Composite Respiratory Morbidity Research Articles

Does antenatal corticosteroid therapy improve neonatal outcomes in late preterm birth?

Background Infants who are born at 34°/7 to 366/7 weeks of gestation (late preterm) are at greater risk for respiratory and other neonatal morbidities. The objective of this study was to examine the effects of the administration of antenatal corticosteroids (ACS) to women at risk for late preterm delivery on the incidence of neonatal outcomes. Method This was a prospective cohort study of singleton gestations at risk of imminent delivery between 34°/7 and 366/7 weeks. Neonatal outcomes were compared between mothers who received ACS and those who did not. The primary outcome was the rate of composite respiratory morbidity defined as the need for treatment within 72 h of life (continuous positive airway pressure or high flow nasal cannula for least 2 h or supplemental oxygen with a fraction of inspired oxygen of at least 0.30 for at least four continuous hours or mechanical ventilation). Results During the 3-year study period, 595 subjects were included in this study, comprising 234 subjects that received ACS and 361 that did not. Administration of ACS significantly reduced the rates of composite respiratory morbidity (aOR 0.63 95% CI 0.40–0.99), the use of CPAP or HFNC for at least 2 h (aOR 0.57 95% CI 0.35–0.94), and transient tachypnea of the newborn (aOR 0.48 95% CI 0.28–0.82). Neonatal hypoglycemia was more significantly increased in the ACS group compared with controls (aOR 1.64 95% CI 1.04–2.59). We found no significant between-group differences in the rate of respiratory distress syndrome, surfactant use, need for resuscitation, jaundice requiring phototherapy, admission to neonatal intensive care or special care nursery, and duration of hospitalization. Conclusion Administration of ACS during the late preterm period decreased neonatal respiratory complications, however, increased the rate of hypoglycemia.

Antenatal Corticosteroids Decrease the Risk of Composite Neonatal Respiratory Morbidity in Planned Early Term Cesarean Deliveries.

While administration of antenatal corticosteroids prior to term elective cesarean deliveries has been shown in international randomized controlled trials to decrease the rates of respiratory distress syndrome and transient tachypnea of the newborn, this is not a standard practice in the United States. We aim to determine if the administration of antenatal corticosteroids for fetal lung maturation within 1 week of scheduled early term cesarean delivery resulted in decreased composite respiratory morbidity. Historical cohort study including women who underwent scheduled early term cesarean delivery of a singleton, non-anomalous neonate at Mount Sinai Hospital between May 2015 and August 2019, comparing those who completed a course of antenatal corticosteroids within 1 week of delivery to those who did not. The primary outcome was composite respiratory morbidity defined as respiratory distress syndrome, transient tachypnea of the newborn, and neonatal intensive care unit admission for respiratory morbidity. Maternal and neonatal characteristics were compared between groups using t-tests or Wilcoxon-Rank Sum tests for continuous measures and Chi-square or Fisher's exact tests for categorical measures, as appropriate. The outcomes were assessed using logistic regression. History of preterm birth was significantly higher in those who received antenatal corticosteroids compared with those who did not (24.0 vs. 10.9%, p = 0.01). Neonates who were not exposed to antenatal corticosteroids were more likely to experience the composite respiratory morbidity compared with those who were exposed (RR 4.1, 95% CI 1.2-13.7; p = 0.02). Between 37 and 38 weeks, neonates who did not receive steroids were at increased risk of composite respiratory morbidity (RR 11.7, 95% CI 1.5-89.0, p < 0.01), however, there was no difference for those born between 38 and 39 weeks. Betamethasone course administered prior to planned early term cesarean delivery was associated with a statistically significant reduction in the neonatal composite respiratory morbidity compared with routine management. · Steroids administered prior to scheduled cesarean lead to decreased neonatal respiratory morbidity.. · Steroid administration was not associated with increased adverse neonatal outcomes.. · Steroid administration was most beneficial between 37 and 38 weeks..

Respiratory morbidity in very low birth weight infants through childhood and adolescence.

To describe the long-term (up to 18 years of age) respiratory outcomes of children and adolescents born at very low birth weight (VLBW;≤1500 g) in comparison with that of children born >1500 g. An observational, longitudinal, retrospective study comparing VLBW infants with matched controls, registered at a large health maintenance organization in Israel. Pulmonary outcomes collected anonymously from the electronic medical files included respiratory illness diagnoses, purchased medications for respiratory problems, office visits with either a pediatric pulmonologist or cardiologist and composite respiratory morbidity combining all these parameters. Our study included 5793 VLBW infants and 11,590 matched controls born between 1998 and 2012. The majority (99%) of VLBW infants were premature (born < 37 weeks' gestation), while 93% of controls were born at term. The composite respiratory morbidity was significantly higher in VLBW infants compared with controls in all age groups (relative risk [95% confidence interval]: 1 year: 1.22 [1.19-1.26], <2 years: 1.30 [1.27-1.34], 2-6 years: 1.29 [1.27-1.32], 6-12 years: 1.53 [1.47-1.59], 12-18 years: 1.46 [1.35-1.56]; respectively). Both VLBW infants and controls demonstrated a steady decline in the composite respiratory morbidity with aging. In VLBW infants, lower gestational age was associated with higher respiratory morbidity only until 2 years of age and the morbidity declined in each gestational age group until adolescence. Our study confirmed a strong association between VLBW and pulmonary morbidity. The higher prevalence of respiratory composite morbidity in VLBW infants persists over the years until adolescence. The respiratory morbidity is most evident in the first year of life and declines afterward.

Does antenatal corticosteroid therapy improve neonatal outcomes in late preterm birth?

Background Infants who are born at 340/7 to 366/7 weeks of gestation (late preterm) are at greater risk for respiratory and other neonatal morbidities. The objective of this study was to examine the effects of administration of antenatal corticosteroids (ACSs) to women at risk for late preterm delivery on the incidence of neonatal outcomes. Methods This was a prospective cohort study of singleton gestations at risk of imminent delivery between 340/7 and 366/7 weeks. Neonatal outcomes were compared between mothers who received ACS and those who did not. Primary outcome was the rate of composite respiratory morbidity defined as the need for treatment within 72 h of life (continuous positive airway pressure or high flow nasal cannula for least 2 h or supplemental oxygen with a fraction of inspired oxygen of at least 0.30 for at least four continuous hours or mechanical ventilation). Results During the 3-year study period, 595 subjects were included in this study, comprising 234 subjects that received ACS and 361 that did not. Administration of ACS significantly reduced the rates of composite respiratory morbidity (adjusted odds ratio (aOR) 0.63, 95% confidence interval (CI) 0.40–0.99), the use of CPAP or HFNC for at least 2 h (aOR 0.57, 95% CI 0.35–0.94) and transient tachypnea of newborn (aOR 0.48, 95% CI 0.28–0.82). Neonatal hypoglycemia was more significantly increased in the ACS group compared with controls (aOR 1.64, 95% CI 1.04–2.59). We found no significant between-group differences in the rate of respiratory distress syndrome, surfactant use, need for resuscitation, jaundice requiring phototherapy, admission to neonatal intensive care or special care nursery and duration of hospitalization. Conclusion Administration of ACS during the late preterm period decreased neonatal respiratory complications, however, increased the rate of hypoglycemia.

206: Does antenatal corticosteroids treatment in twin pregnancies prior to late preterm birth reduce neonatal morbidity?

Antenatal corticosteroids (ACS) administration in the late preterm period (34/0-36/6 weeks of gestation) decreases respiratory morbidity in singleton pregnancies. However, the effect of ACS exposure in twin pregnancies has not been determined. The objective of this study was to assess whether administration of ACS during late-preterm period in twin pregnancies was associated with decreased rate of neonatal complications. A Retrospective cohort study including 209 patients with twin pregnancies who delivered in the late preterm period between 2016-2018 at a single tertiary center. Patients were allocated into two groups according to ACS exposure: 1) patients with ACS exposure (n=76, 152 neonates); and 2) patients without ACS exposure (n=133, 266 neonates). Composite respiratory morbidity was defined as the presence of respiratory distress syndrome, transient tachypnea of the newborn, mechanical ventilation, CPAP use or oxygen requirement. Multivariate logistic regression analysis was employed to adjust for maternal age and body mass index (BMI), the presence of hypertensive disease and gestational diabetes, gestational age (GA) at birth and mode of delivery. Patients exposed to ACS were older and with higher BMI compared to those without ACS exposure (Table 1). They were also more likely to give birth earlier compared to the non-exposure group with a median (interquartile range) GA of 35.6 (34.8-36.1) vs. 36.1 (35.6-36.5) weeks, respectively; p< 0.001. Caesarean delivery was more common among neonates exposed to ACS compared to those not exposed (75.7% vs. 55.3%, respectively); p< 0.001 (Table2). The rates of respiratory morbidity measures did not differ between the two groups. Nevertheless, neonates exposed to ACS had a higher rate of NICU admission as well as hypoglycaemia compared to neonates without prior ACS exposure (28.9% vs. 15.1%); p=0.001 and (48.7% vs. 27.2%); p< 0.001; respectively. Late-preterm ACS administration in twin pregnancies did not reduce the rate of neonatal respiratory morbidity but was associated with higher rates of neonatal hypoglycaemia.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Implementation of an antenatal late-preterm corticosteroid protocol at a high-volume tertiary care center

Since publication of the sentinel antenatal late preterm steroids clinical trial, the use of antenatal steroids has become a routine aspect of the management of pregnancies at risk for late preterm delivery. However, in practice, the administration of antenatal corticosteroids in the late preterm period is widely varied across provider and institution, and the process of implementation of this new practice as well as outcomes associated with implementation are not well understood. The objective was to evaluate institutional adherence to an antenatal late preterm corticosteroid protocol and to assess neonatal outcomes associated with its introduction. This is a retrospective cohort study of all women with singleton pregnancies admitted between 34 to 36 5/7 weeks who presented in the year before ("pre-protocol": November 2012 to October 2013) and after implementation ("post-protocol": April 2016 to March 2017). The protocol recommends corticosteroid administration to women 34 to 36 5/7 weeks gestation at risk for preterm birth who have not received prior corticosteroids. Women with fetal anomalies or pregestational or gestational diabetes were excluded from analysis. The frequency with which eligible women received corticosteroids and ineligible women were appropriately excluded (adherence) was calculated on a monthly basis. Neonatal outcomes of interest were hypoglycemia, receipt of dextrose, birth weight, 5 minute Apgar less than 7, receipt of surfactant, respiratory distress syndrome, transient tachypnea of the newborn, neonatal intensive care unit length of stay, intraventricular hemorrhage, necrotizing enterocolitis, culture positive sepsis, bronchopulmonary dysplasia, and death. Bivariable and multivariable analyses were used to compare neonatal outcomes between 1) all women in the post-protocol cohort to those in the pre-protocol cohort and 2) only women who received adherent care in the post-protocol cohort to all women in the pre-protocol cohort. A total of 452 women were included in the pre-protocol cohort and 451 in the post-protocol cohort. The majority of the post-protocol women (N=366, 81.2%) received adherent care. Women in both cohorts were similar with the exception that women in the post-protocol cohort were more likely to be nulliparous (p=0.013). Compared to the pre-protocol period, neonates of women in the post-protocol period had significantly higher odds of hypoglycemia <50 mg/dL in the first 24 hours of life (aOR 1.37, 95% CI 1.05-1.80), without improvements in respiratory outcomes. Results were similar when restricting the analysis to only women in the post-protocol cohort who received care adherent care (glucose <50 mg/dL: aOR 1.52, 95% CI 1.14-2.03). No differences in composite respiratory morbidity or other neonatal outcomes were observed. Uptake of a new institutional protocol for antenatal late preterm corticosteroids was rapid. Compared with historic controls, neonates exposed to antenatal late preterm corticosteroid experienced increased odds of hypoglycemia, without significant improvements in respiratory morbidities.

Neonatal morbidity in late preterm small for gestational age neonates

Introduction To compare neonatal respiratory morbidity among small for gestational age (SGA; birth weight less than 10th percentile for gestational age) versus appropriate for gestational age (AGA; BW at 10–90th percentile) neonates born in the late preterm period. Methods A secondary analysis of a multicenter randomized trial of antenatal corticosteroids for women at risk for late preterm birth. Singleton, nonanomalous, AGA or SGA births that delivered at 34–36 weeks were included. Women were excluded if they delivered after 37 weeks or had a large for gestational age baby (LGA; weight over 90th for gestational age). The primary outcome was a composite of any of the following: respiratory support by 72 h (continuous positive airway pressure or high flow nasal cannula ≥2 h, oxygen with a fraction of inspired oxygen of ≥30% for ≥4 h, extra corporeal membrane oxygenation or mechanical ventilation) or neonatal death. The secondary outcomes included several neonatal and maternal morbidities. Multivariable Poisson regression models were used to examine the association between neonatal weight and outcomes (using adjusted relative risk [aRR] and 95% confidence intervals [CI]). Results Of the 2831 women in the parent trial, 2315 (82%) women met inclusion criteria; among them, 426 (18%) of the neonates were SGA. There was no significant difference in the risk of the primary outcome between SGA and AGA (13.1 versus 15.1%, aRR 0.85, 95% CI 0.66–1.10). SGA, however, was associated with an increased risk for neonatal intensive care unit admission (68 versus 45%, aRR 1.60, 95% CI 1.47–1.74), hypothermia (12.2 versus 8.8%, aRR 1.36, 95% CI 1.01–1.83), feeding problems (47.2 versus 36.9%, aRR 1.24, 95% CI 1.07–1.45) and a decreased risk of neonatal hyperbilirubinemia (7.5 versus 12.7%, aRR 0.59, 95% CI 0.41–0.84), when compared to AGA. Conclusion In this cohort of late preterm birth, there was no significant difference in the rate of composite respiratory morbidity between SGA and AGA newborns.

Respiratory morbidity in late preterm twin infants.

Antenatal corticosteroids have been shown to decrease neonatal respiratory morbidity in singleton pregnancies when given during the late-preterm period (340/7-366/7 weeks). Whether these findings also apply to late-preterm twins, who account for approximately one-third of infants born at 340/7-356/7 weeks, is currently unclear. The answer to this question depends, in part, on whether the risk of respiratory morbidity among late-preterm twin infants is similar to that observed in late-preterm singletons. We aimed to assess the rate of respiratory morbidity among late-preterm twin infants using a secondary analysis of prospectively collected data from a large international multicenter trial, and to compare that rate with previous studies that used the same definition of respiratory morbidity. This was a secondary analysis of the twin birth study. In the current study, we limited the analysis to women who gave birth during the late preterm period. The primary outcomes were the same primary composite respiratory morbidity variables that were used in the randomized controlled trial of Gyamfi-Bannerman et al., on the administration of betamethasone during the late preterm period in singletons (ALPS trial). The risk of respiratory morbidity among late preterm twins was stratified by gestational week at birth. A total of 1163 women who gave birth to 2324 late preterm twin infants met the inclusion criteria. The rates of respiratory morbidity and severe respiratory morbidity were 16.5% and 8.9%, respectively. The risk of respiratory morbidity was highly dependent on gestational week at birth, being more than fourfold for infants born at 340/7-346/7 weeks (aOR 4.30, 95%-CI 3.01-6.14) and more than twofold for infants born at 350/7-356/7 weeks (aOR 2.12, 95%-CI 1.51-2.98) compared with infants born at 360/7-366/7 weeks. The rate of respiratory morbidity and the theoretical number of women needed to be treated with betamethasone to prevent a single case of respiratory morbidity in the current study were similar to those reported in the APLS trial (16.5% vs. 14.4%, p = 0.103, and NNT 31 vs. 34, respectively). The risk-benefit ratio of betamethasone with regard to neonatal respiratory morbidity in women with twins at risk of late-preterm birth is expected to be similar to that observed in singletons.

Effect of Antenatal Steroids on Respiratory Morbidity of Late Preterm Newborns: A Randomized Controlled Trial.

The objective of this article was to study the effect of antenatal dexamethasone on the respiratory morbidity of late preterm newborns. A randomized controlled trial, conducted in Obstetrics and Gynecology Department in collaboration with Neonatology department at JIPMER, India. In total, 155 women were studied in each group. Intention to treat analysis and per protocol analysis were done. Overall 31 (10%) newborns were admitted to intensive care unit. The composite respiratory morbidity (defined as respiratory distress syndrome and/or transient tachypnea of newborn) was observed in 64 (41.6%) infants in the study and 56 (36.2%) infants in the control group. On multivariable-adjusted analysis, use of steroids was not found to be associated with decrease in composite respiratory morbidity [adjusted relative risk 0.91 (95% confidence interval: 0.7-1.2)]. Antenatal dexamethasone does not reduce the composite respiratory morbidity of babies born vaginally or by emergency cesarean to women with late preterm labor.

Neonatal Outcomes Differ after Spontaneous and Indicated Preterm Birth.

Preterm birth (PTB) at <37 weeks of gestation complicates 10% of pregnancies and requires accurate counseling regarding anticipated neonatal outcomes. PTB classification as spontaneous or indicated is commonly used to cluster PTB into subtypes, but whether neonatal outcomes differ by PTB subtype is unknown. We tested the hypothesis that neonatal morbidity differs based on subtype of PTB. We performed a retrospective cohort study of live-born, non-anomalous preterm infants from 2004 to 2008. Spontaneous PTB was defined as PTB from spontaneous preterm labor or preterm rupture of membranes. Indicated PTB was defined as PTB from any maternal or fetal medical complication necessitating delivery. The primary outcome was a composite of early respiratory morbidity. Secondary outcomes included late composite respiratory morbidity and other neonatal morbidities. Of 1,223 preterm neonates, 60.9% were born after spontaneous PTB and 30.1% after indicated PTB. Composite early respiratory morbidity was significantly higher after indicated PTB versus spontaneous PTB (1.3, 95% confidence interval [CI] 1.2-1.4). Composite late respiratory morbidity (1.8, 95% CI 1.3-2.3) and neonatal death (2.8, 95% CI 1.5-5.1) were also significantly higher after indicated PTB versus spontaneous PTB. Neonatal respiratory outcomes and death differ according to PTB subtype. PTB subtype should be considered while counseling families and anticipating neonatal outcomes after PTB.

Does antenatal steroids treatment prior to elective cesarean section at 34-37weeks of gestation reduce neonatal morbidity? Evidence from a case control study.

To determine whether antenatal corticosteroids administration prior to an elective cesarean section (ECS) at 34-37weeks gestation is associated with improved neonatal outcome. A case control study of women with singleton pregnancies who underwent ECS between 34 and 37weeks of gestation including two groups: (1) study group in which patients were treated with betamethasone prior to ECS (n=58) and (2) control group matched for gestational age at delivery in which patients did not receive betamethasone (n=107). Neonatal measures including respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), oxygen requirement, admission to the special care unit, hypoglycemia, hyperbilirubinemia and length of hospitalization were determined in both groups. Composite respiratory morbidity was defined as the presence of either RDS, TTN, mechanical ventilation or oxygen requirement. There was no significant difference in the rate of composite respiratory morbidity nor its components between patients with and without betamethasone treatment (25.9 vs. 25.2%, respectively, p=0.9). Antenatal treatment with corticosteroids prior to ECS at 34-37weeks of gestation did not result in significant reduction in neonatal respiratory morbidity in our cohort of patients.

The risk of neonatal respiratory morbidity according to the etiology of late preterm delivery.

The risk of neonatal respiratory morbidity between indicated deliveries vs. spontaneous deliveries has not been consistent in previous studies, in spite of the traditional belief that chronic intrauterine stress might have protective effect on fetal lung maturation. We hypothesized that the heterogeneous etiology of indicated preterm delivery may obscure the relationship between the etiologies of preterm birth and neonatal respiratory morbidity. To address this issue, we divided the indicated preterm birth (PTB) into medically-indicated (without fetal compromise) PTB and maternal/fetal-indicated PTB, and compared the neonatal respiratory morbidity according to the etiology of late PTB. Neonatal respiratory morbidities were examined in neonates who were delivered between 34+0 and 36+6 weeks of gestation according to the etiology of PTB: 1) medically-indicated PTB (but without fetal compromise), 2) maternal/fetal-indicated PTB, or 3) spontaneous PTB such as preterm labor or preterm premature rupture of membranes. A total of 710 late preterm neonates were included in the study population, including 31 cases of medically-indicated PTB, 202 cases of maternal/fetal-indicated PTB, and 477 cases of spontaneous PTB. The rate of composite respiratory morbidity in cases of medically-indicated PTB is higher than both maternal/fetal-indicated PTB and spontaneous PTB (19% in medically-indicated PTB, 6% in maternal/fetal-indicated PTB, and 7% in spontaneous PTB). This difference between medically-indicated PTB and maternal/fetal-indicated PTB remained significant after adjustment for confounding variables. The medically-indicated PTB is associated with highest risk of neonatal respiratory morbidity in late PTB.

Short-term respiratory outcomes in late preterm infants.

ObjectiveTo evaluate short-term respiratory outcomes in late preterm infants (LPI) compared with those of term infants (TI).MethodsA retrospective study conducted in a single third level Italian centre (2005–2009) to analyse the incidence and risk factors of composite respiratory morbidity (CRM), the need for adjunctive therapies (surfactant therapy, inhaled nitric oxide, pleural drainage), the highest level of respiratory support (mechanical ventilation – MV, nasal continuous positive airway pressure – N-CPAP, nasal oxygen) and the duration of pressure support (hours in N-CPAP and/or MV).ResultsDuring the study period 14,515 infants were delivered. There were 856 (5.9%) LPI and 12,948 (89.2%) TI. CRM affected 105 LPI (12.4%), and 121 TI (0.9%), with an overall rate of 1.6%. Eighty-four LPI (9.8%) and 73 TI (0.56%) received respiratory support, of which 13 LPI (1.5%) and 16 TI (0.12%) were ventilated. The adjusted OR for developing CRM significantly increased from 3.3 (95% CI 2.0-5.5) at 37 weeks to 40.8 (95% CI 19.7-84.9%) at 34 weeks. The adjusted OR for the need of MV significantly increased from 3.4 (95% CI 1.2-10) at 37 weeks to 34.4 (95% CI 6.7-180.6%) at 34 weeks. Median duration of pressure support was significantly higher at 37 weeks (66.6 h vs 40.5 h). Twin pregnancies were related to a higher risk of CRM (OR 4.3, 95% CI 2.6-7.3), but not independent of gestational age (GA). Cesarean section (CS) was associated with higher risk of CRM independently of GA, but the OR was lower in CS with labour (2.2, 95% CI 1.4-3.4 vs 3.0, 95% CI 2.1-4.2).ConclusionsIn this single third level care study late preterm births, pulmonary diseases and supportive respiratory interventions were lower than previously documented. LPI are at a higher risk of developing pulmonary disease than TI. Infants born from elective cesarean sections, late preterm twins in particular and 37 weekers too might benefit from preventive intervention.

The effect of gestational age on neonatal outcome in low-risk singleton term deliveries

Objective: To assess the association between gestational age at delivery and adverse neonatal outcome among term low-risk singleton neonates.Methods: A retrospective cohort study design was used. The study group included all low-risk singleton term (37 + 0 to 41 + 6 weeks) newborns delivered in a single tertiary university-affiliated medical center over a 5-year period. Outcome of neonates delivered at 37 + 0 to 37 + 6 weeks of gestation (early term) and 41 + 0 to 41 + 6 weeks of gestation (late term) was compared to that of neonates delivered at 39 + 0–39 + 6 weeks of gestation (control).Results: Overall, the outcome of 30 229 neonates was analyzed. The incidence of neonatal mortality was 1.0 per 1000 live-born neonates, with no significant difference between the various gestational age groups. Early term newborns were at higher risk for respiratory morbidity, hypoglycemia, hypocalcemia, thrombocytopenia and unexplained jaundice, and had higher rates of prolonged hospital stay, NICU admission, sepsis workup and antibiotic treatment. On multivariate analysis, early term delivery was an independent predictor for composite respiratory morbidity (OR=2.4, 95% CI 1.6–3.8, p < 0.001), unexplained jaundice (OR=2.1, 95% CI 1.7–2.5, p < 0.001), hypoglycemia (OR=2.5, 95% CI 1.5–4.3, p < 0.001) and NICU admission (OR=1.9, 95% CI 1.5–2.5, p < 0.001). Late term neonates had a significantly higher rate of large for gestational date, but did not differ from controls with respect to the rate of composite neurologic or respiratory complications, NICU admission, birth trauma or infectious morbidity.Conclusion: Even in low-risk singleton deliveries, early term is associated with an increased risk of neonatal morbidity.

A History of Prior Preeclampsia As a Risk Factor for Preterm Birth

The objectives of this study are to evaluate the frequency and type of preterm birth (PTB) in women with prior preeclampsia and to compare neonatal outcomes between spontaneous PTB (SPTB) and medically indicated PTB (IPTB) groups. A secondary analysis of data in women with prior preeclampsia enrolled in a multicenter randomized trial for preeclampsia prevention. Delivery indications were categorized as SPTB and IPTB. Primary outcomes were rates of SPTB and IPTB by gestational age (GA). The rates of composite respiratory morbidity and neonatal intensive care unit (NICU) admission were compared between the PTB groups. Of the 606 pregnancies studied, 142 (23%) pregnancies were delivered at < 37 weeks: 67 (47%) pregnancies were caused by SPTB and 75 (53%) pregnancies were caused by IPTB. Of those who delivered preterm, 89 (63%) were in the late preterm period. The overall rate of the composite neonatal morbidity was 23%. The rates of composite neonatal morbidity, NICU admission, and perinatal death were not different between the groups. The frequency of small for gestational age (SGA) infants was higher in the IPTB group as compared with the SPTB group (21.3 vs. 1.4%, p = 0.01). Women with prior preeclampsia are at high risk for PTB (SPTB and IPTB), particularly late PTB, as well as increased risk for SGA.

The Impact of Medically Indicated and Spontaneous Preterm Birth among Hypertensive Women

To (1) describe the frequency of spontaneous preterm birth (SPTB) and medically indicated preterm birth (PTB) among women with chronic hypertension (CHTN) and (2) to evaluate differences in neonatal outcomes according to SPTB or medically indicated PTB. Retrospective analysis of a previously conducted multicenter randomized trial. Deliveries were categorized as SPTB or medically indicated and stratified by gestational ages (<37 weeks, 34 to 366/7 weeks, 30 to 336/7 weeks, < 30 weeks). Rates of neonatal intensive care unit admission, composite respiratory morbidity, perinatal mortality, and small for gestational age (SGA) were evaluated. Of 765 women, 32.2% (n = 246) delivered at < 37 weeks, of which 10.5% (n = 80) were SPTB and 21.6% (n = 166) were medically indicated. Fifty-nine percent of PTBs occurred in the late preterm period (n = 146). SGA was significantly more frequent among those with medically indicated PTB at < 30 weeks (p = 0.03). There were no other differences in adverse neonatal outcomes between medically indicated versus SPTB at any gestational age (p > 0.05). Nearly one-third of women with CHTN delivered preterm. The majority of PTBs were medically indicated and late preterm, but approximately one-third were due to SPTB.

619: A history of prior preeclampsia is a major risk factor for preterm birth

major risk factor for preterm birth Brendan Connealy, Carlos Carreno, Benjamin Kase, Laura Hart, Sean Blackwell, Baha Sibai University of Texas Health Science Center Houston, Obstetrics, Gynecology, and Reproductive Sciences, Houtson, TX OBJECTIVE: Women with prior preeclampsia are considered at increased risk for adverse pregnancy outcomes (recurrent preeclampsia, fetal growth restriction, abruptio placentae). Limited data exists to describe an association between prior preeclampsia and spontaneous preterm birth (SPTB). Our objective is to evaluate the frequency of SPTB in women with prior preeclampsia and describe neonatal outcomes in these infants compared those with indicated preterm birth (IPTB). STUDY DESIGN: This is a secondary analysis of data in women with prior preeclampsia enrolled in a multicenter randomized trial of low dose aspirin for preeclampsia prevention. Inclusion criteria were women with history of prior preeclampsia, and live fetus. Women with preexisting medical disorders were excluded. Indications for delivery were categorized as SPTB (PTL or PPROM) and IPTB. Primary outcomes were rates of SPTB and IPTB by GA. Composite respiratory morbidity and NICU admission were compared between groups. Chi square and t test were used to establish a difference between the study groups. RESULTS: Of the 606 pregnancies studied, 142 (23%) delivered at 37 weeks. Of those delivered preterm, 47% were due to SPTB and 53% were IPTB. The table below summarizes the frequency of PTB by subtype and GA. There were no significant differences in rates of SPTB or IPTB, or in the rates of composite neonatal morbidity, between the GA groups. There were 14 perinatal deaths (2.3%): of which the majority (13) were at 34 weeks. Additionally, there were no differences in NICU admission between the groups. CONCLUSION: Women with prior preeclampsia have a substantially high rate of preterm birth with almost half being spontaneous and nearly two-thirds occurring in the late preterm. We recommend that prior preeclampsia should be considered a risk factor for both IPTB and SPTB with the potential for early intervention to improve perinatal outcome. 620 Timing of adverse neonatal outcomes in pregnancies complicated by preeclampsia and small for gestational age births in a cohort of high-risk pregnancies Cande Ananth, Jaclyn Coletta-Lucas, Ronald Wapner Columbia University Medical Center, Department of Obstetrics and Gynecology, New York, NY OBJECTIVE: In a group of high-risk women with underlying medical conditions predisposing to preeclampsia and small for gestational age (SGA), the timing of delivery is often based on a worsening maternal condition. We evaluated the risk of adverse neonatal outcomes in early intervention compared to spontaneous delivery. STUDY DESIGN: We performed a secondary analysis of data from the Maternal-Fetal Medicine Units network of a randomized controlled trial of aspirin to prevent preeclampsia in high-risk women (those with chronic hypertension, insulin-dependent diabetes mellitus and women with previous preeclampsia). The trial resulted in no benefit of aspirin on the risk of preeclampsia. We examined risks of adverse composite neonatal outcomes (perinatal death, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, retinopathy of prematurity, patent ductus arteriosus, pulmonary hypertension, neonatal seizures, admission to the neonatal intensive care unit and 5-minute Apgar 5) in relation to preeclampsia and small for gestational age (SGA, birthweight 10% for gestational age). Odds ratio (OR) and 95% confidence interval (CI) were estimated from logistic regression models after adjusting for potential confounders. RESULTS: Of the 1,787 women in the high-risk trial, the overall risk of composite neonatal outcome was 29.3%. The risk of composite outcome was higher in the SGA-only and preeclampsia (with or without SGA) groups, but this association was evident only at preterm gestations (Table). Among infants that were SGA (only), the risk of neonatal morbidity was dramatically higher among women that had a spontaneous rather than indicated preterm birth. CONCLUSION: In a group of women at high-risk for preeclampsia, appropriately timed obstetrical interventions at preterm gestations, relative to spontaneous preterm birth, is associated with reduced risk of neonatal morbidity.

Neonatal respiratory morbidity in the early term delivery

The purpose of this study was to evaluate the risk of respiratory morbidity in neonates delivered at "early term" (37-38 weeks) compared with those delivered at 39 weeks. We conducted a retrospective cohort study of singleton deliveries from 37(0/7) to 39(6/7) weeks' gestation. Our primary outcome was composite respiratory morbidity. Of 2273 deliveries at 37-39 weeks, 51% (n = 1169) delivered in the early term period. Infants delivered at 37-38 weeks had a 2-fold increased risk of respiratory distress syndrome, oxygen use, continuous positive airway pressure use, and composite respiratory morbidity (risk ratio [RR], 2.9; 95% confidence interval [CI], 1.0-7.9; oxygen usage RR, 2.0; 95% CI, 1.4-2.9; continuous positive airway pressure RR, 1.9; 95% CI, 1.1-3.2; composite respiratory morbidity RR, 2.0; 95% CI, 1.4-2.8). The 2-fold increased risk of composite respiratory morbidity of infants in the early term period supports the urgency for limiting nonindicated deliveries to ≥ 39 weeks' gestation.

1344 Respiratory Outcomes of Late Preterm Infants

Several studies have shown that late preterm infants (LPI) are at higher risk for respiratory disorders than term infants.Objective: To evaluate occurrence of respiratory disorders, need for respiratory support, use and timing of specific adjunctive pulmonary therapies in LPI.Methods: Using electronic medical charts, we performed a retrospective analysis of all LPI (34 0/7 to 36 6/7 wks) born from January 2005 to December 2009 in a tertiary level NICU.Results: During the study period, 856/14443 infants born alive were LPI (5.9%). They accounted for 58.9% of preterm births. Majority of LPI were 36 weeks (53.9%), followed by 35 weeks (28.4%) and 34 weeks (17.8%).Transient tachypnea of the newborn (5.8%) was the most common pulmonary illness, followed by respiratory distress syndrome (4.7%), apnea (1.5%), air leak (1.3%) and persistent pulmonary hypertension (0.5%). Composite respiratory morbidity was 12.4%:A total of 69 (8.1%) patients received NCPAP only, 19 (2.2%) mechanical ventilation, 17 (2%) surfactant, 8 (0.9%) chest tube and 4 (0.5%) inhaled nitric oxide.Fig 1 shows the highest levels of respiratory support for each GA.Fig 2 shows times at which each treatment was started.Median length of positive pressure ventilation was 40.5 hours (IQR 16.9-91.6).Mortality was 0.4%.Conclusion: Compared with literature, our population showed lower incidence of mortality, respiratory disorders and need for assisted ventilation, probably due to a great proportion of more mature infants.