Risk Factors For PTB Research Articles

A retrospective, longitudinal cohort study of trends and risk factors for preterm birth in the Northern Territory, Australia

BackgroundPreterm birth (PTB) is the single most important cause of perinatal mortality and morbidity in high income countries. In Australia, 8.6% of babies are born preterm but substantial variability exists between States and Territories. Previous reports suggest PTB rates are highest in the Northern Territory (NT), but comprehensive analysis of trends and risk factors are lacking in this region. The objective of this study was to characterise temporal trends in PTB among First Nations and non-First Nations mothers in the Top End of the NT over a 10-year period and to identify perinatal factors associated with the risk of PTB.MethodsThis was a retrospective population-based cohort study of all births in the Top End of the NT over the 10-year period from January 1st, 2008, to December 31st, 2017. We described maternal characteristics, obstetric complications, birth characteristics and annual trends in PTB. The association between the characteristics and the risk of PTB was determined using univariate and multivariate generalised linear models producing crude risk ratios (cRR) and adjusted risk ratios (aRR). Data were analysed overall, in First Nations and non-First Nations women.ResultsDuring the decade ending in 2017, annual rates of PTB in the Top End of the NT remained consistently close to 10% of all live births. However, First Nations women experienced more than twice the risk of PTB (16%) compared to other women (7%). Leading risk factors for PTB among First Nations women as compared to other women included premature rupture of membranes (RR 12.33; 95% CI 11.78, 12.90), multiple pregnancy (RR 7.24; 95% CI 6.68, 7.83), antepartum haemorrhage (RR 4.36; 95% CI 3.93, 4.84) and pre-existing diabetes (RR 4.18; 95% CI 3.67, 4.76).ConclusionsFirst Nations women experience some of the highest PTB rates globally. Addressing specific pregnancy complications provides avenues for intervention, but the story is complex and deeper exploration is warranted. A holistic approach that also acknowledges the influence of socio-demographic influences, such as remote dwelling and disadvantage on disease burden, will be required to improve perinatal outcomes.

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BackgroundPreterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.MethodsWe searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.ResultsEighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10−6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.ConclusionsThe results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.Trial registrationPROSPERO 2021 CRD42021227296.

The epidemiological characteristics and infection risk factors for extrapulmonary tuberculosis in patients hospitalized with pulmonary tuberculosis infection in China from 2017 to 2021

BackgroundPulmonary tuberculosis (PTB) complicated with extrapulmonary tuberculosis (EPTB) infection can aggravate the disease, but there have been few reports.MethodsRetrospective analysis was used to collect the clinical data of PTB patients with pathogen positive in a teaching hospital from 2017 to 2021. We describe the incidence, the invasive site of EPTB patients, and analyze the infection risk factors for PTB with EPTB by univariate and multivariate logistic regression models. We also compared the complications, disease burden with chi-square test and rank-sum test.ResultsA total of 1806 PTB were included, of which 263 (14.6%) were complicated with EPTB. The common invasive sites for EPTB were neck lymph nodes (16.49%), intestines (16.13%), and meninges (10.75%). Age ≤ 40 (OR = 1.735; 95%CI [1.267–2.376]; P = 0.001), malnutrition (OR = 2.029; 95%CI [1.097–3.753]; P = 0.022), anemia (OR = 1.739; 95%CI[1.127–2.683]; P = 0.012), and osteoporosis (OR = 4.147; 95%CI [1.577–10.905]; P = 0.004) were all independent risk factors for PTB infection with EPTB. The incidence of extrathoracic hydrothorax, intestinal bacterial infection, urinary tract bacterial infection, and abdominal bacterial infection were higher in patients with PTB with EPTB. PTB with EPTB patients also had longer median hospitalization durations (19 vs. 14 days), during which time they incurred higher total costs, laboratory test costs, imaging examination costs, and drug use costs.ConclusionThis study found important risk factors for PTB complicated with EPTB, such as age ≤ 40, malnutrition, anemia, and osteoporosis. PTB with EPTB patients have more extrapulmonary complications and higher hospitalization disease burden.

Cultural considerations and beliefs surrounding preterm birth in Kenya and South Africa

BackgroundPreterm birth (PTB) is a global health epidemic, sub-Saharan Africa is severely impacted due to its limited healthcare resources. Pregnancy knowledge, cultural beliefs and practices play a role in the identification of risk and management of PTB. This study explored knowledge, understandings, cultural beliefs and attitudes to pregnancy and PTB, as well as cultural considerations for the introduction of an intravaginal device which could be used to identify PTB risk.MethodsQualitative research was conducted in South Africa and Kenya. In-depth interviews were conducted using semi-structured guides with women with a history of PTB (n = 10), healthcare providers (n = 16) and health systems experts (n = 10); and 26 focus group discussions with pregnant women seeking antenatal care (n = 132) and community male partners/fathers (n = 54). Interviews/discussions were transcribed, translated, and analysed thematically.ResultsPregnancy knowledge, especially for first time pregnancies was poor, with many reporting late entry to antenatal care. Knowledge about PTB was understood in terms of gestational age, weight or small size of baby, with concerns about long term health and stigma. Various risk factors for PTB were described, including those related to traditions and beliefs of witchcraft/curses. Cultural practices, such as the use of traditional medicines and pica, and religion and its impact on health seeking behaviour were also viewed as risk factors. Although insertion of intravaginal devices was not widely acceptable in traditional communities, especially during pregnancy, it was felt that the use of one to detect risk of PTB would be accepted if proven effective in reducing PTB risk.ConclusionsVarious culturally-informed beliefs exist which explain understandings of and attitudes toward pregnancy, pregnancy risk, and PTB. An inclusive exploratory process is critical to facilitate an understanding of the beliefs and traditions which could impact the introduction and design of a product to detect the risk of PTB.

Oral supplementation of α-lipoic acid (ALA), magnesium, vitamin B6 and vitamin D stabilizes cervical changes in women presenting risk factors for preterm birth.

Recently, the PTB risk has been related to the objective measurement of cervical length (CL), since a CL of less than 25 mm is an accurate predictor of increased risk of PTB. Primary prevention of preterm labor is based on the early identification of symptoms and on pharmacological treatments with tocolytic drugs for inhibition of uterine contractions that are associated with a shortening of the cervix. Unfortunately, most of these drugs have important side effects. This study aimed to evaluate whether the administration of a combination of oral α-lipoic acid (ALA), magnesium, vitamin B6 and vitamin D to pregnant women presenting risk factors for PTB could reduce the rate of cervical shortening at 19-22 weeks of gestational age. A total of 122 women attending the first-trimester aneuploidy screening at 11-14 weeks of pregnancy and presenting risk factors for PTB were included in the study. Cervical length significantly decreased in the control group compared with the treatment group (-3.86 ± 1.97 vs. 1.50 ± 1.26; p=0.02). Although the rate of preterm birth did not significantly decrease (9.5% vs. 5.1%), admission for threatened PTB was statistically reduced in the treatment group compared with the control group (3.4% vs. 14.3%). Oral supplementation of ALA, magnesium, vitamin B6 and vitamin D significantly counteracted cervix shortening in pregnant women presenting risk factors for PTB.

Differences in risk factors for incident and recurrent preterm birth: a population-based linkage of 3.5 million births from the CIDACS birth cohort

BackgroundPreterm birth (PTB) is a syndrome resulting from a complex list of underlying causes and factors, and whether these risk factors differ in the context of prior PTB history is less understood. The aim of this study was to explore whether PTB risk factors in a second pregnancy were different in women with versus without previous PTB.MethodsWe conducted a population-based cohort study using data from the birth cohort of the Center for Data and Knowledge Integration for Health (CIDACS) for the period 2001 to 2015. We used longitudinal transition models with multivariate logistic regression to investigate whether risk factors varied between incident and recurrent PTB.ResultsA total of 3,528,050 live births from 1,764,025 multiparous women were analyzed. We identified different risk factors (Pdifference <0.05) between incident and recurrent PTB. The following were associated with an increased chance for PTB incidence, but not recurrent: household overcrowding (OR 1.09), maternal race/ethnicity [(Black/mixed—OR 1.04) and (indigenous—OR 1.34)], young maternal age (14 to 19 years—OR 1.16), and cesarean delivery (OR 1.09). The following were associated with both incident and recurrent PTB, respectively: single marital status (OR 0.85 vs 0.90), reduced number of prenatal visits [(no visit—OR 2.56 vs OR 2.16) and (1 to 3 visits—OR 2.44 vs OR 2.24)], short interbirth interval [(12 to 23 months—OR 1.04 vs OR 1.22) and (<12 months, OR 1.89, 95 vs OR 2.58)], and advanced maternal age (35–49 years—OR 1.42 vs OR 1.45). For most risk factors, the point estimates were higher for incident PTB than recurrent PTB.ConclusionsThe risk factors for PTB in the second pregnancy differed according to women’s first pregnancy PTB status. The findings give the basis for the development of specific prevention strategies for PTB in a subsequent pregnancy.

Associations between gestational weight gain and preterm birth in Puerto Rico

BackgroundPreterm birth (PTB; gestational age < 37 weeks) is the leading cause of infant morbidity and mortality worldwide. Low and excessive gestational weight gain (GWG) have been previously cited as risk factors for PTB, however the magnitude of association varies across populations. No studies have examined low and excessive GWG as modifiable risk factors for PTB in Puerto Rico, an area with inexplicably high PTB rates.MethodsTo examine the relationship between GWG and PTB, we conducted a retrospective analysis using birth certificate data files from the Puerto Rico Department of Health from 2005 to 2012. GWG was standardized to a 40-week gestational duration and was categorized into low, adequate, or excessive for each category of pre-pregnancy body mass index using American College of Obstetricians and Gynecologists guidelines. Logistic regression was used to determine the crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between GWG and PTB.ResultsThere were 320,695 births included in this analysis; 40.6% with high GWG and 27.3% with low GWG. A greater percentage of women with low GWG were less than 20 years of age, had less than a high school education, and were underweight compared to women with adequate and excessive GWG. Women with low compared to adequate GWG had increased odds of PTB (OR = 1.34, 95% CI = 1.30–1.37). However, excessive compared to adequate GWG was not associated with PTB (OR = 0.99, 95% CI = 0.97–1.02).ConclusionsAmong women in Puerto Rico, low GWG was associated with increased odds of PTB. With the exception of obesity, these associations persisted within all strata of pre-pregnancy body mass index, highlighting the importance of maintaining a healthy weight during pregnancy. Future research should examine other factors that may contribute to GWG, such as dietary nutrients, and explore pathways through which GWG may be contributing to PTB.

Driving Factors of Preterm Birth Risk in Adolescents.

Objective We examined rates of spontaneous and indicated preterm births (S-PTB and I-PTB, respectively) and clinical risk factors for PTB in adolescents. Study Design This is a population-based, retrospective cohort using 2012 U.S. natality data of nulliparous women who delivered a nonanomalous singleton birth between 20 and 42 weeks' gestation. Maternal age included <16, 16 to 19.9, and ≥20 years. Rates of total, S-PTB, and I-PTB were compared across age groups. Multinomial logistic regression tested clinical risk factors for S-PTB. Results In 1,342,776 pregnancies, adolescents were at higher risk for PTB than adults. The rate of total PTB was highest in young adolescents at 10.6%, decreased to 8.3% in older adolescents, and 7.8% in adults. The proportion of S-PTB was highest in the youngest adolescents and decreased toward adulthood; the proportion of I-PTB remained stable across age groups. Risk factors for S-PTB in adolescents included Asian race, underweight body mass index (BMI), and poor gestational weight gain (GWG). In all age groups, carrying a male fetus showed a significant increased S-PTB, and Women, Infants, and Children's (WIC) participation was associated with a significantly decreased risk. Conclusion The higher risk for PTB in adolescents is driven by an increased risk for S-PTB. Low BMI and poor GWG may be potentially modifiable risk factors. Condensation Adolescents have a higher risk for spontaneous PTB than adult women, and risk factors for spontaneous PTB may differ in adolescents.

Maternal genitourinary infections and poor nutritional status increase risk of preterm birth in Gasabo District, Rwanda: a prospective, longitudinal, cohort study

BackgroundPreterm birth (PTB) is a leading cause of early childhood mortality and morbidity, including long-term physical and mental impairment. The risk factors for PTB are complex and include maternal nutritional status and infections. This study aimed to identify potentially modifiable risk factors for targeted interventions to reduce the occurrence of PTB in Rwanda.MethodsWe conducted a prospective, longitudinal cohort study of healthy pregnant women aged 18 to 49 years. Women at 9–15 gestational weeks were recruited from 10 health centers in Gasabo District, Kigali Province between September and October 2017. Pregnancy age was estimated using ultrasonography and date of last menstruation. Anthropometric and laboratory measurements were performed using standard procedures for both mothers and newborns. Surveys were administered to assess demographic and health histories. Categorical and continuous variables were depicted as proportions and means, respectively. Variables with p < 0.25 in bivariate analyses were included in multivariable logistic regression models to determine independent predictors of PTB. The results were reported as odds ratios (ORs) and 95% confidence intervals (CI), with statistical significance set at p < 0.05.ResultsAmong 367 participants who delivered at a mean of 38.0 ± 2.2 gestational weeks, the overall PTB rate was 10.1%. After adjusting for potential confounders, we identified the following independent risk factors for PTB: anemia (hemoglobin < 11 g/dl) (OR: 4.27; 95%CI: 1.85–9.85), urinary tract infection (UTI) (OR:9.82; 95%CI: 3.88–24.83), chlamydia infection (OR: 2.79; 95%CI: 1.17–6.63), inadequate minimum dietary diversity for women (MDD-W) score (OR:3.94; CI: 1.57–9.91) and low mid-upper arm circumference (MUAC) < 23 cm (OR: 3.12, 95%CI; 1.31–7.43). indicators of nutritional inadequacy (low MDD-W and MUAC) predicted risk for low birth weight (LBW) but only UTI was associated with LBW in contrast with PTB.ConclusionTargeted interventions are needed to improve the nutritional status of pregnant women, such as maternal education on dietary diversity and prevention of anemia pre-pregnancy. Additionally, prevention and treatment of maternal infections, especially sexually transmitted infections and UTIs should be reinforced during standard antenatal care screening which currently only includes HIV and syphilis testing.

Outcomes of ultrasound and physical-exam based cerclage: assessment of risk factors and the role of adjunctive progesterone in preventing preterm birth-a retrospective cohort study.

To assess outcomes of ultrasound and physical examination-based cerclage performed at mid to late second trimester and to assess the potential added value of progesterone treatment combined with cerclage for preventing preterm birth. A retrospective cohort study of women who underwent cerclage in a university-affiliated tertiary medical center (2012-2018). Inclusion criteria included only ultrasound-based cerclage and physical examination-based cerclage. Women who underwent history-based cerclage or multiple gestations were excluded. Study groups were stratified by previous PTB < 37weeks and other risk factors for PTB. Primary outcome was the incidence of preterm birth < 35weeks of gestation. Secondary outcomes included the potential added value of progesterone treatment and neonatal outcome. Sixty-nine women underwent cervical cerclage placement between 16-23weeks of gestation. All women had short cervix (cervical length of < 25mm) at presentation. Indications for cerclage placement included: 29% previous PTB, 32% prior cervical interventions (history of at least one D&C, hysteroscopy or cold-knife conization in the past), 22% had cervical dilatation > 1cm at presentation, 12% due to failure of progesterone treatment defined as continued cervical shortening after 14days of progesterone treatment, and 5% had other indications. Overall, 42 women (61%) gave birth at term. 27 women (39%) delivered prior to 37weeks of gestation, of them, 20 women (29%) gave birth prior to 35weeks. Overall median gestational age at delivery was 35 + 5 ± 4.7weeks. Cervical dilatation at presentation of > 1cm was associated with an increased risk for PTB < 35weeks (OR 3.57, CI 1.43-30.81, p = 0.036). Previous PTB, prior cervical interventions and extent of cervical shortening at presentation did not increase the risk of PTB. Progesterone treatment in addition to cerclage did not result in a decreased risk for PTB < 35weeks of gestation (OR 2.83, CI 0.58-13.89, p = 0.199). Late second trimester cerclage is a practical measure for preventing PTB in cases of asymptomatic cervical shortening. Our study did not find adjunctive benefit for progesterone treatment with physical or ultrasound-based cerclage in reducing the rate PTB.

Risk factors for spontaneous miscarriage above 12\u2009weeks or premature delivery in patients undergoing cervical polypectomy during pregnancy

BackgroundIt currently remains unknown whether the resection of cervical polyps during pregnancy leads to miscarriage and/or preterm birth. This study evaluated the risk of spontaneous PTB below 34 or 37 weeks and miscarriage above 12 weeks in patients undergoing cervical polypectomy during pregnancy.MethodsThis was a retrospective monocentric cohort study of patients undergoing cervical polypectomy for clinical indication. Seventy-three pregnant women who underwent polypectomy were selected, and risk factors associated with miscarriage above 12 weeks or premature delivery below 34 or 37 weeks were investigated. A multivariable regression looking for predictors of spontaneous miscarriage > 12 weeks and PTB < 34 or 37 weeks were performed.ResultsSixteen patients (21.9%, 16/73) had spontaneous delivery at < 34 weeks or miscarriage above 12 weeks. A univariate analysis showed that bleeding before polypectomy [odds ratio (OR) 7.7, 95% confidence interval (CI) 1.6–37.3, p = 0.004], polyp width ≥ 12 mm (OR 4.0, 95% CI 1.2–13.1, p = 0.005), the proportion of decidual polyps (OR 8.1, 95% CI 1.00–65.9, p = 0.024), and polypectomy at ≤10 weeks (OR 5.2, 95% CI 1.3–20.3, p = 0.01) were significantly higher in delivery at < 34 weeks than at ≥34 weeks. A logistic regression analysis identified polyp width ≥ 12 mm (OR 11.8, 95% CI 2.8–77.5, p = 0.001), genital bleeding before polypectomy (OR 6.5, 95% CI 1.2–55.7, p = 0.025), and polypectomy at ≤10 weeks (OR 5.9, 95% CI 1.2–45.0, p = 0.028) as independent risk factors for predicting delivery at < 34 weeks. Polyp width ≥ 12 mm and bleeding before polypectomy are risk factors for PTB < 37 wks.ConclusionsOur cohort of patients undergoing polypectomy in pregnancy have high risks of miscarriage or spontaneous premature delivery. It is unclear whether these risks are given by the underlying disease, by surgical treatment or both. This study establishes clinically relevant predictors of PTB are polyp size> 12 mm, bleeding and first trimester polypectomy. PTB risks should be exposed to patients and extensively discussed with balancing against the benefits of intervention in pregnancy.

Bacteriologically-confirmed pulmonary tuberculosis in an Ethiopian prison: Prevalence from screening of entrant and resident prisoners.

BackgroundPulmonary Tuberculosis (PTB) is a major health problem in prisons. Multiple studies of TB in regional Ethiopian prisons have assessed prevalence and risk factors but have not examined recently implemented screening programs for TB in prisons. This study compares bacteriologically-confirmed PTB (BC-PTB) prevalence in prison entrants versus residents and identifies risk factors for PTB in Kality prison, a large federal Ethiopian prison located in Addis Ababa, through a study of an enhanced TB screening program.MethodsParticipating prisoners (n = 13,803) consisted of 8,228 entrants screened continuously and 5,575 residents screened in two cross-sectional waves for PTB symptoms, demographics, TB risk factors, and medical history. Participants reporting at least one symptom of PTB were asked to produce sputum which was examined by microscopy for acid-fast bacilli, Xpert MTB/RIF assay and MGIT liquid culture. Prevalence of BC-PTB, defined as evidence of Mycobacterium tuberculosis (MTB) in sputum by the above methods, was compared in entrants and residents for the study. Descriptive analysis of prevalence was followed by bivariate and multivariate analyses of risk factors.ResultsPrisoners were mainly male (86%), young (median age 26 years) and literate (89%). Prevalence of TB symptoms by screening was 17% (2,334/13,803) with rates in residents >5-fold higher than entrants. Prevalence of BC-PTB detected by screening in participating prisoners was 0.16% (22/13,803). Prevalence in residents increased in the second resident screening compared to the first (R1 = 0.10% and R2 = 0.39%, p = 0.027), but remained higher than in entrants (4.3-fold higher during R1 and 3.1-fold higher during R2). Drug resistance (DR) was found in 38% (5/13) of culture-isolated MTB. Risk factors including being ever diagnosed with TB, history of TB contact and low Body Mass Index (BMI) (<18.5) were significantly associated with BC-PTB (p<0.05).ConclusionsBC-PTB prevalence was strikingly lower than previously reported from other Ethiopian prisons. PTB appears to be transmitted within this prison based on its higher prevalence in residents than in entrants. Whether a sustained program of PTB screening of entrants and/or residents reduces prevalence of PTB in prisons is not clear from this study, but our findings suggest that resources should be prioritized to resident, rather than entrant, screening due to higher BC-PTB prevalence. Detection of multi- and mono-DR TB in both entrant and resident prisoners warrants regular screening for active TB and adoption of methods to detect drug resistance.

Prevention of Preterm Birth

Summary Preterm birth (PTB) is a worldwide problem with great social significance because it is a leading cause of perinatal complications and perinatal mortality. PTB is responsible for more than a half of neonatal deaths. The rate of preterm delivery varies between 5-18% worldwide and has not decreased in recent years, regardless of the development of medical science. One of the leading causes for that is the failure to identify the high-risk group in prenatal care. PTB is a heterogeneous syndrome in which many different factors interfere at different levels of the pathogenesis of the initiation of delivery, finally resulting in delivery before 37 weeks of gestation (wg). The various specificities of risk factors and the unclear mechanism of initiation of labour make it difficult to elaborate standard, unified and effective screening to diagnose pregnant women at high-risk for PTB correctly. Furthermore, they make primary and secondary prophylaxis less effective and render diagnostic and therapeutic measures ineffective and inappropriate. Reliable and accessible screening methods are necessary for antenatal care, and risk factors for PTB should be studied and clarified in search of useful tools to solve issues of risk pregnancies to decrease PTB rates and associated complications.

Comparison of risk and protective factors for preterm birth in rural, suburban, and urban Fresno County, California

Preterm birth (PTB, &lt; 37 weeks’ gestation) may impose lifelong sequelae or death. Fresno County reports the highest rate of PTB in California. A place-based approach investigating local risk factors for PTB may provide important opportunities for intervention and prevention. In this study, we examine risk and protective factors for PTB in rural, suburban, and urban Fresno County, California. The sample was drawn from Fresno County, California singleton births 2007-2012 (n = 81,021). Multivariate models of maternal risk and protective factors for PTB were stratified by rural, suburban, and urban residence. Women with diabetes, hypertension, infection, fewer than three prenatal care visits, previous PTB, interpregnancy interval less than six months, or were of Black race/ethnicity were at increased risk of PTB. The risk of PTB was highest for women residing in rural locations with preeclampsia superimposed on preexisting hypertension (adjusted relative risk (aRR) 5.7, 95% confidence interval (CI) 4.4-7.4). For women living in urban residences, maternal birth in Mexico and overweight body mass index (BMI) offered protection from PTB (aRRs 0.9), whereas participation in the Women, Infants and Children program was protective for women in either urban or rural residences (aRRs 0.8). Public insurance, &lt;12 year of education, underweight BMI, and interpregnancy interval of five years or more were risk factors only for women in urban residences. These findings may provide important opportunities for local intervention.

Different Risk Factors for Very Low Birth Weight, Term-Small-for-Gestational-Age, or Preterm Birth in Japan.

From 1985 to 2013, the mean birth weight of infants in Japan decreased from 3120 g to 3000 g, and the low-birth-weight rate among live births increased from 6.3% to 9.6%. No prospective study has elucidated the risk factors for poor fetal growth and preterm birth in recent Japanese parents, such as increased parental age, maternal body figure, assisted reproductive technology (ART), and socioeconomic status. Participants were mother–infant pairs (n = 18,059) enrolled in a prospective birth cohort in Hokkaido, Japan from 2002 to 2013. Parental characteristics were obtained via self-reported questionnaires during pregnancy. Medical records helped identify very-low-birth-weight (VLBW; <1500 g), term-small-for-gestational-age (term-SGA), and preterm-birth (PTB; <37 weeks) infants. We calculated relative risks (RRs) for PTB, VLBW, and term-SGA birth based on parental characteristics. The prevalence of PTB, VLBW, and term-SGA was 4.5%, 0.4%, and 6.5%, respectively. Aged parents and ART were risk factors for PTB and VLBW. Maternal alcohol drinking during pregnancy increased the risk; a parental educational level of ≥16 years reduced risk of term-SGA. Maternal pre-pregnancy BMI of <18.5 kg/m2 increased the risk of PTB and term-SGA. The RR for low BMI was highest among mothers who have low educational level. Among various factors, appropriate nutritional education to maintain normal BMI is important to prevent PTB and term-SGA in Japan.

Correlates and outcomes of preterm birth, low birth weight, and small for gestational age in HIV-exposed uninfected infants.

BackgroundPreterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) contribute to neonatal mortality. Maternal HIV-1 infection has been associated with an increased risk of PTB, but mechanisms underlying this association are undefined. We describe correlates and outcomes of PTB, LBW, and SGA in HIV-exposed uninfected infants.MethodsThis was a retrospective analysis of cohort study. Between 1999–2002, pregnant, HIV-infected women were enrolled into an HIV-1 transmission study. Logistic regression was used to identify correlates of PTB, LBW and SGA in HIV-negative, spontaneous singleton deliveries. Associations between birth outcomes and mortality were measured using survival analyses.ResultsIn multivariable models, maternal plasma (OR = 2.1, 95% CI = 1.1-3.8) and cervical HIV-1 RNA levels (OR = 1.6, 95% CI = 1.1-2.4), and CD4 < 15% (OR = 2.4, 95% CI = 1.0-5.6) were associated with increased odds of PTB. Abnormal vaginal discharge and cervical polymorphonuclear leukocytes were also associated with PTB. Cervical HIV-1 RNA level (OR = 2.4, 95% CI = 1.5-6.7) was associated with an increased odds of LBW, while increasing parity (OR = 0.46, 95% CI = 0.24-0.88) was associated with reduced odds. Higher maternal body mass index (OR = 0.75, 95% CI = 0.61-0.92) was associated with a reduced odds of SGA, while bacterial vaginosis was associated with >3-fold increased odds (OR = 3.2, 95% CI = 1.4-7.4). PTB, LBW, and SGA were each associated with a >6-fold increased risk of neonatal death, and a >2-fold increased rate of infant mortality within the first year.ConclusionsMaternal plasma and cervical HIV-1 RNA load, and genital infections may be important risk factors for PTB in HIV-exposed uninfected infants. PTB, LBW, and SGA are associated with increased neonatal and infant mortality in HIV-exposed uninfected infants.

P32.09: Sonography cervical surveillance with ultrasound‐indicated cervical cerclage as compared to prophylatic cerclage in pregnants with clinical risk factors for preterm birth

Objectives: To evaluate comparatively two management modalities in women with singleton pregnancies and with clinical risk factors for PTB (based on obstetric and gynecologic history): transvaginal ultrasound (TVU) surveillance of the cervical length and placement of CC indicated by cervical shortening (therapeutic cerclage, TC) versus prophylactic (elective) cerclage (PC). Methods: Data Sources and Study Selection: A search of entries in electronic databases (MEDLINE, EMBASE) was supplemented with references cited in original articles to identify randomized trials and case-control studies comparing pregnancy outcomes after cervical surveillance and TC versus PC in a high-risk population of pregnant women with singleton pregnancies. Case and control groups consisted of women with singleton pregnancies matched for obstetrical and gynecological risk factors for preterm birth. The outcomes assessed were preterm delivery before 35 weeks or prior to 24 weeks of gestation. Studies were excluded if there was no matched control group or if only the abstract was available. Results: Of 5 studies identified, 3 met the inclusion criteria. A total of 367 patients were evaluated, 215 in the cervical surveillance arm and 152 with PC. Compared to women with PC, those who were followed by cervical surveillance, had no increased risk of preterm delivery before 24 or 35 weeks, respectively (RR 1.41; 95%CI 0.58–3.41; RR 1.24; 95%CI 0.75–2.04, respectively). The conservative approach achieved a 62% reduction in the number of patients undergoing CC placement. Conclusions: Serial TVU of the cervix with ultrasound-indicated TC appears a safe alternative to traditional PC and it spares a significant number of pregnant women an intervention with potential inherent complications.

An exploratory study of the variables impacting preterm birth rates in New Mexico

BackgroundPreterm birth (PTB) is a substantial health problem that accounts for significant infant morbidity and mortality and poses an economic burden to both individuals and the state of residence. The goal of this study was to identify maternal risk factors for PTB in New Mexico, a poor state with a unique ethnic background, in order to identify populations at increased risk that would benefit from intervention.MethodsThis was a cross-sectional retrospective exploratory analysis of 377,770 singleton live births in the state of New Mexico from 1991-2005. Gestational age of less than 37 weeks was defined as PTB. The Kotelchuck Index was used as a measure for level of prenatal care described as inadequate, intermediate, adequate, and intensive.ResultsOf the live births analyzed, 28,036 of these were preterm (7.4%). Overall the PTB rate rose at a rate of 0.18% per year from 1991-2005. Among patients with medical risk factors, the absence of prenatal care was associated with higher odds for PTB as compared to adequate prenatal care. Other risk factors were unmarried status, education less than high school, tobacco/alcohol use, black, Asian, and white Hispanic ethnicity, and the presence of one or more medical risk factors. Statistically significant protective factors for PTB were age 25-29, education surpassing high school, and Native American race.ConclusionsThis study identified several factors that correlate with increased PTB in New Mexico, in particular ethnicity and level of prenatal care. The finding that Native American patients have a lower PTB rate compared to other groups, even though this group is traditionally one of low socioeconomic status in New Mexico, signifies that other factors yet to be identified affect PTB.

Cervical length mid trimester in low risk women fails to predict the majority of pre term births

IntroductionPre term birth (PTB) is a leading course of morbidity and mortality. Prediction is possible but lacks sensitivity. Mid trimester ultrasound of cervical length (MCL) can identify women at high...