Perinatal outcomes associated with preterm birth at 33 to 36 weeks' gestation: a population-based cohort study

Previous stillbirth, late preterm, and early-term birth

Subsequent pregnancies are emotionally traumatic for families with previous stillbirths. Such pregnancies have a 2- to 10-fold increase in the risk for stillbirth as well as an increased probability of other adverse obstetrical outcomes. These medical risks as well as anxiety on the part of families and care providers contribute to an increase in late preterm and early-term birth. However, delivery before 39 weeks' gestation has not been proven to reduce the risk of recurrent stillbirth or adverse pregnancy outcomes in women with previous stillbirths. This work reviews data regarding the optimal timing of delivery in subsequent pregnancies after previous stillbirth, as well as for patients at risk from stillbirth in general. Management recommendations from current data are presented and knowledge gaps are highlighted.

Association of late-preterm birth with asthma in young children: practice-based study

OBJECTIVE

To evaluate the association of late-preterm birth with asthma severity among young children.

METHODS

A retrospective cohort study was performed with electronic health record data from 31 practices affiliated with an academic medical center. Participants included children born in 2007 at 34 to 42 weeks of gestation and monitored from birth to 18 months. We used multivariate logistic or Poisson models to assess the impact of late-preterm (34-36 weeks) and low-normal (37-38 weeks) compared with term (39-42 weeks) gestation on diagnoses of asthma and persistent asthma, inhaled corticosteroid use, and numbers of acute respiratory visits.

RESULTS

Our population included 7925 infants (7% late-preterm and 21% low-normal gestation). Overall, 8.3% had been diagnosed with asthma by 18 months. Compared with term gestation, late-preterm gestation was associated with significant increases in persistent asthma diagnoses (adjusted odds ratio [aOR]: 1.68), inhaled corticosteroid use (aOR: 1.66), and numbers of acute respiratory visits (incidence rate ratio: 1.44). Low-normal gestation was associated with increases in asthma diagnoses (aOR: 1.34) and inhaled corticosteroid use (aOR: 1.39).

CONCLUSION

Birth at late-preterm and low-normal gestational ages might be an important risk factor for the development of asthma and for increased health service use in early childhood.

Outcomes of preterm infants: morbidity replaces mortality

Over the last 50 years in the United States a rising preterm birth rate, a progressive decrease in preterm mortality, and a lowering of the limit of viability have made preterm birth a significant public health problem. Neuromaturation, the functional development of the central nervous system (CNS), is a dynamic process that promotes and shapes CNS structural development. This article reviews preterm outcomes, recognizing that multiple factors influence neuromaturation and lead to a range of neurodevelopmental disabilities, dysfunctions, and altered CNS processing. Ways to protect preterm infants and support their growth and development in and beyond intensive care are examined.

Morbidity and mortality in late preterm and early term newborns: a continuum

Late preterm and early term infants are at higher risk for short-term and long-term morbidities and mortality than term infants. Such outcomes are influenced by many factors, the strongest of which is gestational age. Counseling and educating women and families about risks of late preterm and early term births is helpful for timing and route of delivery, managing the pregnancy and infant, and prognosticating outcomes for infants.

Adherence to discharge guidelines for late-preterm newborns

OBJECTIVE

To evaluate trends in adherence to American Academy of Pediatrics recommendations for early discharge of late-preterm newborns and to test the association between hospital characteristics and early discharge.

PATIENTS AND METHODS

This study was a population-based cohort study using statewide birth-certificate and hospital-discharge data for newborns in California, Missouri, and Pennsylvania from 1993 to 2005. A total of 282 601 late-preterm newborns at 611 hospitals were included. Using logistic regression, we studied the association of early discharge with regional and hospital factors, including teaching affiliation, volume, and urban versus rural location, adjusting for patient factors.

RESULTS

From 1995 to 2000, early discharge decreased from 71% of the sample to 40%. However, by 2005, 39% were still discharged early. Compared with Pennsylvania, California (adjusted odds ratio [aOR]: 5.95 [95% confidence interval (CI): 5.03-7.04]), and Missouri (aOR: 1.56 [95% CI: 1.26-1.93]) were associated with increased early discharge. Nonteaching hospitals were more likely than teaching hospitals to discharge patients early if they were uninsured (aOR: 1.91 [95% CI: 1.35-2.69]) or in a health maintenance organization plan (aOR: 1.40 [95% CI: 1.06-1.84]) but not patients with fee-for-service insurance (aOR: 1.04 [95% CI: 0.80-1.34]). A similar trend for newborns on Medicaid was not statistically significant (aOR: 1.77 [95% CI: 0.95-3.30]).

CONCLUSIONS

Despite a decline in the late 1990s, early discharge of late-preterm newborns remains common. We observe differences according to state, hospital teaching affiliation, and patient insurance. Additional research on the safety and appropriateness of early discharge for this population is necessary.

[Short-term complications of late preterm infants]

INTRODUCTION

Late preterm infants, born at 34-36(+6) weeks gestation, are physiologically more immature than term infants. As a consequence, they have an increased risk of morbidity and mortality. Since health outcomes in prematurity may change depending on local factors we have proposed determine the short-term medical problems of these infants in our hospital.

PATIENTS AND METHODS

A retrospective observational study was carried out on all newborn ≥ 34 weeks gestation admitted to Virgen del Rocio hospital from May 2005 to December 2008. We divided this cohort into late preterm (34-36(+6) weeks, n=769) and term (37-41(+6) weeks, n=1460) groups. We compared mortality and morbidity data between the 2 groups.

RESULTS

Late preterm group was associated with assisted reproduction, twin pregnancy, caesarean delivery and preeclampsia during pregnancy. The risk of hospitalization was six times greater in these infants and neonatal intensive care admissions were twice as common. The hospital stay was double in this group. Neonatal respiratory morbidity and jaundice were greater in the preterm group. The use of surfactant, oxygen and respiratory support (CPAP and CMV) was also higher. There were no significant differences in hypoglycaemia and neonatal mortality between both groups.

CONCLUSIONS

Late preterm infants represent a well-defined risk group for developing complications and should be available the necessary resources should be made available for their special care.

Maternal preeclampsia and neonatal outcomes

Preeclampsia is a multiorgan, heterogeneous disorder of pregnancy associated with significant maternal and neonatal morbidity and mortality. Optimal strategies in the care of the women with preeclampsia have not been fully elucidated, leaving physicians with incomplete data to guide their clinical decision making. Because preeclampsia is a progressive disorder, in some circumstances, delivery is needed to halt the progression to the benefit of the mother and fetus. However, the need for premature delivery has adverse effects on important neonatal outcomes not limited to the most premature infants. Late-preterm infants account for approximately two thirds of all preterm deliveries and are at significant risk for morbidity and mortality. Reviewed is the current literature in the diagnosis and obstetrical management of preeclampsia, the outcomes of late-preterm infants, and potential strategies to optimize fetal outcomes in pregnancies complicated by preeclampsia.

Neonatal outcomes in a population of late-preterm infants

The late-preterm infants are a group of premature steadily increasing, different from term infants as immature in terms of respiratory, metabolic, neurological, and immunological features. They may present at birth and during the first week of life various diseases and brain lesions echographically evident. We analyzed the neonatal outcomes of 417 late-preterm infants, born in our Department of Neonatology in a period of two and a half years, evaluating respiratory problems (RDS, transient tachypnea, pneumonia, pneumothorax, and apnea), metabolic problems (hypoglycemia, hypomagnesemia, hypo-hypernatremia, dehydration, hypocalcemia, and hyperbilirubinemia), infections, neurological symptoms associated with electrolyte disturbances, the disease patterns observed by ultrasound examination of the brain, the kidney ultrasound images, genital malformations.

Cognitive deficit in preschoolers born late-preterm

BACKGROUND

late-preterm (LPT) birth accounts for a majority of preterm deliveries and until recently was considered low risk for poor cognitive outcome. Previously, we reported deficits in complicated LPT (cLPT) preschoolers (neonatal intensive care unit [NICU]-admitted).

AIM

to extend our prior study by comparing cognitive outcome in cLPT and uncomplicated LPT (uLPT; NICU non-admitted) preschoolers.

STUDY DESIGN

single center retrospective cohort study of 118 LPT children born in 2004-2006 at 35-36 weeks of gestation; 90 cLPT and 28 uLPT, compared with 100 term-born (≥ 37 weeks of gestation and ≥ 2500 g) participants.

OUTCOME MEASURE

a well-standardized measure of general conceptual ability (GCA), the Differential Ability Scales, Second Edition.

RESULTS

cLPT participants had average mean performances but significantly poorer GCA, Nonverbal Reasoning, and Spatial scores than term-born children, and higher rates of Nonverbal Reasoning and Spatial impairment; uLPT did not differ from TERM. Combined LPT males were at eightfold greater risk than term-born males for nonverbal deficit, and at sevenfold greater risk for GCA impairment than LPT females.

CONCLUSIONS

finding greater risk of cognitive deficit in those NICU-admitted due to clinical instability or birth weight < 2 kg compared with non-admitted preschoolers indicates that neonatal morbidities contribute to subtle cognitive deficits detectable at young age, with male gender an additive risk factor. LPT gestational age alone is an insufficient predictor of long-term neurocognitive outcome. Further study should elucidate salient etiologies for early emerging cognitive weaknesses and suggest appropriate interventions to prepare at-risk LPT preschoolers for elementary school entry.

The paradox of breastfeeding-associated morbidity among late preterm infants

OBJECTIVE

To synthesize the published research pertaining to breastfeeding establishment and outcomes among late preterm infants and to describe the state of the science on breastfeeding within this population.

DATA SOURCES

Online databases Ovid MEDLINE, CINAHL, PubMed, and reference lists of reviewed articles.

STUDY SELECTION

Nine data-based research articles examining breastfeeding patterns and outcomes among infants born between 34 0/7 and 36 6/7 weeks gestation or overlapping with this time period by at least 2 weeks.

DATA EXTRACTION

Effect sizes and descriptive statistics pertaining to breastfeeding initiation, duration, exclusivity, and health outcomes among late preterm breastfed infants.

DATA SYNTHESIS

Among late preterm mother/infant dyads, breastfeeding initiation appears to be approximately 59% to 70% (U.S.), whereas the odds of breastfeeding beyond 4 weeks or to the recommended 6 months (exclusive breastfeeding) appears to be significantly less than for term infants, and possibly less than infants ≤34 to 35 weeks gestation. Breastfeeding exclusivity is not routinely reported. Rehospitalization, often related to "jaundice" and "poor feeding," is nearly twice as common among late preterm breastfed infants as breastfed term or nonbreastfed late preterm infants. Barriers to optimal breastfeeding in this population are often inferred from research on younger preterm infants, and evidence-based breastfeeding guidelines are lacking.

CONCLUSIONS

Late preterm infants are at greater risk for breastfeeding-associated rehospitalization and poor breastfeeding establishment compared to their term (and possibly early preterm) counterparts. Contributing factors have yet to be investigated systematically.

Morbidity and discharge timing of late preterm newborns

Late preterm newborns (LPNs), those with gestational ages (GAs) between 34 weeks and 36 weeks 6 days, account for 70% of preterm births. Because they have a mature appearance and are often cared for in a well baby nursery (WBN), parents may anticipate that the nursery course will be similar to that of a term infant and that their newborn will be discharged with his/her mother. How frequently their hospitalizations are prolonged beyond that of their mothers and the morbidities associated with prolonged hospitalization (PH) have not been well described. The objectives of the study were to (1) determine the proportion of LPNs with a PH and (2) describe the most common morbidities in LPNs and identify those associated with PH. The authors conducted retrospective chart reviews of the neonatal courses of LPNs born between December 2002 and April 2007 at the University of Utah Hospital. They compared maternal and newborn discharge dates to determine the proportion of LPNs with a PH and calculated frequencies of conditions and interventions indicating morbidity and identified associations between each of the conditions/interventions and PH. Of 235 LPNs, 94 (40%) had a PH; 75% of 34-week LPNs had a PH compared with 50% of those with GAs of 35 weeks and 25% of those with GAs of 36 weeks. The most common conditions/interventions were an oxygen need, phototherapy for jaundice, and hypothermia requiring an isolette. A need for nasogastric feeding and antibiotic administration for >3 days was consistently associated with a PH. LPNs whose only intervention was phototherapy for jaundice or IV antibiotics for <3 days did not have a PH. As a group, two thirds of LPNs experienced one or more conditions/interventions indicating morbidity, and 40% had a PH. Both were much more common in LPNs with GAs of 34 weeks compared with LPNs with GAs of 36 weeks. Nursery clinicians should counsel parents of LPNs regarding the likely possibility of morbidity and PH.

Intake of artificially sweetened soft drinks and risk of preterm delivery: a prospective cohort study in 59,334 Danish pregnant women

BACKGROUND

Sugar-sweetened soft drinks have been linked to a number of adverse health outcomes such as high weight gain. Therefore, artificially sweetened soft drinks are often promoted as an alternative. However, the safety of artificial sweeteners has been disputed, and consequences of high intakes of artificial sweeteners for pregnant women have been minimally addressed.

OBJECTIVE

We examined the association between intakes of sugar-sweetened and artificially sweetened soft drinks and preterm delivery.

DESIGN

We conducted prospective cohort analyses of 59,334 women from the Danish National Birth Cohort (1996-2002). Soft drink intake was assessed in midpregnancy by using a food-frequency questionnaire. Preterm delivery ( lt 37 wk) was the primary outcome measure. Covariate information was assessed by telephone interviews.

RESULTS

There was an association between intake of artificially sweetened carbonated and noncarbonated soft drinks and an increased risk of preterm delivery (P for trend: le 0.001, both variables). In comparison with women with no intake of artificially sweetened carbonated soft drinks, the adjusted odds ratio for women who consumed ge 1 serving of artificially sweetened carbonated soft drinks/d was 1.38 (95% CI: 1.15, 1.65). The corresponding odds ratio for women who consumed ge 4 servings of artificially sweetened carbonated soft drinks/d was 1.78 (95% CI: 1.19, 2.66). The association was observed for normal-weight and overweight women. A stronger increase in risk was observed for early preterm and moderately preterm delivery than with late-preterm delivery. No association was observed for sugar-sweetened carbonated soft drinks (P for trend: 0.29) or for sugar-sweetened noncarbonated soft drinks (P for trend: 0.93).

CONCLUSIONS

Daily intake of artificially sweetened soft drinks may increase the risk of preterm delivery. Further studies are needed to reject or confirm these findings.

Determinants of morbidity in late preterm infants

OBJECTIVE

To assess the effect of selected maternal medical conditions and complications of pregnancy on the risk for morbidity among late preterm neonates.

DESIGN

Prospective cohort study.

MATERIAL AND METHODS

A total of 548 late preterm neonates (34(0/7) to 36(6/7)weeks' gestation) delivered from August 2006 to July 2009, were included. Information regarding demographics, gestational age, mode of delivery, maternal age and parity, pre-existing medical conditions and complications of pregnancy were obtained and associated with neonatal morbidity, both independently and as joint exposures. Newborn morbidity was defined by combining specific diagnoses, length of hospital stay, and transfer to the Neonatal Intensive Care Unit.

RESULTS

Overall, 165 (30.1%) of the late preterm infants suffered from morbidity. The morbidity rates were 16.8% at 36 weeks' gestation, and then approximately doubled from 38.2% at 35 weeks to 59.7% at 34 weeks. The joint effect of gestational age (OR 8.43 for 34 weeks and 3.60 for 35 weeks' gestation), small for gestational age (SGA) (OR 4.18), multiple gestation (OR 3.68) and lack of antenatal steroid administration (OR 4.03), was greater than the independent effect of each of these factors, and greater than additive. Emergency caesarean section (OR 1.43) and antepartum haemorrhage (OR 3.07) were also associated with a significant impact on neonatal morbidity.

CONCLUSIONS

The risk for morbidity among late preterm infants, changes with each passing week of gestation. This risk seems to be intensified, when other exposures such as SGA, multiple gestation, emergency caesarean section, lack of antenatal steroid administration and antepartum haemorrhage, are also present.

Scope and impact of early and late preterm infants admitted to the PICU with respiratory illness

OBJECTIVE

To determine the clinical course and outcomes of children born early preterm (EPT, <32 weeks), late preterm (LPT, 32 to 35 weeks), and full term (FT, >or=36 weeks) who were subsequently admitted to the pediatric intensive care unit (PICU) with respiratory illness.

STUDY DESIGN

Retrospective chart review of patients <2 years old admitted to a tertiary PICU with respiratory illness.

RESULTS

Two hundred seventy-one patients met inclusion criteria: 17.3% were EPT, 12.2% were LPT, and 70.5% were FT. Lower respiratory tract infection was the most common diagnosis (55%) for all groups. Median PICU length of stay was longer for EPT (6.3 days) and LPT infants (7.1 days) compared with FT infants (3.7 days; P < .03 for both comparisons). EPT and LPT infants had longer hospital stays (median, 11.7 and 13.8 days, respectively) compared with FT infants (median, 7.1 days; P < .03 and P = .004, respectively). Median hospital charges were also greater for EPT ($85 151) and LPT ($83 576) groups compared with FT group ($55 122; P < .01 and P < .02, respectively).

CONCLUSIONS

EPT and LPT infants comprise a considerable proportion of PICU admissions for respiratory illness and have greater resource utilization than FT infants.

Late preterm infants: birth outcomes and health care utilization in the first year

OBJECTIVE

To distinguish the effects of late preterm birth from the complications associated with the causes of delivery timing, this study used propensity score-matching methods on a statewide database that contains information on both mothers and infants.

METHODS

Data for this study came from Arkansas Medicaid claims data linked to state birth certificate data for the years 2001 through 2005. We excluded all multiple births, infants with birth defects, and infants at <33 weeks of gestation. Late preterm infants (LPIs) (34 to 36 weeks of gestation) were matched with term infants (37-42 weeks of gestation) according to propensity scores, on the basis of infant, maternal, and clinical characteristics.

RESULTS

A total of 5188 LPIs were matched successfully with 15303 term infants. LPIs had increased odds of poor outcomes during their birth hospitalization, including a need for mechanical ventilation (adjusted odds ratio [aOR]: 1.31 [95% confidence interval [CI]: 1.01-1.68]), respiratory distress syndrome (aOR: 2.84 [95% CI: 2.33-3.45]), and hypoglycemia (aOR: 1.60 [95% CI: 1.26-2.03]). Outpatient and inpatient Medicaid expenditures in the first year were both modestly higher (outpatient, adjusted marginal effect: $108 [95% CI: $58-$158]; inpatient, $597 [95% CI: $528-$666]) for LPIs.

CONCLUSIONS

LPIs are at increased risk of poor health-related outcomes during their birth hospitalization and of increased health care utilization during their first year.

Respiratory morbidity and lung function in preterm infants of 32 to 36 weeks' gestational age

Normal lung development follows a series of orchestrated events. Premature birth interrupts normal in utero lung development, which results in significant alterations in lung function and physiology. Increasingly, there are reports documenting the broad range of complications experienced by infants aged 34 to 36 weeks' gestational age (GA). Our objective was to summarize the evidence demonstrating respiratory system vulnerability in infants aged 34 to 36 weeks' GA and to review the developmental and physiologic principles that underlie this vulnerability. A comprehensive search for studies that reported epidemiologic data and respiratory morbidity was conducted on the PubMed, Medline, Ovid Biosis, and Embase databases from 2000 to 2009 by using medical subject headings "morbidity in late preterm infants," "preterm infants and lung development," "prematurity and morbidity," and "prematurity and lung development." Because the number of studies exclusive to infants aged 34 to 36 weeks' GA was limited, selected studies also included infants aged 32 to 36 weeks' GA. Of the 24 studies identified, 16 were retrospective population-based cohort studies; 8 studies were observational. These studies consistently revealed that infants born at 32 to 36 weeks' GA, including infants of 34 to 36 weeks' GA, experience substantial respiratory morbidity compared with term infants. Levels of morbidity were, at times, comparable to those observed in very preterm infants. The developmental and physiologic mechanisms that underlie the increased morbidity rate and alterations in respiratory function are discussed. We also present evidence to demonstrate that the immaturity of the respiratory system of infants 34 to 36 weeks' GA at birth results in increased morbidity in infancy and leads to deficits in lung function that may persist into adulthood.

Women's perceptions regarding the safety of births at various gestational ages

OBJECTIVES

To estimate women's understanding of the definition of full term and the gestational age at which it is safe to deliver an otherwise healthy pregnancy.

METHODS

A national sample of 650 insured women who recently gave birth were surveyed about their beliefs related to the meaning of full term and the safety of delivery at various gestational ages. Descriptive statistics including means and 95% confidence intervals were calculated for the demographic variables and survey measures; multivariate logistic regression analyses were also performed.

RESULTS

Twenty-four percent of women surveyed considered a baby of 34-36 weeks of gestation to be full term, and 50.8% believed full term to occur at 37-38 weeks of gestation, while only 25.2% considered full term to occur at 39-40 weeks of gestation. In response to, "What is the earliest point in pregnancy that it is safe to deliver the baby, should there be no other medical complications requiring early delivery?" 51.7% choose 34-36 weeks of gestation, and 40.7% choose 37-38 weeks of gestation, while only 7.6% choose 39-40 weeks of gestation.

CONCLUSION

The American College of Obstetricians and Gynecologists recommends that elective deliveries not occur before 39 weeks of gestation. However, many women believe that full term is reached before 37 weeks of gestation, and most believe full term occurs before 39 weeks of gestation. Nearly half believe it is safe to deliver before 37 weeks of gestation, and almost all believe it is safe to deliver before 39 weeks of gestation. The data reported here suggest that many women believe that term is reached early and that a safe delivery does not require waiting to 39 weeks of gestation.

LEVEL OF EVIDENCE

III.

Visuospatial and verbal fluency relative deficits in 'complicated' late-preterm preschool children

BACKGROUND

Late-preterm children constitute a majority of all preterm deliveries (75%). Their immature brain development at birth has been associated with an increased risk for morbidities. Data have been sparse regarding neuropsychological outcomes in the preschool years.

AIM

To examine general cognition, attention/working memory, language, manual coordination/motor dexterity, visuomotor, visuospatial, and executive functions in preschoolers born late-preterm (LPT; 34-36 gestational weeks) who required NICU admission compared to term-born participants.

DESIGN

Single-center retrospective cohort study of 95 three-year-old children; 60 born LPT in 2004-2005 and admitted to the NICU compared to 35 healthy term-born participants born > or =37 gestational weeks and > or =2500 g.

RESULTS

LPT birth was associated with visuospatial (p=.005), visuomotor (p=.012), and executive function (noun [p=.018] and action-verb [p=.026] fluency) relative deficits, but not attention/working memory, receptive or expressive language, nonverbal reasoning, or manual coordination/dexterity deficit.

CONCLUSIONS

Late-preterm birth is likely to be associated with negative neuropsychological sequelae, although subtle and selective compared to effects reported for children born at an earlier gestational age. Visuospatial function appears to be especially vulnerable to disruption even at preschool age, and verbal fluency may be useful as an early predictor of executive dysfunction in childhood. Routine preschool neuropsychological evaluation is recommended to identify delay or deficit in LPT children preparing for school entry, and may highlight underlying vulnerable neural networks in LPT children.

Outcomes of late-preterm infants: a retrospective, single-center, Canadian study

OBJECTIVE

To study the prevalence of major morbidities and mortality of inborn, late-preterm infants. Methods. A retrospective review was conducted from 2004 to 2008. Descriptive outcomes were compared with predefined aggregate outcomes of term infants during the same period.

RESULTS

Data on 1193 late-preterm and 8666 term infants were compared. Majority of late-preterm infants were 36 weeks (43.6%), followed by 35 weeks (29.2%) and 34 weeks (27.2%), respectively. The prevalence of intensive care admission, respiratory support, pneumothorax, and mortality in late preterm infants was significantly higher compared with term infants. Mechanical ventilation and continuous positive airway pressure rates substantially decreased with increased gestational age. Although only 1.0% had positive cultures, 28.5% received parenteral antibiotics. The late-preterm group had a 12-fold higher risk of death with an overall mortality rate of 0.8%.

CONCLUSION

This study confirmed the high-risk status of late-preterm infants with worse mortality and morbidities compared with term infants.

Embryo transfer practices in the United States: a survey of clinics registered with the Society for Assisted Reproductive Technology

OBJECTIVE

To gain a better understanding of factors influencing clinicians' embryo transfer practices.

DESIGN

Cross-sectional survey.

SETTING

Web-based survey conducted in December 2008 of individuals practicing IVF in centers registered with the Society for Assisted Reproductive Technology (SART).

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Prevalence of clinicians reporting following embryo transfer guidelines recommended by the American Society for Reproductive Medicine (ASRM), prevalence among these clinicians to deviate from ASRM guidelines in commonly encountered clinical scenarios, and practice patterns related to single embryo transfer.

RESULT(S)

Six percent of respondents reported following their own, independent guidelines for the number of embryos to transfer after IVF. Of the 94% of respondents who reported routinely following ASRM embryo transfer guidelines, 52% would deviate from these guidelines for patient request, 51% for cycles involving the transfer of frozen embryos, and 70% for patients with previously failed IVF cycles. All respondents reported routinely discussing the risks of multiple gestations associated with standard embryo transfer practices, whereas only 34% reported routinely discussing single embryo transfer with all patients.

CONCLUSION(S)

Although the majority of clinicians responding to our survey reported following ASRM embryo transfer guidelines, at least half would deviate from these guidelines in a number of different situations.

[Late preterm infants: A population at underestimated risk]

BACKGROUND AND OBJECTIVE

There has been a gradual rise in prematurity rates recent years, almost exclusively at the expense of the late preterm (34 to 36 weeks). This population, although with less risk than smaller preterm gestational age, has a morbidity rate significantly higher than term infants. However, there is some underestimation regarding developments in the short and long term. The aim of this study was to look at the incidence of prematurity in our institution and to analyze morbidity and mortality in late preterm compared with term infants

SUBJECTS AND METHODS

We performed a retrospective review of newborns in our Hospital from January 1992 until December 31, 2008. Late preterm group was defined as between 34(0/7) and 36(6/7) weeks gestation (N=2003) and term infants from 37 to 42 weeks gestation (N=32015). We formed 2 subgroups according two time periods (1992-1998 and 2000-2008). The morbidity and mortality for each of the groups and subgroups, and the morbidity from week 34 to 42, were analysed and compared.

RESULTS

During the period studied, the prematurity rate increased from 3.9% to 9.8%, exclusively at the expense of the late preterm (79%). The rate of mortality in late preterm was 5 per thousand compared to 1.1 per thousand in the term (P <0.0001, OR 4.71, 95% CI 2.3-9.5). The incidence of admission to the Neonatal Unit, Cesarean rate, twin, respiratory disorders, need for respiratory support in the form of nasal CPAP or mechanical ventilation, incidence of apnea, jaundice requiring phototherapy, hypoglycaemia and need for parenteral nutrition were significantly higher (P<0.0001) in the late preterm group compared with term infants. The morbidity rate decreased significantly as gestational age increased, with the lowest value from 39 weeks.

CONCLUSIONS

Morbidity and mortality in late preterm infants is significantly higher than in term infants. The guidelines for these near term premature babies need to be reviewed, looking for possible causes of prematurity, and trying to reduce their impact, as well as developing a protocol for their care and close monitoring to minimize the associated morbidity. There should be long-term monitoring to find out the consequences on their psychomotor development. The obstetrics group should be made aware of the true risks of births in the near-term gestational ages.

Neurodevelopmental outcome of the premature infant

Advances in antenatal medicine and neonatal intensive care have successfully resulted in improved survival rates of preterm infants. These improvements have been most dramatic in infants born extremely low birth weight (ELBW, <or=1000 g) and at the limits of viability (22 to 25 weeks). But improvements in survival have not been accompanied by proportional reductions in the incidence of disability in this population. Thus, survival is not an adequate measure of success in these infants who remain at high risk for neurodevelopmental and behavioral morbidities. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, not only for ELBW infants but for infants born late preterm.

Risk factors and management of transient tachypnea of the newborn

Transient tachypnea of the newborn (TTN) is the consequence of delayed clearance of fetal lung liquid in the newborn. With recognition of the increased risk in babies born by Cesarean sections, epidemiologic association with maternal asthma and increasing research on the possible role of genetic polymorphisms of ion-channel subunits, our understanding of the pathophysiology of this condition has vastly improved. We now know that the late-preterm infant, born at 34–36 weeks gestation, is at increased risk for both TTN and respiratory distress syndrome due to surfactant deficiency. As the incidence of Cesarean sections rises, there is likelihood of increased respiratory morbidity in newborns that will necessitate additional medical interventions and exposure to complications of intensive care. This review focuses on the risk factors that are associated with the development of TTN and the treatment strategies that are employed for the management of this condition.

Weight for gestational age affects the mortality of late preterm infants

BACKGROUND

Late preterm infant mortality is higher than that for term newborns. The association between weight for gestational age (WGA) category and late preterm mortality has not been well described.

OBJECTIVES

Our objectives for this research were as follows: (1) to compare neonatal and infant mortality rates of SGA, AGA, and LGA late preterm, early term, and term newborns; (2) to determine the relative risk of neonatal and infant death for each WGA category; and (3) to examine causes of neonatal and infant death.

METHODS

We reviewed linked birth and death certificate data for all infants from Utah born between 1999 and 2005 with a GA > or =34 weeks. We calculated neonatal and infant mortality rates for each GA/birth weight stratum and estimated mortality rate ratios using AGA term infants as the reference. International Classification of Diseases, Ninth Revision, codes were used to classify cause of death.

RESULTS

There were 343322 newborns with GA > or =34 weeks from 1999 to 2005. Late preterm SGA infants were approximately 44 times more likely than term AGA newborns to die in their first month and 22 times more likely to die in their first year. When infants dying from congenital conditions were excluded, the differences in mortality rate ratios persisted for SGA infants, especially those born in the late preterm period.

CONCLUSIONS

Being SGA substantially increases the already higher mortality of late preterm and early term newborns. This increased risk cannot be fully explained by an increased prevalence of lethal congenital conditions among SGA late preterm newborns. Clinicians caring for late preterm and early term newborns should be cognizant of their WGA category.

Health issues of the late preterm infant

"Late preterm" birth is not such an unusual occurrence; in fact these infants were the first group of premature infants who pediatricians learned to treat, and did so with such remarkable success that physicians no longer consider them to be of high risk. So, why the sudden interest in this group? There is now enough evidence that this population is not as benign as previously thought. They have increased mortality when compared to term infants and are at increased risk for complications including transient tachypnea of newborn (TTN), respiratory distress syndrome (RDS), persistent pulmonary hypertension (PPHN), respiratory failure, temperature instability, jaundice, feeding difficulties and prolonged neonatal intensive care unit (NICU) stay. Evidence is currently emerging that late preterm infants make up a majority of preterm births, take up significant resources, have increased mortality/morbidity, and may even have long-term neurodevelopmental consequences secondary to their late prematurity.