthweight increased from 3483 to 3525 g. Birthweight increasing from 4000 g was associated with a progressive rise in OBPP risk. Other significant risk factors associated with the injury were shoulder dystocia, breech presentation in vaginal delivery, operative vaginal delivery, diabetes mellitus, induction of labor, protracted active phase, secondary arrest of dilatation, and epidural anesthesia. Cesarean section was associated with a decreased risk of OBPP. If 5000 g is chosen as cut-off for cesarean section, 85% of the infants in this weight class are underestimated using ultrasonography. Approximately, 331 abdominal deliveries have to be performed to avoid one case of OBPP.

CONCLUSIONS

Shoulder dystocia and infant birthweight of 4500 g and more are the strongest risk factors for OBPP in a Swedish population.

Insulin and glyburide therapy: dosage, severity level of gestational diabetes, and pregnancy outcome

OBJECTIVE

We sought to investigate the association between glyburide dose, degree of severity in gestational diabetes mellitus (GDM), level of glycemic control, and pregnancy outcome in insulin- and glyburide-treated patients.

STUDY DESIGN

In a secondary analysis of our previous randomized study, 404 women were analyzed. The association among glyburide dose, severity of GDM, and selected maternal and neonatal factors was evaluated. Severity levels of GDM were stratified by fasting plasma glucose (FPG) from the oral glucose tolerance test (OGTT). Infants with birth weight at or above the 90th percentile were considered large-for-gestational age (LGA). Macrosomia was defined as birth weight > or =4000 g. Well-controlled was defined as mean blood glucose < or =95 mg/dL. The association between glyburide- and insulin-treated patients by severity of GDM and neonatal outcome was evaluated.

RESULTS

The dose received for the glyburide-treated patients was 2.5 mg-32%; 5 mg-23%; 10 mg-17%; 15 mg-8%; and 20 mg-20%. Patients were grouped into low (< or =10 mg) and high (>10 mg) daily dose of glyburide. A comparison between severity of the disease (fasting plasma glucose categories) and highest dose of glyburide revealed a significant difference between the low-95 FPG and the other severity categories (P = .02). Of patients in the well-controlled glycemic group, only 6% required the high dose of glyburide (>10 mg). In patients with poor glycemic control (mean blood glucose >95 mg/dL), 38% received the high dose of glyburide (P = .0001). Comparison between the high glyburide (>10 mg) and the low glyburide dosages (< or =10 mg) revealed that the rate of macrosomia was 16% vs 5% and LGA 22% vs 8%, (P = .01), respectively. No significant difference was found in composite outcome, metabolic complications, and Ponderal Index between the 2 dose groups. Stratification by disease severity revealed a significantly lower rate of LGA for both the glyburide- and insulin-treated subjects. No significant difference was found between metabolic, respiratory, and neonatal intensive care unit (NICU) for patients within each fasting plasma glucose severity category.

CONCLUSION

Glyburide and insulin are equally efficient for treatment of GDM in all levels of disease severity. Achieving the established level of glycemic control, not the mode of pharmacologic therapy, is the key to improving the outcome in GDM.

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.

Protein anabolic effects of insulin and IGF-I in the ovine fetus

We determined the effect of insulin and/or recombinant human (rh)IGF-I infusion on ovine fetal phenylalanine kinetics, protein synthesis, and phenylalanine accretion. The chronically catheterized fetal lamb model was used at 130 days gestation. All studies were performed while fetal glucose and amino acid concentrations were held constant. Experimental infusates were 1). saline, 2). rhIGF-I plus a replacement dose of insulin (40 nmol), 3). insulin (890 mIU/h), and 4). IGF-I plus insulin (40 nmol IGF-I/h and 890 mIU insulin/h). Both hormones increased glucose and amino acid utilization, with insulin having a greater effect. The major effect on phenylalanine kinetics was a pronounced fall in phenylalanine hydroxylation, again with insulin having the greatest effect. Whole body protein breakdown was not significantly altered by either hormone; whole body protein synthesis was significantly increased during the combined infusion. Protein accretion was increased by both hormones, with the greatest increase during combined infusion. The fractional synthetic rate (FSR) of circulating albumin was increased by IGF-I but not by insulin. Both hormones significantly increased skeletal muscle FSR without a synergistic effect. The anabolic effects of insulin and IGF-I were more pronounced in these studies than in previous studies where amino acid concentrations were not maintained. The present data also suggest that insulin and IGF-I promote fetal growth through distinct, organ-specific mechanisms.

The graying of the obstetric population: implications for the older mother

OBJECTIVE

To review the literature on the relationship between advanced maternal age and pregnancy outcomes and to discuss social trends in childbearing.

DATA SOURCES

Computerized searches on CINAHL, MEDLINE, National Institutes of Health, and published birth statistics. Keywords used in this search were the following: advanced maternal age, pregnancy outcomes for older primiparae and older mothers, and pregnancy risks.

STUDY SELECTION

Relevant articles published between 1978 and 2001 were reviewed.

DATA EXTRACTION

Data were extracted and organized under the following headings: childbearing trends in developed countries, maternal morbidity for older mothers, preeclampsia, preterm delivery, operative and assisted delivery, and infant mortality and morbidity.

DATA SYNTHESIS

The existing literature is concentrated on the medical aspects of the risks associated with childbearing at an advanced maternal age. Few systematic investigations have been undertaken of healthy older mothers, an increasingly common obstetric population.

CONCLUSIONS

Lifestyle influences, such as weight, general health, and smoking habits in older mothers, have not been addressed. Little is known about the actual risks of pregnancy complications for healthy older mothers. No clear guidelines exist to direct the obstetric and nursing care of the healthy older mother.

A comparison of glyburide and insulin in women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus are rarely treated with a sulfonylurea drug, because of concern about teratogenicity and neonatal hypoglycemia. There is little information about the efficacy of these drugs in this group of women.

METHODS

We studied 404 women with singleton pregnancies and gestational diabetes that required treatment. The women were randomly assigned between 11 and 33 weeks of gestation to receive glyburide or insulin according to an intensified treatment protocol. The primary end point was achievement of the desired level of glycemic control. Secondary end points included maternal and neonatal complications.

RESULTS

The mean (+/-SD) pretreatment blood glucose concentration as measured at home for one week was 114+/-19 mg per deciliter (6.4+/-1.1 mmol per liter) in the glyburide group and 116+/-22 mg per deciliter (6.5+/-1.2 mmol per liter) in the insulin group (P=0.33). The mean concentrations during treatment were 105+/-16 mg per deciliter (5.9+/-0.9 mmol per liter) in the glyburide group and 105+/-18 mg per deciliter (5.9+/-1.0 mmol per liter) in the insulin group (P=0.99). Eight women in the glyburide group (4 percent) required insulin therapy. There were no significant differences between the glyburide and insulin groups in the percentage of infants who were large for gestational age (12 percent and 13 percent, respectively); who had macrosomia, defined as a birth weight of 4000 g or more (7 percent and 4 percent); who had lung complications (8 percent and 6 percent); who had hypoglycemia (9 percent and 6 percent); who were admitted to a neonatal intensive care unit (6 percent and 7 percent); or who had fetal anomalies (2 percent and 2 percent). The cord-serum insulin concentrations were similar in the two groups, and glyburide was not detected in the cord serum of any infant in the glyburide group.

CONCLUSIONS

In women with gestational diabetes, glyburide is a clinically effective alternative to insulin therapy.