Rates of and factors associated with recurrence of preterm delivery

ArticleinJAMA The Journal of the American Medical Association 283(12):1591-6 · November 1999with11 Reads
Source: PubMed
Information about risk of recurrent preterm delivery is useful to clinicians, researchers, and policy makers for counseling, generating etiologic leads, and measuring the related public health burden. To identify the rate of recurrence of preterm delivery in second pregnancies, factors associated with recurrence, and the percentage of preterm deliveries in women with a history of preterm delivery. Population-based cohort study of data from birth and fetal death certificates from the state of Georgia between 1980 and 1995. A total of 122 722 white and 56174 black women with first and second singleton deliveries at 20 to 44 weeks' gestation. Length of gestation (categorized as 20-31, 32-36, or > or =37 weeks) at second delivery compared with length of gestation at first delivery, by age and race. Most women whose first delivery was preterm subsequently had term deliveries. Of 1023 white women whose first delivery occurred at 20 to 31 weeks, 8.2% (95% confidence interval [CI], 6.6%-10.1%) delivered their second birth at 20 to 31 weeks and 20.1% (95% CI, 17.7%-22.8%) at 32 to 36 weeks. Of 1084 comparable black women, 13.4% (95 % CI, 11.4%-15.6%) delivered at 20 to 31 weeks and 23.4% (95% CI, 20.9%-26.1%) delivered at 32 to 36 weeks. Among women whose first delivery occurred at 32 to 36 weeks, all corresponding rates were lower than those whose first birth was at 20 to 31 weeks; the rates of second birth at 20 to 31 weeks were substantially lower (for white women, 1.9% [95% CI, 1.7%-2.2%]; for black women, 3.8% [95% CI, 3.4%-4.2%]). Compared with women aged 20 to 49 years at their second delivery, women younger than 18 years had twice the risk of recurrence of delivery at 20 to 31 weeks. Of all second deliveries at 20 to 31 weeks, 29.4% for white women and 37.8% for black women were preceded by a preterm delivery. Our data suggest that recurrence of preterm delivery contributes a notable portion of all preterm deliveries, especially at the shortest gestations.
    • "It seems clear, however, that a genetic predisposition can contribute to PTL and PPROM. Women with family and/or personal history of such complications are at high risk for their re-occurrence8910. The well documented discrepancy in the rates of these adverse outcomes among different ethnicities and populations111213 also reinforces the importance of genetic and environmental variations in the susceptibility to develop PTL and PPROM. "
    [Show abstract] [Hide abstract] ABSTRACT: Background A genetic predisposition to Preterm Labor (PTL) and Preterm Premature Rupture of Membranes (PPROM) has been suggested; however the relevance of polymorphisms and ancestry to susceptibility to PTL and PPROM in different populations remains unclear. The aim of this study was to evaluate the contribution of maternal and fetal SNPs in the IL1B, IL6, IL6R, TNFA, TNFR, IL10, TLR2, TLR4, MMP9, TIMP1 and TIMP2 genes and the influence of ancestry background in the susceptibility to PTL or PPROM in Brazilian women. Methods Case–control study conducted at a tertiary hospital in São Paulo State, Brazil. We included women with PTL or PPROM and their babies (PTL: 136 women and 88 babies; PPROM: 65 women and 44 babies). Control group included 402 mother-babies pairs of term deliveries. Oral swabs were collected for identification of AIMs by fragment analysis and SNPs by Taqman® SNP Genotyping Assays and PCR. Linkage Disequilibrium and Hardy-Weinberg proportions were evaluated using Genepop 3.4. Haplotypes were inferred using the PHASE algorithm. Allele, genotype and haplotype frequencies were compared by Fisher’s exact test or χ² and Odds Ratio. Logistic regression was performed. Clinical and sociodemographic data were analyzed by Fisher’s exact test and Mann–Whitney. Results PTL was associated with European ancestry and smoking while African ancestry was protective. The fetal alleles IL10-592C (rs800872) and IL10-819C (rs1800871) were also associated with PTL and the maternal haplotype TNFA-308G-238A was protective. Maternal presence of IL10-1082G (rs1800896) and TLR2A (rs4696480) alleles increased the risk for PPROM while TNFA-238A (rs361525) was protective. Family history of PTL/PPROM was higher in cases, and time to delivery was influenced by IL1B-31T (rs1143627) and TLR4-299G (rs4986790). Conclusion There is an association between European ancestry and smoking and PTL in our Brazilian population sample. The presence of maternal or fetal alleles that modify the inflammatory response increase the susceptibility to PTL and PPROM. The family history of PTL/PPROM reinforces a role for genetic polymorphisms in susceptibility to these outcomes.
    Full-text · Article · Dec 2016
    • "Survivors are at increased risk of cerebral palsy, intellectual disabilities, respiratory problems and other long term conditions [4]. Moreover, despite numerous attempts at intervention, the incidence of prematurity has shown minimal improvement over the last two decades [2]. The risk factors associated with prematurity are many including: adverse sociodemographic status, race/ethnicity, infection, stress, trauma and prior history of a premature birth [4][5][6][7][8][9][10]. "
    [Show abstract] [Hide abstract] ABSTRACT: Understanding the genetic contribution(s) to the risk of preterm birth may lead to the development of interventions for treatment, prediction and prevention. Twin studies suggest heritability of preterm birth is 36-40%. Large epidemiological analyses support a primary maternal origin for recurrence of preterm birth, with little effect of paternal or fetal genetic factors. We exploited an "extreme phenotype" of preterm birth to leverage the likelihood of genetic discovery. We compared variants identified by targeted sequencing of women with 2-3 generations of preterm birth with term controls without history of preterm birth. We used a meta-genomic, bi-clustering algorithm to identify gene sets coordinately associated with preterm birth. We identified 33 genes including 217 variants from 5 modules that were significantly different between cases and controls. The most frequently identified and connected genes in the exome library were IGF1, ATM and IQGAP2. Likewise, SOS1, RAF1 and AKT3 were most frequent in the haplotype library. Additionally, SERPINB8, AZU1 and WASF3 showed significant differences in abundance of variants in the univariate comparison of cases and controls. The biological processes impacted by these gene sets included: cell motility, migration and locomotion; response to glucocorticoid stimulus; signal transduction; metabolic regulation and control of apoptosis.
    Full-text · Article · May 2016
    • "The differences between clinical subtypes in the recurrence were only found in mothers with previous preterm births and no previous spontaneous abortions. This result replicates other findings [14,41], indicating that the strongest risk factor for delivering a preterm neonate is a history of a prior preterm delivery. Unfortunately, we had a small number of mothers whoTable 2. Significant maternal and neonatal outcomes by clinical subtypes. "
    [Show abstract] [Hide abstract] ABSTRACT: 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.
    Full-text · Article · Dec 2015
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