Born too soon: the continuing challenge of preterm labor and birth in the United States

[Research progress on the relationship and mechanisms between periodontal disease and preterm birth and low-birth-weight infants]

Preterm birth (PB) is defined as the birth of a baby less than 37 weeks of gestational age. Low birth weight (LBW) is defined as a newborn baby's weight of less than 2 500 g. PB is often accompanied by LBW. Preterm low birth weight (PLBW) is the leading cause of newborn deaths. Periodontal disease (PD) is a chronic oral infectious disease, and it is closely related with general health. Epidemiological data show that PD is a risk factor for PLBW and other adverse pregnancy outcomes. The possible mechanisms include the direct effects of periodontal bacteria, inflammatory reactions, and immune response; however, the exact pathogenetic mechanism involved remains controversial. This article aims to review the research progress on the relationship between PD and PLBW and their underlying mechanisms, as well as the effects of periodontal treatment on PLBW incidence.

Paid Family Leave to Enhance the Health Outcomes of Preterm Infants

Prematurity is the largest contributor to perinatal morbidity and mortality. Preterm infants and their families are a significant vulnerable population burdened with limited resources, numerous health risks, and poor health outcomes. The social determinants of health greatly shape the economic and psychosocial resources that families possess to promote optimal outcomes for their preterm infants. The purposes of this article are to analyze the resource availability, relative risks, and health outcomes of preterm infants and their families and to discuss why universal paid family leave could be one potential public policy that would promote optimal outcomes for this infant population. First, we discuss the history of family leave in the United States and draw comparisons with other countries around the world. We use the vulnerable populations conceptual model as a framework to discuss why universal paid family leave is needed and to review how disparities in resource availability are driving the health status of preterm infants. We conclude with implications for research, nursing practice, and public policy. Although health care providers, policy makers, and other key stakeholders have paid considerable attention to and allocated resources for preventing and treating prematurity, this attention is geared toward individual-based health strategies for promoting preconception health, preventing a preterm birth, and improving individual infant outcomes. Our view is that public policies addressing the social determinants of health (e.g., universal paid family leave) would have a much greater impact on the health outcomes of preterm infants and their families than current strategies.

Psychological, cultural and neuroendocrine profiles of risk for preterm birth

Background

Preterm birth remains a major obstetrical problem and identification of risk factors for preterm birth continues to be a priority in providing adequate care. Therefore, the purpose of this study was to elucidate risk profiles for preterm birth using psychological, cultural and neuroendocrine measures.

Methods

From a cross sectional study of 515 Mexican American pregnant women at 22–24 weeks gestation, a latent profile analysis of risk for preterm birth using structural equation modeling (SEM) was conducted. We determined accurate gestational age at delivery from the prenatal record and early ultrasounds. We also obtained demographic and prenatal data off of the chart, particularly for infections, obstetrical history, and medications. We measured depression (Beck Depression Inventory), mastery (Mastery scale), coping (The Brief Cope), and acculturation (Multidimensional Acculturation Scale) with reliable and valid instruments. We obtained maternal whole blood and separated it into plasma for radioimmunoassay of Corticotrophin Releasing Hormone (CRH). Delivery data was obtained from hospital medical records.

Results

Using a latent profile analysis, three psychological risk profiles were identified. The “low risk” profile had a 7.7 % preterm birth rate. The “moderate risk” profile had a 12 % preterm birth rate. The “highest risk” profile had a 15.85 % preterm birth rate. The highest risk profile had double the percentage of total infections compared to the low risk profile. High CRH levels were present in the moderate and highest risk profiles.

Conclusion

These risk profiles may provide a basis for screening for Mexican American women to predict risk of preterm birth, particularly after they are further validated in a prospective cohort study. Future research might include use of such an identified risk profile with targeted interventions tailored to the Hispanic culture.

Relationship between periodontal diseases and preterm birth: Recent epidemiological and biological data

Preterm infants are born prior to completion of 37 weeks of gestation. These patients are seen on the rise despite the efforts put in to control them. Global incidence of preterm birth is around 9.6% of all birth representing 12.9 million births with regional disparities: From 12% to 13% in USA, from 5% to 9% in Europe, and 18% in Africa. First reported by Offenbacher et al. in 1996 relationship exist between maternal periodontal disease and delivery of a preterm infant. This article reviews the recent epidemiological and biological data. The articles were searched on Google, PubMed recent articles were selected. Mainly, three hypotheses by which periodontal bacteria can affect the outcome of pregnancy. Biological hypothesis: (a) Bacterial spreading, (b) Inflammatory products dissemination, (c) Role of fetomaternal immune response against oral pathogens. The promotion of the early detection and treatments of periodontal disease in young women before and during pregnancy will be beneficial especially for women at risk.

The role of peer support in the development of maternal identity for "NICU Moms"

OBJECTIVE

To examine first-time neonatal intensive care unit (NICU) mothers' perceptions of the initial effect and stress of their birth experiences and hospitalizations of their infants and what facilitated or hindered the development of their maternal roles within the context of the NICU.

DESIGN

A qualitative descriptive design.

SETTING

A 57-bed, tertiary NICU in Chicago.

PARTICIPANTS

Twenty-three mothers of very low birth weight (VLBW) infants hospitalized in the NICU.

METHODS

Participants were a subset of a larger longitudinal mixed-method study of psychological distress in 69 mothers of VLBW infants. Mothers were interviewed using an adaptation of the Clinical Interview for Parents of High-Risk Infants (CLIP) approximately 6 weeks after the births of their infants. Data were analyzed using conventional content analysis.

RESULTS

Mothers characterized the infants' births and hospitalizations as a time of overwhelming change culminating in a new perspective on life. Primary themes were loss, stress and anxiety, adapting, resilience, peer support, and "I'm a NICU Mom." Mothers rated peer support as the most facilitative and supportive aspect of developing the maternal role in the NICU.

CONCLUSION

Peer support and role modeling by NICU-based breastfeeding peer counselors helped the mothers throughout every stage of their infants' hospitalizations, from giving them hope, to helping them begin to develop maternal identity, to providing anticipatory guidance about taking their infants home. Talking points are provided for nurses who work in NICUs without dedicated peer support to help mothers establish a healthy mother/infant relationship.

The relationship between antenatal care and preterm birth: the importance of content of care

BACKGROUND

Antenatal care can play an important role in the prevention of preterm birth. Evaluation of antenatal care is usually based on the number of visits rather than the content of care, using tools such as the Adequacy of Prenatal Care Use index. This article presents an analysis of the relation between specific elements of antenatal care and the risk of preterm birth compared with considering the number of visits only.

METHODS

A prospective cohort study was conducted in the Brussels Metropolitan Region. In all, 333 women were consecutively recruited at the beginning of their antenatal care trajectory and followed until birth. Information on timing and content for every visit was recorded by structured interview. A new tool was developed to measure the antenatal care trajectory, which included Content and Timing of care in Pregnancy (CTP). Odds ratios (OR) (adjusted and unadjusted) for preterm birth were calculated for the Adequacy of Prenatal Care Use and CTP model.

RESULTS

The number of visits alone was not associated with preterm birth. In contrast, a significant association was found between the content and timing of care and preterm birth. Compared with the CTP lowest ('inadequate') category, women in the CTP 'sufficient' (OR 0.30; 95% CI 0.09-0.94) and CTP 'appropriate' (OR 0.21; 95% CI 0.06-0.68) category had a lower risk.

CONCLUSIONS

This study suggests that measurement of the content and timing of care of antenatal care using the new CTP tool is a better assessment of the risk of preterm birth than assessment of the number of antenatal visits alone.

Schore's regulation theory: maternal-infant interaction in the NICU as a mechanism for reducing the effects of allostatic load on neurodevelopment in premature infants

Premature infants confront numerous physiologic and environmental stressors in the neonatal intensive care unit (NICU) that have the potential to permanently alter their neurodevelopment. Schore's regulation theory postulates that positive maternal-infant interactions can shape the infant's developmental outcomes through inducing mechanistic changes in brain structure and function. The purposes of this article are to explain the regulation of infant neurobiological processes during interactions between mothers and healthy infants in the context of Schore's theory, to identify threats to these processes for premature infants, and to propose principles of clinical practice and areas of research necessary to establish a supportive environment and prevent or reduce maladaptive consequences for these vulnerable infants. A premature birth results in the disruption of neurodevelopment at a critical time. Chronic exposure to stressors related to the NICU environment overwhelms immature physiologic and stress systems, resulting in significant allostatic load, as measured by long-term neurodevelopmental impairments in the premature infant. Positive maternal-infant interactions during NICU hospitalization and beyond have the potential to reduce neurologic deficits and maximize positive neurodevelopmental outcomes in premature infants. The quality of the maternal-infant interaction is affected not only by the infant's developing neurobiology but also by the mother's responses to the stressors surrounding a premature birth and mothering an infant in the NICU environment. Nurses can empower mothers to overcome these stressors, promote sensitive interactions with their infants, and facilitate neurodevelopment. Research is critically needed to develop and test nursing interventions directed at assisting mothers in supporting optimal neurodevelopment for their infants.

Behavior Problems in Relation to Sustained Selective Attention Skills of Moderately Preterm Children

Attention skills may form an important developmental mechanism. A mediation model was examined in which behavioral problems of moderately preterm and term children at school age are explained by attention performance. Parents and teachers completed behavioral assessments of 348 moderately preterm children and 182 term children at 8 years of age. Children were administered a test of sustained selective attention. Preterm birth was associated with more behavioral and attention difficulties. Gestational age, prenatal maternal smoking, and gender were associated with mothers', fathers', and teachers' reports of children's problem behavior. Sustained selective attention partially mediated the relationship between birth status and problem behavior. Development of attention skills should be an important focus for future research in moderately preterm children.

Intrauterine growth restriction is a direct consequence of localized maternal uropathogenic Escherichia coli cystitis

Despite the continually increasing rates of adverse perinatal outcomes across the globe, the molecular mechanisms that underlie adverse perinatal outcomes are not completely understood. Clinical studies report that 10% of pregnant women will experience a urinary tract infection (UTI) and there is an association of UTIs with adverse perinatal outcomes. We introduced bacterial cystitis into successfully outbred female mice at gestational day 14 to follow pregnancy outcomes and immunological responses to determine the mechanisms that underlie UTI-mediated adverse outcomes. Outbred fetuses from mothers experiencing localized cystitis displayed intrauterine growth restriction (20–80%) as early as 48 hours post-infection and throughout the remainder of normal gestation. Robust infiltration of cellular innate immune effectors was observed in the uteroplacental tissue following introduction of UTI despite absence of viable bacteria. The magnitude of serum proinflammatory cytokines is elevated in the maternal serum during UTI. This study demonstrates that a localized infection can dramatically impact the immunological status as well as the function of non-infected distal organs and tissues. This model can be used as a platform to determine the mechanism(s) by which proinflammatory changes occur between non-contiguous genitourinary organs

Acculturation, depressive symptoms, estriol, progesterone, and preterm birth in Hispanic women

We examined the effects of acculturation, depressive symptoms, progesterone, and estriol (E3) as predictors of preterm birth (PTB) in pregnant Hispanic women. This cross-sectional study recruited a sample of 470 Hispanic women between 22- and 24-week gestation from physician practices and community clinics. We used the CES-D to measure maternal depressive symptoms. We measured acculturation by English proficiency on the Bidimensional Acculturation Scale, residence index by years in the USA minus age, nativity, and generational status. Serum progesterone and E3 were analyzed by EIA. Ultrasound and medical records determined gestational age after delivery. In χ (2) analysis, there were a significantly greater percentage of women with higher depressive scores if they were born in the USA. In a structural equation model (SEM), acculturation (English proficiency, residence index, and generational status) predicted the estriol/progesterone ratio (E/P), and the interaction of depressive symptoms with the E/P ratio predicted PTB. Undiagnosed depressive symptoms during pregnancy may have biological consequences increasing the risk for PTB.

Microbiological characteristics and inflammatory cytokines associated with preterm labor

PURPOSE

To evaluate vaginal microflora and interleukin-1β (IL-β), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) concentrations in the cervicovaginal fluid of a group of pregnant women in preterm labor when compared with a group of full-term pregnant women not yet in labor.

METHOD

Case-control study performed in a University tertiary referral maternity in Campinas, Brazil with 45 pregnant women in preterm labor and 45 full-term pregnant women not in labor. All patients underwent speculum examination for the collection of cervicovaginal fluid. Bacterial vaginosis (BV) was diagnosed according to the criteria of Amsel and Nugent. Culture was performed for group B streptococcus (GBS) and lactobacilli, and hybrid capture assay for screening for chlamydial and gonococcal infection. Cytokine concentrations were measured using ELISA technique. Statistical analysis was performed using χ(2), Fisher's exact, and crude and adjusted odds ratios. Significance level was defined at 5%. The main outcome measures were cervicovaginal cytokines in preterm labor.

RESULTS

IL-6 and IL-8 were significantly associated with preterm labor. The changes in vaginal microflora, as well as BV and GBS, were more frequent in women in preterm labor, although BV and GBS showed no statistical significance. The presence of Candida sp., absence of lactobacilli, positive screening for chlamydial and gonococcal infection and the presence of IL-1β and TNF-α were not associated with preterm labor.

CONCLUSIONS

IL-6 and IL-8 and the presence of any type of vaginal infection were the factors that were significantly associated with preterm labor.

Functioning at school age of moderately preterm children born at 32 to 36 weeks' gestational age

OBJECTIVE

To study outcome of low-risk moderately preterm birth between 32 and 36/7 weeks' gestation.

METHODS

377 Moderately preterm children (M: 34.7, SD: 1.2 complete weeks), without need for neonatal intensive care and without dysmaturity or congenital malformations, were compared with 182 term children and assessed at eight years (M: 8.9, SD: 0.54). School situation, IQ, sustained attention, behavior problems, and attention-deficit/hyperactivity characteristics were studied.

RESULTS

Special education was attended by 7.7% of the moderately preterm children, more than twice the rate of 2.8% in the general Dutch population of this age. Additional exploration for two preterm subgroups of 32 to 33 versus 34 to 36 weeks' gestation showed a need for special education in 9.7% versus 7.3% and a significant difference in grade retention for 30% versus 17%, respectively. Of the children attending mainstream primary schools, grade retention was found in 19% of the preterm versus 8% of the comparison children. Adjusting for maternal education, a group difference of 3 points was found in IQ. The preterm children needed more time for the sustained attention task. The preterm children had more behavior problems (specifically internalizing problems with 27% scoring above the borderline cut-off), as well as more attention-deficit/hyperactivity disorder characteristics (specifically attention deficits).

CONCLUSIONS

Cognitive and emotional regulation difficulties affect functioning of moderately preterm children, as school problems, a slightly lower IQ, attention and behavioral problems are found when they are compared with term-born children. Identification and monitoring of precursors of these problems at younger age is needed in view of prevention purposes.

Demographic, clinical and occupational characteristics associated with early onset of delivery: findings from the Duke Health and Safety Surveillance System, 2001-2004

BACKGROUND

This cross-sectional study explores associations between preterm delivery and demographic, clinical and occupational characteristics of women employed within a university and health system.

METHODS

A comprehensive surveillance system linking individual-level data from Human Resources, medical insurance claims and a job-exposure matrix was used to identify women with a single live birth between 2001 and 2004 and describe maternal characteristics during pregnancy.

RESULTS

Preterm delivery occurred in 7.1% (n = 74) of the 1,040 women, a lower preterm delivery prevalence than observed in the general U.S. population. Nearly all (>99.5%) women utilized prenatal care services. Prevalence of preterm delivery was highest for inpatient nurses, nurses' aides and office staff. In multivariate analyses, preterm delivery was positively associated with several clinical conditions: placenta previa, diabetes and cardiovascular disorder/disease.

CONCLUSIONS

We observed associations between preterm delivery and several previously indicated clinical conditions. Further study of the effect of job characteristics on preterm delivery is warranted.

Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine

BACKGROUND

Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy.

METHODS

This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants.

RESULTS

There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled.

CONCLUSIONS

Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.