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Introduction The Maternal and Child Health (MCH) Pipeline Training Program, promotes development of a diverse health workforce by training undergraduate students from underrepresented minorities. We aimed to evaluate the success of this program based on three domains: (1) demographic characteristics, (2) academic and career development, and (3) attitudes towards the field of MCH and the training programs among graduates. Methods Three domains of success were determined through a collaborative effort between current program directors and the funding agency project officers. The survey with questions related to the three domains was distributed via an online platform to graduates from seven sites (one former site and six current sites). Data were analyzed and presented utilizing descriptive statistics. Results The survey was distributed to 550 graduates, 162 responded (37% response rate). Demographically, 78% were female, 54% were Black/African American, 22% were Latinx and 83% did not report any disability. Eighty percent of respondents applied to graduate/professional schools, 67% received admission. Graduates often continued to work in MCH fields (70%). Majority felt confident and knowledgeable in the field (89%) and agreed the faculty were supportive at their training sites (90%). Conclusion The study highlights successes in recruiting from underrepresented minorities, particularly Black/African Americans and first-time college goers in the family into the MCH Pipeline Training Programs. Programs were successful in furthering academic and career development for most trainees. Attitudes towards MCH and the training programs were overwhelmingly positive. Continued support of these programs is critical in addressing health disparities and achieving health equity.

Purpose Presently, there are six undergraduate HRSA-funded MCH pipeline training programs (MCHPTP) in the nation and they have gained significant momentum since inception by recruiting, training and mentoring undergraduate students in a comprehensive MCH-focused approach. This article describes the outcomes from the 6 training programs; and primarily Baylor College of Medicine–Texas Southern University (BCM–TSU’s) collaborative strategy focusing on the MCH research training and outcomes, which align with HRSA’s MCH bureau’s missions. Description Each MCHPTP offers trainees interdisciplinary MCH research experiences through intra/inter-institutional collaborations and partnerships, but BCM–TSU’s MCHPTP was the only one with the primary focus to be research. As a case study, the BCM–TSU Program developed an innovative research curriculum integrated with MCH Foundations Course that comprised 2 hour weekly meetings. Students were split into collaborative research groups of 4–5 students, with multidisciplinary peer-mentors, clinical fellows and MCH research faculty from institutions at the world—renowned Texas Medical Center. Assessment Since the inception of the MCH mentorship programs, all six MCHPTPs have enrolled up to 1890 trainees and/or interns. BCM–TSU Program trainees are defined as undergraduate students in their 1st or 2nd year of college while research interns are upper classmen in their 3rd or 4th year of college. The case study showed that BCM–TSU Program trainees demonstrated outstanding accomplishments in the area of research through primary and co-authorships of 13 peer-reviewed journal publications by 78 trainees, over a period of 3 years, in addition to dozens of presentations at local, regional and national conferences. Conclusions The research productivity of students in the six MCHPTPs is strongly indicative of the success of integrating MCH research mentoring into MCH didactic training. The development of a diverse and robust MCH mentorship program promotes and strengthens research activities in areas of high priority such as addressing health disparities in MCH morbidity and mortality in the U.S.

Introduction Efforts to recruit and retain diverse Maternal and Child Health (MCH) professionals are of paramount public health significance. Culturally congruent mentorship strategies are key to supporting a successful transition from undergraduate to graduate studies. Methods This mixed-method study evaluated a culturally congruent mentorship training used by one of the MCH Pipeline Training programs and described mentorship practices and lessons learned from the six MCH Pipeline programs. A retrospective pre-test post-test survey assessed mentorship competency skills following a mentoring workshop. All MCH Pipeline program leaders completed a questionnaire to elicit responses about mentoring training practices, mentor evaluation strategies, and lessons learned. Results Maternal and Child Health Pipeline Training Programs supported 1890 undergraduate scholars at universities and institutions nationally. Scholars at six MCH Pipeline Programs participated in MCH education and mentored experiential leadership opportunities in clinical practice, research, and public health education. Qualitative program-level mentor survey themes indicated the importance of creating a reflective space and building mentorship teams. Mean mentor self-assessed improvement in mentor competencies was 14.4 points, 95% CI [10.5, 18.3], p Discussion The Health Resources and Services Administration’s Maternal and Child Health Bureau recognized the need to support the development of the next generation of diverse MCH leaders. Pipeline programs that included mentoring workshops and building culturally congruent mentorship teams are two strategies to increase and retain diverse scholars in graduate school and leaders in the public health workforce.

Lack of paternal involvement has been shown to be associated with adverse pregnancy outcomes, including infant morbidity and mortality, but the impact on health care costs is unknown. Various methodological approaches have been used in cost minimization and cost effectiveness analyses and it remains unclear how cost estimates vary according to the analytic strategy adopted. We illustrate a methodological comparison of decision analysis modeling and generalized linear modeling (GLM) techniques using a case study that assesses the cost-effectiveness of potential father involvement interventions. We conducted a 12-year retrospective cohort study using a statewide enhanced maternal-infant database that contains both clinical and nonclinical information. A missing name for the father on the infant’s birth certificate was used as a proxy for lack of paternal involvement, the main exposure of this study. Using decision analysis modeling and GLM, we compared all infant inpatient hospitalization costs over the first year of life. Costs were calculated from hospital charges using department-level cost-to-charge ratios and were adjusted for inflation. In our cohort of 2,243,891 infants, 9.2 % had a father uninvolved during pregnancy. Lack of paternal involvement was associated with higher rates of preterm birth, small-for-gestational age, and infant morbidity and mortality. Both analytic approaches estimate significantly higher per-infant costs for father uninvolved pregnancies (decision analysis model: $1,827, GLM: $1,139). This paper provides sufficient evidence that healthcare costs could be significantly reduced through enhanced father involvement during pregnancy, and buttresses the call for a national program to involve fathers in antenatal care.

Objective To evaluate the role DNA methylation may play in genes associated with preterm birth for higher rates of preterm births in African-American women. Methods Fetal cord blood samples from births collected at delivery and maternal demographic and medical information were used in a cross-sectional study to examine fetal DNA methylation of genes implicated in preterm birth among black and non-black infants. Allele-specific DNA methylation analysis was performed using a methylation bead array. Targeted maximum likelihood estimation was applied to examine the relationship between race and fetal DNA methylation of candidate preterm birth genes. Receiver-operating characteristic analyses were then conducted to validate the CpG site methylation marker within the two racial groups. Bootstrapping, a method of validation and replication, was employed. Results 42 CpG sites were screened within 20 candidate gene variants reported consistently in the literature as being associated with preterm birth. Of these, three CpG sites on TNFAIP8 and PON1 genes (corresponding to: cg23917399; cg07086380; and cg07404485, respectively) were significantly differentially methylated between black and non-black individuals. The three CpG sites showed lower methylation status among infants of black women. Bootstrapping validated and replicated results. Conclusion for Practice Our study identified significant differences in levels of methylation on specific genes between black and non-black individuals. Understanding the genetic/epigenetic mechanisms that lead to preterm birth may lead to enhanced prevention strategies to reduce morbidity and mortality by eventually providing a means to identify individuals with a genetic predisposition to preterm labor.

This paper discusses an important element that is missing from the existing algorithm of preconception care, namely, comparative effectiveness research (CER). To our knowledge, there has been limited assessment of the comparative effectiveness of diverse interventions that promote preconception health, conditions under which these are most effective, for which particular populations, and their comparative costs. CER can improve the decision making process for the funding, development, implementation, and evaluation of comprehensive preconception care programs, specifically by identifying the most effective interventions with acceptable costs to society. This paper will examine the framework behind preconception care and how the inclusion of comparative effectiveness research and evaluation into the existing algorithm of preconception care could foster improvement in maternal and child health. We discuss challenges and opportunities regarding the utilization of CER in the decision making process in preconception health, and finally, we provide recommendations for future directions.

We sought to assess the association between air particulate pollutants and feto-infant morbidity outcomes across racial/ethnic subgroups. This is a retrospective cohort study from 2000 through 2007 based on three linked databases: (1) The Florida Hospital Discharge database; (2) The vital statistics records of singleton live births in Florida; (3) Air pollution and meteorological data from the Environmental Protection Agency. Using computerized mathematical modeling, we assigned exposure values of the air pollutants of interest (PM(2.5), PM(10) and the PM coarse fraction [PM(10) - PM(2.5)]) to mothers over the period of pregnancy based on Euclidean minimum distance from the air pollution monitoring sites. The primary outcomes of interest were: low birth weight, very low birth weight, preterm birth, very preterm birth, and small for gestational age (SGA). We used adjusted odds ratios to approximate relative risks. We observed increased risk for overall feto-infant morbidity outcome in women exposed to any of the three particulate pollutants (values above the median). Exposed women had increased odds for low birth weight, very low birth weight and preterm birth with the greatest risk being that for very low birth weight (AOR = 1.27, 95% CI = 1.08-1.49). Black women exposed to any particulate pollutant had the greatest odds for all the morbidity outcomes, most pronounced for very low birth weight (AOR = 3.32, 95% CI = 2.56-4.30). Environmental particulate pollutants are associated with adverse feto-infant outcomes among exposed women, especially blacks. Black-white disparity in adverse fetal outcomes is widened in the presence of these pollutants, which provide a target for intervention.

Few studies have examined paternal involvement in relation to feto-infant health; therefore we aim to assess the impact of absence of the father on birth outcomes among racial-ethnic subgroups. Florida vital statistics records for singleton births occurring between 1998 and 2005 were used for this study. Births to women less than 20 years of age and births outside the gestational age range of 20-44 weeks were excluded. Adjusted and unadjusted odds ratios and 95% confidence intervals were generated to examine the impact of paternal involvement, as defined by presence of paternal information on the birth certificate, on feto-infant morbidity across racial-ethnic sub-populations. There were higher rates of low birth weight, very low birth weight, preterm birth, very preterm birth, and small for gestational age (SGA) among father-absent births. Within each racial-ethnic subgroup, women with absent fathers had higher risks of poor birth outcomes than their counterparts with involved fathers. Black women with absent fathers had the highest risk of low birth weight, very low birth weight, preterm birth, very preterm birth, and SGA. Promoting paternal involvement during the perinatal period may provide a means to decrease the proportion of infants born of very low birth weight or very preterm, thus potentially reducing the black-white disparity in infant mortality.

Objectives: The objectives of the study were: 1) To determine the risk of infant mortality associated with prenatal cigarette smoking; 2) To assess whether the relationship, if existent, was dose-dependent; 3) To explore the morbidity pathway that explains the effect of tobacco smoke on infant mortality, and 4) to compute excess infant deaths attributable to maternal smoking in the United States. Methods: Retrospective cohort study on 3,004,616 singleton live births that occurred in 1997 in the United States using the US national linked birth/infant death data. Excess infant deaths due to maternal smoking were computed using the population-attributable risk (PAR). Results: Overall, 13.2% of pregnant women who delivered live births in 1997 smoked during pregnancy. The rate of infant mortality was 40% higher in this group as compared to nonsmoking gravidas (P < 0.0001). This risk increased with the amount of cigarettes consumed prenatally in a dose-dependent fashion (p for trend

Based on their higher risk of type 2 diabetes, non-Hispanic blacks (NHBs) would be expected to have higher gestational diabetes mellitus (GDM) risk compared to non-Hispanic whites (NHWs). However, previous studies have reported lower GDM risk in NHBs versus NHWs. We examined whether GDM risk was lower in NHBs and NHWs, and whether this disparity differed by age group. The cohort consisted of 462,296 live singleton births linked by birth certificate and hospital discharge data from 2004 to 2007 in Florida. Using multivariable regression models, we examined GDM risk stratified by age and adjusted for body mass index (BMI) and other covariates. Overall, NHBs had a lower prevalence of GDM (2.5 vs. 3.1 %, p < 0.01) and a higher proportion of preconception DM births (0.5 vs. 0.3 %, p ≤ 0.01) than NHWs. Among women in their teens (risk ratio 0.56, p < 0.01) and 20–29 years of age (risk ratio 0.85, p < 0.01), GDM risk was lower in NHBs than NHWs. These patterns did not change with adjustment for BMI and other covariates. Among women 30–39 years (risk ratio 1.18, p < 0.01) and ≥40 years (risk ratio 1.22, p < 0.01), GDM risk was higher in NHBs than NHWs, but risk was higher in NHWs after adjustment for BMI. Associations between BMI and GDM risk did not vary by race/ethnicity or age group. NHBs have lower risk of GDM than NHWs at younger ages, regardless of BMI. NHBs had higher risk than NHWs at older ages, largely due to racial/ethnic disparities in overweight/obesity at older ages.

(1) Assess the accuracy of public health data sources used to investigate primary late preterm cesarean delivery (PLPCD) and (2) compare differences in data accuracy by hospital PLPCD rate classification. This analysis uses data from the Florida Investigation of Late Preterm and Cesarean Delivery (FILPCD), an investigation of singleton, PLPCD's that occurred from 2006 to 2007 in hospitals classified with either a low or high PLPCD rate (high rate 39.4-58.3 %, low rate 11.9-25.1 %). Three data sources were validated with maternal medical records: birth certificates, hospital discharge data, and combined birth certificate and hospital discharge data. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa values were calculated. A summary measure of kappa values was compared by hospital PLPCD rate classification using the paired sample Wilcoxon signed rank test. Large variations in accuracy of data elements were found by hospital PLPCD rate classification, with low PLPCD rate hospitals demonstrating higher overall data accuracy. The summary measure of agreement was significantly higher for low PLPCD rate hospitals compared to high PLPCD rate hospitals (0.60 vs. 0.50, p < 0.01). Accurate estimates of CD and late preterm birth are vital for public health practitioners and policy makers who seek to address the growing concern over recent increases in CD and late preterm birth. Understanding the potential for systematic differences in reporting accuracy by hospital PLPCD rate is important to data quality improvement efforts.

We sought to assess (1) the relationship between air particulate pollutants and feto-infant morbidity outcomes and (2) the impact of a Federal Healthy Start program on this relationship. This is a retrospective cohort study using de-identified hospital discharge information linked to vital records, and air pollution data from 2000 through 2007 for the zip codes served by the Central Hillsborough Federal Healthy Start Project in Tampa, Florida. Mathematical modeling was employed to compute minimal Euclidean distances to capture exposure to ambient air particulate matter. The outcomes of interest were low birth weight (LBW), very low birth weight (VLBW), small for gestational age, preterm (PTB), and very preterm birth. We used odds ratios to approximate relative risks. A total of 12,356 live births were analyzed. Overall, women exposed to air particulate pollutants were at elevated risk for LBW (AOR = 1.24; 95% CI = 1.07–1.43), VLBW (AOR = 1.58; 95% CI = 1.09–2.29) and PTB (AOR = 1.18; 95% CI = 1.03–1.34). Analysis by race/ethnicity revealed that the adverse effects of air particulate pollutants were most profound among black infants. Infants of women who received services provided by the Central Hillsborough Federal Healthy Start Project experienced improved feto-infant morbidity outcomes despite exposure to air particulate pollutants. Environmental air pollutants represent important risk factors for adverse birth outcomes, particularly among black women. Multi-level interventional approaches implemented by the Central Hillsborough Federal Healthy Start were found to be associated with reduced likelihood for feto-infant morbidities triggered by exposure to ambient air particulate pollutants.

This study sought to examine the association between maternal HIV/AIDS infection and neonatal neurologic conditions in the state of Florida. We analyzed all births in the state of Florida from 1998 to 2007 using hospital discharge data linked to birth certificate records. The main outcomes of interest included selected neonatal neurologic complications, namely: fetal distress, cephalohematoma, intracranial hemorrhage, seizure, feeding difficulties, and other central nervous system complications. The sample size for this study was 1,645,515 records. All forms of substance abuse as well as cesarean section deliveries were more frequent in mothers with HIV/AIDS. Infants born to HIV-infected mothers showed higher proportions of feeding difficulties and seizures whereas HIV-negative mothers had a greater proportion of cases of fetal distress and cephalohematoma. Seizures and feeding difficulties are common among infants born to HIV/AIDS infected mothers. This population-based retrospective cohort study provides further understanding of the association between maternal HIV/AIDS status and neonatal neurological outcomes.

The purpose of this study was to examine the association between prenatal alcohol consumption and the occurrence of placental abruption and placenta previa in a population-based sample. We used linked birth data files to conduct a retrospective cohort study of singleton deliveries in the state of Missouri during the period 1989 through 2005 (n = 1,221,310). The main outcomes of interest were placenta previa, placental abruption and a composite outcome defined as the occurrence of either or both lesions. Multivariate logistic regression was used to generate adjusted odd ratios, with non-drinking mothers as the referent category. Women who consumed alcohol during pregnancy had a 33% greater likelihood for placental abruption during pregnancy (adjusted odds ratio (OR), 95% confidence interval (CI) = 1.33 [1.16–1.54]). No association was observed between prenatal alcohol use and the risk of placenta previa. Alcohol consumption in pregnancy was positively related to the occurrence of either or both placental conditions (adjusted OR [95% CI] = 1.29 [1.14–1.45]). Mothers who consumed alcohol during pregnancy were at elevated risk of experiencing placental abruption, but not placenta previa. Our findings underscore the need for screening and behavioral counseling interventions to combat alcohol use by pregnant women and women of childbearing age.

We investigated the association between 2009 IOM recommendations and adverse infant outcomes by maternal prepregnancy body mass index (BMI). Birth outcomes for 570,672 women aged 18–40 years with a singleton full-term live-birth were assessed using 2004–2007 Florida live-birth certificates. Outcomes included large-for-gestational-age (LGA) and small-for-gestational-age (SGA). Associations between gestational weight change and outcomes were assessed for 10 BMI groups by calculating proportions, and logistic regression modeling was used to produce adjusted odds ratios (aORs) to account for the effect of confounders. We created comparison categories below and above recommendations using 2009 IOM recommendations as a reference. Of importance, 41.6% of women began pregnancy as overweight and obese and 51.2% gained weight excessively during pregnancy on the basis of 2009 IOM recommendations. Proportions of LGA were higher among obese women and increased with higher weight gain. Compared with recommended weight gain, aORs for LGA were lower with less than recommended gain (aOR range: 0.27–0.77) and higher with more than recommended gain (aOR range: 1.27–5.99). However, SGA was less prevalent among obese women, and the proportion of SGA by BMI was similar with higher weight gain. Gain less than recommended was associated with increased odds of SGA (aOR range: 1.11–2.97), and gain greater than recommended was associated with decreased odds of SGA (aOR range: 0.38–0.83). Gestational weight gain influenced the risk for LGA and SGA in opposite directions. Minimal weight gain or weight loss lowered risk for LGA among obese women. Compared with 1990 IOM recommendations, 2009 recommendations include weight gain ranges that are associated with lower risk of LGA and higher risk of SGA. Awareness of these tradeoffs may assist with clinical implementation of the 2009 IOM gestational weight gain recommendations. However, our results did not consider other maternal and infant outcomes related to gestational weight gain; therefore, the findings should be interpreted with caution.

To investigate the nature of very low birth weight (VLBW) births in Georgia—a major contributor to the overall and the black–white disparity in infant mortality—as a step toward elucidating strategies for reducing VLBW births. This population-based retrospective cohort study utilized maternally linked vital records data from Georgia to examine the status of and contributors to the VLBW rate for non-Hispanic blacks and whites by comparing trends in the proportion represented by singleton versus multiple gestations, first versus recurrent events, and specific subtypes over three, consecutive 4-year periods (1994–1996 through 2003–2005); and logistic regression to model the risk of various subtypes of VLBW as a function of maternal and obstetrical characteristics. Georgia’s VLBW rate remained unchanged from 1994–1996 to 2003–2005, although there was a significant decrease in the rates of twin and first VLBW and a significant increase in recurrent VLBW. For both first and recurrent VLBW, there was a statistically significant increase for blacks and a decrease for whites. The strongest risk factor for a VLBW birth of any subtype for blacks and whites was a prior VLBW, with recurrent VLBW accounting for 4.8–16% of all VLBW depending upon the subtype. From 1994–1996 to 2003–2005, the rate of recurrent VLBW increased while the rate of first VLBW decreased in Georgia. For both first and recurrent VLBW, the black–white disparity widened. Because the strongest risk factor for a VLBW birth is a previous one, there is a need to identify strategies to prevent a woman’s first VLBW birth and to reduce recurrences.

Despite appreciable improvement in the overall reduction of infant mortality in the United States, black infants are twice as likely to die within the first year of life as white infants, even after controlling for socioeconomic factors. There is consensus in the literature that a complex web of factors contributes to racial health disparities. This paper presents these factors utilizing the socioecological framework to underscore the importance of their interaction and its impact on birth outcomes of Black women. Based on a review of evidence-based research on Black-White disparities in infant mortality, we describe in this paper a missing potent ingredient in the application of the ecological model to understanding Black-White disparities in infant mortality: the historical context of the Black woman in the United States. The ecological model suggests that birth outcomes are impacted by maternal and family characteristics, which are in turn strongly influenced by the larger community and society. In addition to infant, maternal, family, community and societal characteristics, we present research linking racism to negative birth outcomes and describe how it permeates and is embedded in every aspect of the lives of African American women. Understanding the contribution of history to the various factors of life of Black women in the United States will aid in developing more effective policies and programs to reduce Black infant mortality.

OBJECTIVE: We evaluate the impact of the Healthy Start intervention program on feto-infant morbidity within a community setting. METHODS: Prospective data from 2002 to 2007 within the ongoing Federally funded Healthy Start intervention project in Central Hillsborough County were merged with corresponding birth outcomes data from the Florida Department of Health. The impact of the project on the following feto-infant morbidity indices was assessed among service recipients: low birth weight (LBW), very low birth weight (VLBW), preterm, very preterm, small for gestational age (SGA) and a composite feto-infant morbidity outcome. Program effectiveness and impact were measured using odds ratios from logistic regression models and number needed to treat (NNT). RESULTS: The risk for low birth weight (OR = 0.7; 95% CI = 0.5-1.0), preterm (OR = 0.7; 95% CI = 0.5-0.9) and the composite feto-infant morbidity outcome (OR = 0.8; 95% CI = 0.6-0.9) was reduced among service recipients (N = 536) as compared to non-recipients (N = 2,815). A clinically important level of risk reduction was also noted for very low birth weight (OR = 0.5; 95% CI = 0.2-1.1) and very preterm (OR = 0.6; 95% CI = 0.3-1.2) although these did not reach statistical significance. The adjusted NNT was lowest for the composite feto-infant morbidity outcome (18), preterm birth (21) and low birth weight (24), and highest for very preterm (86) and very low birth weight (74) events. CONCLUSIONS: In a disadvantaged community setting, the Healthy Start intervention program was found to reduce the risk for very low birth weight and preterm births by about one-third.

Introduction Reducing racial/ethnic disparities is a key objective of the Healthy People 2010 initiative. Unfortunately, racial disparities among women delaying initiation of childbearing have received limited attention. As more women in the US are delaying initiation of childbearing, it is important to examine racial disparities in reproductive health outcomes for this subgroup of women. Objective To examine racial disparities in perinatal outcomes, interpregnancy interval, and to assess the risk for adverse outcomes in subsequent pregnancy for women delaying initiation of childbearing until age 30 or older compared to those initiating childbearing at age 20–29. Methods We conducted a retrospective cohort study using the Missouri maternally linked cohort files 1978–1997. Final study sample included 239,930 singleton sibling pairs (Whites and African Americans). Outcome variables included first and second pregnancy outcomes (fetal death, low birth weight, preterm delivery and small-for-gestational age) and interpregnancy interval between first and second pregnancy. Independent variables included maternal age at first pregnancy and race. Analysis strategies used involved stratified analyses and multivariable unconditional logistic regression; interactions between maternal race, age and interpregnancy interval were examined in the regression models. Results Compared to Whites, African American mothers initiating childbearing at age 30 or older had significantly higher rates of adverse outcomes in the first and second pregnancy (P

Objective: The objective of this study is to determine the association between unmarried status and infant mortality among twins born to teenagers. Methods: We conducted a retrospective cohort study on twin live births to teenagers in the United States from 1995 through 1998 using the Vital Records assembled by the National Center for Health Statistics. We compared mortality estimates among twins of single to those of married mothers using the generalized estimating equation framework, which also adjusted for intracluster correlations. Results: Analysis involved 28592 individual twins of teenager mothers, with both cluster members being live-born. Out of these, 21.8% (n = 6238) were born to married and 78.2% (n = 22,354) to single mothers. Infant and postneonatal mortality was 17% and 36% higher among twins of single teenager mothers (odds ratio (OR) = 1.17; 95% confidence interval (CI) = 1.01–1.40) and (OR = 1.36; 95% CI = 1.01–1.87), respectively. However, neonatal mortality was comparable (OR = 1.12; 95% CI = 0.92–1.34). Twins of single mothers were also more likely to be of low birth weight, very low birth weight, preterm and very preterm (p < 0.0001) but had the same risk level for smallness for gestational age as compared to twins of married teenagers. Conclusions: Single motherhood was associated with increased infant mortality among twins born to teenagers. The critical time of elevated risk was the postneonatal period and the survival disadvantage of twins of single mothers was as a result of the higher-than-expected level of preterm rather than small for gestational age births. These findings have potential clinical and public health relevance.

The objectives of the study were: 1) To determine the risk of infant mortality associated with prenatal cigarette smoking; 2) To assess whether the relationship, if existent, was dose-dependent; 3) To explore the morbidity pathway that explains the effect of tobacco smoke on infant mortality, and 4) to compute excess infant deaths attributable to maternal smoking in the United States.Retrospective cohort study on 3,004,616 singleton live births that occurred in 1997 in the United States using the US national linked birth/infant death data. Excess infant deaths due to maternal smoking were computed using the population-attributable risk (PAR).Overall, 13.2% of pregnant women who delivered live births in 1997 smoked during pregnancy. The rate of infant mortality was 40% higher in this group as compared to nonsmoking gravidas (P0.0001). This risk increased with the amount of cigarettes consumed prenatally in a dose-dependent fashion (p for trend0.0001). Small-for-gestational age rather than preterm birth is the main mechanism through which smoking causes excess infant mortality. We estimated that about 5% of infant deaths in the United States were attributable to maternal smoking while pregnant, with variations by race/ethnicity. The proportion of infant deaths attributable to maternal smoking was highest among American Indians at 13%, almost three times the national average. If pregnant smokers were to halt tobacco use a total of 986 infant deaths would be averted annually.Smoking during pregnancy accounts for a sizeable number of infant deaths in the United States. This highlights the need for infusion of more resources into existing smoking cessation campaigns in order to achieve higher quit rates, and substantially diminish current levels of smoking-associated infant deaths.