Association between maternal serum cytokine profiles at 7-10 weeks' gestation and birthweight in small for gestational age infants

Maternal Immune Activation During Pregnancy and Obstetric Outcomes: A Population-Based Cohort Study

OBJECTIVE

Maternal immune activation has been proposed as a mechanism for adverse pregnancy outcomes, yet the mechanisms and effects of timing remain unclear. Immune disruption in early gestation may be particularly detrimental as this is an important period for placental development, which has been associated with the pathology of adverse obstetric outcomes. To increase our understanding of risk factors for adverse obstetric outcomes, we aim to investigate the association between multiple inflammatory and angiogenic markers during early pregnancy and adverse pregnancy outcomes in a large population-based cohort.

DESIGN

Prospective population-based pregnancy cohort study (n = 7513).

SETTING

Rotterdam, the Netherlands.

POPULATION

Pregnant women in Rotterdam between April 2002 and January 2006.

METHODS

Serum inflammatory markers (high-sensitivity (HS)-C-reactive protein (CRP), interleukin (IL)-1β, IL-6, IL-17a, IL-23, interferon (IFN)-γ) and angiogenic factors (sFlt-1 and PlGF) were analysed in repeated measures around 13-20 weeks gestation. A cytokine index was created using principal component analysis.

MAIN OUTCOME MEASURES

Hypertensive disorders of pregnancy, spontaneous preterm birth and small for gestational age at birth.

RESULTS

HS-CRP, but not the cytokine index, was associated with increased risk of spontaneous preterm birth after multiple testing correction. We found no association of HS-CRP or the cytokine index with hypertensive disorders of pregnancy and small for gestational age at birth after multiple testing correction. Inflammatory and angiogenic factors were associated with each other, yet effect sizes were small.

CONCLUSIONS

We found no strong evidence of a link between early gestation typical inflammatory marker levels and the risk of adverse pregnancy outcomes.

Maternal serum midkine level in fetal growth restriction: a case-control study

OBJECTIVES

To compare maternal serum midkine (MK) level in pregnant women with idiopathic fetal growth restriction (FGR) and healthy. In addition, we assessed the value of maternal serum MK level in predicting neonatal intensive care unit (NICU) admission.

METHODS

A total of 144 pregnant women were included, 72 with idiopathic FGR and 72 healthy in this study. The control group was matched for the mother's age, parity, gestational age, and pre-pregnancy body mass index (BMI) with the idiopathic FGR group at the time of recruitment into the study and sample collection.

RESULTS

Serum MK level is higher in the idiopathic FGR than the control group (0.24 ng/mL (0.19-0.32) vs. 0.18 ng/mL (0.14-0.23), p<0.001). In addition, we compared the maternal serum MK level of those with and without NICU admission in the FGR group (0.25 ng/mL (0.19-0.37) vs. 0.21 ng/mL (0.18-0.28), p=0.014). We performed ROC curve analysis to serum MK level predicting NICU admission in the FGR group (AUC: 0.668, %95 CI [0.550, 0.785], p=0.014). A sensitivity of 63% and a specificity of 62% for the serum MK level were achieved with a cut-off value of 0.22 for NICU admission.

CONCLUSIONS

To the best of our knowledge, this study is the first to compare maternal serum MK level in pregnant women with idiopathic FGR and healthy. We showed that maternal serum MK level was significantly elevated in pregnant women with FGR than healthy.

Longitudinal changes in serum immune markers during normal pregnancy in a North-Indian population

PROBLEM

The objective of this study was to examine levels of cytokines across normal term pregnancy in an Indian population. Additionally we have also explored for possible associations between inflammatory markers and fetal growth parameters.

METHOD OF STUDY

A multiplex panel of 24 analytes was used to examine levels of inflammatory markers in maternal serum at three time points during pregnancy and in cord blood from women with no reported comorbidities who delivered a singleton live baby at term (N = 23), enrolled in the GARBH-Ini pregnancy cohort. Linear mixed models were applied to construct longitudinal cytokine trajectories with gestational age. Pearson correlation was used to calculate intra-visit correlation between cytokines. Principal component analysis (PCA) was performed to examine cytokine combinations prevalent across pregnancy, and their association with fetal growth parameters was determined by multivariable regression.

RESULTS

Significant increase in sFLT-1, Flt3L, PLGF, IL-4, and IL-18 and a decrease in VCAM-1 concentrations was seen across pregnancy. The cytokine concentrations in cord blood differed substantially as compared to maternal levels across gestation. Some cytokines were closely correlated with each other in distinct patterns across pregnancy. Gestational age specific combination of cytokines were seen to be associated with different fetal growth parameters.

CONCLUSIONS

This study for the first time provides reference concentrations for the longitudinal expression of immune markers across pregnancy in an Indian population providing a much needed baseline to compare with pregnancies leading to adverse outcomes. Growth factors showed maximum longitudinal variation with gestational age and strong correlations were identified between various cytokines at all time points across pregnancy.

Cytokine Patterns in Maternal Serum From First Trimester to Term and Beyond

Pregnancy implies delicate immunological balance between two individuals, with constant changes and adaptions in response to maternal capacity and fetal demands. We performed cytokine profiling of 1149 longitudinal serum samples from 707 pregnant women to map immunological changes from first trimester to term and beyond. The serum levels of 22 cytokines and C-reactive protein (CRP) followed diverse but characteristic trajectories throughout pregnancy, consistent with staged immunological adaptions. Eotaxin showed a particularly robust decrease throughout pregnancy. A strong surge in cytokine levels developed when pregnancies progressed beyond term and the increase was amplified as labor approached. Maternal obesity, smoking and pregnancies with large fetuses showed sustained increase in distinct cytokines throughout pregnancy. Multiparous women had increased cytokine levels in the first trimester compared to nulliparous women with higher cytokine levels in the third trimester. Fetal sex affected first trimester cytokine levels with increased levels in pregnancies with a female fetus. These findings unravel important immunological dynamics of pregnancy, demonstrate how both maternal and fetal factors influence maternal systemic cytokines, and serve as a comprehensive reference for cytokine profiles in normal pregnancies.

Maternal Proinflammatory Adipokines Throughout Pregnancy and Neonatal Size and Body Composition: A Prospective Study

BACKGROUND

Increased maternal adiposity and inflammation have impacts on fetal growth.

OBJECTIVES

The purpose of this prospective study was to investigate the associations of 3 proinflammatory adipokines in pregnancy with neonatal anthropometry.

METHODS

In a sample of 321 US pregnant women from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singleton Cohort (NCT00912132), plasma IL-6, fatty acid binding protein-4 (FABP4), and chemerin were measured in plasma samples collected at 10-14, 15-26, 23-31, and 33-39 weeks of gestation. Generalized linear models were used to estimate associations of adipokines with neonatal weight, thigh, and crown-heel length, and skinfolds at birth. Models adjusted for age, race/ethnicity, education, nulliparity, prepregnancy BMI, and weeks of gestation at blood collection.

RESULTS

At each time point, higher IL-6 was associated with lower neonatal birthweight and thigh length. At 15-26 weeks of gestation, a 1 SD pg/mL increase in IL-6 was associated with -84.46 g lower neonatal birthweight (95% CI: -150.70, -18.22), -0.17 cm shorter thigh length (95% CI: -0.27, -0.07), -0.43 cm shorter crown-heel length (95% CI: -0.75, -0.10), and -0.75 mm smaller sum of skinfolds (95% CI: -1.19, -0.31), with similar associations at 23-31 and 33-39 weeks of gestation. There were no associations of FABP4 and chemerin with neonatal anthropometry.

CONCLUSIONS

Starting as early as 15 weeks of gestation, higher maternal IL-6 concentrations in pregnancy were associated with lower neonatal birthweight, thigh and crown-heel length, and skinfolds. These data provide insight into the relevance of maternal inflammatory markers with neonatal anthropometry.

Cytokines and pregnancy: Potential regulation by histone deacetylases

Cytokines are important regulators of pregnancy and parturition. Aberrant expression of proinflammatory cytokines during pregnancy contributes towards preterm labor, pre-eclampsia, and gestational diabetes mellitus. The regulation of cytokine expression in human cells is highly complex, involving interactions between environment, transcription factors, and feedback mechanisms. Recent developments in epigenetic research have made tremendous advancements in exploring histone modifications as a key epigenetic regulator of cytokine expression and the effect of their signaling molecules on various organ systems in the human body. Histone acetylation and subsequent deacetylation by histone deacetylases (HDACs) are major epigenetic regulators of protein expression in the human body. The expression of various proinflammatory cytokines, their role in normal and abnormal pregnancy, and their epigenetic regulation via HDACs will be discussed in this review.

Maternal Serum Cytokine Concentrations in Healthy Pregnancy and Preeclampsia

The maternal immune response is essential for successful pregnancy, promoting immune tolerance to the fetus while maintaining innate and adaptive immunity. Uncontrolled, increased proinflammatory responses are a contributing factor to the pathogenesis of preeclampsia. The Th1/Th2 cytokine shift theory, characterised by bias production of Th2 anti-inflammatory cytokine midgestation, was frequently used to reflect the maternal immune response in pregnancy. This theory is simplistic as it is based on limited information and does not consider the role of other T cell subsets, Th17 and Tregs. A range of maternal peripheral cytokines have been measured in pregnancy cohorts, albeit the changes in individual cytokine concentrations across gestation is not well summarised. Using available data, this review was aimed at summarising changes in individual maternal serum cytokine concentrations throughout healthy pregnancy and evaluating their association with preeclampsia. We report that TNF-α increases as pregnancy progresses, IL-8 decreases in the second trimester, and IL-4 concentrations remain consistent throughout gestation. Lower second trimester IL-10 concentrations may be an early predictor for developing preeclampsia. Proinflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-8, and IL-6) are significantly elevated in preeclampsia. More research is required to determine the usefulness of using cytokines, particularly IL-10, as early biomarkers of pregnancy health.

Maternal serum levels of C-reactive protein at early pregnancy to predict fetal growth restriction and preterm delivery: A prospective cohort study

Background

A considerable evidence suggests that maternal inflammation dysregulation may play as a risk factor for both maternal and neonatal outcomes. Objective: The study's objectives were designed to evaluate the correlation between serum C-reactive protein (CRP) levels, as an inflammation factor, preterm delivery, and small for gestational age (SGA) births.

Materials and Methods

This prospective cohort study was conducted on 120 singleton pregnant women with gestational age less than 20 wk. Maternal CRP serum concentration was measured before 20 wk gestation. Patients were followed-up until the delivery and final outcomes of pregnancy were recorded in terms of preterm delivery and SGA births. Results: Serum CRP levels in participants with normal fetuses and SGA births were 4.09 ± 1.35 mg/l and 6.04 ± 3.29 mg/l, respectively (p = 0.19), while in cases of preterm delivery, it was 9.63 ± 5.78 mg/l (p < 0.001). By using receiver operating characteristic (ROC) curve, serum CRP levels (cut-off point 5.27 mg/l, area 0.836) had acceptable diagnostic accuracy value in distinguishing preterm delivery (sensitivity (75%), specificity (86.1%), positive predictive value (37.5%), negative predictive value (96.87%), accuracy (85%)) and serum CRP levels (cut-off point 6.67 mg/l, area 0.673) in distinguishing SGA births (sensitivity (50%), specificity (91.2%), positive predictive value (23.07%), and negative predictive value (97.19%), and accuracy (89.16 %)).

Conclusion

Higher maternal serum CRP levels measured early in pregnancy may associate with higher risk of preterm delivery and SGA.

Cytokine profiles in maternal serum are candidates for predicting an optimal timing for the delivery in early-onset fetal growth restriction

OBJECTIVE

We examined whether maternal serum cytokine profiles of mothers with early-onset fetal growth restriction (FGR) were associated with delivery within 2 weeks after sampling during the third trimester.

STUDY DESIGN

This exploratory prospective cross-sectional study included a total of 20 singleton fetuses with early-onset FGR and 31 healthy controls. Maternal serum samples during the early third trimester were analyzed for 23 cytokines.

RESULTS

Of 20 fetuses with early-onset FGR, 14 had delivery within 2 weeks after sampling. Multivariate analysis revealed that maternal serum concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble CD40 ligand (sCD40L) were independently associated with delivery within 2 weeks in early-onset FGR. Among cases of early-onset FGR, concentrations of almost all maternal serum cytokines were similar. Maternal serum sVEGFR-1 concentrations were high when delivery occurred within 2 weeks. Maternal serum sCD40L concentrations were elicited only in cases in which delivery within 2 weeks occurred due to fetal deterioration.

CONCLUSION

We identified two biomarkers, one specific for FGR and the other dependent on severity, that were significant components of angiogenic activities and inflammation factors. Imbalances in serum protein expression may have a substantial effect on the pathogenesis of FGR.

Pro-inflammatory immune cell gene expression during the third trimester of pregnancy is associated with shorter gestational length and lower birthweight

PROBLEM

Altered maternal immune function predicts risk for shorter gestation and low birthweight. Few studies examine associations between prenatal immune cell gene expression and gestational length or birthweight. No studies examine which cell types drive associations. The purpose of this study is to explore associations between peripheral blood immune cell gene expression and gestational length and birthweight, using transcript origin analysis.

METHOD OF STUDY

Eighty-nine women were drawn from the Community Child Health Network cohort. Third trimester maternal dried blood spots were used for genome-wide transcriptional (mRNA) profiling. Gestational length and birthweight were obtained from medical charts. Covariates were age, race/ethnicity, pre-pregnancy body mass index, smoking, gestational age at blood sampling, and pregnancy infections. Associations between gene expression profiles and gestational length and birthweight were tested using general linear models. The Transcription Element Listening System (TELiS) bioinformatics analysis quantified upstream transcription factor activity. Transcript origin analysis identified leukocyte subsets mediating observed effects.

RESULTS

Shorter gestation was predicted by increased NF-kB (TFBM ratio = -0.582 ± 0.172, P < .001) and monocyte activity (diagnosticity score = 0.172 ± 0.054, P < .001). Longer gestation was associated with increased dendritic cell activity (diagnosticity score = 0.194 ± 0.039, P < .001). Increased AP-1 activity predicted lower birthweight (TFBM ratio = -0.240 ± 0.111, P = .031). Dendritic cells and CD4+ and CD8+ T cells predicted birthweight-related gene expression differences (diagnosticity score P's < 0.021).

CONCLUSION

Higher third trimester pro-inflammatory gene expression predicted shorter gestation and lower birthweight. Variations in monocyte and dendritic cell biology contributed to both effects, and T-cell biology contributed to higher birthweight. These analyses clarify the role of myeloid/lymphoid lineage immune regulation in pregnancy outcomes.

Brief Report: Markers of Spontaneous Preterm Delivery in Women Living With HIV: Relationship With Protease Inhibitors and Vitamin D

BACKGROUND

Women living with HIV (WLHIV) have increased risk of spontaneous preterm delivery (SPTD). We sought to identify plasma predictors of SPTD and their correlations with factors that increase the risk of SPTD, such as vitamin D deficiency and use of protease inhibitors.

DESIGN

Plasma was obtained from 103 WLHIV with SPTD (≤35 weeks gestation) and 205 controls with term deliveries (TDs; ≥37 weeds) matched to cases 2:1 by race and gestational age at blood draw. TNFα, IFNγ, IL6, IL8, IL1β, IL18, IL17, granulocyte colony stimulating factor (GCSF), MCP1, IP10, sIL2Rα, sCD14, vascular endothelial factor a, monocyte colony stimulation factor, GROα, MMP9, IL10, TGFβ, sCTLA4, and eicosanoids were compared between cases adjusting for known SPTD risk factors.

RESULTS

Participants had similar demographic characteristics, but cases had higher plasma HIV RNA, lower CD4 cells, and more advanced HIV disease compared with controls. High sIL2Rα was associated with increased risk of SPTD. High sCD14, GCSF, PGF2α, and 5-HEPE were marginally associated with increased risk of SPTD. Women who initiated protease inhibitors-containing antiretroviral treatment before or during the first trimester had higher levels of GCSF and 5-HEPE compared with women without such exposure before plasma collection. Vitamin D insufficiency was associated with higher inflammatory sCD14 and PGF2α, and lower anti-inflammatory 5-HEPE.

CONCLUSIONS

The best plasma predictor of SPTD in WLHIV was sIL2Rα, a marker of T-cell activation. Markers of monocyte activation and eicosanoids were marginally increased in WLHIV and SPTD, suggesting that they may also play a role in the pathogenesis of this disorder.

Maternal blood biomarkers and adverse pregnancy outcomes: a systematic review and meta-analysis

Background: Pregnancy is a vulnerable period for the mother and the infant and exposures to environmental chemicals in utero can influence neonatal morbidity and mortality. There is a momentum toward understanding and exploring the current maternal biological mechanisms specific to in utero effects, to improve birth outcomes. This study aims to examine the current understanding of the role of biomarkers that may be associated with term of pregnancy, infant birth weights and infant development in utero.Methods: Electronic searches were conducted in PubMed, Embase, OvidMD, and Scopus databases; and all relevant research articles in English were retrieved. Studies were selected if they evaluated maternal blood plasma/serum biomarkers proposed to influence adverse birth outcomes in the neonate. Data were extracted on characteristics, quality, and odds ratios from each study and meta-analysis was conducted.Results: A total of 54 studies (35 for meta-analysis), including 43,702 women, 50 plasma markers and six descriptors of birth outcomes were included in the present study. The random effect point estimates for risk of adverse birth outcomes were 1.61(95%CI: 1.39-1.85, p < 0.0001) for inflammation-related biomarkers and 1.65(95%CI: 1.22-2.25, p = 0.0013) for growth factor/hormone-related biomarkers. All subgroups of plasma markers showed significant associations with adverse birth outcomes with no apparent study bias.Conclusions: The two subsets of plasma markers identified in this study (inflammation-related and growth factor/hormone-related) may serve as potentially valuable tools in the investigation of maternal molecular mechanisms, especially select pathways underlying inflammatory and immunological mediation in terms of modulating adverse infant outcomes. Future large, prospective cohort studies are needed to validate the promising plasma biomarkers, and to examine other maternal biological matrices such as cervicovaginal fluid and urine.

Serum podocalyxin at 11-13 weeks of gestation in the prediction of small for gestational age neonates

OBJECTIVE

To investigate a potential new marker for the prediction of small for gestational age (SGA) infants.

STUDY DESIGN

Nested case-control study involving 280 uncomplicated pregnancies and 70 cases of SGA without pre-eclampsia. Serum podocalyxin was measured at 11-13 weeks of gestation and results were expressed in multiples of the median (MoM). The performance of screening by a combination of maternal history and podocalyxin levels was assessed with ROC curves.

RESULTS

SGA was predicted by maternal age, height, South Asian ethnicity, and previous delivery without pre-eclampsia. Median podocalyxin levels were higher in affected than uncomplicated pregnancies (1.303 versus 0.994 MoM, p < 0.001). At a 10% false-positive rate, maternal history identified 40.0% of the cases (AUC = 0.74, 95%CI 0.671-0.809). The addition of podocalyxin increased the detection to 54.3% (AUC = 0.78, 95%CI 0.771-0.842, p = 0.027 for the difference in ROC curves).

CONCLUSION

First-trimester podocalyxin may be useful in screening for SGA infants.

Differential effects of high-fat diets before pregnancy and/or during pregnancy on fetal growth development

AIMS

The aim of the study was to investigate the effects of high-fat diets before pregnancy and/or during pregnancy on fetal development.

MAIN METHODS

Female mice were fed with standard diets (SD) or high-fat diets (HFD). After 12 weeks, females were mated. In the SD + SD and HFD + SD groups, pregnant mice were fed with standard diets. In the SD + HFD and HFD + HFD groups, pregnant mice were fed with high-fat diets. All pregnant mice were sacrificed on gestational day (GD) 16.

KEY FINDINGS

Fetal weight and crown-rump length were increased in SD + HFD-fed mice, whereas were decreased in HFD + SD-fed mice. The levels of CRP and TNF-α in maternal serum and amniotic fluid were elevated in all HFD-fed mice. Placenta weight was elevated in SD + HFD-fed but not in HFD + SD-fed mice. Blood sinusoid areas, and the number of Ki67-positive cells, a marker of cell proliferation, were elevated in placental labyrinth layer of SD + HFD-fed mice, but decreased in HFD + SD-fed mice. Finally, placental Fatp1, a fatty acid transporter gene, was up-regulated in SD + HFD-fed mice. By contrary, placental Fatp1, and Snat2, an amino acid transporter, were down-regulated in HFD + SD-fed mice. Moreover, the levels of placental FATP4 and SNAT2 were up-regulated in SD + HFD-fed mice.

SIGNIFICANCE

HFD before pregnancy and HFD during pregnancy differentially disturb fetal growth development. HFD before pregnancy-induced fetal SGA might be partially attributed to inflammatory cytokines and mediators derived from maternal adipose tissue. By contrary, HFD during pregnancy-induced fetal overweight may be partially attributed to the increase of placental nutrient transport capacity.

Biomarkers of maternal environmental enteric dysfunction are associated with shorter gestation and reduced length in newborn infants in Uganda

Background

Adverse birth outcomes, including preterm birth and stunting at birth, have long-term health implications. The relation between adverse birth outcomes and chronic, asymptomatic gastrointestinal inflammation (environmental enteric dysfunction-EED) is poorly understood.

Objective

We aimed to examine the relation between maternal EED and adverse birth outcomes in a sample of pregnant Ugandan women and their newborn infants.

Design

We conducted a prospective cohort study in Mukono, Uganda. A total of 258 pregnant women were enrolled at their first prenatal visit (∼18 weeks of gestation). EED was measured by urinary lactulose:mannitol (L:M) ratio and serum concentrations of antibodies to the bacterial components flagellin and LPS. Covariates were obtained from survey data collected at 2 time points. Associations were assessed through the use of unadjusted and adjusted simple linear regression models.

Results

Complete birth outcome data were recorded for 220 infants within 48 h of delivery. Mean ± SD gestational age was 39.7 ± 2.1 wk, and 7% were born preterm. Mean ± SD length and length-for-age z score (LAZ) at birth were 48.1 ± 3.2 cm and -0.44 ± 1.07, respectively. L:M ratio was not associated with any birth outcome. In adjusted models, higher concentrations of natural log-transformed anti-flagellin immunoglobin G (IgG) and anti-LPS IgG were significantly associated with shorter length of gestation (β: -0.89 wk; 95% CI: -1.77, -0.01 wk, and β: -1.01 wk; 95% CI: -1.87, -0.17 wk, respectively) and with reduced length (β: -0.80 cm; 95% CI: -1.55, -0.05 cm, and β: -0.79 cm; 95% CI: -1.54, -0.04 cm, respectively) and LAZ at birth (β -0.44 z score; 95% CI: -0.83, -0.05, and β: -0.40 z score; 95% CI: -0.79, -0.01, respectively).

Conclusion

Maternal anti-flagellin and anti-LPS IgG concentrations in pregnancy, but not L:M ratio, were associated with shorter gestation and reduced infant length at birth. Further research on the relation between maternal EED and birth outcomes is warranted.

Patterns of Systemic and Cervicovaginal Fluid Inflammatory Cytokines throughout Pregnancy

OBJECTIVE

 This study describes the normal variations in serum and cervicovaginal fluid (CVF) cytokine levels throughout pregnancy.

STUDY DESIGN

 This multicenter, prospective study examined trimester-specific maternal serum and CVF cytokines (interleukin [IL]-1α, IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α, and C-reactive protein [CRP]). A two-factor linear mixed modeling approach compared cytokine distribution, while pairwise comparisons evaluated differences over time.

RESULTS

 Trimester-specific serum cytokine data were available for 288, 243, and 221 patients, whereas CVF cytokine data were available for 273, 229, and 198 patients. CVF had significantly higher concentrations of IL-1α, IL-1β, IL-6, IL-8, and matrix metalloproteinase-8 (p < 0.001), irrespective of the trimester. At all time points, IL-10 and CRP concentrations were higher in serum than CVF (p < 0.001). Serum IL-10 increased significantly throughout pregnancy (p < 0.001).

CONCLUSION

 Differences in cytokine distribution across different biological fluids are evident throughout pregnancy. These findings provide a framework for examining patterns of changes in cytokines throughout pregnancy.

Screening for fetal growth restriction using fetal biometry combined with maternal biomarkers

Fetal growth restriction is a major determinant of perinatal morbidity and mortality. Screening for fetal growth restriction is a key element of prenatal care but it is recognized to be problematic. Screening using clinical risk assessment and targeting ultrasound to high-risk women is the standard of care in the United States and United Kingdom, but the approach is known to have low sensitivity. Systematic reviews of randomized controlled trials do not demonstrate any benefit from universal ultrasound screening for fetal growth restriction in the third trimester, but the evidence base is not strong. Implementation of universal ultrasound screening in low-risk women in France failed to reduce the risk of complications among small-for-gestational-age infants but did appear to cause iatrogenic harm to false positives. One strategy to making progress is to improve screening by developing more sensitive and specific tests with the key goal of differentiating between healthy small fetuses and those that are small through fetal growth restriction. As abnormal placentation is thought to be the major cause of fetal growth restriction, one approach is to combine fetal biometry with an indicator of placental dysfunction. In the past, these indicators were generally ultrasonic measurements, such as Doppler flow velocimetry of the uteroplacental circulation. However, another promising approach is to combine ultrasonic suspicion of small-for-gestational-age infant with a blood test indicating placental dysfunction. Thus far, much of the research on maternal serum biomarkers for fetal growth restriction has involved the secondary analysis of tests performed for other indications, such as fetal aneuploidies. An exemplar of this is pregnancy-associated plasma protein A. This blood test is performed primarily to assess the risk of Down syndrome, but women with low first-trimester levels are now serially scanned in later pregnancy due to associations with placental causes of stillbirth, including fetal growth restriction. The development of "omic" technologies presents a huge opportunity to identify novel biomarkers for fetal growth restriction. The hope is that when such markers are measured alongside ultrasonic fetal biometry, the combination would have strong predictive power for fetal growth restriction and its related complications. However, a series of important methodological considerations in assessing the diagnostic effectiveness of new tests will have to be addressed. The challenge thereafter will be to identify novel disease-modifying interventions, which are the essential partner to an effective screening test to achieve clinically effective population-based screening.

Maternal systemic or cord blood inflammation is associated with birth anthropometry in a Tanzanian prospective cohort

OBJECTIVES

HIV infection is associated with chronic systemic inflammation, with or without antiretroviral therapy. Consequences for foetal growth are not understood, particularly in settings where multiple maternal infections and malnutrition are common. The study was designed to examine maternal systemic circulating and umbilical cord blood cytokine concentrations in relation to birth anthropometry in a Tanzanian prospective cohort.

METHODS

A 9-plex panel of maternal plasma cytokines in HIV-positive (n = 44) and HIV-negative (n = 70) mothers and the same cytokines in umbilical cord blood collected at delivery was assayed. Linear regression modelled associations between maternal or cord blood cytokines and birth anthropometry.

RESULTS

Health indicators (haemoglobin, mid-upper-arm circumference, body mass index) in HIV-positive mothers without considerable immunosuppression did not differ from HIV-negative women. Despite this, HIV-exposed infants had lower birthweight and length. Subgroup analyses indicated that HIV management using HAART was associated with lower plasma TNF-α, as were longer durations of any antiretroviral therapy (≥2 months). Greater maternal plasma TNF-α was associated with earlier delivery (-1.7 weeks, P = 0.039) and lower birthweights (-287 g; P = 0.020), while greater umbilical cord TNF-α (-1.43 cm; P = 0.036) and IL-12p70 (-2.4 cm; P = 0.008) were associated with shorter birth length. Birthweight was inversely associated with cord IL-12p70 (-723 g; P = 0.001) and IFN-γ (-482 g, P = 0.007). Maternal cytokines during pregnancy did not correlate with umbilical cord cytokines at delivery.

CONCLUSIONS

Systemic inflammation identified in maternal plasma or umbilical cord blood was associated with poorer birth anthropometrics in HIV-exposed and HIV-unexposed infants. Controlling maternal and/or foetal systemic inflammation may improve birth anthropometry.

Potential pathways by which maternal second-hand smoke exposure during pregnancy causes full-term low birth weight

It is well documented that maternal exposure to second-hand smoke (SHS) during pregnancy causes low birth weight (LBW), but its mechanism remains unknown. This study explored the potential pathways. We enrolled 195 pregnant women who delivered full-term LBW newborns, and 195 who delivered full-term normal birth weight newborns as the controls. After controlling for maternal age, education level, family income, pre-pregnant body mass index, newborn gender and gestational age, logistic regression analysis revealed that LBW was significantly and positively associated with maternal exposure to SHS during pregnancy, lower placental weight, TNF-α and IL-1β, and that SHS exposure was significantly associated with lower placental weight, TNF-α and IL-1β. Structural equation modelling identified two plausible pathways by which maternal exposure to SHS during pregnancy might cause LBW. First, SHS exposure induced the elevation of TNF-α, which might directly increase the risk of LBW by transmission across the placenta. Second, SHS exposure first increased maternal secretion of IL-1β and TNF-α, which then triggered the secretion of VCAM-1; both TNF-α and VCAM-1 were significantly associated with lower placental weight, thus increasing the risk of LBW. In conclusion, maternal exposure to SHS during pregnancy may lead to LBW through the potential pathways of maternal inflammation and lower placental weight.

Angiogenic and inflammatory biomarkers in midpregnancy and small-for-gestational-age outcomes in Tanzania

OBJECTIVE

We sought to investigate the relationship between a panel of angiogenic and inflammatory biomarkers measured in midpregnancy and small-for-gestational-age (SGA) outcomes in sub-Saharan Africa.

STUDY DESIGN

Concentrations of 18 angiogenic and inflammatory biomarkers were determined in 432 pregnant women in Dar es Salaam, Tanzania, who participated in a trial examining the effect of multivitamins on pregnancy outcomes. Infants falling below the 10th percentile of birthweight for gestational age relative to the applied growth standards were considered SGA. Multivariate binomial regression models with the log link function were used to determine the relative risk of SGA associated with increasing quartiles of each biomarker. Restricted cubic splines were used to test for nonlinearity of these associations.

RESULTS

A total of 60 participants (13.9%) gave birth to SGA infants. Compared to those in the first quartile, the risk of SGA was reduced among those in the fourth quartiles of vascular endothelial growth factor-A (adjusted risk ratio [RR], 0.38; 95% confidence interval [CI], 0.19-0.74), placental growth factor (adjusted RR, 0.28; 95% CI, 0.12-0.61), soluble fms-like tyrosine kinase-1 (adjusted RR, 0.48; 95% CI, 0.23-1.01), monocyte chemoattractant protein-1 (adjusted RR, 0.48; 95% CI, 0.25-0.92), and leptin (adjusted RR, 0.46; 95% CI, 0.22-0.96).

CONCLUSION

Our findings provide evidence of altered angiogenic and inflammatory mediators, at midpregnancy, in women who went on to deliver SGA infants.

Birth weight and two possible types of maternal effects on male sexual orientation: a clinical study of children and adolescents referred to a Gender Identity Service

This study tested predictions regarding two hypothesized maternal immune responses influencing sexual orientation: one affecting homosexual males with high fraternal birth order and another affecting firstborn homosexual individuals whose mothers experience repeated miscarriage after the birth of the first child. Low birth weight was treated as a marker of possible exposure to a maternal immune response during gestation. Birth weight was examined relative to sibship characteristics in a clinical sample of youth (N = 1,722) classified as heterosexual or homosexual based on self-reported or probable sexual orientation. No female sexual orientation differences in birth weight were found. Homosexual, compared to heterosexual, males showed lower birth weight if they had one or more older brothers--and especially two or more older brothers--or if they were an only-child. These findings support the existence of two maternal immune responses influencing male sexual orientation and possibly also cross-gender behavior and identity.

Novel biomarkers for predicting intrauterine growth restriction: a systematic review and meta-analysis

BACKGROUND

Several biomarkers for predicting intrauterine growth restriction (IUGR) have been proposed in recent years. However, the predictive performance of these biomarkers has not been systematically evaluated.

OBJECTIVE

To determine the predictive accuracy of novel biomarkers for IUGR in women with singleton gestations.

SEARCH STRATEGY

Electronic databases, reference list checking and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of novel biomarkers proposed for predicting IUGR.

DATA COLLECTION AND ANALYSIS

Data were extracted on characteristics, quality and predictive accuracy from each study to construct 2×2 tables. Summary receiver operating characteristic curves, sensitivities, specificities and likelihood ratios (LRs) were generated.

MAIN RESULTS

A total of 53 studies, including 39,974 women and evaluating 37 novel biomarkers, fulfilled the inclusion criteria. Overall, the predictive accuracy of angiogenic factors for IUGR was minimal (median pooled positive and negative LRs of 1.7, range 1.0-19.8; and 0.8, range 0.0-1.0, respectively). Two small case-control studies reported high predictive values for placental growth factor and angiopoietin-2 only when IUGR was defined as birthweight centile with clinical or pathological evidence of fetal growth restriction. Biomarkers related to endothelial function/oxidative stress, placental protein/hormone, and others such as serum levels of vitamin D, urinary albumin:creatinine ratio, thyroid function tests and metabolomic profile had low predictive accuracy.

CONCLUSIONS

None of the novel biomarkers evaluated in this review are sufficiently accurate to recommend their use as predictors of IUGR in routine clinical practice. However, the use of biomarkers in combination with biophysical parameters and maternal characteristics could be more useful and merits further research.

The placenta in preeclampsia

The root cause of preeclampsia is the placenta. Preeclampsia begins to abate with the delivery of the placenta and can occur in the absence of a fetus but with the presence of trophoblast tissue with hydatidiform moles. In view of this, study of the placenta should provide insight into the pathophysiology of preeclampsia. In this presentation we examine placental pathological and pathophysiological changes with preeclampsia and fetal growth restriction (FGR). It would seem that this comparison should be illuminating as both conditions are associated with similarly abnormal placentation yet only in preeclampsia is there a maternal pathophysiological syndrome. Similar insights about early and late onset preeclampsia should also be provided by such information.We report that the placental abnormalities in preeclampsia are what would be predicted in a setting of reduced perfusion and oxidative stress. However, the differences from FGR are inconsistent. The most striking differences between the two conditions are found in areas that have been the least studied. There are differences between the placental findings in early and late onset preeclampsia but whether these are qualitative, indicating different diseases, or simply quantitative differences within the same disease is difficult to determine.We attempt to decipher the true differences, seek an explanation for the disparate results and provide recommendations that we hope may help resolve these issues in future studies.

Dynamics of regulatory T-cells during pregnancy: effect of HIV infection and correlations with other immune parameters

Objectives

Regulatory T cells (Treg) increase in the context of HIV infection and pregnancy. We studied Treg subpopulations in HIV-infected and uninfected women during pregnancy and their relationship with inflammation, activation and cell-mediated immunity (CMI).

Design and Methods

Blood obtained from 20 HIV-infected and 18 uninfected women during early and late gestation was used to measure Treg and activated T cells (Tact) by flow cytometry; plasma cytokines and inflammatory markers by ELISA and chemoluminescence; and CMI against varicella-zoster virus (VZV) by lymphocyte proliferation.

Results and Conclusions

Compared with uninfected women, HIV-infected participants had higher frequencies of Treg subpopulations in early pregnancy, including CD4+CD25+FoxP3+%, CD8+CD25+FoxP3+%, CD4+TGFβ+% and CD4+IL10+%. In contrast, Treg frequencies were lower during late pregnancy in HIV-infected compared with uninfected women, including CD8+TGFβ+%, CD4+CTLA4+% and CD8+CTLA4+%. VZV-CMI, which was lower in HIV-infected compared with uninfected pregnant women, was inversely correlated with CD4+FoxP3+%, CD8+FoxP3+% and CD8+TGFβ+% in HIV-infected, but not in uninfected pregnant women. β_2-microglobulin, neopterin, IL1, IL4, IL8, IL10, IFNγ and TNFα plasma concentrations as well as Tact were higher in HIV-infected compared with uninfected women throughout pregnancy. In HIV-infected, but not in uninfected women, inflammatory, Th1, Th2 and regulatory cytokines increased with higher Treg%, suggesting that inflammation and regulation have a common pathophysiologic origin in the context of HIV infection. In HIV-infected and more commonly in uninfected pregnant women, higher Treg% correlated with lower Tact%. We conclude that Treg have different dynamics during pregnancy in HIV-infected and uninfected women. Higher levels of inflammatory cytokines and lower Treg% during late pregnancy in HIV-infected women may contribute to their increased incidence of maternal-fetal morbidity.

Progesterone interactions with the cervix: translational implications for term and preterm birth

The uterine cervix plays a vital role in maintaining pregnancy and an equally important role in allowing parturition to occur. Progesterone, either endogenously produced or supplied exogenously, supports the function of the cervix in sustaining intrauterine pregnancy, and the withdrawal of progesterone, either through natural processes or pharmacologic intervention, leads to delivery which underscores the importance of the progesterone's biological activities manifest in normal gestation and pregnancy that ends prematurely. Research crossing many scientific disciplines has demonstrated that progesterone is a pleotropic compound that affects the cervix through cytoplasmic and membrane receptors with profound effects on cellular and molecular functions that influence inflammatory cascades and extracellular matrix, both of which have consequences for parturition. Beyond the local cell and molecular biology of progesterone, it has systemic effects of relevance to pregnancy as well. This paper examines the biology of the cervix from its gross to cellular structure and biological activities of its cell and molecular processes that may be affected by progesterone. The implications of these processes for preterm birth are explored, and direction of current research is in relation to translational medicine implications for diagnostic, prognostic, and therapeutic approaches to threatened preterm birth.