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Fetal growth restriction (FGR) affects up to 5 % of pregnancies worldwide, and trophoblast function plays a significant role on the outcome. An epidemiological study has linked vitamin D deficiency to adverse perinatal outcomes, which include decreased birth weight. The placenta as an important source of vitamin D regulates its metabolism through the vitamin D receptor (VDR), but the mechanism by which VDR regulates trophoblast function is poorly understood. Our study aimed at determining placental VDR expression in FGR and gestation-matched control (GMC) pregnancies and identifying the actions of VDR in trophoblast differentiation and apoptosis. Placentae were collected from a well-defined cohort of idiopathic FGR and GMC pregnancies. VDR mRNA and protein expressions were determined by PCR, immunohistochemistry and immunoblotting, while functional consequences of VDR inactivation in vitro were determined on BeWo cells by determining changes in differentiation, attachment and apoptosis. Significant decreases in VDR mRNA expression ( p  = 0.0005) and protein expression ( p  = 0.0003) were observed in the FGR samples, while VDR inactivation, which showed markers for differentiation, cell attachment and apoptosis, was significantly increased. Thus, decreased placental VDR may contribute to uncontrolled premature differentiation and apoptosis of trophoblasts that are characteristics of idiopathic FGR pregnancies. Key message Fetal growth restriction (FGR) affects up to 5 % of all pregnancies worldwide. FGR is the second highest cause of perinatal mortality and morbidity. The placenta plays a pivotal role in vitamin D metabolism during pregnancy. Vitamin D deficiency is associated with adverse pregnancy outcomes. Placental vitamin D receptor expression is decreased in FGR.

We have previously shown that placentae from patients with gestational diabetes mellitus who did not receive insulin had lower glucose transport and utilisation than non-diabetic control subjects. To assess the placental glucose handling characteristics of women with gestational diabetes mellitus receiving insulin, we examined glucose transport and utilisation in placentae from three groups of women after term delivery: those with gestational diabetes mellitus and receiving insulin (n = 9, insulin group); those with gestational diabetes mellitus and not receiving insulin (n = 10, no insulin group); and those with normal, non-diabetic pregnancies (n = 9, control group). Dual perfusion of an isolated placental lobule was done using maternal glucose concentrations of 4, 8, 16 and 24 mmol/l. Glucose and L-lactate concentrations in the maternal and fetal effluents were measured. Direct glucose transfer from the maternal to the fetal effluent was measured using 14C-D-glucose. Mean rates in micromol ming(-1) (wet tissue) at maternal glucose concentration of 8 mmol/l are shown. Glucose uptake from the maternal perfusate (insulin group 0.57, no insulin group 0.30) and net glucose transfer to the fetal effluent (insulin group 0.41, no insulin group 0.20) both increased in the placentae of women receiving insulin compared with the diabetic group not receiving insulin. Both groups of patients had lower placental glucose utilisation than the control group (insulin group 0.16, no insulin group 0.10, control group 0.25). These results suggest that materno-fetal glucose transport increases in the placentae of women with gestational diabetes mellitus who receive insulin compared with those women who do not receive insulin.

Genome scans in Icelandic, Australian and New Zealand, and Finnish families have localized putative susceptibility loci for preeclampsia/eclampsia to chromosome 2. The locus mapped in the Australian and New Zealand study (designated PREG1) was thought to be the same locus as that identified in the Icelandic study. In both these studies, two distinct quantitative trait locus (QTL) regions were evident on chromosome 2. Here, we describe our fine mapping of the PREG1 locus and a genetic analysis of two positional candidate genes. Twenty-five additional microsatellite markers were genotyped within the 74-cM linkage region defined by the combined Icelandic and Australian and New Zealand genome scans. The overall position and shape of the localization evidence obtained using nonparametric multipoint analysis did not change from that seen previously in our 10-cM resolution genome scan; two peaks were displayed, one on chromosome 2p at marker D2S388 (107.46 cM) and the other on chromosome 2q at 151.5 cM at marker D2S2313. Using the robust two-point linkage analysis implemented in the Analyze program, all 25 markers gave positive LOD scores with significant evidence of linkage being seen at marker D2S2313 (151.5 cM), achieving a LOD score of 3.37 under a strict diagnostic model. Suggestive evidence of linkage was seen at marker D2S388 (107.46 cM) with a LOD score of 2.22 under the general diagnostic model. Two candidate genes beneath the peak on chromosome 2p were selected for further analysis using public single nucleotide polymorphisms (SNPs) within these genes. Maximum LOD scores were obtained for an SNP in TACR1 (LOD = 3.5) and for an SNP in TCF7L1 (LOD = 3.33), both achieving genome-wide significance.However, no evidence of association was seen with any of the markers tested. These data strongly support the presence of a susceptibility gene on chromosome 2p11-12 and substantiate the possibility of a second locus on chromosome 2q23.

Background/Aims: Pre-eclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality. PE is defined clinically as the onset of maternal hypertension and proteinuria following 20 weeks of gestation. It is associated with altered maternal uterine decidual spiral artery remodelling, which may lead to reduced blood flow and increased thrombosis within the uteroplacental vasculature. Proteoglycans (PGs) are macromolecules which have (in combination with glycosaminoglycans) important anticoagulant roles in vascular endothelial environments, including the uteroplacental circulation. The hypothesis under consideration in this study was that differential expression of placental PGs may be associated with PE. Methods: PE and control placental samples were collected with ethics approval and patient consent. RNA and protein were extracted and real-time PCR and Western immunoblotting were performed to determine the expression of the PGs in the samples. Results: Of the nine PGs investigated, none showed increased expression, whereas the mRNA and protein expression of five of them was significantly decreased in the placentae of pre-eclamptic women compared to gestation-matched controls. Conclusion: Therefore, the results of this study support the hypothesis that a placental PG deficiency may contribute to the placental thrombotic lesions characteristic of PE.

Gestational diabetes is associated with complications for the offspring before, during and after delivery. Poor maternal glucose control, however, is a weak predictor of these complications. Given its position at the interface of the maternal and fetal circulations, the placenta possibly plays a crucial part in protecting the fetus from adverse effects from the maternal diabetic milieu. We hypothesised that gestational diabetes may result in changes in placental function, particularly with respect to the uptake, transfer, and/or utilisation of glucose. We aimed to examine glucose transport and utilisation in intact human placental lobules from women with gestational diabetes and those from normal pregnancies. Dual perfusion of an isolated placental lobule was done on placentae from diet treated gestational diabetic (n = 7) and normal pregnant patients (n = 9) using maternal glucose concentrations of 4, 8, 16 and 24 mmol/l in random order over a 4-h experiment. Results were expressed in micromol x min(-1) x g(-1). D-glucose uptake from the maternal circulation (control 0.492 vs gestational diabetes mellitus 0.248, at 8 mmol/l maternal glucose), D-glucose utilisation by the placenta (0.255 vs 0.129), D-glucose transfer to the fetal circulation (direct 0.979 vs 0.402; net transfer 0.269 vs 0.118) and L-lactate maternal release into both the fetal (0.052 vs 0.042) and maternal (0.255 vs 0.129) circulation were significantly reduced during in vitro perfusion of placentae from patients with gestational diabetic pregnancies. Transfer of 3H-L-glucose also significantly reduced in the diabetic group (8.1% vs 2.6%). These results suggest that placental transport and metabolism of D-glucose is altered during gestational diabetes.

In European and Japanese but not in Australian, American, and South African women, the C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism has been reported to be a genetic risk factor pre-eclampsia/eclampsia (PE/E). The recently described A1298C MTHFR gene polymorphism also results in reduced MTHFR enzyme activity, although to a lesser extent than the previously described C677T polymorphism. Heterozygotes for both polymorphisms are reported to have an even lower MTHFR enzymatic activity than seen in homozygotes for the C677T genotype. In this current study we determined the allele frequency of the A1298C MTHFR gene polymorphism in an Australian population and examined this polymorphism alone and in combination with the C677T MTHFR polymorphism for an association with PE/E. Neither the A1298C polymorphism alone nor a combination of both polymorphisms showed an association with PE/E in our population of Australian women.

This study involving women with suspected preeclampsia showed that an sFlt-1:PlGF ratio of 38 or less has a very high negative predictive value for the development of preeclampsia in the next week and thus may be clinically useful. Preeclampsia, a heterogeneous, multisystem disorder defined by the new onset of hypertension and proteinuria after 20 weeks of gestation, affects 2 to 5% of pregnancies worldwide. 1 – 5 Preeclampsia is associated with high risks of iatrogenic preterm delivery, intrauterine growth restriction, placental abruption, and perinatal mortality, along with maternal morbidity and mortality. 6 , 7 The cause of preeclampsia is incompletely understood, but the disorder is thought to be due to placental malperfusion resulting from abnormal remodeling of maternal spiral arteries. 8 , 9 In preeclampsia, circulating maternal serum levels of soluble fms-like tyrosine kinase 1 (sFlt-1) are increased, and placental growth factor (PlGF) levels . . .

Atrial natriuretic factor (ANF), produced by cytotrophoblast cells of the human placenta, may be involved in the regulation of uteroplacental blood flow. Pre-eclampsia is associated with maternal hypertension and reduced uteroplacental perfusion. The relationship between pre-eclampsia and placental production of ANF is not known. This study measured pro-ANF mRNA levels by Northern blot analysis in placentae delivered by caesarean section at preterm and term gestations from women with normotensive and pre-eclamptic pregnancies and found no significant difference between pre-eclampsia and normal pregnancy at either gestation. This result suggests that placental production of ANF is not altered at the pretranslational level during pre-eclampsia.

Elucidating the genetic architecture of preeclampsia is a major goal in obstetric medicine. We have performed a genome-wide association study (GWAS) for preeclampsia in unrelated Australian individuals of Caucasian ancestry using the Illumina OmniExpress-12 BeadChip to successfully genotype 648,175 SNPs in 538 preeclampsia cases and 540 normal pregnancy controls. Two SNP associations (rs7579169, p = 3.58×10(-7), OR = 1.57; rs12711941, p = 4.26×10(-7), OR = 1.56) satisfied our genome-wide significance threshold (modified Bonferroni p<5.11×10(-7)). These SNPs reside in an intergenic region less than 15 kb downstream from the 3' terminus of the Inhibin, beta B (INHBB) gene on 2q14.2. They are in linkage disequilibrium (LD) with each other (r(2) = 0.92), but not (r(2)<0.80) with any other genotyped SNP ±250 kb. DNA re-sequencing in and around the INHBB structural gene identified an additional 25 variants. Of the 21 variants that we successfully genotyped back in the case-control cohort the most significant association observed was for a third intergenic SNP (rs7576192, p = 1.48×10(-7), OR = 1.59) in strong LD with the two significant GWAS SNPs (r(2)>0.92). We attempted to provide evidence of a putative regulatory role for these SNPs using bioinformatic analyses and found that they all reside within regions of low sequence conservation and/or low complexity, suggesting functional importance is low. We also explored the mRNA expression in decidua of genes ±500 kb of INHBB and found a nominally significant correlation between a transcript encoded by the EPB41L5 gene, ∼250 kb centromeric to INHBB, and preeclampsia (p = 0.03). We were unable to replicate the associations shown by the significant GWAS SNPs in case-control cohorts from Norway and Finland, leading us to conclude that it is more likely that these SNPs are in LD with as yet unidentified causal variant(s).

The C677T methylenetetrahydrofolate reductase (MTHFR) gene polymorphism results in reduced MTHFR enzymatic activity. This in turn results in increased levels of homocysteine. It has been suggested that increased levels of homocysteine cause vascular disease, which is known to increase the risk of developing pre-eclampsia (PE) during pregnancy. However, recent studies on Japanese, Italian and American populations have failed to reach agreement on an association between the C677T polymorphism and PE. In this study, 156 cases of eclampsia (E)/PE and 79 normal pregnant control cases from an Australian population were genotyped for this mutation. No significant difference could be found in the incidence of the homozygote mutation or in the allele frequency. We conclude from this study that the C677T mutation in our population is not associated with the development of PE/E.