Racial disparities in recurrent preterm delivery risk: mediation analysis of prenatal care timing.

OBJECTIVES: We estimated the degree to which the association between race and spontaneous recurrent preterm delivery is mediated by the timing of the first prenatal care visit. METHODS: A retrospective population-based cohort study was conducted using the U.S. National Center for Health Statistics Natality Files. We identified 644,576 women with a prior PTB who delivered singleton live neonates between 2011 and 2017. A mediation analysis was conducted using log-binomial regression to evaluate the mediating effect of timing of first prenatal care visit. RESULTS: During the seven-year period, 349,293 (54.2%) White non-Hispanic women, 131,296 (20.4%) Black non-Hispanic women, 132,367 (20.5%) Hispanic women, and 31,620 (4.9%) Other women had a prior preterm delivery. The risk of late prenatal care initiation was higher in Black non-Hispanic women, Hispanic women, and Other women (women of other racial/ethnic backgrounds) compared to White non-Hispanic women, and the risk of preterm delivery was higher in women with late prenatal care initiation. Between 8 and 15% of the association between race and spontaneous recurrent preterm delivery acted through the delayed timing of the first prenatal care visit. CONCLUSIONS: Racial disparities in spontaneous recurrent preterm delivery rates can be partly, but not primarily, attributed to timing of first prenatal care visit.

Direct and Vicarious Racial Discrimination at Three Life Stages and Preterm Labor: Results from the African American Women's Heart & Health Study.

INTRODUCTION: Health disparities research has demonstrated a negative relationship between racial discrimination and African American women's maternal health outcomes. Yet, the relationship between racial discrimination and preterm labor, a key measure of maternal health, remains understudied. This study sought to examine the associations between preterm labor and direct and vicarious racial discrimination among African American women at three life stages: childhood, adolescence, and adulthood. METHODS: Logistic regression methods were used to analyze cross-sectional data from the African American Women's Heart & Health Study (AAWHHS; N = 173). The AAWHHS includes detailed maternal health information on a community sample of African American women residing in the San Francisco Bay Area. RESULTS: Findings indicated each unit increase in adolescent direct racial discrimination was associated with a 48% increase in the odds of preterm labor (OR: 1.480, 95% CI 1.002-2.187, p < 0.05) and each unit increase in childhood vicarious racial discrimination was associated with a 45% increase in the odds of preterm labor (OR: 1.453, 95% CI 1.010-2.092, p < 0.05) after adjusting for number of pregnancies and socioeconomic variables. DISCUSSION: This study provides evidence of an association between life-stage racial discrimination and preterm labor risk among African American women, underscoring a need to consider how both directly and vicariously experienced racial discrimination at different developmental periods impact racial disparities in birth outcomes.

The Association Between Socio-demographic Factors, Dental Problems, and Preterm Labor for Pregnant Women Residing in Hawai'i.

Periodontal disease during pregnancy has the potential to increase the risk of adverse perinatal outcomes including preterm labor (PTL), prematurity, and low birth weight (LBW). Despite professional recommendations on the importance and safety of dental assessments and treatments, the rate of dental care utilization during pregnancy remains low. The purpose of this study was to document the utilization of dental services and explore the relationships among socio-demographic factors, dental problems, and PTL in pregnant women residing in Hawai'i. Hawai'i Pregnancy Risk Assessment Monitoring System (PRAMS) survey results were analyzed from 4,309 women who experienced live births between the years 2009-2011. Results revealed that 2 in 5 women in Hawai'i had their teeth cleaned during pregnancy, while 1 in 5 reported seeing a dentist for a dental problem. Women who reported having a dental problem during pregnancy were more likely to experience PTL (OR=1.46, 95% CI=1.10-1.94, P=.008) compared to women without a dental problem. In addition, Native Hawaiian and Part-Hawaiian women were more likely to experience PTL (OR=1.73, 95% CI=1.22-2.46, P=.002) compared to Caucasian women. These findings document the underutilization of dental services in pregnant women in Hawai'i and reveal an association between poor dental care and PTL. Identification of groups at risk for maternal complications may assist in the development of programs that are sensitive to the diverse cultures and variability of community resources that exist throughout Hawai'i.

The impact of fetal gender and ethnicity on the risk of spontaneous preterm delivery in women with symptoms of preterm labor.

OBJECTIVE: The objective of this study is to evaluate the relation among fetal gender, ethnicity, and preterm labor (PTL) and preterm delivery (PTD). METHODS: A secondary analysis was performed of a prospective cohort study including women with symptoms of PTL between 24 and 34 weeks. The proportion of women carrying a male or female fetus at the onset of PTL was calculated. Gestational age at delivery and risk of PTD of both fetal genders was compared and interaction of fetal gender and maternal ethnicity on the risk of PTD was evaluated. RESULTS: Of the 594 included women, 327 (55%) carried a male fetus. Median gestational age at delivery in women pregnant with a male fetus was 37 5/7 (IQR 34 4/7-39 1/7) weeks compared with 38 1/7 (IQR 36 0/7-39 5/7) weeks in women pregnant with a female fetus (p = 0.032). The risk of PTD did not differ significantly. In Caucasians, we did find an increased risk of PTD before 37 weeks in women pregnant with a male fetus (OR 1.9 (95% CI 1.2-3.0)). CONCLUSIONS: The majority of women with PTL are pregnant with a male fetus and these women deliver slightly earlier. Race seems to affect this disparity.

Post-hoc analysis of vitamin D status and reduced risk of preterm birth in two vitamin D pregnancy cohorts compared with South Carolina March of Dimes 2009-2011 rates.

BACKGROUND: Two vitamin D pregnancy supplementation trials were recently undertaken in South Carolina: The NICHD (n=346) and Thrasher Research Fund (TRF, n=163) studies. The findings suggest increased dosages of supplemental vitamin D were associated with improved health outcomes of both mother and newborn, including risk of preterm birth (<37 weeks gestation). How that risk was associated with 25(OH)D serum concentration, a better indicator of vitamin D status than dosage, by race/ethnic group and the potential impact in the community was not previously explored. While a recent IOM report suggested a concentration of 20 ng/mL should be targeted, more recent work suggests optimal conversion of 25(OH)D-1,25(OH)2D takes place at 40 ng/mL in pregnant women. OBJECTIVE: Post-hoc analysis of the relationship between 25(OH)D concentration and preterm birth rates in the NICHD and TRF studies with comparison to Charleston County, South Carolina March of Dimes (CC-MOD) published rates of preterm birth to assess potential risk reduction in the community. METHODS: Using the combined cohort datasets (n=509), preterm birth rates both for the overall population and for the subpopulations achieving 25(OH)D concentrations of ≤20 ng/mL, >20 to <40 ng/mL, and ≥40 ng/mL were calculated; subpopulations broken down by race/ethnicity were also examined. Log-binomial regression was used to test if an association between 25(OH)D serum concentration and preterm birth was present when adjusted for covariates; locally weighted regression (LOESS) was used to explore the relationship between 25(OH)D concentration and gestational age (weeks) at delivery in more detail. These rates were compared with 2009-2011 CC-MOD data to assess potential risk reductions in preterm birth. RESULTS: Women with serum 25(OH)D concentrations ≥40 ng/mL (n=233) had a 57% lower risk of preterm birth compared to those with concentrations ≤20 ng/mL [n=82; RR=0.43, 95% confidence interval (CI)=0.22,0.83]; this lower risk was essentially unchanged after adjusting for covariates (RR=0.41, 95% CI=0.20,0.86). The fitted LOESS curve shows gestation week at birth initially rising steadily with increasing 25(OH)D and then plateauing at ∼40 ng/mL. Broken down by race/ethnicity, there was a 79% lower risk of preterm birth among Hispanic women with 25(OH)D concentrations ≥40 ng/mL (n=92) compared to those with 25(OH)D concentrations ≤20 ng/mL (n=29; RR=0.21, 95% CI=0.06,0.69) and a 45% lower risk among Black women (n=52 and n=50; RR=0.55, 95% CI=0.17,1.76). There were too few white women with low 25(OH)D concentrations for assessment (n=3). Differences by race/ethnicity were not statistically significant with 25(OH)D included as a covariate. Compared to the CC-MOD reference group, women with serum concentrations ≥40 ng/mL in the combined cohort had a 46% lower rate of preterm birth overall (n=233, p=0.004) with a 66% lower rate among Hispanic women (n=92, p=0.01) and a 58% lower rate among black women (n=52, p=0.04). CONCLUSIONS: In this post-hoc analysis, achieving a 25(OH)D serum concentration ≥40 ng/mL significantly decreased the risk of preterm birth compared to ≤20 ng/mL. These findings suggest the importance of raising 25(OH)D levels substantially above 20 ng/mL; reaching 40 ng/mL during pregnancy would reduce the risk of preterm birth and achieve the maximal production of the active hormone.

Population-level correlates of preterm delivery among black and white women in the U.S.

OBJECTIVE: This study examined the ability of social, demographic, environmental and health-related factors to explain geographic variability in preterm delivery among black and white women in the US and whether these factors explain black-white disparities in preterm delivery. METHODS: We examined county-level prevalence of preterm delivery (20-31 or 32-36 weeks gestation) among singletons born 1998-2002. We conducted multivariable linear regression analysis to estimate the association of selected variables with preterm delivery separately for each preterm/race-ethnicity group. RESULTS: The prevalence of preterm delivery varied two- to three-fold across U.S. counties, and the distributions were strikingly distinct for blacks and whites. Among births to blacks, regression models explained 46% of the variability in county-level risk of delivery at 20-31 weeks and 55% for delivery at 32-36 weeks (based on R-squared values). Respective percentages for whites were 67% and 71%. Models included socio-environmental/demographic and health-related variables and explained similar amounts of variability overall. CONCLUSIONS: Much of the geographic variability in preterm delivery in the US can be explained by socioeconomic, demographic and health-related characteristics of the population, but less so for blacks than whites.

Early gestational weight gains within current recommendations result in increased risk of gestational diabetes mellitus among Korean women.

BACKGROUND: We prospectively assessed whether maternal weight gain at 24-28 weeks of gestation (MWG24) influences the risk of developing gestational complications, such as gestational diabetes mellitus (GDM) and other adverse pregnancy outcomes, in pregnant Korean women. METHODS: Maternal weight gain from self-reported pre-pregnancy weight until 24-28 weeks of gestation was measured in 731 pregnant women, and an expected MWG24 was determined using the Institute of Medicine 2009 guidelines. Glucose tolerance, insulin resistance, insulin secretory capacity, anthropometric measurements, lipid profiles, nutrient intakes and pregnancy outcomes were evaluated at 24-28 weeks of gestation. The adjusted odds ratios (ORs) for GDM, large-for-gestational-age infants, small-for-gestational-age infants and preterm delivery were determined according to maternal weight gain by logistic regression analysis after adjusting for covariates. RESULTS: Compared with a normal MWG24, an inadequate MWG24 reduced the OR (0.565) for GDM, but an excessive MWG24 did not affect the OR (0.854). However, ORs for preterm delivery were significantly higher in both inadequate and excessive MWG24 groups in comparison with the normal MWG24. There were no other adverse pregnancy outcomes due to the inadequate MWG24. MWG24 was not associated with a significant increase in ORs for delivering large-for-gestational-age or small-for-gestational-age infants or delivery by caesarean section. Although energy intake was less than the estimated energy requirement in all groups, MWG24 was linearly associated with energy intake such that energy balance was positive in the excessive MWG24 group. CONCLUSIONS: This study suggests that both target weight gain and energy intake recommendations for early pregnancy may not be optimal for Korean women and that race-specific recommendations are needed to decrease the risk of GDM without increasing adverse pregnancy outcomes.

Psychological birth trauma in adolescents experiencing an early birth.

PURPOSE: To explore and compare associations among demographics, childbirth-related stressors, depressive symptoms, gestational age, and psychological birth trauma (PBT) among adolescents. STUDY DESIGN AND METHODS: : This cross-sectional, descriptive, comparative study compared two groups of adolescents for PBT. From a larger study dataset, we identified all adolescents delivering prior to 38 weeks (n = 30) and randomly selected 30 adolescents delivering between 38 and 42 weeks gestation for comparison. PBT was defined via birth appraisal, assessed by a one-item rating scale, and trauma impact, assessed via the Impact of Event Scale. Surveys, including the Center for Epidemiological Studies-Depression Scale, were completed within 72 hours of birth. We used frequencies and percentages to describe the sample and Chi square, Spearman Rank-Order Correlation, and Pearson's Product Moment Correlation to determine relationships between variables. Chi square and ANOVA statistical tests determined group differences. RESULTS: Adolescents were primarily Latina, single, primigravidas, and over 16 years of age. Adolescents delivering before 38 weeks experiencing cesarean births reported symptoms of depression and were highest risk for PBT. Additionally adolescents delivering before 38 weeks reported lack of pain control and unsupportive caregivers in labor. CLINICAL IMPLICATIONS: Healthcare professionals cognizant of the potential risk factors for PBT can help vulnerable adolescents through caregiver support, adequate pain control in labor, education, and screening and treatment of depressive symptoms. Follow-up postdischarge, especially for high-risk adolescents, should be arranged to monitor for continued, delayed, or remitting symptoms of depression and PBT.

Attitudes of healthcare providers towards non-initiation and withdrawal of neonatal resuscitation for preterm infants in Mongolia.

Antenatal parental counselling by healthcare providers is recommended to inform parents and assist with decision-making before the birth of a child with anticipated poor prognosis. In the setting of a low-income country, like Mongolia, attitudes of healthcare providers towards resuscitation of high-risk newborns are unknown. The purpose of this study was to examine the attitudes of healthcare providers regarding ethical decisions pertaining to non-initiation and withdrawal of neonatal resuscitation in Mongolia. A questionnaire on attitudes towards decision-making for non-initiation and withdrawal of neonatal resuscitation was administered to 113 healthcare providers attending neonatal resuscitation training courses in 2009 in Ulaanbaatar, the capital and the largest city of Mongolia where -40% of deliveries in the country occur. The questionnaire was developed in English and translated into Mongolian and included multiple choices and free-text responses. Participation was voluntary, and anonymity of the participants was strictly maintained. In total, 113 sets of questionnaire were completed by Mongolian healthcare providers, including neonatologists, paediatricians, neonatal and obstetrical nurses, and midwives, with 100% response rate. Ninety-six percent of respondents were women, with 73% of participants from Ulaanbaatar and 27% (all midwives) from the countryside. The majority (96%) of healthcare providers stated they attempt pre-delivery counselling to discuss potential poor outcomes when mothers present with preterm labour. However, most (90%) healthcare providers stated they feel uncomfortable discussing not initiating or withdrawing neonatal resuscitation for a baby born alive with little chance of survival. Religious beliefs and concerns about long-term pain for the baby were the most common reasons for not initiating neonatal resuscitation or withdrawing care for a baby born too premature or with congenital birth-defects. Most Mongolian healthcare providers provide antenatal counselling to parents regarding neonatal resuscitation. Additional research is needed to determine if the above-said difficulty with counselling stems from deficiencies in communication training and whether these same counselling-related issues exist in other countries. Future educational efforts in teaching neonatal resuscitation in Mongolia should incorporate culturally-sensitive training on antenatal counselling.

Innate immune system gene polymorphisms in maternal and child genotype and risk of preterm delivery.

OBJECTIVE: There is little information about the combination of genetic variability in pregnant women and their children in relation to the risk of preterm delivery (PTD). In a sub-cohort of 487 non-Hispanic white and 288 African-American mother/child pairs, the Pregnancy Outcomes and Community Health Study assessed 10 functional polymorphisms in 9 genes involved in innate immune function. METHODS: Race-stratified weighted logistic regression models were used to calculate odds ratios for genotype and PTD/PTD subtypes. Polymorphisms significantly associated with PTD/PTD subtypes were tested for mother/child genotype interactions. RESULTS: Three maternal polymorphisms (IL-1 receptor antagonist intron two repeat (IL-1RN), matrix metalloproteinase- -C1562T, and TNF receptor two M196R (TNFR2)) and three child polymorphisms (IL1-RN, tumor necrosis factor-alpha -G308A, and TNFR2) were associated with PTD, but associations varied by PTD subtype and race. Two interactions were detected for maternal and child genotype. Among non-Hispanic white women, the odds of PTD was higher when both mother and child carried the IL-1RN allele two (additive interaction p < 0.05). Among African-American women, the odds of PTD were higher when both mother and child carried the TNFR2 R allele (multiplicative interaction p < 0.05). CONCLUSION: These results highlight the importance of assessing both maternal and child genotype in relation to PTD risk.

Quantifying risks of preterm birth in the Arkansas Medicaid population, 2001-2005.

OBJECTIVE: The objective of this study was to examine risks of preterm births, quantify the explanatory power achieved by adding medical and obstetric risk factors to the models and to examine temporal changes in preterm birth due to changes in Medicaid eligibility and the establishment of a maternal-fetal medicine referral system. STUDY DESIGN: The study used data from the 2001 to 2005-linked Arkansas (AR) Medicaid claims and birth certificates of preterm and term singleton deliveries (N=89 459). Logistic regression modeled the association among gestational age, demographic characteristics and risk factors, pooled and separately by year. RESULT: Physiological risk factors were additive with demographic factors and explained more of the preterm birth ≤32 weeks than later preterm birth. Changing eligibility requirements for Medicaid recipients and increasing the financial threshold from 133 to 200% of federal poverty level had an impact on temporal changes. The proportion of births ≤32 weeks declined to 33%, from 3.0 to 2.0. However, later preterm births declined and then increased in the last year. CONCLUSION: Physiological conditions are strongly associated with early preterm birth. Maternal behaviors and other stressors are predictive of later preterm birth. Unmeasured effects of poverty continue to have a role in preterm birth. Further examination of the referral system is needed.

National trends and racial differences in late preterm induction.

OBJECTIVE: The objective of the study was to determine the trends and racial differences in late preterm induction (LPI) of labor in the United States. STUDY DESIGN: Data from the National Vital Statistics System were used to identify women eligible for induction between 34 and 42 weeks' gestation from 1991 to 2006. Annual LPI rates were calculated, and maternal race/ethnicity was classified into 4 groups. Changes in the frequency and odds of LPI, stratified by race/ethnicity, were assessed using logistic regression. RESULTS: Among the 42.0 million eligible women, LPI rates increased from 0.46% to 1.37% (P < .01) over 16 years. LPI rates were highest for black women (P < .01) each year, and after adjusting for confounding factors, the odds of LPI were highest (P < .01) and rose most rapidly (P < .01) for black women (non-Hispanic white: odds ratio [OR], 1 [referent]; Hispanic white: OR, 0.76; black: OR, 1.31; other: OR, 0.81; P < .01). CONCLUSION: LPI rates were persistently highest and rose most rapidly for black women.

Optimal gestational age of delivery to decrease neonatal morbidity in preterm pregnancies in Korea.

AIMS: Preterm birth is the most common cause of neonatal morbidity and mortality. Neonatal morbidity and mortality are known to decrease significantly after 34 weeks in preterm births following preterm labor, and after 32 weeks in preterm births following preterm rupture of the membranes. However, these outcomes may not apply to Korean preterm neonates. This study analyzed the morbidity of preterm neonates based on gestational age to determine the optimal gestational age of delivery following preterm labor. MATERIALS AND METHODS: We retrospectively analyzed the medical records of preterm neonates and their mothers who delivered at Seoul St. Mary's Hospital between January 1995 and December 2007. RESULTS: Among 1234 preterm neonates, 1008 were singletons and 226 were multiple births. In both singleton and multifetal pregnancies, the maternal characteristics did not differ based on gestational age. The 1- and 5-min Apgar scores were significantly lower than at 35 weeks in singleton births, and at 33 weeks in multiple births. Major complications, such as intraventricular hemorrhage and the use of a respirator, decreased significantly after 35 weeks in singleton births, and after 33 weeks in multiple births. CONCLUSIONS: The optimal gestational age for decreasing the morbidity of major complications in preterm neonates was 1 week later than the American College of Obstetricians and Gynecologists recommendations. For Korean mothers with preterm labor, delivery needs to be delayed until 35 weeks in singletons, 33 weeks in twins, and 32 weeks in singletons with preterm rupture of the membranes.

Skipping meals and less walking among African Americans diagnosed with preterm labor.

PURPOSE: The aim was to compare meal frequency, macronutrient intake, and physical activity between African Americans with preterm labor and those without preterm labor. DESIGN: A descriptive comparative study was used with 80 pregnant African Americans. METHODS: Three 24-hour diet recalls, the Block 2005 food frequency questionnaire, International Physical Activity Questionnaire, and Perceived Stress Scale were collected at 24 to 34 weeks of gestation. FINDINGS: The odds of skipping meals for women in the preterm labor group was 3.57 times the odds of skipped meals for women in the term labor group (95% confidence interval [CI] 1.28-10.16, p=.006). The association was increased to 6.86 (95% CI 2.13-22.12, p<.001) after adjustment for age, prepregnancy body mass index, education, and income. Walking was significantly less in terms of total amount of walking in the preterm labor group (p=.03). CONCLUSIONS: Results have implications for prenatal counseling regarding the importance of frequent meal and snack consumption throughout the day. Further research is necessary to establish the mechanisms by which energy consumption contributes to risk for preterm labor. CLINICAL RELEVANCE: Pregnancy is a time when health professionals monitor women regularly and presents a unique opportunity for practitioners to communicate the importance of frequent meals and snacks throughout pregnancy, as well as the health benefits of walking as a form of physical activity.

Disparate rates of persistent smoking and drug use during pregnancy of women of Hawaiian ancestry.

BACKGROUND: Significant disparity in smoking rates has been previously reported in pregnant and non-pregnant women of Native Hawaiian ancestry. Disparities in drug use rates have also been reported in non-pregnant women of Native Hawaiian ancestry. OBJECTIVE: We undertook this study to compare rates of smoking and drug use during pregnancy among women in Hawaii to see if these differences are associated with disparities in pregnancy complications among Native Hawaiian women. METHODS: Women were enrolled in the Pacific Research Center on Early Human Development study from July 2007 to January 2008, according to approved protocols. Persistent smoking was defined as self-reported smoking within 1 week of admission for labor. Drug use data was assessed by self-report, or if available, toxicology tests at the time of labor. RESULTS: There were 868 women enrolled in the study during this period. Women of Hawaiian/part-Hawaiian ancestry comprised 22% of the study population. Rates of persistent smoking and drug use among Hawaiian women were significantly higher than the remainder of the study population (21% and 8.3% vs. 7.8% and 2.1%, respectively, P < .001 for both). Methamphetamine use was associated with an almost 5-fold increase in preterm birth and smoking a 3.4% decrease in birth weights. DISCUSSION AND CONCLUSION: Women of Hawaiian ancestry continue to smoke and use illicit drugs during pregnancy at significantly higher rates than women of other ethnic groups in Hawaii. In addition to the immediate effects on pregnancy, long-term adverse outcomes of in utero exposures of the offspring remain an important health disparity.

Maternal height and length of gestation: does this impact on preterm labour in Asian women?

BACKGROUND: Both maternal height and ethnicity may influence the gestation length, but their independent effect is unclear. AIM: This study was performed to examine the relationship between maternal height and gestational length in women with singleton pregnancies in a Chinese and southeast Asian population. METHODS: A retrospective cohort study was performed on women carrying singleton pregnancies with spontaneous labour in a 48-month period managed under our department to determine the relationship between maternal height, expressed in quartiles, with the mean gestational age and incidence of preterm labour. RESULTS: Of the 16 384 women who delivered within this period, the 25th, 50th and 75th percentile values of maternal height were 153 cm, 156 cm and 160 cm respectively. Excluded from analysis were 6597 women because of multifetal pregnancy, teenage pregnancy (maternal age < or = 19 years old), induction of labour or elective caesarean section, or incomplete data due to no antenatal booking in our hospital. Significant differences were found in the maternal weight and body mass index, incidences of multiparity and smokers, gestational age and birthweight among the four quartiles. There was significantly increased incidence of preterm birth between 32 and 37 weeks gestation in women with shorter stature. CONCLUSIONS: In our population, maternal height has an influence on gestational length, and the lower three quartiles was associated with increased odds of labour at > 32 to < 37 weeks. This effect should be taken into consideration in the adoption of international recommendations in obstetric management and intervention.

Prepregnancy depressive mood and preterm birth in black and white women: findings from the CARDIA Study.

OBJECTIVES: We examine associations among race, prepregnancy depressive mood, and preterm birth (<37 weeks gestation) in a cohort study of black and white women. METHODS: We tested for mediation of the association between race and preterm birth by prepregnancy depressive mood among 555 women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. RESULTS: Black women had significantly higher levels of prepregnancy depressive mood (modified CES-D score 13.0 vs. 9.5, t = -4.64, p < 0.001). After adjustment for covariates, black women had 2.70 times the odds of preterm birth as white women (95% confidence interval [CI] 1.41, 5.17). When adding prepregnancy depressive mood to this model, higher depressive mood was associated with greater odds of preterm birth (odds ratio [OR] 1.04; 95% CI 1.01, 1.07), and the effect of black race was attenuated (OR 2.47, 95% CI 1.28, 4.77). CONCLUSIONS: Our data suggest that prepregnancy depressive mood may be a risk factor for preterm birth among black and white women.

Explaining the low risk of preterm birth among arab americans in the United States: an analysis of 617451 births.

OBJECTIVES: Arab Americans have a lower risk for preterm birth than white Americans. We assessed factors that may contribute to the association between ethnicity and preterm birth risk in Michigan, the state with the largest concentration of Arab Americans in the United States. Factors assessed as potential contributors to the ethnicity/preterm birth risk association were maternal age, parity, education, marital status, tobacco use, and maternal birthplace. METHODS: Data were collected about all births in Michigan between 2000 and 2005. Stratified analyses, trivariate analyses, and manual stepwise logistic regression model building were used to assess potential contributors to the ethnicity/preterm birth risk association. RESULTS: Arab ethnicity was associated with lower preterm birth risk compared with non-Arab white subjects in the unadjusted model. Maternal birthplace inside or outside the United States explained 0.17 of the difference in preterm birth risk between Arab ethnicity and non-Arab white mothers; ethnic differences in marital status and tobacco use explained less of the observed ethnic difference in preterm birth risk. In the final model adjusted for all explanatory variables, Arab ethnicity was no longer associated with preterm birth risk. CONCLUSIONS: Maternal birthplace, marital status, and tobacco use may contribute to the preterm birth risk difference between Arab ethnicity and non-Arab white mothers. Additional work is needed to consider the mechanisms relating factors such as maternal birthplace and marital status to ethnic differences in preterm birth risk.

Effect of smoking among Indigenous and non-Indigenous mothers on preterm birth and full-term low birthweight.

OBJECTIVE: To estimate the percentage of preterm (< 37 weeks) and full-term low-birthweight (37-41 weeks, < 2500 g) babies born to mothers who smoke, stratified by Indigenous status and statistically adjusted for the potential confounding effects of social and demographic factors, medical conditions and pregnancy complications. DESIGN, SETTING AND PARTICIPANTS: Population-based study of singleton babies born to mothers resident in Queensland who gave birth in Queensland from 1 July 2005 to 31 December 2006. MAIN OUTCOME MEASURES: Adjusted percentages of preterm birth and full-term low birthweight for babies born to Indigenous and non-Indigenous mothers. RESULTS: Of the 79 803 babies studied, 4228 (5.3%) were born to Indigenous mothers and 16 395 (20.5%) were born to mothers who smoked during pregnancy. The percentage of Indigenous mothers who smoked (54%) was almost triple that for non-Indigenous mothers (risk ratio, 2.90; 95% CI, 2.81-2.99). The adjusted outcomes for babies born to Indigenous non-smokers were similar to those for non-Indigenous non-smokers (preterm, 7.1% v 6.1%; full-term low birthweight, 1.6% v 1.1%). The adjusted percentages for smokers were high regardless of Indigenous status (preterm, Indigenous v non-Indigenous, 8.3% v 7.8%; full-term low birthweight, Indigenous v non-Indigenous, 5.3% v 3.7%). CONCLUSIONS: Antenatal smoking remains an important cause of poor health among both Indigenous and non-Indigenous newborn babies. Most pregnant smokers receive their antenatal care in the public sector. State and federal governments, who directly fund this sector, have a particular responsibility to ensure that interventions are offered to all pregnant smokers to help them quit smoking.

The experience of Thai women facing the onset of preterm labor.

PURPOSE: To gain an understanding of the lived experience of pregnant women in Thailand who have preterm labor. STUDY DESIGN AND METHODS: Phenomenology using purposeful sampling with pregnant Thai women diagnosed with preterm labor and admitted to two government hospitals in Bangkok, Thailand. A semi-structured interview was conducted in the native language of the participants. Transcripts were analyzed for common themes as appropriate for phenomenological inquiry. Words, statements, and paragraphs were extracted to identify the meaning of the onset of preterm labor to these women. RESULTS: These participants shared a change in the pregnancy experience from a joyful life-cycle event to a medical complication that threatened fetal and family well-being. Three themes emerged from the data: knowing something was wrong, concern for fetal well-being, and taking on the sick role. CLINICAL IMPLICATIONS: The findings from this research demonstrate the importance of acknowledging and incorporating a woman's personal knowledge of her body and the associated changes in planning nursing care and patient education guidelines.