Risk of adverse perinatal outcomes among African-born Black women in California, 2011-2020.

BACKGROUND: African-born women have a lower risk of preterm birth and small for gestational age (SGA) birth compared to United States (US)-born Black women, however variation by country of origin is overlooked. Additionally, the extent that nativity disparities in adverse perinatal outcomes to Black women are explained by individual-level factors remains unclear. METHODS: We conducted a population-based study of non-anomalous singleton live births to US- and African-born Black women in California from 2011-2020 (n=194,320). We used age-adjusted Poisson regression models to estimate risk of preterm birth and SGA, and reported risk ratios (RR) and 95% confidence intervals (CI). Decomposition using Monte Carlo integration of the g-formula computed the percentage of disparities in adverse outcomes between US- and African-born women explained by individual-level factors. RESULTS: Eritrean women (RR 0.4; 95%CI: 0.3, 0.5) had the largest differences in risk of preterm birth and Cameroonian women (RR 0.5; 95% CI: 0.3, 0.6) in SGA birth, compared to US-born Black women. Ghanaian women had smaller differences in risk of preterm birth (RR 0.8; 95%CI: 0.7, 1.0) and SGA (RR 0.9; 95% CI 0.8, 1.1) compared to US-born women. Overall, we estimate that absolute differences in socio-demographic and clinical factors contributed to 32% of nativity-based disparities in the risk of preterm birth and 26% of disparities in SGA. CONCLUSIONS: We observed heterogeneity in risk of adverse perinatal outcomes for African- compared to US-born Black women, suggesting that nativity disparities in adverse perinatal outcomes were not fully explained by differences in individual-level factors.

Resuscitation, survival and morbidity of extremely preterm infants in California 2011-2019.

OBJECTIVE: To describe changes over time in resuscitation, survival, and morbidity of extremely preterm infants in California. STUDY DESIGN: This population-based, retrospective cohort study includes infants born ≤28 weeks. Linked birth certificates and hospital discharge records were used to evaluate active resuscitation, survival, and morbidity across two epochs (2011-2014, 2015-2019). RESULTS: Of liveborn infants, 0.6% were born ≤28 weeks. Active resuscitation increased from 16.9% of 22-week infants to 98.1% of 25-week infants and increased over time in 22-, 23-, and 25-week infants (p-value ≤ 0.01). Among resuscitated infants, survival to discharge increased from 33.2% at 22 weeks to 96.1% at 28 weeks. Survival without major morbidity improved over time for 28-week infants (p-value < 0.01). CONCLUSION: Among infants ≤28 weeks, resuscitation and survival increased with gestational age and morbidity decreased. Over time, active resuscitation of periviable infants and morbidity-free survival of 28-week infants increased. These trends may inform counseling around extremely preterm birth.

The validity of hospital diagnostic and procedure codes reflecting morbidity in preterm neonates born <32 weeks gestation.

OBJECTIVE: To determine the validity of diagnostic hospital billing codes for complications of prematurity in neonates <32 weeks gestation. STUDY DESIGN: Retrospective cohort data from discharge summaries and clinical notes (n = 160) were reviewed by trained, blinded abstractors for the presence of intraventricular hemorrhage (IVH) grades 3 or 4, periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC), stage 3 or higher, retinopathy of prematurity (ROP), and surgery for NEC or ROP. Data were compared to diagnostic billing codes from the neonatal electronic health record. RESULTS: IVH, PVL, ROP and ROP surgery had strong positive predictive values (PPV > 75%) and excellent negative predictive values (NPV > 95%). The PPVs for NEC (66.7%) and NEC surgery (37.1%) were low. CONCLUSION: Diagnostic hospital billing codes were observed to be a valid metric to evaluate preterm neonatal morbidities and surgeries except in the instance of more ambiguous diagnoses such as NEC and NEC surgery.

Predicting the risk of 7-day readmission in late preterm infants in California: A population-based cohort study.

Background and aims: The American Academy of Pediatrics describes late preterm infants, born at 34 to 36 completed weeks' gestation, as at-risk for rehospitalization and severe morbidity as compared to term infants. While there are prediction models that focus on specific morbidities, there is limited research on risk prediction for early readmission in late preterm infants. The aim of this study is to derive and validate a model to predict 7-day readmission. Methods: This is a population-based retrospective cohort study of liveborn infants in California between January 2007 to December 2011. Birth certificates, maintained by California Vital Statistics, were linked to a hospital discharge, emergency department, and ambulatory surgery records maintained by the California Office of Statewide Health Planning and Development. Random forest and logistic regression were used to identify maternal and infant variables of importance, test for association, and develop and validate a predictive model. The predictive model was evaluated for discrimination and calibration. Results: We restricted the sample to healthy late preterm infants (n = 122,014), of which 4.1% were readmitted to hospital within 7-day after birth discharge. The random forest model with 24 variables had better predictive ability than the 8 variable logistic model with c-statistic of 0.644 (95% confidence interval 0.629, 0.659) in the validation data set and Brier score of 0.0408. The eight predictors of importance length of stay, delivery method, parity, gestational age, birthweight, race/ethnicity, phototherapy at birth hospitalization, and pre-existing or gestational diabetes were used to drive individual risk scores. The risk stratification had the ability to identify an estimated 19% of infants at greatest risk of readmission. Conclusions: Our 7-day readmission predictive model had moderate performance in differentiating at risk late preterm infants. Future studies might benefit from inclusion of more variables and focus on hospital practices that minimize risk.

Developing a resiliency model for survival without major morbidity in preterm infants.

OBJECTIVE: Develop and validate a resiliency score to predict survival and survival without neonatal morbidity in preterm neonates <32 weeks of gestation using machine learning. STUDY DESIGN: Models using maternal, perinatal, and neonatal variables were developed using LASSO method in a population based Californian administrative dataset. Outcomes were survival and survival without severe neonatal morbidity. Discrimination was assessed in the derivation and an external dataset from a tertiary care center. RESULTS: Discrimination in the internal validation dataset was excellent with a c-statistic of 0.895 (95% CI 0.882-0.908) for survival and 0.867 (95% CI 0.857-0.877) for survival without severe neonatal morbidity, respectively. Discrimination remained high in the external validation dataset (c-statistic 0.817, CI 0.741-0.893 and 0.804, CI 0.770-0.837, respectively). CONCLUSION: Our successfully predicts survival and survival without major morbidity in preterm babies born at <32 weeks. This score can be used to adjust for multiple variables across administrative datasets.

Incidence, Risk Factors, and Reasons for 30-Day Hospital Readmission Among Healthy Late Preterm Infants.

OBJECTIVE: Late preterm infants have an increased risk of morbidity relative to term infants. We sought to determine the rate, temporal trend, risk factors, and reasons for 30-day readmission. METHODS: This is a retrospective cohort study of infants born at 34 to 42 weeks' gestation in California between January 1, 2011, and December 31, 2017. Birth certificates maintained by California Vital Statistics were linked to discharge records maintained by the California Office of Statewide Health Planning and Development. Multivariable logistic regression was used to identify risk factors and derive a predictive model. RESULTS: Late preterm infants represented 4.3% (n = 122 014) of the study cohort (n = 2 824 963), of which 5.9% (n = 7243) were readmitted within 30 days. Compared to term infants, late preterm infants had greater odds of readmission (odds ratio [OR]: 2.34 [95% confidence interval (CI): 2.28-2.40]). The temporal trend indicated increases in all-cause and jaundice-specific readmission infants (P < .001). The common diagnoses at readmission were jaundice (58.9%), infections (10.8%), and respiratory complications (3.5%). In the adjusted model, factors that were associated with greater odds of readmission included assisted vaginal birth, maternal age ≥34 years, diabetes, chorioamnionitis, and primiparity. The model had predictive ability of 60% (c-statistic 0.603 [95% CI: 0.596-0.610]) in late preterm infants who had <5 days length of stay at birth. CONCLUSION: The findings contribute important information on what factors increase or decrease the risk of readmission. Longitudinal studies are needed to examine promising hospital predischarge and follow-up care practices.

Interpregnancy Interval and Birth Outcomes: A Propensity Matching Study in the California Population.

INTRODUCTION: Previous studies that used traditional multivariable and sibling matched analyses to investigate interpregnancy interval (IPI) and birth outcomes have reached mixed conclusions about a minimum recommended IPI, raising concerns about confounding. Our objective was to isolate the contribution of interpregnancy interval to the risk for adverse birth outcomes using propensity score matching. METHODS: For this retrospective cohort study, data were drawn from a California Department of Health Care Access and Information database with linked vital records and hospital discharge records (2007-2012). We compared short IPIs of < 6, 6-11, and 12-17 months to a referent IPI of 18-23 months using 1:1 exact propensity score matching on 13 maternal sociodemographic and clinical factors. We used logistic regression to calculate the odds of preterm birth, early-term birth, and small for gestational age (SGA). RESULTS: Of 144,733 women, 73.6% had IPIs < 18 months, 5.5% delivered preterm, 27.0% delivered early-term, and 6.0% had SGA infants. In the propensity matched sample (n = 83,788), odds of preterm birth were increased among women with IPI < 6 and 6-11 months (OR 1.89, 95% CI 1.71-2.0; OR 1.22, 95% CI 1.13-1.31, respectively) and not with IPI 12-17 months (OR 1.01, 95% CI 0.94-1.09); a similar pattern emerged for early-term birth. The odds of SGA were slightly elevated only for intervals < 6 months (OR 1.10, 95% CI 1.00-1.20, p < .05). DISCUSSION: This study demonstrates a dose response association between short IPI and adverse birth outcomes, with no increased risk beyond 12 months. Findings suggest that longer IPI recommendations may be overly proscriptive.

Risk of early birth by body mass index in a propensity score-matched sample: A retrospective cohort study.

OBJECTIVE: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. DESIGN: Retrospective cohort analysis. SETTING: California, USA. POPULATION: Singleton live births from 2011-2017. METHODS: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. MAIN OUTCOME MEASURES: Early birth. RESULTS: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28-31 weeks (relative risk [RR] 1.2, 95% CI 1.1-1.4), 32-36 weeks (RR 1.3, 95% CI 1.2-1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1-1.1). Women with BMI ≥25.0 kg/m2 were at 1.2-1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8-0.9) and birth during the 37th or 38th week (RR 0.9). CONCLUSION: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. TWEETABLE ABSTRACT: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.

Targeted newborn metabolomics: prediction of gestational age from cord blood.

OBJECTIVE: Our study sought to determine whether metabolites from a retrospective collection of banked cord blood specimens could accurately estimate gestational age and to validate these findings in cord blood samples from Busia, Uganda. STUDY DESIGN: Forty-seven metabolites were measured by tandem mass spectrometry or enzymatic assays from 942 banked cord blood samples. Multiple linear regression was performed, and the best model was used to predict gestational age, in weeks, for 150 newborns from Busia, Uganda. RESULTS: The model including metabolites and birthweight, predicted the gestational ages within 2 weeks for 76.7% of the Ugandan cohort. Importantly, this model estimated the prevalence of preterm birth <34 weeks closer to the actual prevalence (4.67% and 4.00%, respectively) than a model with only birthweight which overestimates the prevalence by 283%. CONCLUSION: Models that include cord blood metabolites and birth weight appear to offer improvement in gestational age estimation over birth weight alone.

Evaluation of heparinized syringes for measuring newborn metabolites in neonates with a central arterial line.

Newborn metabolic screening is emerging as a novel method for predicting neonatal morbidity and mortality in neonates born very preterm (<32 weeks gestation). The purpose of our study was to determine if blood collected by an electrolyte-balanced dry lithium heparin syringe, as is routine for blood gas measurements, affects targeted metabolite and biomarker levels. Two blood samples (one collected with a heparinized syringe and the other with a non-heparinized syringe) were obtained at the same time from 20 infants with a central arterial line and tested for 49 metabolites and biomarkers using standard procedures for newborn screening. Overall, the median metabolite levels did not significantly differ by syringe type. However, there was wide variability, particularly for amino acids and immunoreactive trypsinogen, for individual paired samples and therefore, consideration should be given to sample collection when using these metabolites in prediction models of neonatal morbidity and mortality.

The independent and combined influences of small for gestational age and socioeconomic status on newborn metabolite levels.

OBJECTIVES: To determine whether socioeconomic status (SES) and small birthweight for gestational age (SGA) exhibit independent or joint effects on infant levels of 42 metabolites. STUDY DESIGN: Population-based retrospective cohort of metabolic newborn screening information linked to hospital discharge data. SGA infants defined by birthweight <10th percentile for gestational age by sex. SES was determined by a combined metric including education level, participation in the WIC nutritional assistance program, and receiving California MediCal insurance. We performed linear regression to determine the effects of SES independently, SGA independently, and the interaction of SGA and SES on 42 newborn metabolite levels. RESULTS: 736,435 California infants born in 2005-2011 were included in the analysis. SGA was significantly associated with 36 metabolites. SES was significantly associated with 41 of 42 metabolites. Thirty-eight metabolites exhibited a dose-response relationship between SGA and metabolite levels as SES worsened. Fourteen metabolites showed significant interaction between SES and SGA. Eight metabolites showed significant individual and joint effects of SES and SGA: alanine, glycine, free carnitine, C-3DC, C-5DC, C-16:1, C-18:1, and C-18:2. CONCLUSIONS: SES and SGA exhibited independent effects on a majority of metabolites and joint effects on select metabolites. A better understanding of how SES and SGA status are related to infant metabolites may help identify maternal and newborn interventions that can lead to better outcomes for infants born SGA.

Racial disparities in emergency mental healthcare utilization among birthing people with preterm infants.

BACKGROUND: Birthing people of color are more likely to deliver low birthweight and preterm infants, populations at significant risk of morbidity and mortality. Birthing people of color are also at higher risk for mental health conditions and emergency mental healthcare utilization postpartum. Although this group has been identified as high risk in these contexts, it is not known whether racial and ethnic disparities exist in mental healthcare utilization among birthing people who have delivered preterm. OBJECTIVE: We sought to determine if racial and ethnic disparities exist in postpartum mental healthcare-associated emergency department visits or hospitalizations for birthing people with preterm infants in a large and diverse population. STUDY DESIGN: This population-based historic cohort study used a sample of Californian live-born infants born between 2011 and 2017 with linked birth certificates and emergency department visit and hospital admission records from the California Statewide Health Planning and Development database. The sample was restricted to preterm infants (<37 weeks' gestation). Self-reported race and ethnicity groups included Hispanic, non-Hispanic Black, non-Hispanic Asian, non-Hispanic White, and non-Hispanic others. Mental health diagnoses were identified from the International Classification of Diseases Ninth and Tenth revision codes recorded in emergency department and hospital discharge records. Logistic regression analysis was used to estimate the association between mental health-related emergency department visits and rehospitalizations by race or ethnicity compared with non-Hispanic White birthing people and controlling for the following characteristics and health condition covariates: age, parity, previous preterm birth, body mass index, smoking, alcohol use, hypertension, diabetes, previous mental health diagnosis, and prenatal care. RESULTS: Of 204,539 birthing people who delivered preterm infants in California, 1982 visited the emergency department and 836 were hospitalized in the first year after preterm birth for a mental health-related illness. Black birthing people were more likely to have a mental health-related emergency department visit and hospitalization (risk ratio, 1.8; 95% confidence interval, 1.5-2.0 and risk ratio, 1.9; 95% confidence interval, 1.5-2.3, respectively) within the first postpartum year than White birthing people. Hispanic and Asian birthing people were less likely to have mental health-related emergency department visits (adjusted risk ratio, 0.7; 95% confidence interval, 0.7-0.8 and adjusted risk ratio, 0.2; 95% confidence interval, 0.2-0.3, respectively) and hospitalizations (adjusted risk ratio, 0.6; 95% confidence interval, 0.5-0.7 and adjusted risk ratio, 0.2; 95% confidence interval, 0.1-0.3, respectively). When controlling for birthing people with a previous mental health diagnosis and those without, the disparities remained the same. CONCLUSION: Racial and ethnic disparities exist in emergency mental healthcare escalation among birthing people who have delivered preterm infants. Our findings highlight a need for further investigation into disparate mental health conditions, exacerbations, access to care, and targeted hospital and legislative policies to prevent emergency mental healthcare escalation and reduce disparities.

The association of COVID-19 infection in pregnancy with preterm birth: A retrospective cohort study in California.

INTRODUCTION: Our understanding of the association between coronavirus disease 19 (COVID-19) and preterm or early term birth among racially and ethnically diverse populations and people with chronic medical conditions is limited. METHODS: We determined the association between COVID-19 and preterm (PTB) birth among live births documented by California Vital Statistics birth certificates between July 2020 and January 2021 (n=240,147). We used best obstetric estimate of gestational age to classify births as very preterm (VPTB, <32 weeks), PTB (< 37 weeks), early term (37 and 38 weeks), and term (39-44 weeks), as each confer independent risks to infant health and development. Separately, we calculated the joint effects of COVID-19 diagnosis, hypertension, diabetes, and obesity on PTB and VPTB. FINDINGS: COVID-19 diagnoses on birth certificates increased for all racial/ethnic groups between July 2020 and January 2021 and were highest for American Indian/Alaska Native (12.9%), Native Hawaiian/Pacific Islander (11.4%), and Latinx (10.3%) birthing people. COVID-19 diagnosis was associated with an increased risk of VPTB (aRR 1.6, 95% CI [1.4, 1.9]), PTB (aRR 1.4, 95% CI [1.3, 1.4]), and early term birth (aRR 1.1, 95% CI [1.1, 1.2]). There was no effect modification of the overall association by race/ethnicity or insurance status. COVID-19 diagnosis was associated with elevated risk of PTB in people with hypertension, diabetes, and/or obesity. INTERPRETATION: In a large population-based study, COVID-19 diagnosis increased the risk of VPTB, PTB, and early term birth, particularly among people with medical comorbidities. Considering increased circulation of COVID-19 variants, preventative measures, including vaccination, should be prioritized for birthing persons. FUNDING: UCSF-Kaiser Department of Research Building Interdisciplinary Research Careers in Women's Health Program (BIRCWH) National Institute of Child Health and Human Development (NICHD) and the Office of Research on Women's Health (ORWH) [K12 HD052163] and the California Preterm Birth Initiative, funded by Marc and Lynn Benioff.

Maternal nativity and risk of adverse perinatal outcomes among Black women residing in California, 2011-2017.

OBJECTIVE: Examine the risk of adverse perinatal outcomes among the United States (US)-born and foreign-born Black women in California. STUDY DESIGN: The study comprised all singleton live births to Black women in California between 2011 and 2017. We defined maternal nativity as US-born or foreign-born. Using Poisson regression, we computed risk ratios (RR) and 95% confidence intervals (CI) for three adverse perinatal outcomes: preterm birth, small for gestational age deliveries, and infant mortality. RESULTS: Rates of adverse perinatal outcomes were significantly higher among US-born Black women. In adjusted models, US-born Black women experienced an increased risk of preterm birth (RR 1.51, 95% CI 1.39, 1.65) and small for gestational age deliveries (RR 1.52, 95% CI 1.41, 1.64), compared to foreign-born Black women. CONCLUSIONS: Future studies should consider experiences of racism across the life course when exploring heterogeneity in the risk of adverse perinatal outcomes by nativity among Black women in the US.

Cannabis-related diagnosis in pregnancy and adverse maternal and infant outcomes.

BACKGROUND: Cannabis use and cannabis use disorders are increasing in prevalence, including among pregnant women. The objective was to evaluate the association of a cannabis-related diagnosis (CRD) in pregnancy and adverse maternal and infant outcomes. METHODS: We queried an administrative birth cohort of singleton deliveries in California between 2011-2017 linked to maternal and infant hospital discharge records. We classified pregnancies with CRD from International Classification of Disease codes. We identified nicotine and other substance-related diagnoses (SRD) in the same manner. Outcomes of interest included maternal (hypertensive disorders) and infant (prematurity, small for gestational age, NICU admission, major structural malformations) adverse outcomes. RESULTS: From 3,067,069 pregnancies resulting in live births, 29,112 (1.0 %) had a CRD. CRD was associated with an increased risk of all outcomes studied; the strongest risks observed were for very preterm birth (aRR 1.4, 95 % CI 1.3, 1.6) and small for gestational age (aRR 1.4, 95 % CI 1.3, 1.4). When analyzed with or without co-exposure diagnoses, CRD alone conferred increased risk for all outcomes compared to no use. The strongest effects were seen for CRD with other SRD (preterm birth aRR 2.3, 95 % CI 2.2, 2.5; very preterm birth aRR 2.6, 95 % CI 2.3, 3.0; gastrointestinal malformations aRR 2.0, 95 % CI 1.6, 2.6). The findings were generally robust to unmeasured confounding and misclassification analyses. CONCLUSIONS: CRD in pregnancy was associated with increased risk of adverse maternal and infant outcomes. Providing education and effective treatment for women with a CRD during prenatal care may improve maternal and infant health.

The association between preterm birth and postpartum mental healthcare utilization among California birthing people.

BACKGROUND: While mental health conditions such as postpartum depression are common, little is known about how mental healthcare utilization varies after term versus preterm delivery. OBJECTIVE: This study aimed to determine whether preterm birth is associated with postpartum inpatient and emergency mental healthcare utilization. STUDY DESIGN: The study sample was obtained from a database of live-born neonates delivered in California between the years of 2011 and 2017. The sample included all people giving birth to singleton infants between the gestational age of 20 and 44 weeks. Preterm birth was defined as <37 weeks' gestation. Emergency department visits and hospitalizations with a mental health diagnosis within 1 year after birth were identified using International Classification of Diseases codes. Logistic regression was used to compare relative risks of healthcare utilization among people giving birth to preterm infants vs term infants, adjusting for the following covariates: age, race or ethnicity, parity, previous preterm birth, body mass index, tobacco use, alcohol or drug use, hypertension, diabetes mellitus, adequacy of prenatal care, education, insurance payer, and the presence of a mental health diagnosis before birth. Results were then stratified by mental health diagnosis before birth to determine whether associations varied based on mental health history. RESULTS: Of our sample of 3,067,069 births, 6.7% were preterm. In fully adjusted models, compared with people giving birth to term infants, people giving birth to preterm infants had a 1.5 times (relative risk; 95% confidence interval, 1.4-1.7) and 1.3 times (relative risk; 95% confidence interval, 1.2-1.4) increased risk of being hospitalized with a mental health diagnosis within 3 months and 1 year after delivery, respectively. People giving birth to preterm infants also had 1.4 times (95% confidence interval, 1.3-1.5) and 1.3 times (95% confidence interval, 1.2-1.4) increased risk of visiting the emergency department for a mental health diagnosis within 3 months and 1 year after birth, respectively. Stratifying by preexisting mental health diagnosis, preterm birth was associated with an elevated risk of mental healthcare utilization for people with and without a previous mental health diagnosis. CONCLUSION: We found that preterm birth is an independent risk factor for postpartum mental healthcare utilization. Our findings suggest that screening for and providing mental health resources to birthing people after delivery are crucial, particularly among people giving birth to preterm infants, regardless of mental health history.

Racial and ethnic disparities in outcomes through 1 year of life in infants born prematurely: a population based study in California.

OBJECTIVES: To investigate racial/ethnic differences in rehospitalization and mortality rates among premature infants over the first year of life. STUDY DESIGN: A retrospective cohort study of infants born in California from 2011 to 2017 (n = 3,448,707) abstracted from a California Office of Statewide Health Planning and Development database. Unadjusted Kaplan-Meier tables and logistic regression controlling for health and sociodemographic characteristics were used to predict outcomes by race/ethnicity. RESULTS: Compared to White infants, Hispanic and Black early preterm infants were more likely to be readmitted; Black late/moderate preterm (LMPT) infants were more likely to be readmitted and to die after discharge; Hispanic and Black early preterm infants with BPD were more likely to be readmitted; Black LMPT infants with RDS were more likely to be readmitted and die after discharge. CONCLUSIONS: Racial/ethnic disparities in readmission and mortality rates exist for premature infants across several co-morbidities. Future studies are needed to improve equitability of outcomes.

Risk of Early Birth among Women with a Urinary Tract Infection: A Retrospective Cohort Study.

Objective The aim of the study is to evaluate the risk of preterm birth (PTB, <37 weeks) and early term (37 and 38 weeks) birth among women with an emergency department (ED) visit or hospitalization with a urinary tract infection (UTI) by trimester of pregnancy. Methods The primary sample was selected from births in California between 2011 and 2017. UTIs were identified from the ED or hospital discharge records. Risk of PTB, by subtype, and early term birth were evaluated by trimester of pregnancy and by type of visit using log-linear regression. Risk ratios were adjusted for maternal factors. Antibiotic usage was examined in a population of privately insured women from Iowa. Results Women with a UTI during pregnancy were at elevated risk of a birth <32 weeks, 32 to 36 weeks, and 37 to 38 weeks (adjusted risk ratios [aRRs] 1.1-1.4). Of the women with a diagnostic code for multiple bacterial species, 28.8% had a PTB. A UTI diagnosis elevated risk of PTB regardless of antibiotic treatment (aRR 1.4 for treated, aRR 1.5 for untreated). Conclusion UTIs are associated with early birth. This association is present regardless of the trimester of pregnancy, type of PTB, and antibiotic treatment.