A prospective study of maternal serum insulin-like growth factor-I in pregnancies with appropriately grown or growth restricted fetuses

Investigating the IGF axis as a pathway for intergenerational effects

Early nutritional and growth experiences can impact development, metabolic function, and reproductive outcomes in adulthood, influencing health trajectories in the next generation. The insulin-like growth factor (IGF) axis regulates growth, metabolism, and energetic investment, but whether it plays a role in the pathway linking maternal experience with offspring prenatal development is unclear. To test this, we investigated patterns of maternal developmental weight gain (a proxy of early nutrition), young adult energy stores, age, and parity as predictors of biomarkers of the pregnancy IGF axis (n = 36) using data from the Cebu Longitudinal Health and Nutrition Survey in Metro Cebu, Philippines. We analyzed maternal conditional weight measures at 2, 8, and 22 years of age and leptin at age 22 (a marker of body fat/energy stores) in relation to free IGF-1 and IGFBP-3 in mid/late pregnancy (mean age = 27). Maternal IGF axis measures were also assessed as predictors of offspring fetal growth. Maternal age, parity, and age 22 leptin were associated with pregnancy free IGF-1, offspring birth weight, and offspring skinfold thickness. We find that free IGF-1 levels in pregnancy are more closely related to nutritional status in early adulthood than to preadult developmental nutrition and demonstrate significant effects of young adult leptin on offspring fetal fat mass deposition. We suggest that the previously documented finding that maternal developmental nutrition predicts offspring birth size likely operates through pathways other than the maternal IGF axis, which reflects more recent energy status.

Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells

Insulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual IGFBP-1 secretion/phosphorylation are poorly understood. Using decidualized primary human endometrial stromal cells (HESCs) from first-trimester placenta, we tested the hypothesis that mTORC1 signaling mechanistically links hypoxia to decidual IGFBP-1 secretion/phosphorylation. Hypoxia inhibited mechanistic target of rapamycin (mTORC1) (p-P70-S6K/Thr389, -47%, p = 0.038; p-4E-BP1/Thr70, -55%, p = 0.012) and increased IGFBP-1 (total, +35%, p = 0.005; phosphorylated, Ser101/+82%, p = 0.018; Ser119/+88%, p = 0.039; Ser 169/+157%, p = 0.019). Targeted parallel reaction monitoring-mass spectrometry (PRM-MS) additionally demonstrated markedly increased dual IGFBP-1 phosphorylation (pSer98+Ser101; pSer169+Ser174) in hypoxia. IGFBP-1 hyperphosphorylation inhibited IGF-1 receptor autophosphorylation/ Tyr1135 (-29%, p = 0.002). Furthermore, silencing of tuberous sclerosis complex 2 (TSC2) activated mTORC1 (p-P70-S6K/Thr389, +68%, p = 0.038; p-4E-BP1/Thr70, +30%, p = 0.002) and reduced total/site-specific IGFBP-1 phosphorylation. Importantly, TSC2 siRNA prevented inhibition of mTORC1 and the increase in secretion/site-specific IGFBP-1 phosphorylation in hypoxia. PRM-MS indicated concomitant changes in protein kinase autophosphorylation (CK2/Tyr182; PKC/Thr497; PKC/Ser657). Overall, mTORC1 signaling mechanistically links hypoxia to IGFBP-1 secretion/phosphorylation in primary HESC, implicating decidual mTORC1 inhibition as a novel mechanism linking uteroplacental hypoxia to fetal growth restriction.

Color Doppler sonography of the aortic isthmus in intrauterine growth-restricted fetuses and normal fetuses

Intrauterine growth restriction is associated with a significant increase in morbidity and perinatal mortality, and increases the likelihood of fetal death, asphyxia, meconium aspiration, hypoglycemia, and neonatal hypothermia. The aim of this study was to determine aortic isthmus flow difference by using color doppler sonography in Intrauterine growth restriction and normal fetuses. The data presented were obtained from 30 mothers, who referred to the radiology department of Akbarabadi Hospital of Tehran with a diagnosis of intrauterine growth restriction. An ultrasound was performed to determine the status of placenta, fetus, and amniotic fluid. The umbilical arterial doppler assessment was used to confirm diagnosis of intrauterine growth restriction. Thirteen (43.3%) were nulliparous mothers and 17 (56.7%) were multiparous mothers. 30 pregnant women with healthy fetuses were enrolled as control group. According to the ultrasound findings, Dactus Venus wave type was recorded in intrauterine growth restriction fetuses, which was reported as normal (26 subjects; 86.7%) and abnormal (4 subjects; 13.3%). All together, this study provides appropriate guidance to use doppler for delivery timing and to control risk factors.

Relationship between dairy product intake during pregnancy and neonatal and maternal outcomes among Portuguese women

BACKGROUND

The role played by dairy product intake during pregnancy on neonatal outcomes has raised interest in the last few years. However, studies on this association remain scarce. Thus, the aim of this study was to determine the association between dairy product consumption during pregnancy and neonatal and maternal outcomes.

METHODS

A prospective study was conducted with 98 pregnant women, aged 18-40, from the city of Porto, Portugal. Socio-demographic and lifestyle characteristics were assessed through a questionnaire. Dairy product consumption was assessed with a three-day food diary completed during the first and second trimesters. Postpartum medical records were examined for neonatal and maternal outcomes. Multivariate linear regression analyses were performed to assess the association between dairy intake and neonatal and maternal outcomes, adjusting for dietary variables and maternal characteristics.

RESULTS

Compared to the first trimester pregnant women had higher energy intake and lower calcium, iodine and yogurt intake in the second trimester (P<0.05). Total dairy and yogurt intake in the first trimester were positively associated with head circumference and placental weight (respectively β=0.002, P=0.014, β=0.333, P=0.012). Change in total dairy intake between the second and first trimester was negatively associated with maternal weight gain during pregnancy (β=-0.007, P=0.020).

CONCLUSION

The findings of this study suggest that dairy product intake during pregnancy may have an effect on neonatal head circumference, placental weight, and gestational weight gain.

More than fetal urine: enteral uptake of amniotic fluid as a major predictor for fetal growth during late gestation

The purpose of our study was to investigate the importance of amniotic fluid (AF) for fetal growth during late gestation using esophageal atresia (EA) patients as a model. In this retrospective cohort study, we compared the z-scores adapted for birth weights (BW z-scores) for each of 517 European newborns with congenital pre-gastric intestinal atresia, i.e., EA, to a European reference population. To account for the influence of the intestinal atresia on fetal growth per se, we compared adapted birth weights for each of 504 European newborns with post colonic intestinal atresia (anorectal malformation (ARM) with atresia of the anus) to the same European reference population. Analysis of the complete cohort showed (i) a significantly higher rate of small for gestational age newborns among EA compared to ARM newborns (p < 0.001) and (ii) significantly lower BW z-scores among EA compared to ARM newborns (p < 0.001). BW z-scores of EA newborns were significantly lower in term compared to preterm newborns with an inverse correlation with gestational age (GA) (Spearman correlation coefficient, r = -0.185, p < 0.001).

CONCLUSIONS

Enteral uptake of AF seems to play a pivotal role in fetal growth during late gestation.

WHAT IS KNOWN

• Peak velocity of fetal weight gain occurs at 33 weeks of gestation and continues until birth. During this period, fetal growth is mainly characterized by cellular hypertrophy. • Amniotic fluid (AF) comprises large amounts of hormones and growth regulators. What is New: • A significantly higher rate of small for gestational age and lower birth weights and z-scores are observed among newborn infants with congenital pre-gastric intestinal atresia. • These findings suggest that enteral uptake of AF is a major predictor for fetal growth during late gestation.

Oxidation of placental insulin and insulin-like growth factor receptors in mothers with diabetes mellitus or preeclampsia complicated with intrauterine growth restriction

Placental insulin receptor (IR) and insulin-like growth factor receptors (IGFRs) are essential for fetal growth. We investigated structural changes of these receptors exposed to increased oxidative stress in mothers diagnosed with diabetes mellitus (DM) or preeclampsia (PE) complicated with intrauterine growth restriction. Increased amount of IR and decreased amounts of IGF1R and IGF2R were found in both pathologies, accompanied by significant elevation in protein carbonyls. When isolated receptors were examined, increased carbonylation of IR and IGF1R in PE placentas was detected, whereas the amounts of carbonylated IR and IGF1R were similar in DM and healthy placentas. Carbonylation status of IGF2R did not change due to pathology, confirming the detrimental role of primary structure and conformation in oxidative susceptibility. Ligand binding was similar in all three groups of samples and did not seem to be affected by receptor oxidation. Since babies delivered by mothers with PE were smaller than the referent population, increased carbonylation of receptors might have affected downstream receptor signaling post-ligand binding.

Chinese herbal medicine for miscarriage affects decidual micro-environment and fetal growth

INTRODUCTION

Intrauterine growth restriction complicates 5-10% of pregnancies. This study aims to test the hypothesis that Chinese herbal formula, JLFC01, affects pregnancy and fetal development by modulating the pro-inflammatory decidual micro-environment.

METHODS

Human decidua from gestational age-matched elective terminations or incomplete/missed abortion was immunostained using anti-CD68 + anti-CD86 or anti-CD163 antibodies. qRT-PCR and Luminex assay measured the effects of JLFC01 on IL-1β- or TNF-α-induced cytokine expression in first trimester decidual cells and on an established spontaneous abortion/intrauterine growth restriction (SA/IUGR)-prone mouse placentae. The effect of JLFC01 on human endometrial endothelial cell angiogenesis was evaluated by average area, length and numbers of branching points of tube formation. Food intake, litter size, fetal weight, placental weight and resorption rate were recorded in SA/IUGR-prone mouse treated with JLFC01. qRT-PCR, Western blot and immunohistochemistry assessed the expression of mouse placental IGF-I and IGF-IR.

RESULTS

In spontaneous abortion, numbers of decidual macrophages expressing CD86 and CD163 are increased and decreased, respectively. JLFC01 reduces IL-1β- or TNF-α-induced GM-CSF, M-CSF, C-C motif ligand 2 (CCL2), interferon-γ-inducible protein-10 (IP-10), CCL5 and IL-8 production in first trimester decidual cells. JLFC01 suppresses the activity of IL-1β- or TNF-α-treated first trimester decidual cells in enhancing macrophage-inhibited angiogenesis. In SA/IUGR-prone mice, JLFC01 increases maternal food intake, litter size, fetal and placental weight, and reduces fetal resorption rate. JLFC01 induces IGF-I and IGF-IR expression and inhibits M-CSF, CCL2, CCL5, CCL11, CCL3 and G-CSF expression in the placentae.

DISCUSSION

JLFC01 improves gestation by inhibiting decidual inflammation, enhancing angiogenesis and promoting fetal growth.

Effect of maternal anthropometry and metabolic parameters on fetal growth

OBJECTIVE

The aim of this study was to determine the effect of maternal anthropometry and metabolic parameters on neonatal anthropometry.

MATERIALS AND METHODS

This observational cross-sectional study was conducted from January 2008 to June 2009 at a single tertiary care center. Maternal anthropometry and metabolic parameters like fasting serum insulin, lipid profile, and random blood glucose were estimated in 50 pregnant women at term. Detailed anthropometry of the neonates was performed.

RESULTS

Large for gestational age (LGA) babies had higher maternal body mass index (BMI), fasting serum insulin, and cord blood insulin levels, and lower maternal high density lipoprotein (HDL) compared to appropriate for gestational age (AGA) group (P < 0.001). Among the maternal parameters, BMI, gestational age, fasting serum insulin, and random blood sugar (RBS) had significant positive correlation, while HDL had negative correlation with birth weight (P < 0.05). However, only maternal BMI was the significant predictor of neonatal birth weight on multiple regression analysis (ß = 0.340, P = 0.01).

CONCLUSION

The BMI of glucose-tolerant mother is more important than metabolic parameters in determining the birth weight of term babies.

Maternal concentrations of insulin-like growth factor I and insulin-like growth factor binding protein 1 during pregnancy and birth weight of offspring

Maternal concentrations of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 1 (IGFBP-1) may influence fetal growth. Offspring birth weight related to maternal IGF-I and IGFBP-1 measured in pregnancy was studied in 368 randomly selected women without preeclampsia who delivered a singleton liveborn child in Norway between 1992 and 1994. Maternal IGF-I concentrations were not consistently associated with birth weight, but a 1-standard deviation stronger increase in IGF-I from the first to second trimester was associated with an 82-g (95% confidence interval (CI): 11, 153) higher birth weight. IGFBP-1 concentrations were inversely associated with birth weight: Birth weight was 71 g (95% CI: 14, 128) lower per 1-standard deviation higher IGFBP-1 in the second trimester, and an increase in IGFBP-1 from the first (below median) to second (above median) trimester was associated with a 342-g (95% CI: 124, 560) lower birth weight, compared with having low IGFBP-1 (below median) in both trimesters. Conversely, low IGFBP-1 in both trimesters was associated with a 200-350-g higher birth weight compared with other combinations of IGFBP-1. In conclusion, persistently low IGFBP-1 in pregnancy is associated with relatively higher birth weight. Maternal insulin resistance may provide a link between IGFBP-1 and offspring birth weight.

Effects of exercise training on maternal hormonal changes in pregnancy

CONTEXT & OBJECTIVE

A recent paper by our group reported that regular aerobic exercise during pregnancy led to lower foetal IGF-I and IGF-II concentrations and a modest reduction in offspring birth weight when compared with the offspring of nontraining control participants. Maternal hormonal alterations in response to exercise training may be associated with the regulation of nutrient availability for foetal growth through placental regulation of maternal metabolism.

OBJECTIVE

To determine whether the reduction in offspring size was associated with changes in the maternal IGF axis [including placental growth hormone (PGH)], leptin and/or free fatty acids (FFA) in response to aerobic exercise training in the second half of pregnancy.

DESIGN AND SETTING

A randomized, controlled trial of exercise in pregnancy.

PATIENTS

Eighty-four healthy nulliparous women (mean±SD age 30±4 year, BMI 25·5±4 kg/m(2) ).

MEASUREMENTS

Serum samples were drawn at 19 and 35 weeks gestation to determine serum IGF-I, IGF-II, IGF-binding protein-1, IGF-binding protein-3, PGH, leptin and FFA.

RESULTS

Exercise training in pregnancy had no impact on the pregnancy-related changes in the maternal IGF axis. Women in the exercise group experienced a 29% increase in leptin in late gestation (P=0·026 vs control) and a trend towards lower FFA (P=0·07 vs control). Late pregnancy changes in maternal leptin were inversely related to offspring birth weight (r= -0·24, P<0·05) and BMI (r= -0·25, P<0·05).

CONCLUSIONS

An increase in leptin in exercising pregnant women may reflect subtle changes within the placenta in response to regular exercise and may contribute to the reduction in offspring size previously reported in this cohort.

The relationship between maternal insulin-like growth factors 1 and 2 (IGF-1, IGF-2) and IGFBP-3 to gestational age and preterm delivery

AIMS

To investigate the relationship between levels of insulin-like growth factors 1 and 2 (IGF-1, IGF-2), and insulin-like growth factor binding protein 3 (IGFBP-3) in antenatal maternal serum and gestational age at delivery.

METHODS

Prospective cohort study of 1650 low-risk Caucasian women in a London University teaching hospital. Maternal IGF-1, IGF-2 and IGFBP-3 were measured in maternal blood at booking and analyzed with respect to gestational age at delivery.

RESULTS

There was no significant association between maternal IGF-1 or IGF-2 and preterm birth (PTB). A significant reduction in mean IGFBP-3 levels was noted with delivery <32 completed weeks (P=0.02).

CONCLUSION

Maternal mean IGFBP-3 levels are significantly reduced in cases complicated by delivery <32 completed weeks.

Increased levels of human placental growth hormone in the amniotic fluid of pregnancies affected by Down syndrome

OBJECTIVE

To evaluate the concentrations of human placental growth hormone (hPGH) in amniotic fluid (AF) at gestational mid-trimester in normal pregnancies and in pregnancies complicated by Down's syndrome.

DESIGN

AF samples from 21 women with Down's syndrome pregnancies were analyzed retrospectively. About 47 AF samples from women with singleton, uncomplicated pregnancies, who gave birth to healthy neonates with birth weight appropriate for gestational age were used as controls. All AF samples were obtained during amniocentesis for fetal karyotyping at 16-23 weeks' gestation. hPGH levels were measured by a solid phase immunoradiometric assay using two different epitopes.

RESULTS

The mean hPGH values in the AF of the Down's syndrome-affected pregnancies were significantly higher (P<0.05) compared to those of normal pregnancies, at 16-23 weeks' gestation: mean-value+/-SD in the AF was 1.96+/-1.35 microg/l vs. 0.82+/-0.67 microg/l.

CONCLUSIONS

Higher hPGH levels in AF were found in pregnancies affected by Down's syndrome as compared to normal pregnancies at gestational mid-trimester. hPGH was detected in all AF samples, and it provides evidence that this pregnancy-specific hormone enters the fetal compartment and is not limited to the maternal circulation. The physiological role and effect of hPGH on fetal growth in normal and pathological pregnancies needs further investigation.

Abnormalities of IGF-I signaling in the pathogenesis of diseases of the bone, brain, and fetoplacental unit in humans

IGF-I action is essential for the regulation of tissue formation and remodeling, bone growth, prenatal growth, brain development, and muscle metabolism. Cellular effects of IGF-I are mediated through the IGF-I receptor, a transmembrane tyrosine kinase that phosphorylates intracellular substrates, resulting in the activation of multiple intracellular signaling cascades. Dysregulation of IGF-I actions due to impairment in the postreceptor signaling machinery may contribute to multiple diseases in humans. This article will review current information on IGF-I signaling and illustrate recent results demonstrating how impaired IGF-I signaling and action may contribute to the pathogenesis of human diseases, including osteoporosis, neurodegenerative disorders, and reduced fetal growth in utero.

Human placental growth hormone is increased in maternal serum in pregnancies affected by Down syndrome

OBJECTIVE

To evaluate the relationship between maternal serum levels of human placental growth hormone (hPGH) and fetal Down syndrome at gestational midtrimester.

METHODS

We retrospectively analyzed samples of serum from 21 women with Down syndrome pregnancies detected at gestational midtrimester. The samples were obtained at 16-23 weeks' gestation during amniocentesis for fetal karyotyping. Sixty-two serum samples were used as controls, which were obtained at 16-23 weeks' gestation from women with singleton, uncomplicated pregnancies, who gave birth to healthy neonates with a birth weight appropriate for gestational age. The hPGH levels were measured by a solid-phase immunoradiometric assay using 2 different epitopes.

RESULTS

The median hPGH values in the serum of the Down-syndrome-affected pregnancies were significantly higher (p < 0.05) than those of the normal pregnancies at 16-23 weeks' gestation: the median value in the serum was 9.4 ng/ml (5th to 95th percentiles = 1.49-39.03) versus 4.7 ng/ml (0.53-7.88).

CONCLUSION

The hPGH levels in maternal serum were found to be higher at 16-23 weeks' gestation in pregnancies affected by fetal Down syndrome. Further investigation is needed to examine if maternal serum hPGH could be used as an additional marker in prenatal screening of Down syndrome at gestational midtrimester.

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.

Gestational age and fetal growth in relation to maternal ovarian cancer risk in a Swedish cohort

BACKGROUND

Pregnancy influences subsequent maternal ovarian cancer risk. To date, there is limited evidence whether two characteristics of pregnancy, gestational age and birth weight, could modify risk.

MATERIALS AND METHODS

We studied 1.1 million Swedish women who delivered singleton births between 1973 and 2001. Information on infant gestational age and birth weight was abstracted from the nationwide Swedish Birth Register. Women were followed prospectively through linkage with other population-based registers for occurrence of ovarian cancer, death, or emigration through 2001. Hazard ratios [relative risk (RR), 95% confidence interval (95% CI)] from Cox models were used to estimate associations between gestational age, birth weight, and epithelial ovarian cancer risk.

RESULTS

During 12.6 million person-years, 1,017 epithelial ovarian cancers occurred. Mean age at diagnosis was 43 years. Compared with women with term deliveries (>/=40 weeks), women with moderately (35-36 weeks) or very (<35 weeks) preterm deliveries had increased risks of epithelial ovarian cancer (RR 1.4, 95% CI 1.0-2.0 and RR 2.3, 95% CI 1.3-3.8, respectively). In contrast, women giving birth to small-for-gestational-age babies had a reduced risk (RR 0.7, 95% CI 0.4-1.0). Stratifying on birth weight and gestational age, there was a strong protective effect of low birth weight on maternal risk of epithelial ovarian cancer among term deliveries, whereas birth weight seemed to have little effect among preterm births (P(interaction) = 0.022).

CONCLUSIONS

Our results lend further support that the hormonal milieu of a pregnancy may modify long-term risk of developing ovarian cancer. 32).

Longitudinal study of the maternal insulin-like growth factor system before, during and after pregnancy in relation to fetal and infant weight

BACKGROUND

The maternal insulin-like growth factor (IGF) system is considered to be involved in fetal growth regulation. However, available data linking this system to fetal growth are contradictory and incomplete.

AIMS

To measure components of the IGF system before, during and after pregnancy in healthy women and to relate these results, and their changes during pregnancy, to fetal weight (gestational week 31) and birth weight.

METHODS

Serum concentrations of IGF-I, IGF-II, IGF-binding protein (IGFBP)-1, IGFBP-3 and IGFBP-3 protease activity were assessed in 23 women before conception, at weeks 8, 14, 20, 32 and 35 of pregnancy and 2 weeks postpartum. The data were analyzed using simple and multiple linear regression.

RESULTS

One third of the variability in fetal weight was explained by IGF-I in combination with IGFBP-3 protease activity, both assessed at gestational week 32 (p = 0.013). Birth weight was negatively correlated (r = -0.43 to -0.59) with IGFBP-1 at gestational week 20 (p = 0.041), 32 (p = 0.012) and 35 (p = 0.003).

CONCLUSION

We propose there is a finely tuned balance among the components of the IGF system, providing a means for fetal growth regulation.

Insulin-like growth factor (IGF)-I and insulin in normal and growth-restricted mother/infant pairs

Insulin-like growth factor (IGF)-I and insulin are essential for fetal growth. We investigated perinatal changes of both factors in 40 mothers and their 20 appropriate-for-gestational-age (AGA) and 20 intrauterine-growth-restricted (IUGR) fetuses and neonates on day 1 (N1) and day 4 (N4) postpartum. Fetal and N1, but not N4, IGF-I levels were increased in AGA (P < .001 and P = .037, resp.). N1 insulin levels were lower in IUGR (P = .048). Maternal, fetal, and N1 IGF-I, and fetal insulin levels positively correlated with customized centiles (r = .374, P = .035, r = .608, P < .001, r = .485, P = .006, and r = .654, P = .021, resp.). Female infants presented elevated fetal and N4 IGF-I levels (P = .023 and P = .016, resp.). Positive correlations of maternal, fetal, and neonatal IGF-I levels, and fetal insulin levels with customized centiles underline implication of both hormones in fetal growth. IUGR infants present gradually increasing IGF-I levels. Higher IGF-I levels are documented in females.

Insulin-like growth factor-1 receptor expression in the placentae of diabetic and normal pregnancies

BACKGROUND

Septal hypertrophic cardiomyopathy (sHCM) is a characteristic anomaly of the infant of diabetic mother (IDM). Insulin-like growth factor-1 (IGF-1) has been identified as a mediator of tissue overgrowth and we have previously shown that maternal IGF-1 levels were significantly elevated among neonates with asymmetrical sHCM. IGF-1 does not cross the placenta; it exerts physiologic action through binding to the IGF-1 receptor (IGF-1R). Localisation and expression of IGF-1R in term diabetic pregnancies are largely unclear. We have studied IGF-1R in the placentae of diabetic and normal pregnancies and this receptor expression in association with neonates with sHCM.

METHODS

IGF-1R localization and expression in the placentae of six diabetic pregnancies associated with neonatal sHCM were compared with six each of randomly selected diabetic and normal pregnancies without neonatal sHCM by immunohistochemistry. The staining for IGF-1R in the deciduas, cytotrophoblasts, syncytiotrophoblasts and villous endothelium for these 18 samples were assessed and scored by two pathologists who were blinded to the respective diagnoses.

RESULTS

Placental IGF-1R staining was negative in the villous endothelium for all three groups. IGF-1R staining was present in deciduas, cytotrophoblasts and syncytiotrophoblasts but the staining was weaker in the entire group of infants with sHCM compared to those without sHCM.

CONCLUSIONS

IGF-1R is localized in all cell types of the placenta except in villous endothelium. Weaker placental IGF-1R staining in the placentae of diabetic pregnancies associated with sHCM suggests reduced expression of IGF-1R. This may be a down-regulatory response to elevated maternal IGF with neonatal sHCM outcome.

Management of fetal growth restriction

Fetal growth restriction (FGR) is challenging because of the difficulties in reaching a definitive diagnosis of the cause and planning management. FGR is associated not only with a marked increased risk in perinatal mortality and morbidity but also with long-term outcome risks. Combinations of fetal biometry, amniotic fluid volume, heart rate patterns, arterial and venous Doppler, and biophysical variables allow a comprehensive fetal evaluation of FGR. However, no evidence supports that the use of cardiotocography or the biophysical profile improves perinatal outcome. Therefore, obstetricians aim to identify fetuses with early FGR so delivery can be planned according to gestational age and severity of the condition. The balance of risks and the need for the availability of services mean that the involvement of neonatologists in FGR management is vital. In this review, the focus is on the pathophysiology and management of FGR caused by placental diseases.

Maternal insulin-like growth factors-I and -II act via different pathways to promote fetal growth

The placenta transports substrates and wastes between the maternal and fetal circulations. In mice, placental IGF-II is essential for normal placental development and function but, in other mammalian species, maternal circulating IGF-II is substantial and may contribute. Maternal circulating IGFs increase in early pregnancy, and early treatment of guinea pigs with either IGF-I or IGF-II increases placental and fetal weights by mid-gestation. We now show that these effects persist to enhance placental development and fetal growth and survival near term. Pregnant guinea pigs were infused with IGF-I, IGF-II (both 1 mg/kg.d), or vehicle sc from d 20-38 of pregnancy and killed on d 62 (term = 69 d). IGF-II, but not IGF-I, increased the mid-sagittal area and volume of placenta devoted to exchange by approximately 30%, the total volume of trophoblast and maternal blood spaces within the placental exchange region (+29% and +46%, respectively), and the total surface area of placenta for exchange by 39%. Both IGFs reduced resorptions, and IGF-II increased the number of viable fetuses by 26%. Both IGFs increased fetal weight by 11-17% and fetal circulating amino acid concentrations. IGF-I, but not IGF-II, reduced maternal adipose depot weights by approximately 30%. In conclusion, increased maternal IGF-II abundance in early pregnancy promotes fetal growth and viability near term by increasing placental structural and functional capacity, whereas IGF-I appears to divert nutrients from the mother to the conceptus. This suggests major and complementary roles in placental and fetal growth for increased circulating IGFs in early to mid-pregnancy.

Customized birthweight centiles predict SGA pregnancies with perinatal morbidity

OBJECTIVES

To determine the following: (1) the proportion of babies reclassified as small or appropriately grown using customized and population centiles; and (2) the relative risks of perinatal morbidity, including abnormal umbilical Doppler studies, in babies classified as small for gestational age (SGA) and appropriate for gestational age (non-SGA) using the two centile calculations.

DESIGN

Cohort study in SGA and general hospital populations.

SETTING

National Women's Hospital, Auckland, NZ.

POPULATION

A cohort of SGA pregnancies (n= 374) and a general obstetric population (n= 12,879).

METHODS

Pregnancy outcomes were compared between 'non-SGA both' (> or =10th% by population and customized centiles) and those who were 'SGA both' (<10th% by population and customized centiles), 'SGA customized only' (SGA by customized but non-SGA by population centiles) and 'SGA population only' (SGA by population but non-SGA by customized centiles).

MAIN OUTCOME MEASURES

Maternal and newborn morbidity and perinatal death.

RESULTS

In the SGA cohort 271 (72%) babies were 'SGA both', 27 (7%) were 'SGA customized only', 32 (9%) were 'population SGA only' and 44 (12%) were 'non-SGA both'. In the general obstetric population 863 (6.7%) babies were 'SGA both', 445 (3.5%) were 'customized SGA only', 285 (2.2%) were 'population SGA only' and 11,286 (88%) were 'non-SGA both'. Perinatal death and newborn morbidity including nursery admission and long hospital stay were increased and comparable between 'SGA both' and 'customized SGA only' in both study populations. Newborn morbidity was low and comparable between 'population SGA only' and 'non-SGA both'. No perinatal deaths occurred in 'population SGA only' babies. Abnormal Doppler studies were more common in 'SGA both' or 'customized SGA only' but not in 'population SGA only' groups compared with 'non-SGA both'.

CONCLUSIONS

Customized birthweight centiles identified small babies at risk of morbidity and mortality. Use of customized centiles is likely to detect more babies at risk of perinatal morbidity and mortality than would be detected by population centiles.

Birth weight and psychological distress at age 45-51 years: results from the Aberdeen Children of the 1950s cohort study

BACKGROUND

It is unclear whether the effect of low birth weight on common affective disorders in later life is direct or mediated through childhood factors.

AIMS

To determine whether birth weight has a direct effect on psychological distress in adulthood not mediated by childhood IQ or behavioural problems.

METHOD

Participants (n=5572) of the Aberdeen Children of the 1950s study had data on birth weight for gestational age and adult psychological distress. Logistic regression was used to examine the association between these factors, with adjustment for confounders and potential childhood mediators.

RESULTS

Children born full term but weighing less than 5.5 lb had increased odds of psychological distress in later life after adjustment for potential confounders (OR=1.49, 95% CI 1.01-2.20). Further adjustment for childhood IQ and behaviour did not attenuate the association. A 1 s.d. decrease in birth weight for gestational age was associated with a 4% increased odds of psychological distress in adulthood (OR=1.04, 95% CI 0.97-1.12).

CONCLUSIONS

Low birth weight for gestational age, particularly at term, was associated with adult psychological distress. This was not mediated by childhood factors, suggesting a direct effect of early life factors on adult mental health. A neurodevelopmental pathway may therefore be implicated.

The use of biochemical markers in prenatal diagnosis of intrauterine growth retardation: insulin-like growth factor I, Leptin, and alpha-fetoprotein

OBJECTIVE

To determine the relation between weight deficit at birth and IGF-I, IGFBP-I, Leptin, and AFP levels in amniotic fluid after 14-18 weeks; to assess the diagnostic usefulness of these biochemical markers.

STUDY DESIGN

Longitudinal, prospective study. Amniocentesis was performed in pregnant women after 14-18 weeks of gestation.

STUDY POPULATION

86 controls, 18 IUGR <10 percentile, and 17 IUGR <5 percentile.

RESULTS

No significant correlation was found between severity of IUGR and IGF-I, IGFBP-I, or Leptin. AFP was inversely correlated with severity of IUGR; results for the IUGR <10 percentile were: S: 65.7%, SP: 56.9%, PPV: 38.3%, NPV: 80.3%, and an overall diagnostic capacity of 65.6%. Results for the IUGR <5 percentile were: S: 76.4%, SP: 54.8%, PPV: 21.6%, NPV: 93.4% were obtained, and an overall capacity of 70.6%.

CONCLUSIONS

Elevated values of AFP in amniotic fluid may help early detection of populations at risk of developing IUGR.

Prognosis of premenopausal breast cancer and childbirth prior to diagnosis

PURPOSE

The time interval between last childbirth and subsequent breast cancer diagnosis is emerging as an important prognostic factor for premenopausal women.

PATIENTS AND METHODS

We studied, prospectively, 750 women diagnosed with primary invasive breast cancer before age 45 years who participated in the population-based Australian Breast Cancer Family Study (ABCFS).

RESULTS

Median follow-up time was 4.9 years (range, 0.8 to 10.8 years). Compared with nulliparous women, women who gave birth within 2 years prior to diagnosis were more likely to have axillary node-positive (58% v 41%; P =.01), and estrogen receptor-negative (58% v 39%; P =.005) tumors. The unadjusted hazard ratios for death were 2.3 (95% CI, 1.3 to 3.8; P =.002), 1.7 (95% CI, 1.1 to 2.6; P =.03), and 0.9 (95% CI, 0.6 to 1.5; P =.8) for patients who gave birth less than 2 years, 2 to 5 years, and 5 or more years before diagnosis, respectively. After adjusting for tumor characteristics, these hazard ratios were reduced to 1.9 (95%CI, 1.1 to 3.2; P =.02), 1.3 (95% CI, 0.8 to 2.1; P =.3), and 0.9 (95%CI, 0.5 to 1.4; P =.5). Modeling showed that, compared with nulliparous women, the mortality hazard ratio in parous women was 1.9, decreasing by 8% (95%CI, 4% to 13%; P <.001) for each year between last birth and breast cancer diagnosis.

CONCLUSION

Proximity of last childbirth to subsequent breast cancer diagnosis is a predictor of mortality independent of histopathological tumor characteristics. Clinicians should be aware that women diagnosed with breast cancer within a few years following childbirth may have a worse outcome than that suggested solely by the standard histopathological prognostic factors of their cancer.

Increased serum IGF-I during pregnancy is associated with progression of diabetic retinopathy

The IGF system has been associated with development and progression of diabetic retinopathy. We examined whether a simple measurement of the IGF system (serum total IGF-I) correlated with progression of diabetic retinopathy in pregnancy in type 1 diabetes. A prospective observational study was performed in 103 pregnant women with type 1 diabetes. Serum IGF-I was measured in maternal serum from week 14, every fourth week until week 30, and every second week until delivery. Twenty-four-hour blood pressure was measured with a portable oscillometry monitor. The women had visual acuity testing and fundus photography before pregnancy, once in each trimester, and 4 months after birth. Each eye was assigned an overall retinopathy grade on a scale from 1 to 6 independently by two experienced graders. During pregnancy, serum IGF-I increased with increasing gestational age until a plateau was reached in week 32. Progression of retinopathy was significantly associated with a higher level of IGF-I (P < 0.01). Serum IGF-I increased with increasing progression of retinopathy. Change of retinopathy was significantly associated with level of IGF-I (P < 0.01). During pregnancy, serum IGF-I increased with increasing birth weight until a plateau was reached in week 32. Birth weight was significantly associated with a higher level of serum IGF-I (P < 0.01).

Three-dimensional ultrasound in the assessment of normal fetal thigh volume

Accurate assessment of the fetal organ volumes is very important in the evaluation of fetal well-being and maturation. Previous investigators have pointed out that fetal thigh volume (ThiV) may be a useful predictive factor of intrauterine growth retardation. Yet, 2-D ultrasound (US) is limited in assessing fetal ThiV accurately. With the recent advance of 3-D US, the limitation in assessing fetal ThiV by 2-D US can be overcome. To establish a normal reference chart of fetal ThiV for clinical use, a prospective and cross-sectional study using 3-D US was undertaken to assess the fetal ThiV in normal pregnancy. In total, 204 singleton fetuses ranging between 20 and 40 weeks of gestation and fitting the criteria of normal pregnancies were enrolled in this study. Our results showed that fetal ThiV is highly correlated with the gestational age (GA). Furthermore, using GA as the independent variable and ThiV as the dependent variable, the best-fit regression equation was ThiV (mL) = 35.494 - 4.985 x GA + 0.183 x GA(2) (r = 0.91, n = 204, p < 0.0001). For further clinical use, a chart of normal growth centiles of fetal ThiV was then calculated based on this equation. Furthermore, common indexes of fetal biometry, such as biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW), were all highly correlated with ThiV (all p < 0.0001). In conclusion, our data of fetal ThiV assessed by 3-D US can serve as a useful reference in evaluating fetal growth and nutrition status during normal gestation.

Increase in maternal placental growth hormone during pregnancy and disappearance during parturition in normal and growth hormone-deficient pregnancies

OBJECTIVE

The purpose of this study was to evaluate placental growth hormone levels in maternal circulation throughout pregnancy in normal and growth hormone-deficient women with the use of a specific assay and to determine the clearance of placental growth hormone from maternal circulation after birth.

STUDY DESIGN

Seventeen healthy pregnant women and 1 patient with growth hormone deficiency substituted with recombinant growth hormone during pregnancy participated in a longitudinal study from early pregnancy until birth with repetitive blood sampling and measurement of placental growth hormone levels throughout pregnancy. Furthermore, serial blood samples were drawn before, during, and after elective caesarean deliveries in 5 healthy women to calculate the half-life of placental growth hormone. Placental growth hormone was measured with the use of two monoclonal antibodies in a commercially available solid-phase iodine 125-labeled immunoradiometric assay (Biocode, Liège, Belgium).

RESULTS

Placental growth hormone levels were detectable from as early as 8 weeks of gestation in some of the women and increased throughout gestation, with a maximum at approximately 35 to 36 weeks of gestation (13.7 ng/mL; range, 5.9-24.4 ng/mL) and large interindividual variations. Placental growth hormone levels did not correlate with birth weight or placental weight. In the patient with isolated growth hormone deficiency, placental growth hormone levels were detectable from 11 weeks of gestation (3.4 ng/mL) and increased throughout pregnancy to 13.9 ng/mL, which is similar to values that are obtained in the healthy pregnant women. Substitution therapy with recombinant human growth hormone did not suppress the increase in placental growth hormone. We found a mean half-life of placental growth hormone of 13.8 minutes (range, 11.5-15.2 minutes) in healthy pregnant women and an apparently similar half-life of placental growth hormone (15.8 minutes) in the growth hormone-deficient patient, assuming a monoexponential disappearance of placental growth hormone during the first 30 minutes after the delivery. After the initial 30 minutes, approximately 75% (range, 65%-89%) of the placental growth hormone had been cleared from the maternal circulation.

CONCLUSION

Levels of placental growth hormone in maternal circulation increase throughout pregnancy from as early as 8 weeks of pregnancy, with maximum levels around the week 35 of gestation. The pregnancy-induced rise in placental growth hormone levels in the growth hormone-deficient patient was comparable to the rise seen during normal pregnancies and was not suppressed by the concurrent human growth hormone treatment. We speculate that maternal serum levels of placental growth hormone reflect placental function and fetal growth. However, further studies are needed to evaluate the potential clinical use of placental growth hormone determinations.

Predictive value of hormone measurements in maternal and fetal complications of pregnancy

Intrauterine tissues (placenta, amnion, chorion, decidua) express hormones and cytokines that play a decisive role in maternal-fetal physiological interactions. The excessive or deficient release of some placental hormones in association with gestational diseases may reflect an abnormal differentiation of the placenta, an impaired fetal metabolism, or an adaptive response of the feto-placental unit to adverse conditions. This review is focused on the applicability of hormone measurements in the risk assessment, early diagnosis, and management of pregnancies complicated by Down's syndrome, fetal growth restriction, preeclampsia, preterm delivery, and diabetes mellitus. Combined hormonal tests or the combination of hormones and ultrasound may achieve reasonable sensitivity, but research continues to simplify the screening programs without sacrificing their accuracy. Only in a few instances is there sufficient evidence to firmly recommend the routine use of hormone tests to predict maternal and fetal complications, but the judicious use of selected tests may enhance the sensitivity of the risk assessment based solely on clinical and ultrasound examination.

Maternal serum activin A, inhibin A, and follistatin in pregnancies with appropriately grown and small-for-gestational-age fetuses classified by umbilical artery Doppler ultrasound

OBJECTIVE

The purpose of this study was to examine the relationship of maternal serum activin A, inhibin A, and follistatin with fetal growth and placental function.

STUDY DESIGN

Inhibin A, activin A, and follistatin were measured in maternal serum that was stored from normally grown (control subjects, n = 50) and small-for-gestational-age pregnancies (n = 49), prospectively classified as normal small-for-gestational-age pregnancy or fetal growth-restricted pregnancy with the use of umbilical artery Doppler ultrasound.

RESULTS

Activin A and inhibin A were significantly increased in fetal growth-restricted pregnancies compared with control subjects (activin A: regression coefficient, 0.54, P <.001; inhibin A: regression coefficient, 0.47, P =.003). The activin:follistatin ratio was significantly higher in fetal growth-restricted pregnancies compared with control subjects (P <.001). There were no significant differences between analyte levels of normal small-for-gestational-age pregnancies and control subjects.

CONCLUSION

Maternal serum activin A, inhibin A, and activin:follistatin ratio are raised in fetal growth-restricted pregnancies but not in normal small-for-gestational age pregnancies. This provides further evidence of the difference between subgroups within small-for-gestational-age pregnancies and emphasizes the need to stratify for this in research.

Amniotic IGF-I supplements improve gut growth but reduce circulating IGF-I in growth-restricted fetal sheep

Insulin-like growth factor I (IGF-I) is an important regulator of fetal growth, and circulating concentrations are reduced in intrauterine growth-restricted (IUGR) fetuses. We investigated whether IGF-I administered into amniotic fluid could ameliorate IUGR in fetal sheep. Fetuses were assigned to control (n = 9), IUGR+saline (n = 12), or IUGR+IGF-I groups (daily intra-amniotic IGF-I injections of 20 microg, n = 13). IUGR was induced by placental embolization from 114 to 120 days. Treatment was from 120 to 130 days of gestation. Embolization produced asymmetrically IUGR fetuses with decreased body weight and lighter, thinner-walled guts. Fetal plasma and amniotic IGF-I levels were reduced. During treatment, fetal plasma, but not amniotic, IGF-I levels recovered in the saline group but remained depressed in the IGF-I-treated group. IGF-I treatment restored gut weight and wall thickness to control levels and increased the number of crypt mitoses. Fetal weight was similar to that of controls, but spleen, liver, and thymic weights were reduced by 30-37%, and placentome growth was altered. Amniotic fluid IGF-I supplementation may provide the basis of future therapeutic approaches to IUGR, but the systemic effects require further investigation.

Maternal insulin-like growth factor binding protein-1, body mass index, and fetal growth

AIM

To examine the hypothesis that the maternal insulin-like growth factor system may constrain fetal growth.

METHODS

A prospective observational study of maternal serum insulin-like growth factor binding protein-1 (IGFBP-1) and fetal growth was undertaken in neonates with birthweights below the 5th centile. They had been classified either as having fetal growth restriction (FGR) due to placental dysfunction (increased umbilical artery Doppler pulsatility index (PI); n = 25) or as being small for gestational age (SGA; normal umbilical artery PI, growth velocity and amniotic fluid; n = 27). Eighty nine controls had normal birthweights (5th-95th centile), umbilical artery PI, growth velocity, and amniotic fluid. IGFBP-1 was measured by radioimmunoassay.

RESULTS

Among the controls, there was no significant correlation between IGFBP-1 and birthweight after allowing for body mass index (BMI). Maternal BMI was high in FGR and after adjusting for this, IGFBP-1 was increased (109 ng/ml) compared with SGA babies (69 ng/ml) and controls (57 ng/ml) and correlated with the umbilical artery PI.

CONCLUSIONS

Maternal IGFBP-1 is probably not part of normal placental function. Its increase in FGR could be the cause or consequence of impaired placental perfusion, but high IGFBP-1 concentrations might further reduce the availability of maternal IGF-I to the placenta. This could worsen placental function and so adversely affect fetal growth.

Maternal serum insulin-like growth factor binding protein-2 and -3 and fetal growth

This was a prospective observational study of maternal insulin-like growth factor binding protein-2 and -3 and fetal growth in 141 pregnant women after 24 weeks gestation who were scanned and venesected fortnightly. Cases (birthweight <5th centile) were sub-divided into those with growth restriction due to placental dysfunction (n = 25) and normal small (n = 27) and there were 89 normally grown controls. Maternal binding protein-3 was measured by radioimmunoassay and the overall pattern of the binding proteins and their proteolytic modifications were assessed by Western ligand blotting and immunoblotting followed by densitometric analysis. In controls, there was no correlation between binding protein-3 and birthweight, and binding protein-3 was elevated in the normal small but not the placental dysfunction group. Complete proteolysis of the 40 kDa doublet of binding protein-3 was observed in all pregnancies. Maternal serum binding protein-2 concentrations were unchanged in normal pregnancy compared to non-pregnant controls but elevated in the growth-restricted group and in all pregnancies binding protein-2 was predominantly present as a 14 kDa proteolysed fragment. These results suggest that compensatory changes in binding protein-2 and -3 or their proteolysis do not increase bioavailability and so do not confound the low maternal insulin-like growth factor-I in growth restricted pregnancies.