Emma Cook

Study protocol. A prospective cohort study of unselected primiparous women: the pregnancy outcome prediction study

BackgroundThere have been dramatic changes in the approach to screening for aneuploidy over the last 20 years. However, the approach to screening for other complications of pregnancy such as intra-uterine growth restriction, pre-eclampsia and stillbirth remains largely unchanged. Randomised controlled trials of routine application of high tech screening methods to the general population have generally failed to show improvement in outcome. We have previously reviewed this and concluded it was due, in large part, to poor performance of screening tests. Here, we report a study design where the primary aim is to generate clinically useful methods to screen women to assess their risk of adverse pregnancy outcome.Methods/designWe report the design of a prospective cohort study of unselected primiparous women recruited at the time of their first ultrasound scan. Participation involves serial phlebotomy and obstetric ultrasound at the dating ultrasound scan (typically 10–14 weeks), 20 weeks, 28 weeks and 36 weeks gestation. In addition, maternal demographic details are obtained; maternal and paternal height are measured and maternal weight is serially measured during the pregnancy; maternal, paternal and offspring DNA are collected; and, samples of placenta and membranes are collected at birth. Data will be analysed as a prospective cohort study, a case-cohort study, and a nested case-control study.DiscussionThe study is expected to provide a resource for the identification of novel biomarkers for adverse pregnancy outcome and to evaluate the performance of biomarkers and serial ultrasonography in providing clinically useful prediction of risk.

Activation of mutated K‐ras in donor endometrial epithelium and stroma promotes lesion growth in an intact immunocompetent murine model of endometriosis

Endometriosis is a common chronic gynaecological condition, affecting 5–10% of women of child‐bearing age. Its study has been hampered by lack of genetically tractable models. We transplanted steroid‐manipulated, menstrual‐like endometrium from K‐rasG12V/+/Ah‐Cre+/+/ROSA26R‐LacZ+/+ mice into gonad‐intact immunocompetent wild‐type mice. This led to endometriosis‐like lesion development. Long‐term lesion survival depended on the presence of the activated K‐ras in the small proportion of the cells in the mature lesion that had undergone Cre‐mediated K‐ras activation. LacZ activity demonstrated Cre‐mediated recombination in both endometrial epithelial cells and stromal cells, and transgenic K‐ras expression was confirmed by RT‐PCR. The endometriosis lesions developed without exogenous oestradiol supplementation and anti‐oestrogen (fulvestrant, ICI 182780) treatment greatly suppressed their growth. Immunohistochemistry confirmed that as in human endometriosis, there was invasion and activation of fibroblasts, endothelial cells, and macrophages, with marked collagen deposition in the lesions. This model provides an opportunity to investigate endometriosis lesion establishment, growth, and regression in genetically tractable, immunocompetent, and hormonally intact mice. Furthermore, for the first time it provides a suitable model to test clinically validated driver genes in a faithful mouse model of the predisposing endometriotic lesion, thus providing the correct cellular context and microenvironment for ovarian clear cell carcinogenesis. Copyright

Progestin regulates chemokine (C-X-C motif) ligand 14 transcript level in human endometrium

Leukocyte populations change profoundly in the human endometrium during the menstrual cycle. However the predominant cell, the uterine natural killer (uNK) cell does not contain steroid receptors. From gene array analysis we identified a transcript encoding chemokine (C-X-C motif) ligand 14 (CXCL14) which is markedly up-regulated in the secretory phase of the cycle. We confirm this data by northern blotting and quantitative PCR. Using in situ hybridization we localized CXCL14 mRNA to the glandular epithelial cells where it was detected only in the secretory phase of the cycle. Candidate progesterone response elements were identified at positions -2028/-2007 and -722/-697 (PRE1 and PRE2, respectively) relative to the translation start site. These were functionally tested using luciferase reporter deletion constructs, electrophoretic mobility shift assays and site-directed mutagenesis. The deletion/mutation of these sites reduced progesterone induction by 40 and 20%, respectively. Finally, we demonstrated that recombinant CXCL14 stimulated uNK cell chemotaxis in vitro. We therefore conclude that CXCL14 is likely to be regulated by progesterone in human endometrium and that it may exert a chemoattractive effect on uNK cells and in part be responsible for their clustering around the epithelial glands.

Prediction of Preeclampsia Using the Soluble fms-Like Tyrosine Kinase 1 to Placental Growth Factor Ratio

We sought to assess the ratio of sFlt-1 (soluble fms-like tyrosine kinase 1) to PlGF (placental growth factor) in maternal serum as a screening test for preeclampsia in unselected nulliparous women with a singleton pregnancy. We studied 4099 women recruited to the POP study (Pregnancy Outcome Prediction) (Cambridge, United Kingdom). The sFlt-1:PlGF ratio was measured using the Roche Cobas e411 platform at ≈20, ≈28, and ≈36 weeks of gestational age (wkGA). Screen positive was defined as an sFlt-1:PlGF ratio >38, but higher thresholds were also studied. At 28 wkGA, an sFlt-1:PlGF ratio >38 had a positive predictive value (PPV) of 32% for preeclampsia and preterm birth, and the PPV was similar comparing women with low and high prior risk of disease. At 36 wkGA, an sFlt-1:PlGF ratio >38 had a PPV for severe preeclampsia of 20% in high-risk women and 6.4% in low-risk women. At 36 wkGA, an sFlt-1:PlGF ratio >110 had a PPV of 30% for severe preeclampsia, and the PPV was similar comparing low- and high-risk women. Overall, at 36 wkGA, 195 (5.2%) women either had an sFlt-1:PlGF ratio of >110 or an sFlt-1:PlGF ratio >38 plus maternal risk factors: 43% of these women developed preeclampsia, about half with severe features. Among low-risk women at 36 wkGA, an sFlt-1:PlGF ratio ⩽38 had a negative predictive value for severe preeclampsia of 99.2%. The sFlt-1:PlGF ratio provided clinically useful prediction of the risk of the most important manifestations of preeclampsia in a cohort of unselected nulliparous women.

Influence of speed of sample processing on placental energetics and signalling pathways: implications for tissue collection.

Introduction The placenta is metabolically highly active due to extensive endocrine and active transport functions. Hence, placental tissues soon become ischaemic after separation from the maternal blood supply. Ischaemia rapidly depletes intracellular ATP, and leads to activation of stress-response pathways aimed at reducing metabolic demands and conserving energy resources for vital functions. Therefore, this study aimed to elucidate the effects of ischaemia ex vivo as may occur during tissue collection on phosphorylation of placental proteins and kinases involved in growth and cell survival, and on mitochondrial complexes. Methods Eight term placentas obtained from normotensive non-laboured elective caesarean sections were kept at room-temperature and sampled at 10, 20, 30 and 45 min after delivery. Samples were analyzed by Western blotting. Results Between 10 and 45 min the survival signalling pathway intermediates, P-AKT, P-GSK3α and β, P-4E-BP1 and P-p70S6K were reduced by 30–65%. Stress signalling intermediates, P-eIF2α increased almost 3 fold after 45 min. However, other endoplasmic reticulum stress markers and the Heat Shock Proteins, HSP27, HSP70 and HSP90, did not change. Phosphorylation of AMPK, an energy sensor, was elevated 2 fold after 45 min. Contemporaneously, there was an ∼25% reduction in mitochondrial complex IV subunit I. Discussion and conclusions These results suggest that for placental signalling studies, samples should be taken and processed within 10 min of caesarean delivery to minimize the impact of ischaemia on protein phosphorylation.

Screening for fetal growth restriction using ultrasound and the sFLT1/PlGF ratio in nulliparous women: a prospective cohort study

BACKGROUND Fetal growth restriction is a major determinant of perinatal morbidity and mortality. This condition has no gold standard definition, but a widely used proxy is delivery of a small for gestational age infant (<10th percentile) combined with an adverse pregnancy outcome. Effective screening for fetal growth restriction is an area of unmet clinical need. We aimed to determine the diagnostic effectiveness of a combination of ultrasonic fetal biometry and measurement of the ratio of soluble fms-like tyrosine kinase receptor 1 (sFLT1) to placental growth factor (PlGF) in predicting adverse pregnancy outcomes associated with delivery of a small for gestational age infant. METHODS In this prospective cohort study, using serial antenatal blood sampling and blinded ultrasound scans, we investigated the association between the combination of an elevated sFLT1/PlGF ratio (>85th percentile) and ultrasonically suspected small for gestational age (<10th percentile) at both 28 and 36 weeks of gestational age. The outcome following the 28 week measurement was preterm delivery of a small for gestational age infant. The outcome following the 36 week measurement was subsequent delivery of a small for gestational infant associated with maternal pre-eclampsia or perinatal morbidity or mortality. All definitions of exposure and outcome were predefined before we did our data analysis. FINDINGS Between Jan 14, 2008, and July 31, 2012, we recruited 4512 nulliparous women. 4098 women (91%) had a sFLT1/PlGF ratio measurement and estimated fetal weight at 28 or 36 weeks of gestational age, and outcome data available. 3981 women were analysed for 28 weeks of gestational age measurements and 3747 women were analysed for 36 weeks of gestational age measurements. At 28 weeks, 47 (1%) of 3981 women had the combination of ultrasonic small for gestational age and an elevated sFLT1/PlGF ratio. The positive likelihood ratio for preterm delivery of a small for gestational age infant associated with this combination was 41·1 (95% CI 23·0-73·6), the sensitivity was 38·5% (21·1-59·3), the specificity was 99·1% (98·7-99·3), and the positive predictive value was 21·3% (11·6-35·8). At 36 weeks, 102 (3%) of 3747 women had the combination of ultrasonic small for gestational age and an elevated sFLT1/PlGF ratio. The positive likelihood ratio for delivery of a small for gestational age infant associated with maternal pre-eclampsia or perinatal morbidity or mortality was 17·5 (95% CI 11·8-25·9), the sensitivity was 37·9% (26·1-51·4), the specificity was 97·8% (97·3-98·3), and the positive predictive value was 21·6% (14·5-30·8). The positive likelihood ratios at both gestational ages were higher than previously described definitions of suspected fetal growth restriction using purely ultrasonic assessment. INTERPRETATION The combination of ultrasonically suspected small for gestational age plus an elevated sFLT1/PlGF ratio in unselected nulliparous women identified a relatively small proportion of women who have high absolute risks of clinically important adverse outcomes. Screening and intervention based on this approach could result in net benefit and this could be an appropriate subject for a randomised controlled trial. FUNDING NIHR Cambridge Comprehensive Biomedical Research Centre, Medical Research Council, and Stillbirth and neonatal death society (Sands).

VEGF-A loss in the haematopoietic and endothelial lineages exacerbates age-induced renal changes.

Renal function declines with age and this is more pronounced in males than females. VEGF-A is essential for glomerular development and function but its role in other aspects of renal function is poorly understood. We therefore investigated the role of VEGF-A, derived specifically from haematopoietic and endothelial lineages in the kidney. We crossed VavCre and floxed Vegf-a mice allowing specific ablation of a single Vegf-a allele in the haematopoietic and endothelial lineages. Mutants were viable and fertile and had normal haematological composition, indicating that 50% gene dosage of Vegf-a in the Vav-expressing lineage is sufficient for establishing a functional haematopoietic system and mature vascular network. However, several abnormalities were observed in the kidney of the adult mutants. These included the formation of inclusion bodies in the proximal tubular cells, tubular atrophy and interstitial fibrosis. These features were observed in 9-11 month-old mutant animals. Most of these abnormalities have been described in aging kidneys in man, and were also observed in the older control mice (24 months). The pathological features appeared in mutant male animals at a younger age than in female mutants. This indicates that reduction in Vegf-a gene dosage in haematopoietic and endothelial lineages accelerates renal aging, suggesting that VEGF-A derived from these lineages may play a role in protecting the kidney from age-associated damage.

Placental polyamine metabolism differs by fetal sex, fetal growth restriction, and preeclampsia

Preeclampsia and fetal growth restriction (FGR) are major causes of the more than 5 million perinatal and infant deaths occurring globally each year, and both are associated with placental dysfunction. The risk of perinatal and infant death is greater in males, but the mechanisms are unclear. We studied data and biological samples from the Pregnancy Outcome Prediction (POP) study, a prospective cohort study that followed 4,212 women having first pregnancies from their dating ultrasound scan through delivery. We tested the hypothesis that fetal sex would be associated with altered placental function using multiomic and targeted analyses. We found that spermine synthase (SMS) escapes X-chromosome inactivation (XCI) in the placenta and is expressed at lower levels in male primary trophoblast cells, and male cells were more sensitive to polyamine depletion. The spermine metabolite N1,N12-diacetylspermine (DiAcSpm) was higher in the female placenta and in the serum of women pregnant with a female fetus. Higher maternal serum levels of DiAcSpm increased the risk of preeclampsia but decreased the risk of FGR. To our knowledge, DiAcSpm is the first maternal biomarker to demonstrate opposite associations with preeclampsia and FGR, and this is the first evidence to implicate polyamine metabolism in sex-related differences in placentally related complications of human pregnancy.