Preterm birth and genitourinary tract infections: assessing gene-environment interaction.

BACKGROUND: Preterm birth (PTB) is the leading cause of perinatal morbimortality worldwide. Genetic and environmental factors could raise PTB risk. The aim of this study was to analyze the contribution of the statistical interaction between genes and vaginal-urinary tract infections (VI-UTI) to the risk of PTB by clinical subtype. METHODS: Twenty-four SNPs were genotyped in 18 candidate genes from 352 fetal triads and 106 maternal triads. Statistical interactions were evaluated with conditional logistic regression models based on genotypic transmission/disequilibrium test. RESULTS: In PTB-idiopathic subtype mothers exposed to UTI, fetal SNPs rs11686474 (FSHR), rs4458044 (CRHR1, allele G), rs883319 (KCNN3), and maternal SNP rs1882435 (COL4A3) showed a nominal significant increment in prematurity risk. In preterm premature rupture of membranes (PPROM), fetal SNP rs2277698 (TIMP2) showed a nominal significant risk increment. In mothers exposed to VI, fetal SNP rs5742612 (IGF1) in PTB-PPROM and maternal SNP rs4458044 (CRHR1, allele C) in spontaneous PTB showed nominal significant increment in prematurity risk. CONCLUSIONS: Certain maternal and fetal genes linked to infectious/inflammatory and hormonal regulation processes increase prematurity risk according to clinical subtype when mothers are exposed to UTI or VI. These findings may help in the understanding of PTB etiology and PTB prevention. IMPACT: Preterm birth is a major cause of perinatal morbimortality worldwide and its etiology remains unknown. This work provides evidence on the statistical interaction of six genes with gestational vaginal or urinary infections leading to the occurrence of preterm births. Statistical interactions vary according to infection type, genotype (maternal and fetal), and clinical subtype of prematurity. Certain maternal and fetal genetic variants of genes linked to infectious/inflammatory and hormonal regulation processes would increase the risk of prematurity according to clinical subtype and infection type. Our findings may help in the study of etiology of preterm birth and its prevention.

Odon device for instrumental vaginal deliveries: results of a medical device pilot clinical study.

BACKGROUND: A prolonged and complicated second stage of labour is associated with serious perinatal complications. The Odon device is an innovation intended to perform instrumental vaginal delivery presently under development. We present an evaluation of the feasibility and safety of delivery with early prototypes of this device from an early terminated clinical study. METHODS: Hospital-based, multi-phased, open-label, pilot clinical study with no control group in tertiary hospitals in Argentina and South Africa. Multiparous and nulliparous women, with uncomplicated singleton pregnancies, were enrolled during the third trimester of pregnancy. Delivery with Odon device was attempted under non-emergency conditions during the second stage of labour. The feasibility outcome was delivery with the Odon device defined as successful expulsion of the fetal head after one-time application of the device. RESULTS: Of the 49 women enrolled, the Odon device was inserted successfully in 46 (93%), and successful Odon device delivery as defined above was achieved in 35 (71%) women. Vaginal, first and second degree perineal tears occurred in 29 (59%) women. Four women had cervical tears. No third or fourth degree perineal tears were observed. All neonates were born alive and vigorous. No adverse maternal or infant outcomes were observed at 6-weeks follow-up for all dyads, and at 1 year for the first 30 dyads. CONCLUSIONS: Delivery using the Odon device is feasible. Observed genital tears could be due to the device or the process of delivery and assessment bias. Evaluating the effectiveness and safety of the further developed prototype of the BD Odon Device™ will require a randomized-controlled trial. TRIAL REGISTRATION: ANZCTR ACTRN12613000141741 Registered 06 February 2013. Retrospectively registered.

Association of candidate gene polymorphisms with clinical subtypes of preterm birth in a Latin American population.

BackgroundPreterm birth (PTB) is the leading cause of neonatal mortality and morbidity. PTB is often classified according to clinical presentation as follows: idiopathic (PTB-I), preterm premature rupture of membranes (PTB-PPROM), and medically induced (PTB-M). The aim of this study was to evaluate the associations between specific candidate genes and clinical subtypes of PTB.MethodsTwenty-four single-nucleotide polymorphisms (SNPs) were genotyped in 18 candidate genes in 709 infant triads. Of them, 243 were PTB-I, 256 were PTB-PPROM, and 210 were PTB-M. These data were analyzed with a Family-Based Association.ResultsPTB was nominally associated with rs2272365 in PON1, rs883319 in KCNN3, rs4458044 in CRHR1, and rs610277 in F3. Regarding clinical subtypes analysis, three SNPs were associated with PTB-I (rs2272365 in PON1, rs10178458 in COL4A3, and rs4458044 in CRHR1), rs610277 in F3 was associated with PTB-PPROM, and rs883319 in KCNN3 and rs610277 in F3 were associated with PTB-M.ConclusionOur study identified polymorphisms potentially associated with specific clinical subtypes of PTB in this Latin American population. These results could suggest a specific role of such genes in the mechanisms involved in each clinical subtype. Further studies are required to confirm our results and to determine the role of these genes in the pathophysiology of clinical subtypes.

Maternal and neonatal epidemiological features in clinical subtypes of preterm birth.

OBJECTIVE: This study was designed to characterize and compare the maternal and newborn epidemiological characteristics through analysis of environmental factors, sociodemographic characteristics and clinical characteristics between the different clinical subtypes of preterm birth (PTB): Idiopathic (PTB-I), premature rupture of the membranes (PTB-PPROM) and medically indicated (PTB-M). The two subtypes PTB-I and PTB-PPROM grouped are called spontaneous preterm births (PTB-S). METHODS: A retrospective, observational study was conducted in 1.291 preterm nonmalformed singleton live-born children to nulliparous and multiparous mother's in Tucumán-Argentina between 2005 and 2010. Over 50 maternal variables and 10 newborn variables were compared between the different clinical subtypes. The comparisons were done to identify heterogeneity between subtypes of preterm birth: (PTB-S) versus (PTB-M), and within spontaneous subtype: (PTB-I) versus (PTB-PPROM). In the same way, two conditional logistic multivariate regressions were used to compare the odds ratio (OR) between PTB-S and PTB-M, as well as PTB-I and PTB-PPROM. We matched for maternal age when comparing maternal variables and gestational age when comparing infant variables. RESULTS: The PTB-I subtype was characterized by younger mothers of lower socio-economic status, PTB-PPROM was characterized by environmental factors resulting from inflammatory processes, and PTB-M was characterized by increased maternal or fetal risk pregnancies. CONCLUSIONS: The main risk factor for PTB-I and PTB-M was having had a prior preterm delivery; however, previous spontaneous abortion was not a risk factor, suggesting a reproductive selection mechanism.

Feasibility and safety study of a new device (Odón device) for assisted vaginal deliveries: study protocol.

BACKGROUND: Intrapartum complications are responsible for approximately half of all maternal deaths, and two million stillbirth and neonatal deaths per year. Prolonged second stage of labour is associated with potentially fatal maternal complications such as haemorrhage and infection and it is a major cause of stillbirth and newborn morbidity and mortality. Currently, the three main options for managing prolonged second stage of labour are forceps, vacuum extractor and caesarean section. All three clinical practices require relatively expensive equipment (e.g., a surgical theatre for caesarean section) and/or highly trained staff which are often not available in low resource settings. The specific aim of the proposed study is to test the safety and feasibility of a new device (Odón device) to effectively deliver the fetus during prolonged second stage of labour. The Odón device is a low-cost technological innovation to facilitate operative vaginal delivery and designed to minimize trauma to the mother and baby. These features combined make it a potentially revolutionary development in obstetrics, particularly for improving intrapartum care and reducing maternal and perinatal morbidity and mortality in low resource settings. METHODS/DESIGN: This will be a hospital-based, multicenter prospective phase 1 cohort study with no control group. Delivery with the Odón device will be attempted under normal labour and non-emergency conditions on all the women enrolled in the study. One-hundred and thirty pregnant women will be recruited in tertiary care facilities in Argentina. Safety will be assessed by examining maternal and infant outcomes until discharge. Feasibility will be evaluated by observing successful expulsion of the fetal head after one-time application of the device under standardized conditions (full cervical dilation, anterior presentation, +2 station, normal fetal heart rate). TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR). Identifier: ACTRN12613000141741.

Sequence variants in oxytocin pathway genes and preterm birth: a candidate gene association study.

BACKGROUND: Preterm birth (PTB) is a complex disorder associated with significant neonatal mortality and morbidity and long-term adverse health consequences. Multiple lines of evidence suggest that genetic factors play an important role in its etiology. This study was designed to identify genetic variation associated with PTB in oxytocin pathway genes whose role in parturition is well known. METHODS: To identify common genetic variants predisposing to PTB, we genotyped 16 single nucleotide polymorphisms (SNPs) in the oxytocin (OXT), oxytocin receptor (OXTR), and leucyl/cystinyl aminopeptidase (LNPEP) genes in 651 case infants from the U.S. and one or both of their parents. In addition, we examined the role of rare genetic variation in susceptibility to PTB by conducting direct sequence analysis of OXTR in 1394 cases and 1112 controls from the U.S., Argentina, Denmark, and Finland. This study was further extended to maternal triads (maternal grandparents-mother of a case infant, N=309). We also performed in vitro analysis of selected rare OXTR missense variants to evaluate their functional importance. RESULTS: Maternal genetic effect analysis of the SNP genotype data revealed four SNPs in LNPEP that show significant association with prematurity. In our case-control sequence analysis, we detected fourteen coding variants in exon 3 of OXTR, all but four of which were found in cases only. Of the fourteen variants, three were previously unreported novel rare variants. When the sequence data from the maternal triads were analyzed using the transmission disequilibrium test, two common missense SNPs (rs4686302 and rs237902) in OXTR showed suggestive association for three gestational age subgroups. In vitro functional assays showed a significant difference in ligand binding between wild-type and two mutant receptors. CONCLUSIONS: Our study suggests an association between maternal common polymorphisms in LNPEP and susceptibility to PTB. Maternal OXTR missense SNPs rs4686302 and rs237902 may have gestational age-dependent effects on prematurity. Most of the OXTR rare variants identified do not appear to significantly contribute to the risk of PTB, but those shown to affect receptor function in our in vitro study warrant further investigation. Future studies with larger sample sizes are needed to confirm the findings of this study.

Genome-wide analysis of DNA methylation in human amnion.

The amnion is a specialized tissue in contact with the amniotic fluid, which is in a constantly changing state. To investigate the importance of epigenetic events in this tissue in the physiology and pathophysiology of pregnancy, we performed genome-wide DNA methylation profiling of human amnion from term (with and without labor) and preterm deliveries. Using the Illumina Infinium HumanMethylation27 BeadChip, we identified genes exhibiting differential methylation associated with normal labor and preterm birth. Functional analysis of the differentially methylated genes revealed biologically relevant enriched gene sets. Bisulfite sequencing analysis of the promoter region of the oxytocin receptor (OXTR) gene detected two CpG dinucleotides showing significant methylation differences among the three groups of samples. Hypermethylation of the CpG island of the solute carrier family 30 member 3 (SLC30A3) gene in preterm amnion was confirmed by methylation-specific PCR. This work provides preliminary evidence that DNA methylation changes in the amnion may be at least partially involved in the physiological process of labor and the etiology of preterm birth and suggests that DNA methylation profiles, in combination with other biological data, may provide valuable insight into the mechanisms underlying normal and pathological pregnancies.

Environmental risk factors and perinatal outcomes in preterm newborns, according to family recurrence of prematurity.

OBJECTIVE: We analyzed the role of environmental risk factors, sociodemographic characteristics, clinical characteristics, and reproductive history in preterm births and their associated perinatal outcomes in families classified according to their histories of preterm recurrence among siblings. STUDY DESIGN: A retrospective study was conducted at Nuestra Señora de la Merced Maternity Hospital in the city of Tucumán, Argentina. A total of 348 preterm, non-malformed, singleton children born to multipara women were reviewed. The family history score described by Khoury was applied, and families were classified as having no, medium, or high genetic aggregation. RESULTS: Families with no familial aggregation showed a higher rate of short length of cohabitation, maternal urinary tract infections during the current pregnancy, and maternal history of miscarriage during the previous pregnancy. Families with a high level of aggregation had a significantly higher incidence of pregnancy complications, such as diabetes, hypertension, and immunologic disorders. CONCLUSION: Reproductive histories clearly differed between the groups, suggesting both a different response to environmental challenges based on genetic susceptibility and the activation of different pathophysiological pathways to determine the duration of pregnancy in each woman.

Replication of a genome-wide association study of birth weight in preterm neonates.

OBJECTIVE: To examine associations between rs9883204 in ADCY5 and rs900400 near LEKR1 and CCNL1 with birth weight in a preterm population. Both markers were associated with birth weight in a term population in a recent genome-wide association study of Freathy et al. STUDY DESIGN: A meta-analysis of mother and infant samples was performed for associations of rs900400 and rs9883204 with birth weight in 393 families from the US, 265 families from Argentina, and 735 mother-infant pairs from Denmark. Z-scores adjusted for infant sex and gestational age were generated for each population separately and regressed on allele counts. Association evidence was combined across sites by inverse-variance weighted meta-analysis. RESULTS: Each additional C allele of rs900400 (LEKR1/CCNL1) in infants was marginally associated with a 0.069 SD lower birth weight (95% CI, -0.159 to 0.022; P = .068). This result was slightly more pronounced after adjusting for smoking (P = .036). No significant associations were identified with rs9883204 or in maternal samples. CONCLUSIONS: These results indicate the potential importance of this marker on birth weight regardless of gestational age.

Prenatal screening for chromosome abnormalities in a region with no access to termination of pregnancy.

OBJECTIVE: To analyze the different variables that affect couples' decision-making about prenatal screening of chromosome abnormalities in a population with limited access to prenatal diagnosis and no legal termination of pregnancy (TOP). METHODS: From February through August 2004, 79 couples who requested for prenatal screening at centers from Argentina and Uruguay participated in a study. A cross-sectional survey was administered to assess attitudes toward prenatal screening, the decision-making process, and knowledge and attitudes toward TOP. RESULTS: Mean maternal age was 32.8 +/- 0.4 years. Among the couples, 88.61% knew that TOP due to fetal anomalies is not legal in their countries. When asked about the possibility of TOP in case of a serious fetal anomaly, 53% would contemplate this option. CONCLUSION: Prenatal screening is a common practice worldwide. However, unlike most developed countries, our region has a limited access to prenatal diagnosis and no legal TOP. Those couples who stated that 'reassurance about fetal well-being' was the most important reason to perform prenatal screening had more positive attitudes toward TOP than those who considered this screening important 'to be better prepared to receive the baby'. Our findings can be used to inform and revise current health-care policies.

Prevención de los defectos congénitos y trastornos genéticos. Diagnóstico prenatal de defectos congénitos: prevención secundaria y terciaria / Prevention of the congenital defects and genetic disorders. Prenatal diagnosis of congenital defects: secondary and terciary prevention

Los defectos congénitos constituyen en la actualidad una de las principales causas de morbimortalidad perinatal. Esto es debido a la disminución de la mortalidad infantil asociada a infecciones y desnutrición. Una de cada cinco muertes en el primer año de vida en los Estados Unidos de Norteamérica son atribuibles a los defectos congénitos. De persistir la disminución en la mortalidad, tal como se observa en la mayoría de los países de América Latina, los defectos congénitos se convertirán en prioridad en el área de la salud. El diagnóstico prenatal ha incrementado el interés tanto en la comunidad médica como en la sociedad en su conjunto sobre los defectos congénitos. La identificación de factores de riesgo genéticos y ambientales son esenciales para la prevención primaria y secundaria de los mismos y está íntimamente relacionada con el diagnóstico y tratamiento prenatal. Los programas de vigilancia epidemiológica de los defectos congénitos pueden ser utilizados para evaluar la efectividad y eficacia de las acciones de prevención, programas de tamizaje, diagnóstico y tratamiento prenatal.

Prevención primaria de defectos de desarrollo fetal en poblaciones de Latinoamérica: análisis de un modelo para modificar la estructura etaria materna / Primary prevention of fetal development defects in Latinamerica: analysis of a model to modify the maternal age distribution

Evaluar el impacto que, posibles acciones sobre la estructura etaria materna que tiendad a transferir la ocurrencia de embarazos en los extremos del ciclo reproductivo hacia edades maternas asociadas a un menor riesgo perinatal, representarian en la frecuencia de diversas anomalias del desarrollo