First-trimester assessment of placenta function and the prediction of preeclampsia and intrauterine growth restriction

Combined Screening for Early Detection of Pre-Eclampsia

Although the precise pathophysiology of pre-eclampsia remains unknown, this condition continues to be a major cause of maternal and fetal mortality. Early prediction of pre-eclampsia would allow for timely initiation of preventive therapy. A combination of biophysical and biochemical markers are superior to other tests for early prediction of the development of pre-eclampsia. Apart from the use of parameters in first-trimester aneuploidy screening, cell-free fetal DNA quantification is emerging as a promising marker for prediction of pre-eclampsia. This article reviews the current research of the most important strategies for prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters, and biomarkers.

Predictive accuracy of the first trimester Doppler scan: a meta-study

AIM

To determine sensitivity and cut-off indices of the uterine artery Doppler (UAD) in prediction of preeclampsia and fetal growth restriction (FGR).

METHODS

Seventy-six studies published in 1995-2014, present 298,329 prenatal Doppler screenings performed in nullipara in the first and early second trimesters of singleton pregnancies. The sample is stratified into four groups based on the Doppler sensitivity and specificity indices pertaining to the major clinical endpoints of the cohort.

RESULTS

The FGR diagnostic specificity (r = 0.728) and bilateral notching index (r = 0.803) correlations indicate that the UAD accuracy depends on the placental bed and the screening mode.

CONCLUSIONS

Predictive sensitivity of the UAD increases after 16 weeks + 3 days (115 days) of gestation. The best predictive parameter of preeclampsia and FGR is the placental side uterine artery resistance index which confers to the highest means when the placenta is on the midline (OR 0.9).

Prediction of early- and late-onset pregnancy-induced hypertension using placental volume on three-dimensional ultrasound and uterine artery Doppler

OBJECTIVES

To determine whether uterine artery (UtA) Doppler findings and three-dimensional (3D) ultrasound measurement of placental volume during the first trimester allowed prediction of early- and late-onset pregnancy-induced hypertension (early PIH and late PIH).

METHODS

Subjects with singleton pregnancy who underwent an ultrasound scan at 11-13 weeks' gestation and delivered between 2011 and 2013 were enrolled prospectively into the study. The UtA Doppler indices and placental volume on 3D ultrasound at 11-13 weeks' gestation in cases that developed early PIH (< 34 weeks) or PIH later in pregnancy (≥ 34 weeks) were compared with values in unaffected pregnancies.

RESULTS

Ten cases of early PIH, 67 cases of late PIH and 1285 unaffected pregnancies were analyzed. The UtA pulsatility index (PI) was higher in cases of early PIH than that in unaffected pregnancies (median, 2.35 vs. 1.79; P = 0.043) but did not differ between cases of late PIH and unaffected pregnancies. Placental volume was smaller in cases of early PIH than that in unaffected pregnancies (median, 43 cm3 vs. 62 cm(3) ; P = 0.003) but did not differ between cases of late PIH and unaffected pregnancies. The area under the receiver-operating characteristics curve for the prediction of early PIH, by combining UtA-PI and placental volume, was 0.832 (95% CI, 0.742-0.921), with this combination providing a detection rate for early PIH of 67.5% for a 5% false-positive rate.

CONCLUSIONS

High UtA-PI and small placental volume were observed more often in cases of early PIH compared with unaffected pregnancies, but not in cases of late PIH. These results may indicate that there are differences in pathophysiology between early PIH and late PIH.

First-trimester uterine artery Doppler analysis in the prediction of later pregnancy complications

Uterine artery Doppler waveform analysis has been extensively studied in the second trimester of pregnancy as a predictive marker for the later development of preeclampsia and fetal growth restriction. The use of Doppler interrogation of this vessel in the first trimester has gained momentum in recent years. Various measurement techniques and impedance indices have been used to evaluate the relationship between uterine artery Doppler velocimetry and adverse pregnancy outcomes. Overall, first-trimester Doppler interrogation of the uterine artery performs better in the prediction of early-onset than late-onset preeclampsia. As an isolated marker of future disease, its sensitivity in predicting preeclampsia and fetal growth restriction in low risk pregnant women is moderate, at 40–70%. Multiparametric predictive models, combining first-trimester uterine artery pulsatility index with maternal characteristics and biochemical markers, can achieve a detection rate for early-onset preeclampsia of over 90%. The ideal combination of these tests and validation of them in various patient populations will be the focus of future research.

A description of the methods of the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (nuMoM2b)

OBJECTIVE

The primary aim of the "Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be" is to determine maternal characteristics, which include genetic, physiologic response to pregnancy, and environmental factors that predict adverse pregnancy outcomes.

STUDY DESIGN

Nulliparous women in the first trimester of pregnancy were recruited into an observational cohort study. Participants were seen at 3 study visits during pregnancy and again at delivery. We collected data from in-clinic interviews, take-home surveys, clinical measurements, ultrasound studies, and chart abstractions. Maternal biospecimens (serum, plasma, urine, cervicovaginal fluid) at antepartum study visits and delivery specimens (placenta, umbilical cord, cord blood) were collected, processed, and stored. The primary outcome of the study was defined as pregnancy ending at <37+0 weeks' gestation. Key study hypotheses involve adverse pregnancy outcomes of spontaneous preterm birth, preeclampsia, and fetal growth restriction.

RESULTS

We recruited 10,037 women to the study. Basic characteristics of the cohort at screening are reported.

CONCLUSION

The "Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be" cohort study methods and procedures can help investigators when they plan future projects.

UNDERSTANDING THE PLACENTAL AETIOLOGY OF FETAL GROWTH RESTRICTION; COULD THIS LEAD TO PERSONALIZED MANAGEMENT STRATEGIES?

Fetal growth restriction (FGR) is defined as the failure of a fetus to attain its full genetic growth potential. It is a leading cause of stillbirth, prematurity, cerebral palsy and perinatal mortality. Small size at birth increases surviving infants’ lifelong risk of adverse health outcomes associated with the metabolic syndrome. The pathophysiology of abnormal fetal growth is extremely complex and incompletely understood, with a plethora of genetic, signalling and metabolic candidates under investigation, many of which may result in abnormal structure and function of the placenta. In contrast to, or maybe because of, the underlying complexities of FGR, the strategies clinicians have for identifying and managing this outcome are conspicuously limited. Current clinical practice is restricted to identifying pregnancies at risk of FGR, and when FGR is detected, using intensive monitoring to guide the timing of delivery to optimise fetal outcomes. Abnormal Doppler indices in the umbilical artery are strongly associated with poor perinatal outcomes and are currently the “gold standard” for clinical surveillance of the growth-restricted fetus.

First-trimester 3D power Doppler of the uteroplacental circulation space and fetal growth restriction

OBJECTIVE

The objective of the study was to compare the 3-dimensional power Doppler (3DPD) of the uteroplacental circulation space in the first trimester between women who subsequently deliver growth-restricted vs normally grown neonates.

STUDY DESIGN

This was a prospective observational study of singleton pregnancies at 11-14 weeks' gestation. The 3DPD indices, vascularization index, flow index, and vascularization flow index were determined on a uteroplacental circulation space sphere biopsy with the virtual organ computer-aided analysis program. Growth restriction was defined as a birthweight less than the 10th percentile for gestational age and was evaluated using both population-based and customized birth curves.

RESULTS

Five hundred seventy-seven women were enrolled. Five hundred twenty-six were eligible for analysis using population centiles, and 497 were available for evaluation using customized centiles. There was no difference in the first-trimester 3DPD indices between patients with growth-restricted and normally grown neonates using either curve.

CONCLUSION

Three-dimensional power Doppler indices of the uteroplacental circulation space in the first trimester are similar between neonates who develop growth restriction and those who will grow normally.

Lower macrophage migration inhibitory factor concentrations in maternal serum before pre-eclampsia onset

Macrophage migration inhibitory factor (MIF) plays a pivotal role in pregnancy-related proinflammatory processes, such as placentation and labor. Differential MIF concentrations have been correlated with pathological events during pregnancy, such as recurrent miscarriages and severe pre-eclampsia (PE). The aim of this study was to prospectively investigate whether maternal MIF serum levels are already altered in early pregnancy before PE onset. Women (n=2,821) before 20 weeks of gestational age were recruited for a prospective study on early markers of PE. Forty-eight consecutive pregnancies that developed PE and 79 normotensive pregnancies that delivered at term were chosen. Maternal MIF serum levels were assessed by ELISA. We found significantly lower MIF serum levels in women who developed PE (4,967 ± 3,119 pg/mL) compared to controls (7,640 ± 5,519 pg/mL) (mean ± standard deviation, P<0.001). Our findings indicate that low maternal MIF serum levels in early pregnancy may contribute to abnormal placental development.

New directions in the prediction of pre-eclampsia

Pre-eclampsia remains an important worldwide cause of maternal and perinatal morbidity and mortality. Improved prediction of those destined to develop this condition would allow for timely initiation of prophylactic therapy, appropriate antenatal surveillance and better targeted research into preventive interventions. This paper reviews recent research into strategies for the prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters and biomarkers. The most promising strategies involve multiparametric approaches, which use a variety of individual parameters in combination, as has been established in first-trimester aneuploidy screening. The paper concludes with a discussion of the issues around the introduction of such testing into clinical practice.

First-trimester levels of pregnancy-associated plasma protein A2 (PAPP-A2) in the maternal circulation are elevated in pregnancies that subsequently develop preeclampsia

Recent studies have consistently found pregnancy-associated plasma protein A2 (PAPP-A2) to be upregulated in preeclamptic placentae at term. We tested whether first-trimester circulating PAPP-A2 levels differed between complicated and uncomplicated pregnancies. We measured maternal PAPP-A2 levels at 10 to 14 weeks of gestational age in 17 pregnancies resulting in small-for-gestational-age (SGA) infants, 6 which developed preeclampsia (PE), 1 which developed PE and resulted in an SGA infant, and 37 gestational age-matched controls. The concentration of the PAPP-A2 isoform corresponding to the full-length protein was significantly higher in pregnancies that developed PE (35 ng/mL) compared with those that did not (23 ng/mL; P < .044). In contrast, we found no difference in PAPP-A2 levels between pregnancies that did or did not result in an SGA infant. The upregulation of PAPP-A2 that has previously been observed in PE at term appears to begin early in pregnancy, well before the symptoms develop.

The long non-coding RNA NEAT1 is increased in IUGR placentas, leading to potential new hypotheses of IUGR origin/development

INTRODUCTION

Intrauterine Growth Restriction (IUGR) is a multifactorial disease defined by an inability of the fetus to reach its growth potential. IUGR not only increases the risk of neonatal mortality/morbidity, but also the risk of metabolic syndrome during adulthood. Certain placental proteins have been shown to be implicated in IUGR development, such as proteins from the GH/IGF axis and angiogenesis/apoptosis processes.

METHODS

Twelve patients with term IUGR pregnancy (birth weight < 10th percentile) and 12 CTRLs were included. mRNA was extracted from the fetal part of the placenta and submitted to a subtraction method (Clontech PCR-Select cDNA Subtraction).

RESULTS

One candidate gene identified was the long non-coding RNA NEAT1 (nuclear paraspeckle assembly transcript 1). NEAT1 is the core component of a subnuclear structure called paraspeckle. This structure is responsible for the retention of hyperedited mRNAs in the nucleus. Overall, NEAT1 mRNA expression was 4.14 (±1.16)-fold increased in IUGR vs. CTRL placentas (P = 0.009). NEAT1 was exclusively localized in the nuclei of the villous trophoblasts and was expressed in more nuclei and with greater intensity in IUGR placentas than in CTRLs. PSPC1, one of the three main proteins of the paraspeckle, co-localized with NEAT1 in the villous trophoblasts. The expression of NEAT1_2 mRNA, the long isoform of NEAT1, was only modestly increased in IUGR vs. CTRL placentas.

DISCUSSION/CONCLUSION

The increase in NEAT1 and its co-localization with PSPC1 suggests an increase in paraspeckles in IUGR villous trophoblasts. This could lead to an increased retention of important mRNAs in villous trophoblasts nuclei. Given that the villous trophoblasts are crucial for the barrier function of the placenta, this could in part explain placental dysfunction in idiopathic IUGR fetuses.

Immune balance at the foeto-maternal interface as the fulcrum of reproductive success

Viviparity has many evolutionary advantages but brings with it the problem of the semi-allogeneic foetus having to coexist with the mother for the duration of pregnancy. In species with haemochorial placentation this problem is particularly evident as foetal trophoblast cells are extensively intermingled with maternal tissue and are directly exposed to maternal blood. Fascinating adaptations on both the foetal and maternal side have allowed for this interaction to be re-directed away from an immune rejection response not only towards immunotolerance, but in fact towards actively supporting reproductive success. Recent data have shown that some of these remarkable adaptations are conserved between mice and humans. Thus, a subset of trophoblast cells that is directly exposed to the maternal uterine environment shares the feature of expressing an unusual antigen repertoire on their surface. Paternal antigens can be recognized by maternal immune cells, in particular uterine natural killer cells that express cognate receptors, to regulate the extensive remodelling events that take place at the implantation site. Detailed genetic dissection experiments in the mouse have further demonstrated the direct impact of antigenic dissimilarity on foetal growth. With the availability of inbred strains, in vitro culture systems of trophoblast stem cells, and in-depth genetic, genomic and epigenomic data the mouse will be a valuable model system to study the intricate immune crosstalk at the foeto-maternal boundary. These insights will pave the way towards unravelling the mutual and synergistic interactions between trophoblast and its surrounding maternal environment, and in doing so help understand pregnancy pathologies.

Value of adding second-trimester uterine artery Doppler to patient characteristics in identification of nulliparous women at increased risk for pre-eclampsia: an individual patient data meta-analysis

OBJECTIVE

To investigate the value of adding second-trimester uterine artery Doppler ultrasound to patient characteristics in the identification of nulliparous women at risk for pre-eclampsia.

METHODS

For this individual patient data meta-analysis, studies published between January 1995 and December 2009 were identified in MEDLINE and EMBASE. Studies were eligible in which Doppler assessment of the uterine arteries had been performed among pregnant women and in which gestational age at ultrasound, Doppler ultrasound findings and data on the occurrence of pre-eclampsia were available. We invited corresponding authors to share their original datasets. Data were included of nulliparous women who had had a second-trimester uterine artery Doppler ultrasound examination. Shared data were checked for consistency, recoded to acquire uniformity and merged into a single dataset. We constructed random intercept logistic regression models for each of the patient and Doppler characteristics in isolation and for combinations. We compared goodness of fit, discrimination and calibration.

RESULTS

We analyzed eight datasets, reporting on 6708 nulliparous women, of whom 302 (4.5%) developed pre-eclampsia. Doppler findings included higher, lower and mean pulsatility index (PI) and resistance index (RI) and any or bilateral notching. Of these, the best predictors were combinations of mean PI or RI and bilateral notching, with areas under the receiver-operating characteristics curve (AUC) of 0.75 (95% confidence interval (CI), 0.56-0.95) and 0.70 (95% CI, 0.66-0.74), respectively. Addition of Doppler findings to the patient characteristics blood pressure or body mass index (BMI) significantly improved discrimination. A model with blood pressure, PI and bilateral notching had an AUC of 0.85 (95% CI, 0.67-1.00).

CONCLUSIONS

The addition of Doppler characteristics of mean PI or RI and bilateral notching to patient characteristics of blood pressure or BMI improves the identification of nulliparous women at risk for pre-eclampsia.

Associations between ambient air pollution and Hypertensive Disorders of Pregnancy

BACKGROUND

Exposure to ambient air pollution is linked to adverse pregnancy outcomes. Previous reports examining the relationship between ambient air pollution and Hypertensive Disorders of Pregnancy have been inconsistent.

OBJECTIVES

We evaluated the effects of ambient air pollution on the odds of Hypertensive Disorder of Pregnancy and whether these associations varied by body mass index (BMI).

METHODS

We conducted a retrospective, case-control study among 298 predominantly Hispanic women (136 clinically confirmed cases) who attended the Los Angeles County+University of Southern California Women's and Children's Hospital during 1996-2008. Trimester-specific carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and particulate matter with aerodynamic diameter <10 μm and <2.5 μm (PM10, PM2.5) exposure were estimated based on 24-hour exposure level at residential address. Logistic regression models were fitted to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for two standard deviation increase in exposure levels.

RESULTS

Exposures to CO and PM2.5 in the 1st trimester were significantly associated with Hypertensive Disorders of Pregnancy, and these associations were modified by BMI. In non-obese women (BMI <30), 1st trimester exposures to PM2.5 and CO were significantly associated with increased odds of Hypertensive Disorder of Pregnancy (ORs per 2-standard deviation increase in PM2.5 (7 μg/m(3)) and CO (1 ppm) exposures were 9.10 [95% CI: 3.33-24.6] and 4.96 [95% CI: 1.85-13.31], respectively). Additionally, there was a significantly positive association between exposure to O3 in the 2nd trimester and Hypertensive Disorder of Pregnancy (OR per 15 ppb=2.05; 95% CI: 1.22-3.46).

CONCLUSION

Among non-obese women, 1st trimester exposure to PM2.5 and carbon monoxide are associated with increased odds of Hypertensive Disorder of Pregnancy.

MicroRNAs in Human Placental Development and Pregnancy Complications

MicroRNAs (miRNAs) are small non-coding RNAs, which function as critical posttranscriptional regulators of gene expression by promoting mRNA degradation and translational inhibition. Placenta expresses many ubiquitous as well as specific miRNAs. These miRNAs regulate trophoblast cell differentiation, proliferation, apoptosis, invasion/migration, and angiogenesis, suggesting that miRNAs play important roles during placental development. Aberrant miRNAs expression has been linked to pregnancy complications, such as preeclampsia. Recent research of placental miRNAs focuses on identifying placental miRNA species, examining differential expression of miRNAs between placentas from normal and compromised pregnancies, and uncovering the function of miRNAs in the placenta. More studies are required to further understand the functional significance of miRNAs in placental development and to explore the possibility of using miRNAs as biomarkers and therapeutic targets for pregnancy-related disorders. In this paper, we reviewed the current knowledge about the expression and function of miRNAs in placental development, and propose future directions for miRNA studies.

Towards a multifactorial approach for prediction of bipolar disorder in at risk populations

BACKGROUND

The high prevalence, recurrence rate, chronicity, and illness burden in bipolar disorder (BD) are well documented. Moreover, insufficient response with conventional pharmacological and manual-based psychosocial interventions, as well as evidence of illness progression and acceleration, invite the need for early detection and primary prevention.

METHODS

Herein we comprehensively review extant studies reporting on a bipolar prodrome. The overarching aim is to propose a predictive algorithm (i.e. prediction of BD in at-risk populations) integrating genetic (i.e. family history), environmental (e.g. childhood maltreatment) and biological markers (i.e. BDNF, inflammatory and oxidative stress markers). Computerized databases i.e. Pubmed, PsychInfo, Cochrane Library and Scielo were searched using the followed terms: bipolar disorder cross-referenced with prodromal, preclinical, at risk mental states, clinical high risk, ultra high risk, biomarkers, brain-derived neurotrophic factor, inflammation, cytokines, oxidative stress, prediction and predictive model.

RESULTS

Available evidence indicates that a prodrome to bipolar disorder exists. Commonly encountered features preceding the onset of a manic episode are affective lability, irritability, anger, depression, anxiety, substance use disorders, sleep disorders, as well as disturbances in attention and cognition. Non-specificity and insufficient sensitivity have hampered the development of an adequate prediction algorithm.

LIMITATIONS

Limitations include biases associated with retrospective studies, poor characterization of clinical high risk, inadequacy of prospective studies regarding sample selection and absence of specificity of risk states.

CONCLUSION

We propose a hypothetical prediction algorithm that is combinatorial in approach that attempts to integrate family history, early adversity, and selected biomarkers.

Fetal sex-related dysregulation in testosterone production and their receptor expression in the human placenta with preeclampsia

OBJECTIVE

To determine the effects of fetal sex on aromatase and androgen receptor (AR) expression in the placenta of normal and preeclamptic pregnancies.

STUDY DESIGN

Placentae from preeclamptic (five female and six male fetuses) and healthy pregnancies (seven female and seven male fetuses) were examined by immunofluorescence, western blotting and quantitative reverse transcriptase PCR.

RESULT

Placental AR levels were significantly higher (P<0.05) in placentae of both male and female fetuses compared with their respective sexes in normal pregnancies. The placental aromatase levels varied depending on fetal sex. If the fetus was female, aromatase levels were substantially higher (P<0.05) in preeclamptic than in normal placentae. If the fetus was male, the aromatase levels were significantly lower (P<0.05) in preeclamptic than in normal placentae. Placental aromatase levels were significantly higher (P<0.05) in male- than in female-bearing normal placentae.

CONCLUSION

Dysregulation in androgen production and signaling in preeclamptic placentae may contribute to placental abnormalities, increasing the frequency of maternal-fetal complications associated with preeclampsia.

First-trimester screening for large-for-gestational-age infants

OBJECTIVES

To examine the relationship between newborn birth weight and first-trimester uterine artery (UtA) pulsatility index (PI), maternal characteristics, serum pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (β-hCG) and fetal nuchal translucency (NT) thickness. We also examined the results of screening for large-for-gestational-age (LGA) neonates by an integrated first-trimester approach incorporating these parameters.

METHODS

We evaluated maternal characteristics, fetal NT, PAPP-A, free β-hCG and UtA-PI in 2097 singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation. Linear models based on quasi Akaike's Information Criterion were used to determine the best predictive model for fetal birth weight. The patient-specific risk of delivering an LGA infant was derived from multiple logistic regression analysis and the performance of screening was determined by receiver-operating characteristics curve analysis.

RESULTS

The best predictive models for fetal birth weight included UtA-PI, PAPP-A, NT, parity, maternal age, smoking status, weight, height and free β-hCG. In pregnancies delivering LGA newborns compared with non-LGA pregnancies, PAPP-A and NT thickness were significantly increased (P = 0.016 and 0.001, respectively) and UtA-PI was significantly decreased (P = 0.011). A combination of maternal factors with PAPP-A, fetal NT and UtA-PI identified 34.4% of LGA newborns for a false-positive rate of 10%.

CONCLUSIONS

This study showed an association between newborn birth weight and maternal factors, and first-trimester PAPP-A, β-hCG, fetal NT and UtA-PI. Together, these factors can be used to identify over a third of pregnancies that will deliver LGA infants.

Management of abnormal serum markers in the absence of aneuploidy or neural tube defects

OBJECTIVE

Few guidelines address the management of pregnancies complicated by abnormal maternal serum analytes (MSAs) in the absence of aneuploidy or neural tube defects (NTDs). Our objective was to gather preliminary data regarding current opinions and management strategies among perinatologists in the US.

METHODS

This survey of Maternal Fetal Medicine (MFM) physicians and fellows used a secure electronic web-based data capture tool.

RESULTS

A total of 545 potential participants were contacted, and 136 (25%) responded. The majority were experienced academic physicians with robust practices. Nearly all (97.7%) respondents reported a belief in an association between abnormal MSAs and adverse pregnancy outcomes other than aneuploidy or NTDs. Plasma protein A (PAPP-A) and α-fetoprotein (AFP) were most often chosen as markers demonstrating a strong association with adverse outcomes. Most (86.9%) respondents acknowledged that abnormal MSAs influenced their counseling approach, and the majority (80.1%) offered additional ultrasound examinations. Nearly half started at 28 weeks and almost one-third at 32 weeks. Respondents acknowledging a relevant protocol in their hospital or practice were more likely to offer additional antenatal testing (p = 0.01).

CONCLUSIONS

Although most perinatologists were in agreement regarding the association of MSAs with adverse pregnancy outcomes, a lack of consensus exists regarding management strategies.

Plasma kisspeptin levels in pregnancies with diabetes and hypertensive disease as a potential marker of placental dysfunction and adverse perinatal outcome

BACKGROUND

The aim of this study was to prospectively evaluate plasma kisspeptin levels in 129 singleton pregnancies with diabetes [pregestational insulin-dependent diabetes mellitus (type 1) and gestational diabetes (GD)] and hypertensive disease [chronic hypertension (CH), gestational hypertension, and preeclampsia (PE)] as a potential marker of placental dysfunction and adverse perinatal outcome.

STUDY DESIGN

Kisspeptin levels were evaluated in the first, second, and third trimesters in patients with type 1 diabetes (16 patients), H (22), and healthy control (25) and in the second and third trimesters in patients with GD (20), gestational hypertension (18), and PE (28). Maternal kisspeptin levels were correlated with pregnancy outcome, parameters of fetoplacental circulation, ultrasound-detected abnormalities of placental morphology, and placental weight at delivery.

RESULTS

In pregnancies with type 1 diabetes and H, mean kisspeptin levels were significantly lower compared with the control group (p<0.001 in the first and second trimesters and p<0.05 in the third trimester). Decreased plasma kisspeptin levels in the second and third trimesters were found in patients with GD (p<0.001 in the second and third trimesters) and PE (p<0.001 in the second trimester and p<0.05 in the third trimester). In patients with PE and placental dysfunction, low kisspeptin levels in the third trimester were associated with adverse perinatal outcome.

CONCLUSIONS

Our study demonstrates reduced kisspeptin levels in pregnancies with diabetes, H, PE, and placental dysfunction. In patients with PE and placental dysfunction, decreased kisspeptin levels were associated with adverse perinatal outcome. Larger studies are needed to investigate the role of kisspeptin as a potential marker of placental dysfunction and adverse perinatal outcome.

First-trimester prediction of preeclampsia using metabolomic biomarkers: a discovery phase study

OBJECTIVE

We tested the hypothesis that first-trimester metabolic biomarkers offered a unique profile in women with preeclampsia (PE) in the second half of pregnancy, compared with controls.

METHOD

We conducted a nested case-control study within a prospective cohort of pregnant women followed from the first-trimester to delivery. Cases were those who developed PE at any gestational age, and these were compared with a control group without adverse pregnancy outcome, matched for gestational age within 3 days. We analyzed maternal blood obtained at 11-14 weeks' gestation for 40 acylcarnitine species (C2-C18 saturated, unsaturated, and hydroxylated) and 32 amino acids by liquid chromatography tandem mass spectrometry. Logistic regression modeling estimated the association of each metabolite with development of PE.

RESULTS

We compared 41 cases with PE with 41 controls and found four metabolites (hydroxyhexanoylcarnitine, alanine, phenylalanine, and glutamate) that were significantly higher in the cases with PE. The area under the curve (AUC) using these metabolites individually to predict PE varied from 0.77 to 0.80, and when combined, the AUC improved to 0.82 [95% confidence interval (95% CI): 0.80-0.85] for all cases of PE and 0.85 (95% CI: 0.76-0.91) for early onset PE.

CONCLUSION

Our findings suggest a potential role for first-trimester metabolomics in screening for PE.

Placental 3-D power Doppler angiography--regional variation and reliability of two ultrasonic sphere biopsy techniques

Three-dimensional power Doppler angiography and 4D View allows quantification of placental "vascularity" using sonobiopsy or manual tracing. We used two vascular "biopsy" techniques: nontargeted sphere placement and systematic uniform random sphere placement (SURS). We hypothesised that random application of spheres would result in less reliability and the basal zone would display higher values than the chorionic zone. Forty women between 18+6 to 21+6 weeks gestation were recruited. A single volume of the placenta was acquired. Data was analysed twice by a single observer. Significantly higher values were seen for all vascular indices in the basal zone. Reliability was greatest for the whole placental technique with intraclass correlation coefficients of 0.9 and limits of agreement for flow index (FI) of -3.81 to 2.50 (equivalent to -7.8% to 5.1%) compared with 0.6 and -13.2 to 18.3 (-64.6% to 78.2%) for the nontargeted sphere technique. Whole placental values are more reliable than biopsy techniques with significantly different results seen with each technique.

Altered levels of insulin-like growth factor binding protein proteases in preeclampsia and intrauterine growth restriction

Intrauterine growth restriction (IUGR) and preeclampsia (PE) are leading causes of perinatal and maternal morbidity and mortality. Many studies have found association between low levels of insulin-like growth factor binding protein (IGFBP) proteases in the first trimester maternal circulation and the risk of subsequent development of PE and/or IUGR. These results are generally interpreted to reflect decreased production of the proteases by the placenta, leading to reduced proteolysis of IGFBPs and lower free levels of insulin-like growth factor (IGF), resulting in diminished feto-placental development. However, the association between low circulating levels of placental proteins early in pregnancy and the subsequent development of IUGR and/or PE could be due to low exchange in the placenta and not due to reduced production. In contrast, late in pregnancy, the circulating levels of these proteins and their expression in the placenta are often elevated in PE, which may reflect upregulation to compensate for abnormal placental development, that is an adaptive mechanism to increase IGFBP proteolysis, increase local IGF levels and promote feto-placental growth. Further research into the biological mechanisms underlying these associations will aid the identification of high-risk pregnancies and the development of therapeutic targets for diseases for which there are presently no preventative measures.

Utero-placental Doppler ultrasound for improving pregnancy outcome

BACKGROUND

Impaired placentation can cause some of the most important obstetrical complications such as pre-eclampsia and intrauterine growth restriction and has been linked to increased fetal morbidity and mortality. The failure to undergo physiological trophoblastic vascular changes is reflected by the high impedance to the blood flow at the level of the uterine arteries. Doppler ultrasound study of utero-placental blood vessels, using waveform indices or notching, may help to identify the 'at-risk' women in the first and second trimester of pregnancy, such that interventions might be used to reduce maternal and fetal morbidity and/or mortality.

OBJECTIVES

To assess the effects on pregnancy outcome, and obstetric practice, of routine utero-placental Doppler ultrasound in first and second trimester of pregnancy in pregnant women at high and low risk of hypertensive complications.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2010) and the reference lists of identified studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of Doppler ultrasound for the investigation of utero-placental vessel waveforms in first and second trimester compared with no Doppler ultrasound. We have excluded studies where uterine vessels have been assessed together with fetal and umbilical vessels.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. We checked data entry.

MAIN RESULTS

We found two studies involving 4993 participants. The methodological quality of the trials was good. Both studies included women at low risk for hypertensive disorders, with Doppler ultrasound of the uterine arteries performed in the second trimester of pregnancy. In both studies, pathological finding of uterine arteries was followed by low-dose aspirin administration.We identified no difference in short-term maternal and fetal clinical outcomes.We identified no randomised studies assessing the utero-placental vessels in the first trimester or in women at high risk for hypertensive disorders.

AUTHORS' CONCLUSIONS

Present evidence failed to show any benefit to either the baby or the mother when utero-placental Doppler ultrasound was used in the second trimester of pregnancy in women at low risk for hypertensive disorders. Nevertheless, this evidence cannot be considered conclusive with only two studies included. There were no randomised studies in the first trimester, or in women at high risk. More research is needed to investigate whether the use of utero-placental Doppler ultrasound may improve pregnancy outcome.