Long-term outcome of infants born preterm

Trends in infants born at low birthweight and disparities by maternal race and education from 2003 to 2018 in the United States

BACKGROUND

Understanding current levels, as well as past and future trends, of the percentage of infants born at low birthweight (LBW) in the United States is imperative to improving the health of our nation. The purpose of this study, therefore, was to examine recent trends in percentage of LBW, both overall and by maternal race and education subgroups. Studying disparities in percentage of LBW by these subgroups can help to further understand the health needs of the population and can inform policies that can close race and class disparities in poor birth outcomes.

METHODS

Trends of percentage of LBW in the U.S. from 2003 to 2018, both overall and by race/ethnicity, and from 2007 to 2018 by education and race by education subgroups were analyzed using CDC WONDER Natality data. Disparities were analyzed using between group variance methods.

RESULTS

Percentage of LBW experienced a significant worsening in the most recent 5 years of data, negating nearly a decade of prior improvement. Stark differences were observed by race/ethnicity and by education, with all subgroups experiencing increasing rates in recent years. Disparities also worsened over the course of study. Most notably, all disparities increased significantly from 2014 to 2018, with annual changes near 2-5%.

CONCLUSIONS

Recent reversals in progress in percentage of LBW, as well as increasing disparities particularly by race, are troubling. Future study is needed to continue monitoring these trends and analyzing these issues at additional levels. Targets must be set and solutions must be tailored to population subgroups to effectively make progress towards equitable birth outcomes and maternal health.

Variable maternal stress in rats alters locomotor activity, social behavior, and recognition memory in the adult offspring

Rats repeatedly exposed to variable prenatal stress (PNS) exhibit behavioral signs that are similar to those manifested in several neuropsychiatric disorders such as deficits in attention and inhibitory control, and impairments in memory-related task performance. The purpose of the study described here was to conduct a comprehensive battery of tests to further characterize the behavioral phenotype of PNS rats as well as to evaluate the sensitivity of the model to therapeutic interventions (i.e., to compounds previously shown to have therapeutic potential in neuropsychiatric disorders). The results of this study indicated that PNS in rats is associated with: 1) increased locomotor activity and stereotypic behaviors, 2) elevated sensitivity to the psychostimulant amphetamine, 3) increased aggressive behaviors toward both adult and juvenile rats and 4) delay-dependent deficits in recognition memory. There was no evidence that PNS rats exhibited deficits in other areas of motor function/learning, sensorimotor gating, spatial learning and memory, social withdrawal, or anhedonia. In addition, the results revealed that the second generation antipsychotic risperidone attenuated amphetamine-related increases in locomotor activity in PNS rats; however, the effect was not sustained over time. Furthermore, deficits in recognition memory in PNS rats were attenuated by the norepinephrine reuptake inhibitor, atomoxetine, but not by the α7 nicotinic acetylcholine receptor partial agonist, GTS-21. This study supports the supposition that important phenomenological similarities exist between rats exposed to PNS and patients afflicted with neuropsychiatric disorders thus further establishing the face validity of the model for evaluating potential therapeutic interventions.

Impact of a prenatal cognitive-behavioral stress management intervention on salivary cortisol levels in low-income mothers and their infants

Recent findings suggest that elevated stress levels during the pre- and postpartum period are related to poor maternal and infant health outcomes; yet, few studies have prospectively examined the efficacy of stress management interventions on regulating stress levels among mothers and their infants. The current study examined whether a prenatal cognitive behavioral stress management (CBSM) intervention would be effective in regulating salivary cortisol (a biological marker of stress) and self-reported stress levels among mothers and their infants at six and 18 months postpartum, relative to two control groups. Our sample was comprised of predominantly Spanish-speaking, low-income women (80%; mean age=25±5 years) who were screened for depression during their second trimester of pregnancy (M=16±5 weeks of gestation). Women at high risk for depression [i.e., having either a past history of major depression or current elevated symptoms of depression (≥16 on CES-D)] were randomized to either a CBSM group (n=24) or a usual care (UC) group (n=33), while a low risk comparison (LRC) group (n=29) was comprised of women not meeting either depression criteria. ANCOVA analyses demonstrated that: (1) infants of women in the CBSM and LRC groups had significantly lower cortisol levels than infants of women in the UC group at six months postpartum (p<.001); and (2) women in the CBSM group had lower cortisol levels than women in the UC group at 18 months postpartum (p<.01). These results suggest that prenatal CBSM interventions may be efficacious in regulating biological markers of stress among mothers and their infants, thereby decreasing their risk for developing health complications over time.

A meta-analysis of depression during pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction

CONTEXT

Maternal depressive symptoms during pregnancy have been reported in some, but not all, studies to be associated with an increased risk of preterm birth (PTB), low birth weight (LBW), and intrauterine growth restriction (IUGR).

OBJECTIVE

To estimate the risk of PTB, LBW, and IUGR associated with antenatal depression.

DATA SOURCES AND STUDY SELECTION

We searched for English-language and non-English-language articles via the MEDLINE, PsycINFO, CINAHL, Social Work Abstracts, Social Services Abstracts, and Dissertation Abstracts International databases (January 1980 through December 2009). We aimed to include prospective studies reporting data on antenatal depression and at least 1 adverse birth outcome: PTB (<37 weeks' gestation), LBW (<2500 g), or IUGR (<10th percentile for gestational age). Of 862 reviewed studies, 29 US-published and non-US-published studies met the selection criteria.

DATA EXTRACTION

Information was extracted on study characteristics, antenatal depression measurement, and other biopsychosocial risk factors and was reviewed twice to minimize error.

DATA SYNTHESIS

Pooled relative risks (RRs) for the effect of antenatal depression on each birth outcome were calculated using random-effects methods. In studies of PTB, LBW, and IUGR that used a categorical depression measure, pooled effect sizes were significantly larger (pooled RR [95% confidence interval] = 1.39 [1.19-1.61], 1.49 [1.25-1.77], and 1.45 [1.05-2.02], respectively) compared with studies that used a continuous depression measure (1.03 [1.00-1.06], 1.04 [0.99-1.09], and 1.02 [1.00-1.04], respectively). The estimates of risk for categorically defined antenatal depression and PTB and LBW remained significant when the trim-and-fill procedure was used to correct for publication bias. The risk of LBW associated with antenatal depression was significantly larger in developing countries (RR = 2.05; 95% confidence interval, 1.43-2.93) compared with the United States (RR = 1.10; 95% confidence interval, 1.01-1.21) or European social democracies (RR = 1.16; 95% confidence interval, 0.92-1.47). Categorically defined antenatal depression tended to be associated with an increased risk of PTB among women of lower socioeconomic status in the United States.

CONCLUSIONS

Women with depression during pregnancy are at increased risk for PTB and LBW, although the magnitude of the effect varies as a function of depression measurement, country location, and US socioeconomic status. An important implication of these findings is that antenatal depression should be identified through universal screening and treated.

Neurosensory disabilities at school age in geographic cohorts of extremely low birth weight children born between the 1970s and the 1990s

OBJECTIVE

To contrast the rates of neurosensory disabilities at age 8 years in extremely low birth weight (ELBW; birth weight 500 to 999 g) children born in the state of Victoria, Australia in 4 four distinct eras from the late 1970s to the late 1990s.

STUDY DESIGN

Study subjects were assessed at age 8 years. Results were compared among 4 ELBW cohorts (87 of 89 children born in 1979-1980, 206 of 212 born in 1985-1987, 224 of 241 born in 1991-1992, and 160 of 170 born in 1997), and between each of these ELBW cohorts and normal birth weight (NBW; birth weight > 2499 g) controls.

RESULTS

The survival rate for ELBW children rose from 25% for the 1979-1980 cohort to 73% for the 1997 cohort. No statistically significant differences in the disability rates were seen in the 4 eras; however, in the 1997 cohort, disability rates were significantly higher in the ELBW children compared with NBW controls: mild disability, 36.7% vs 9.8%; moderate disability, 10.1% vs 2.3%; and severe disability, 8.2% vs 0.6%.

CONCLUSIONS

The survival rate of ELBW children continues to rise over time. Despite this, however, the rates of disability in these vulnerable children at school age have remained stable and high relative to controls.

Hypothalamic-pituitary-adrenal axis function and the cellular immune response in former preterm children

CONTEXT

Animal data suggest that adverse early experiences may affect endocrine and immune functioning in later life.

OBJECTIVE

Our objective was to assess the impact of preterm delivery on hypothalamus-pituitary-adrenal axis functioning, heart rate responses, and immune function.

PARTICIPANTS

Former preterm children [aged 8-14 yr (n = 18)], sex and age-matched full-term born control children (n = 18), data on birth weight, gestational age, birth weight for gestational age (in sd units), actual body weight, height, and body mass index were assessed.

DESIGN AND OUTCOME MEASURES

Subjects were exposed to a standardized laboratory stressor ("Trier Social Stress Test for Children"). Cortisol in saliva was determined in 10-min intervals before and after the stress test; heart rates were obtained continuously during the stress test. Additional assessment of saliva cortisol was performed: 1) on 3 consecutive days after awakening and at +10, +20, and +30 min (morning cortisol); and 2) at 0800, 1400, 1600, and 1900 h (short diurnal profile). Measurement of the delayed type hypersensitivity reaction to seven recall antigens [Multitest cellular mediated immunity (Multitest-Immignost, Biosyn, Fellbach, Germany)].

RESULTS

Exposure to the Trier Social Stress Test for Children yielded significantly increased cortisol levels [F (8, 232) = 19.86; P < 0.001] and heart rates [F (38, 988) = 10.46; P < 0.001], however, no difference between former preterms and full-terms could be observed. No between-group differences were found in the short diurnal cortisol profile. Former preterms showed significantly higher cortisol levels after awakening [F (3, 102) = 3.14; P < 0.05]. In addition, a significantly suppressed delayed type hypersensitivity response [reduced number of positive antigens (t = -2.64, P < 0.05); induration (t = -2.4, P < 0.05)] was found in former preterms.

CONCLUSION

The data suggest that preterm delivery may be associated with altered endocrine and immune functions well into late childhood.

Développement cognitif et performances attentionnelles de l'ancien prématuré « normal » à l'âge scolaire

OBJECTIVE

A preterm birth can exert an influence on cognitive development. The aim of this study was to determine whether preterm birth may impact on attention executive processes, at school age, in children without neurological sequelae.

DESIGN AND METHODS

Prematurely born children admitted in the level III NICU of the Maternité régionale of Nancy between 1992 and 1994, underwent at 8 to 10 years 8 subtests of the mental processing scales of the K-ABC, which assess process categories involved in learning. The children were also submitted to 3 tests that evaluate attention mechanisms efficiency (category fluency task, backward digits span, Tower of London). The controls were children born at term recruted in schools of the same area.

RESULTS

The 124 children were born with birth weight appropriate for gestational age, and were in the school grades expected for their ages, in 3rd, 4rth, and 5fth grades. Fifty-three children were born at term, 29 were prematurely born (33-36 w), and 42 were very prematurely born (28-32 w). Birth term was significantly correlated (P < 0.001) with scores at sequential processing scale, at simultaneous processing scale and at the mental processing composite scale. At this scale, the children born at term obtained a median score of 112, the children prematurely born of 101, and the children very prematurely born of 98.5. For 40 third grade children (18 born at term, 10 prematurely born, and 12 very prematurely born), birth term was significantly correlated with performances at the 3 tests of attention. In all cases, preterm was inversely correlated with performances.

CONCLUSION

The results are consistent with a lower efficiency in attention executive processes which may be related to the higher frequency of learning disabilities associated with prematurity.

Mechanisms of paracrine regulation by fetal membranes of human uterine quiescence

OBJECTIVE

To test the hypothesis that fetal membranes (chorion or amnion) release one or more factors responsible for myometrial quiescence.

METHODS

Myometrial samples were excised from women at elective term cesarean delivery prior to the onset of labor. Fetal membranes were obtained after cesarean delivery either before or during labor, and either term (greater than 37 weeks) or preterm (less than or equal to 36 weeks). Myometrial strips were placed in organ baths and contractions stimulated by oxytocin (10(-8) M). Contractility was measured under isometric conditions before and after exposure to fetal membranes or conditioned medium. The impact of either membrane or conditioned media on contractility was determined before and after myometrial K+ channel blockade.

RESULTS

Both chorion and amnion and their respective conditioned mediums decrease oxytocin-stimulated myometrial contraction. The inhibitory effect was greatest with membranes from preterm pregnancies (mean gestation 32 weeks, P <.05). The inhibitory effect was detectable in the presence of term labor, but was absent when the fetal membranes were obtained after preterm labor. Iberiotoxin, an inhibitor of large conductance Ca2+-activated K+ channels (BK(Ca)) reduced the effect of fetal membranes by 50% (P <.05).

CONCLUSION

We conclude that human fetal membranes release one or more factors that inhibit oxytocin-induced myometrial contractility. We suggest this factor (or factors) acts mainly by opening myometrial BK(Ca). The findings further support our hypothesis that the fetal membranes release a factor (or factors) that is central to myometrial quiescence and its premature loss leads to preterm delivery.

Improved neurosensory outcome at 8 years of age of extremely low birthweight children born in Victoria over three distinct eras

AIM

To determine neurosensory outcome at 8 years of age of extremely low birthweight (ELBW) children born in the 1990s, how it varies with birth weight, and how it compares with ELBW children born in the 1980s and 1970s.

METHODS

Subjects were born in the state of Victoria during 1991-92 and comprised 224 of 241 consecutive survivors with a birth weight of 500-999 g, and 223 of 262 normal birthweight (NBW) controls who had been randomly selected at birth. The comparison cohorts from earlier eras comprised 87 of 89 consecutive ELBW survivors born in 1979-80, 206 of 212 consecutive ELBW survivors born in 1985-87, and 51 of 60 randomly selected NBW survivors born in 1981-82. Survivors were assessed for neurological impairments (cerebral palsy, blindness, deafness, intellectual impairment) and disabilities at 8 years of age by paediatricians and psychologists blinded to perinatal details.

RESULTS

For the 1991-92 cohorts, the rate of neurosensory disability was substantially higher in ELBW children compared with NBW controls (p<0.0001). Within the ELBW group, neurosensory disability was more prevalent in children with a birth weight of <750 g compared with a birth weight of 750-999 g (p = 0.024). Disability rates were lower in the 1991-92 ELBW cohort compared with the ELBW cohort born in 1979-80 (p = 0.046).

CONCLUSIONS

Neurosensory disability rates at school age were more common in ELBW children born in the 1990s compared with NBW controls, and were significantly more common in the 500-749 g birthweight subgroup, but have improved compared with ELBW children born in earlier eras.

Predictive power of maternal serum and amniotic fluid CRP and PAPP-A concentrations at the time of genetic amniocentesis for the preterm delivery

OBJECTIVE

To investigate whether maternal serum and amniotic fluid CRP and PAPP-A concentrations at the time of genetic amniocentesis are markers of preterm delivery.

STUDY DESIGN

One hundred and forty-one pregnant women were included in this prospective study. Amniotic fluid and maternal serum CRP and PAPP-A concentrations were determined by using commercially available kits. Receiver-operating characteristic (ROC) analysis was performed to determine the efficacy of maternal serum and amniotic fluid CRP and PAPP-A levels in predicting women with preterm delivery.

RESULTS

The prevalence of spontaneous preterm delivery before 37 weeks of gestation was 9.9%. ROC analysis revealed that amniotic fluid CRP level was the only parameter, which had a significant power in the prediction of preterm delivery. The optimum cut-off level was 0.65 mg/L. The sensitivity and specificity were 92.9% and 78.7%, respectively.

CONCLUSION

The amniotic fluid CRP level has a high sensitivity and specificity in the prediction of preterm delivery and this may be helpful in predicting preterm delivery during genetic amniocentesis.

Maternal prenatal anxiety and corticotropin-releasing hormone associated with timing of delivery

OBJECTIVE

The high rate of preterm births is an imposing public health issue in the United States. Past research has suggested that prenatal stress, anxiety, and elevated levels of maternal plasma corticotropin-releasing hormone (CRH) are associated with preterm delivery in humans and animals. Studies to date have not examined all three variables together; that is the objective of this paper.

METHODS

Data from 282 pregnant women were analyzed to investigate the effect of maternal prenatal anxiety and CRH on the length of gestation. It was hypothesized that at both 18 to 20 weeks (Time 1) and 28 to 30 weeks gestation (Time 2), CRH and maternal prenatal anxiety would be negatively associated with gestational age at delivery. CRH was also expected to mediate the relationship between maternal prenatal anxiety and gestational age at delivery.

RESULTS

Findings supported the mediation hypothesis at Time 2, indicating that women with high CRH levels and high maternal prenatal anxiety at 28 to 30 weeks gestation delivered earlier than women with lower CRH levels and maternal prenatal anxiety. Women who delivered preterm had significantly higher rates of CRH at both 18 to 20 weeks gestation and 28 to 30 weeks gestation (p <.001) compared with women who delivered term.

CONCLUSIONS

These findings are the first to link both psychosocial and neuroendocrine factors to birth outcomes in a prospective design.

Perinatal risk factors for adverse neurodevelopmental outcome after spontaneous preterm birth

OBJECTIVE

The aim of this study was to investigate to what extend perinatal factors contribute to the neurodevelopmental outcome in a group neonates born after spontaneous preterm labour with or without prolonged rupture of the membranes (PROM).

METHODS

In a cohort of neonates born after the spontaneous onset of labour with or without PROM before 34 weeks of gestation a stepwise forward logistic regression was performed to analyse the influence of antenatal and postnatal variables on adverse outcome. Adverse neurodevelopmental outcome was defined as a Griffith's developmental score <85, cerebral palsy, a major disability or perinatal death associated with severe cerebral damage.

RESULTS

The study group consisted of 185 neonates. Seven neonates died with severe cerebral damage. After a forward logistic regression analysis three factors appeared to have an independent influence: gestational age protected against an adverse outcome (odds ratio (OR) per day increase 0.95, 95% confidence interval (CI) 0.90-0.97) while abnormal cranial ultrasound (intraventricular haemorrhage and periventricular leucomalacia) (OR 6.33, 95% CI 2.16-18.52) and the need for a second course of antibiotics (OR 1.85, 95% CI 1.02-3.33) increased the risk for adverse outcome. Comparing the group with a normal neurodevelopmental outcome with those with cerebral palsy, cranial ultrasound abnormalities were independently associated with cerebral palsy (OR 48.75, 95% CI 11.78-201.76).

CONCLUSION

The most important way of preventing neurological damage in infants is to increase gestational age at birth and to avoid the development of intraventricular haemorrhage and periventricular leucomalacia.

The neurobiology of stress in human pregnancy: implications for prematurity and development of the fetal central nervous system

Adverse early experience, including prenatal maternal psychosocial stress, has the potential to negatively influence developmental processes through both physiological and behavioral mechanisms. This in turn may have adverse consequences for the mental and physical health, well-being and aging of the individual throughout the entire life-span. We have initiated a program of research on humans to examine the consequences of maternal stress and related factors in pregnancy on the length of gestation, fetal growth, and brain development. We have also investigated the physiological mechanisms that are involved. In this chapter we outline the theoretical rationale for this work and give an overview of our findings to date. These findings support a significant and independent role for behavioral processes such as maternal prenatal stress in the etiology of prematurity-related outcomes, and suggest that these effects are mediated, in part, by the maternal-placental-fetal neuroendocrine axis; specifically by placental corticotropin-releasing hormone. Using a fetal challenge paradigm as a novel method for quantifying fetal neurologic maturity in utero, we have found that the maternal environment exerts a significant influence on the fetal autonomic nervous system and on central nervous system processes related to recognition, memory and habituation. Finally, our findings provide preliminary evidence to support the notion that the influence of prenatal stress and maternal-placental hormones on the developing fetus may persist after birth, as assessed by measures of temperament and behavioral reactivity in the first 3 years of postnatal life. The implications of these studies for life-span development and health are discussed.

Brain preparations for maternity--adaptive changes in behavioral and neuroendocrine systems during pregnancy and lactation. An overview

Pregnancy, parturition and lactation comprise a continuum of adaptive changes necessary for the development and maintenance of the offspring. The endocrine changes that are driven by the conceptus and are essential for the maintenance of pregnancy and are involved in the preparations for motherhood are outlined. These changes include large increases in the secretion of sex steroid hormones, and the secretion of peptide hormones that are unique to pregnancy. The ability of these pregnancy hormones to alter several aspects of brain function in pregnancy is considered, and the adaptive importance of some of these changes is discussed, for example in metabolic and body fluid adjustments, and the induction of maternal behavior. The importance of sex steroids in determining the timing of the various adaptive changes in preparing for parturition and maternal behavior is emphasized, and the concept that the actions of prolactin and oxytocin, quintessential mammalian motherhood neuropeptides, can serve to coordinate a spectrum of adaptive changes is discussed. The part played by oxytocin neurons and their regulatory mechanisms is reviewed to illustrate how neural systems involved in maternity are prepared in pregnancy via changes in phenotype, synaptic organization and in the relative importance of their different inputs, to function optimally when needed. For oxytocin neurons secreting from the posterior pituitary, important in parturition and essential in lactation, these changes include mechanisms to restrain their premature activation, and adaptations to support synchronized burst firing for pulsatile oxytocin secretion in response to stimulation via afferents from the birth canal, olfactory system or suckled nipples. Within the brain, expression of oxytocin receptors permits centrally released oxytocin to facilitate the expression of maternal behavior. Changes in other neuroendocrine systems are similarly extensive, leading to lactation, suppression of ovulation, reduced stress responses and increased appetite; these changes in lactation are driven by the suckling stimulus. The possible link between these adaptations and changes in cognition and mood in pregnancy and post partum are considered, as well as the dysfunctions that lead to common problems of depression and puerperal psychoses.

Predicting risk of preterm delivery by second-trimester measurement of maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations

OBJECTIVE

Many women who have preterm labor have abnormally high plasma concentrations of the placental peptide corticotropin-releasing hormone and the fetal product alpha-fetoprotein in early pregnancy. This study was designed to evaluate the ability of these biochemical tests and a clinical risk factor score to prospectively discriminate pregnancies at high risk for preterm delivery.

STUDY DESIGN

Eight hundred sixty women were studied prospectively from the early second trimester until delivery. A risk factor score for preterm delivery was calculated from the clinical history and maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations were measured by radioimmunoassay between 17 and 30 weeks' gestation. The risk factor score, corticotropin-releasing hormone concentration, and alpha-fetoprotein concentration for each woman were expressed as individual odds or likelihood ratios for preterm delivery and as a combined risk estimate derived from the 3 tests.

RESULTS

Sixty women had preterm deliveries (n = 37 spontaneous labor, n = 23 planned deliveries), and these women had significantly higher concentrations of corticotropin-releasing hormone (median 1.92 multiples of the median) and alpha-fetoprotein (median 1.32 multiples of the median) than did women with term deliveries (median 1.00 multiples of the median, P <.001 for both tests), with these abnormalities being evident from early in the second trimester. The risk factor score was >/=10 in 28% of women with preterm delivery and 7% of women with term delivery. The combination of all 3 markers resulted in a higher detection rate and a higher positive predictive value than the risk factor score, corticotropin-releasing hormone concentration, or alpha-fetoprotein concentration alone, correctly discriminating 37% of women who would have preterm deliveries with a false-positive rate of 5%. The positive predictive value was also 37% (odds of being affected given a positive result were 1:1.7).

CONCLUSIONS

The combination of measurement of maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations in the second trimester with risk factor scoring provides a more accurate indicator of the risk of preterm delivery than does risk factor scoring alone. This method of risk assessment may therefore be of use in targeting prevention strategies.

Longitudinal study of neuropsychological outcome in blind extremely-low-birthweight children

This study evaluated neurological and psychological development in 10 blind children over a 4-year period. Five of the children were born preterm with an extremely low birthweight (ELBW) and a diagnosis of retinopathy, whereas the other five were term. All children received their first neurological examination at a mean age of 10 months and then annual follow ups. In addition, the Bielefeld Developmental Test for Blind Infants and Preschoolers (BDTB) was administered every 6 months (from the ages of 18 to 48 months) to assess developmental outcome in different domains (e.g. cognition, language, gross motor abilities). Results showed a higher number of peri- and neonatal complications in blind ELBW children as well as a significantly higher number of neurological symptoms over the 4-year period. At the mean age of 4 years 10 months, blind ELBW children had a significantly lower body weight, body height, head circumference, and body-mass index compared with the term children. Findings on psychological development revealed that blind ELBW children also had significantly lower scores on all domains covered by the BDTB. Finally, the overall score on the BDTB correlated significantly with gestational age, birthweight, duration of mechanical respiration, and days spent in hospital after delivery.

Evaluation of neurodevelopmental outcome in high-risk infants in Australia

An understanding of the neurodevelopmental outcome of long-term survivors of neonatal intensive care is essential for the informed management of preterm or high risk infants. This annotation looks at the current status of neonatal follow-up services in Australasia and highlights problems in the collection and interpretation of data. It suggests that we should work towards achieving a consensus on standard definitions and test regimes and on national data collection.

Prenatal psychosocial factors and the neuroendocrine axis in human pregnancy

OBJECTIVE

Physiological processes including neuroendocrine function have been proposed as mediators of the relationship between prenatal psychological state and pregnancy outcome; however, there are virtually no human studies that have systematically assessed such mechanisms. Neuroendocrine processes are significantly altered during pregnancy, and are characterized by the evolution of a transient neuroendocrine system, the placenta, and modifications in endocrine control mechanisms. Because these alterations have implications for neuroendocrine responsivity to exogenous conditions, the aim of the present study was to examine the cross-sectional association between prenatal psychosocial factors and stress-related neuroendocrine parameters during human pregnancy.

METHOD

Fifty-four adult women with a singleton, intrauterine pregnancy were recruited before 28 weeks of gestation. Maternal antecubital venous blood samples were withdrawn at 28 weeks of gestation for bioassays of adrenocorticotropin hormone (ACTH), beta-endorphin (beta E), and cortisol. Measures of prenatal stress, social support, and personality were collected using a two-part, self-report questionnaire administered at 28 and 30 weeks of gestation. Biomedical data were obtained from the medical record. Factors known to influence neuropeptide and hormone levels during pregnancy were controlled, including gestational age, circadian variation, and obstetric risk.

RESULTS

In the present sample, prenatal psychosocial stress, social support, and personality variables were associated with neuroendocrine parameters in two primary ways. First, certain psychosocial factors were significantly associated with plasma levels of ACTH, beta E, and cortisol, and second, psychosocial factors were associated with a measure of disregulation of the normal relationship between two pro-opiomelanocortin (POMC) derivatives, ACTH and beta E. Furthermore, a combination of the maternal psychosocial and sociodemographic factors during pregnancy accounted for 36% of the variance in ACTH, 22% of the variance in the ACTH-beta E disregulation index, 13% of the variance in cortisol, and 3% of the variance in beta E.

CONCLUSIONS

The present findings are consistent with the premise that maternal-placental-fetal neuroendocrine parameters are significantly associated, both in magnitude and specificity, with features of maternal psychosocial functioning in pregnancy despite the systemic alterations associated with the endocrinology of pregnancy. These findings provide a basis for further investigations of the role of the neuroendocrine system as a putative mediating pathway between prenatal psychosocial factors and birth outcome, and possibly also as a mechanism linking features of the maternal psychosocial environment to fetal/infant brain development.

[Neurologic development in premature infants under 33 weeks of gestational age: determination of risk of neurological abnormalities in a prospective regional survey with a control group]

AIM

The purpose of this population-based study was to compare the incidence of neurodevelopmental disability and its risk factors between preterm and full-term infants matched as control group.

POPULATION AND METHODS

The preterm cohort included 203 infants born between 25 and 33 weeks of gestational age in the region of Franche-Comté (France) during a two-year-period. The control group included 196 full-term infants born in the same maternities. Survival up to the date of follow-up was 171/203 (84%) for preterms and 195/196 (99.5%) for full-term infants (uncorrected age, mean 12 months). Neurodevelopmental assessments were performed by pediatricians or physicians on 164/171 surviving preterms (96% follow-up) and 179/195 full-terms (92%).

RESULTS

Thirty-two (19.5%) preterm infants had disability, ten of these (6%) showing severe disability. Five (2.8%) full-term infants had disability, one of these (.5%) having severe disability. Risk factors predicting a disability included in a multivariate approach: prematurity (odds-ratio [OR]: 7.8), maternal age > 37 (OR: 3.0), lack of profession for both parents (OR: 3.7), male gender (OR: 2.9). The pediatrician observed a disability more frequently than the physician (OR: 2.46). Likewise, risk factors predicting a severe disability included: prematurity (OR: 10.8), lack of profession for both parents (OR: 5.8) and monochorial twin-placentation (OR: 4.5).

CONCLUSIONS

Prematurity is not the only risk factor to be taken into account for neurodevelopmental evaluation of premature infants, but its influence still remains widely predominant.

Prevention of preterm birth

Preterm labour and delivery remain a major cause of perinatal morbidity, mortality and long-term adverse neurodevelopmental outcome. An effective primary prevention strategy is desirable, but current approaches appear largely ineffective at present. Understanding the aetiology of the onset of preterm labour continues to improve with the recognition of the role played by subclinical infection in a significant proportion of cases. The investigation of hormonal influences in the aetiology of preterm labour is at an early stage, but there appears to be a relationship between raised serum relaxin concentrations and preterm delivery (Petersen et al, 1992). The naturally occurring phospholipase A2-inhibitor gravidin, believed to be important in pregnancy maintenance, is found in a reduced concentration in women delivering preterm (Wilson, 1993). The relationship between hormonal levels, socio-economic influences, subclinical infection and actual preterm labour and delivery remains to be established. Secondary prevention with tocolysis remains unsatisfactory, owing to the low therapeutic index of currently available agents and their varied maternal and neonatal adverse effects. The investigation of newer tocolytic agents remains a worthwhile pursuit, whilst the underlying aetiology of preterm labour and effective prevention remains to be elucidated. The widespread recognition of the benefits of antenatal corticosteroid administration and subsequent adoption into clinical practice has reduced, and will continue to reduce, the morbidity associated with preterm birth while newer methods of accelerating fetal maturation are explored and applied in clinical practice.

New perspectives for the effective treatment of preterm labor

Preterm birth (before 37 completed weeks of gestation) continues to account for the vast majority of neonatal morbidity and mortality. The incidence of preterm birth can be reduced by appropriate social interventions and antenatal care. Currently available tocolytic agents suffer from low uterospecificity and prolong pregnancy only marginally, although postponement of birth by a few days may be of some value. Further progress is needed in at least four areas: prevention of preterm labor; identification of preterm labor; selection of candidates for tocolysis, and treatment of preterm labor. Effective, early treatment of vaginosis offers particular promise for the prevention of preterm labor and identification of specific biochemical markers will facilitate early detection of this process. Oxytocin antagonists offer greater specificity than current tocolytics and can be expected to show improved efficacy and risk profiles. Such compounds will allow more effective treatment of preterm labor with a lower risk of side effects.