Severe Maternal Morbidity from Pregnancy through 1-year Postpartum

BACKGROUND

Few recent studies have examined the rate of severe maternal morbidity (SMM) occurring during the antenatal and/or the postpartum period through 42 days postpartum. However, little is known about the rate of SMM occurring beyond 42 days postpartum.

OBJECTIVE

To examine the distribution of SMM and its indicators during antenatal, delivery, and postpartum hospitalizations through 365 days postpartum, and to estimate the increase in SMM rate and its indicators after accounting for antenatal and postpartum SMM through 365 days postpartum.

STUDY DESIGN

We conducted a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from Michigan, Oregon, and South Carolina from 2008-2020. We examined the distribution of SMM, non-transfusion SMM, and SMM indicators during antenatal, delivery, and postpartum hospitalizations through 365 days postpartum. We subsequently examined "SMM cases added," which represent cases among unique individuals that are included by considering the antenatal and postpartum periods but that would be missed if only the delivery hospitalization cases were included.

RESULTS

A total of 64,661 (2.5%) individuals experienced SMM while 37,112 (1.4%) individuals experienced non-transfusion SMM during antenatal, delivery, and/or postpartum hospitalization. A total of 31% of SMM cases were added after accounting for SMM occurring during the antenatal or postpartum hospitalization through 365 days postpartum while 49% of non-transfusion SMM cases were added after accounting for non-transfusion SMM occurring during the antenatal or postpartum periods. SMM occurring between 43 and 365 days postpartum contributed to 12% of all SMM cases while non-transfusion SMM occurring between 43 and 365 days postpartum contributed to 19% of all non-transfusion SMM cases.

CONCLUSION

We showed that a total of 31% of SMM and 49% of non-transfusion SMM cases were added after accounting for SMM occurring during the antenatal or postpartum hospitalization through 365 days postpartum. Our findings highlight the importance of expanding the SMM definition beyond the delivery hospitalization to better capture the full period of increased risk, identify contributing factors, and design strategies to mitigate this risk. Only then, can we improve outcomes for mothers and subsequently the quality of life of their infants.

Association between stillbirth and severe maternal morbidity

BACKGROUND

Severe maternal morbidity has been increasing in the past few decades. Few studies have examined the risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries.

OBJECTIVE

This study aimed to examine the prevalence and risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries during delivery hospitalization as a primary outcome and during the postpartum period as a secondary outcome.

STUDY DESIGN

This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from California (2008-2018), Michigan (2008-2020), Missouri (2008-2014), Pennsylvania (2008-2014), and South Carolina (2008-2020). Relative risk regression analysis was used to examine the crude and adjusted relative risks of severe maternal morbidity along with 95% confidence intervals among individuals with stillbirths vs individuals with live-birth deliveries, adjusting for birth year, state of residence, maternal sociodemographic characteristics, and the obstetric comorbidity index.

RESULTS

Of the 8,694,912 deliveries, 35,012 (0.40%) were stillbirths. Compared with individuals with live-birth deliveries, those with stillbirths were more likely to be non-Hispanic Black (10.8% vs 20.5%); have Medicaid (46.5% vs 52.0%); have pregnancy complications, including preexisting diabetes mellitus (1.1% vs 4.3%), preexisting hypertension (2.3% vs 6.2%), and preeclampsia (4.4% vs 8.4%); have multiple pregnancies (1.6% vs 6.2%); and reside in South Carolina (7.4% vs 11.6%). During delivery hospitalization, the prevalence rates of severe maternal morbidity were 791 cases per 10,000 deliveries for stillbirths and 154 cases per 10,000 deliveries for live-birth deliveries, whereas the prevalence rates for nontransfusion severe maternal morbidity were 502 cases per 10,000 deliveries for stillbirths and 68 cases per 10,000 deliveries for live-birth deliveries. The crude relative risk for severe maternal morbidity was 5.1 (95% confidence interval, 4.9-5.3), whereas the adjusted relative risk was 1.6 (95% confidence interval, 1.5-1.8). For nontransfusion severe maternal morbidity among stillbirths vs live-birth deliveries, the crude relative risk was 7.4 (95% confidence interval, 7.0-7.7), whereas the adjusted relative risk was 2.0 (95% confidence interval, 1.8-2.3). This risk was not only elevated among individuals with stillbirth during the delivery hospitalization but also through 1 year after delivery (severe maternal morbidity adjusted relative risk, 1.3; 95% confidence interval, 1.1-1.4; nontransfusion severe maternal morbidity adjusted relative risk, 1.2; 95% confidence interval, 1.1-1.3).

CONCLUSION

Stillbirth was found to be an important contributor to severe maternal morbidity.

Trends in maternal opioid use: Statewide differences by sociodemographic characteristics in Florida from 2000 to 2019

BACKGROUND

Maternal opioid use (MOU) remains a public health concern. Studies have demonstrated significant increases in MOU, but estimates using ICD-10-CM or stratified by sociodemographic variables are limited.

OBJECTIVES

Using a statewide, population-based dataset of Florida resident deliveries from 2000 to 2019, we examined the trend of MOU by age, race/ethnicity, education level, and insurance.

METHODS

Florida administrative data was used to conduct a retrospective cohort study. MOU was identified using opioid-related hospital discharge diagnoses documented prenatally or at delivery. Maternal sociodemographic variables were obtained from Florida vital statistics. Joinpoint regression was used to identify statistically significant changes in the trends overall and stratified by sociodemographic variables. Results are presented as annual percentage changes (APC) and 95% confidence intervals.

RESULTS

Our sample included over 3.6 million Florida resident mothers; of which, MOU was identified in 1% (n = 22,828) of the sample. From 2000 to 2019, MOU increased over ten-fold from 8.7 to 94.7 per 10,000 live birth deliveries. MOU increased significantly from 2000 to 2011 (APC: 32.8; 95% CI: 29.4, 36.2), remained stable from 2011 to 2016, and decreased significantly from 2016 to 2019 (APC: 3.9; 95% CI: -6.6, -1.0). However, from 2016 to 2019, MOU increased among non-Hispanic Black mothers (APC: 9.2; 95% CI: 7.5, 11.0), and those ages 30-34 (APC: 2.9; 95% CI: 1.2, 4.6) and 35-39 (APC: 6.4; 95% CI: 4.3, 8.4).

CONCLUSIONS

Accurate prevalence estimates of MOU by sociodemographic factors are necessary to fully understand prevalence trends, describe the burden among sub-populations, and develop targeted interventions.

Preconception Counseling in Women With Diabetes: The SEARCH for Diabetes in Youth Study

Preconception counseling is recommended for all women with diabetes starting at puberty to convey the importance of optimal diabetes management for maternal and fetal outcomes. This study included 622 female participants from the SEARCH for Diabetes in Youth study with a mean age of 22.2 years (range 14-35 years). Only 53.7% reported ever receiving preconception counseling, which was significantly lower among women seeing pediatric providers than those seeing adult or all-age providers. Older age and history of prior pregnancy were associated with increased odds of reporting having received preconception counseling. Identification of barriers to delivering preconception counseling to young females with diabetes and strategies to overcome them are needed to reduce the risk for pregnancy complications and adverse offspring health outcomes.

Association of Sickle Cell Disease With Racial Disparities and Severe Maternal Morbidities in Black Individuals

Importance

Little is known about the association between sickle cell disease (SCD) and severe maternal morbidity (SMM).

Objective

To examine the association of SCD with racial disparities in SMM and with SMM among Black individuals.

Design, Setting, and Participants

This cohort study was a retrospective population-based investigation of individuals with and without SCD in 5 states (California [2008-2018], Michigan [2008-2020], Missouri [2008-2014], Pennsylvania [2008-2014], and South Carolina [2008-2020]) delivering a fetal death or live birth. Data were analyzed between July and December 2022.

Exposure

Sickle cell disease identified during the delivery admission by using International Classification of Diseases, Ninth Revision and Tenth Revision codes.

Main Outcomes and Measures

The primary outcomes were SMM including and excluding blood transfusions during the delivery hospitalization. Modified Poisson regression was used to estimate risk ratios (RRs) adjusted for birth year, state, insurance type, education, maternal age, Adequacy of Prenatal Care Utilization Index, and obstetric comorbidity index.

Results

From a sample of 8 693 616 patients (mean [SD] age, 28.5 [6.1] years), 956 951 were Black individuals (11.0%), of whom 3586 (0.37%) had SCD. Black individuals with SCD vs Black individuals without SCD were more likely to have Medicaid insurance (70.2% vs 64.6%), to have a cesarean delivery (44.6% vs 34.0%), and to reside in South Carolina (25.2% vs 21.5%). Sickle cell disease accounted for 8.9% and for 14.3% of the Black-White disparity in SMM and nontransfusion SMM, respectively. Among Black individuals, SCD complicated 0.37% of the pregnancies but contributed to 4.3% of the SMM cases and to 6.9% of the nontransfusion SMM cases. Among Black individuals with SCD compared with those without, the crude RRs of SMM and nontransfusion SMM during the delivery hospitalization were 11.9 (95% CI, 11.3-12.5) and 19.8 (95% CI, 18.5-21.2), respectively, while the adjusted RRs were 3.8 (95% CI, 3.3-4.5) and 6.5 (95% CI, 5.3-8.0), respectively. The SMM indicators that incurred the highest adjusted RRs included air and thrombotic embolism (4.8; 95% CI, 2.9-7.8), puerperal cerebrovascular disorders (4.7; 95% CI, 3.0-7.4), and blood transfusion (3.7; 95% CI, 3.2-4.3).

Conclusions and Relevance

In this retrospective cohort study, SCD was found to be an important contributor to racial disparities in SMM and was associated with an elevated risk of SMM among Black individuals. Efforts from the research community, policy makers, and funding agencies are needed to advance care among individuals with SCD.

Trends in Resources for Neonatal Intensive Care at Delivery Hospitals for Infants Born Younger Than 30 Weeks' Gestation, 2009-2020

Importance

In an ideal regionalized system, all infants born very preterm would be delivered at a large tertiary hospital capable of providing all necessary care.

Objective

To examine whether the distribution of extremely preterm births changed between 2009 and 2020 based on neonatal intensive care resources at the delivery hospital.

Design, Setting, and Participants

This retrospective cohort study was conducted at 822 Vermont Oxford Network (VON) centers in the US between 2009 and 2020. Participants included infants born at 22 to 29 weeks' gestation, delivered at or transferred to centers participating in the VON. Data were analyzed from February to December 2022.

Exposures

Hospital of birth at 22 to 29 weeks' gestation.

Main Outcomes and Measures

Birthplace neonatal intensive care unit (NICU) level was classified as A, restriction on assisted ventilation or no surgery; B, major surgery; or C, cardiac surgery requiring bypass. Level B centers were further divided into low-volume (<50 inborn infants at 22 to 29 weeks' gestation per year) and high-volume (≥50 inborn infants at 22 to 29 weeks' gestation per year) centers. High-volume level B and level C centers were combined, resulting in 3 distinct NICU categories: level A, low-volume B, and high-volume B and C NICUs. The main outcome was the change in the percentage of births at hospitals with level A, low-volume B, and high-volume B or C NICUs overall and by US Census region.

Results

A total of 357 181 infants (mean [SD] gestational age, 26.4 [2.1] weeks; 188 761 [52.9%] male) were included in the analysis. Across regions, the Pacific (20 239 births [38.3%]) had the lowest while the South Atlantic (48 348 births [62.7%]) had the highest percentage of births at a hospital with a high-volume B- or C-level NICU. Births at hospitals with A-level NICUs increased by 5.6% (95% CI, 4.3% to 7.0%), and births at low-volume B-level NICUs increased by 3.6% (95% CI, 2.1% to 5.0%), while births at hospitals with high-volume B- or C-level NICUs decreased by 9.2% (95% CI, -10.3% to -8.1%). By 2020, less than half of the births for infants at 22 to 29 weeks' gestation occurred at hospitals with high-volume B- or C-level NICUs. Most US Census regions followed the nationwide trends; for example, births at hospitals with high-volume B- or C-level NICUs decreased by 10.9% [95% CI, -14.0% to -7.8%) in the East North Central region and by 21.1% (95% CI, -24.0% to -18.2%) in the West South Central region.

Conclusions and Relevance

This retrospective cohort study identified concerning deregionalization trends in birthplace hospital level of care for infants born at 22 to 29 weeks' gestation. These findings should serve to encourage policy makers to identify and enforce strategies to ensure that infants at the highest risk of adverse outcomes are born at the hospitals where they have the best chances to attain optimal outcomes.

Metabolome-Wide Associations of Gestational Weight Gain in Pregnant Women with Overweight and Obesity

Excessive gestational weight gain (GWG) is associated with adverse pregnancy outcomes. This metabolome-wide association study aimed to identify metabolomic markers for GWG. This longitudinal study included 39 Black and White pregnant women with a prepregnancy body mass index (BMI) of ≥ 25 kg/m2. Untargeted metabolomic profiling was performed using fasting plasma samples collected at baseline (mean: 12.1 weeks) and 32 weeks of gestation. The associations of metabolites at each time point and changes between the two time points with GWG were examined by linear and least absolute shrinkage and selection operator (LASSO) regression analyses. Pearson correlations between the identified metabolites and cardiometabolic biomarkers were examined. Of the 769 annotated metabolites, 88 metabolites at 32 weeks were individually associated with GWG, with four (phosphatidylcholine (PC) 34:4, triacylglycerol (TAG) 52:6, arachidonic acid, isoleucine) jointly associated with GWG (area under the receiver operating characteristic curve (AUC) for excessive GWG: 0.80, 95% CI: 0.67, 0.93). No correlations were observed between the 88 metabolites and insulin, C-peptide, and high-sensitivity C-reactive protein at 32 weeks. Twelve metabolites at baseline (AUC for excessive GWG: 0.80, 95% CI: 0.62, 0.99) and three metabolite changes (AUC for excessive GWG: 0.73, 95% CI: 0.44, 1.00) were jointly associated with GWG. We identified novel metabolites in the first and third trimesters associated with GWG, which may shed light on the pathophysiology of GWG.

Transfer Patterns of Very Low Birth Weight Infants for Convalescent Care

OBJECTIVES

To examine the prevalence, characteristics, clinical course, and length of stay (LOS) among 4 groups of infants who were transferred for convalescence and subsequently discharged from the hospital; failed transfer for convalescence and were (a) either readmitted, or (b) transferred again; and were not transferred for convalescence.

METHODS

Among very low birth weight infants hospitalized at US Vermont Oxford Network centers between 2006 and 2020, we examined the distribution of characteristics, delivery room and NICU usage measures, outcomes, and LOS among the 4 groups of infants.

RESULTS

Among 641 712 infants, a total of 28 985 (4.5%) infants were transferred for convalescent care; of 28 186 infants, 182 (0.65%) died before hospital discharge and 2551 (9.1%) failed the transfer (1771 [6.3%] were readmitted and 780 [2.8%] were transferred again). There were major regional and NICU variations in the practice of the transfer for convalescence; New England (18.8%) had the highest whereas East South Central (2.2%) had the lowest percentage of transfer for convalescence. Infants who transferred for convalescence and were discharged from the hospital had a similar LOS and similar distribution of NICU usage measures and outcomes to infants who were not transferred for convalescence. Infants who failed the transfer for convalescence had a longer LOS than infants who were transferred for convalescence and then discharged from the hospital.

CONCLUSIONS

The rates of transfer for convalescence and transfer for convalescence failure were low. Future studies should weigh the risks and benefits of transfer for convalescence, which might differ on the basis of geography.

Outcomes of Moderately Preterm Infants of Insulin-Dependent Diabetic Mothers

OBJECTIVE

 Little is known about the hospital outcomes of moderately preterm (MPT; 29 0/7-33 6/7 weeks gestational age) infants born to insulin-dependent diabetic mothers (IDDMs). We evaluated characteristics and outcomes of MPT infants born to IDDMs compared with those without IDDM (non-IDDM).

STUDY DESIGN

 Cohort study of infants from 18 centers included in the MPT infant database from 2012 to 2013. We compared characteristics and outcomes of infants born to IDDMs and non-IDDMs.

RESULTS

 Of 7,036 infants, 527 (7.5%) were born to IDDMs. Infants of IDDMs were larger at birth, more often received continuous positive pressure ventilation in the delivery room, and had higher risk of patent ductus arteriosus (adjusted relative risk or aRR: 1.49, 95% confidence interval [CI]: 1.20-1.85) and continued hospitalization at 40 weeks postmenstrual age (aRR: 1.55, 95% CI: 1.18-2.05).

CONCLUSION

 MPT infants of IDDM received more respiratory support and prolonged hospitalizations, providing further evidence of the important neonatal health consequences of maternal diabetes.

KEY POINTS

· Little data are available on moderate preterm infants of IDDMs.. · MPT infants of IDDMs need more respiratory support.. · Longer neonatal intensive care unit stays among MPT infants of IDDMs..

Changes in hospital quality at hospitals serving black and hispanic newborns below 30 weeks' gestation

OBJECTIVE

Examine whether the quality of Black and Hispanic serving (BHS) compared with not BHS (NBHS) NICUs has changed differentially over time.

STUDY DESIGN

Infants 24-29 weeks' gestation born at U.S. Vermont Oxford Network centers (2006-2018) were studied. We calculated adjusted hospital quality scores as the predicted probabilities of composite in-hospital mortality and morbidities from a logistic model. We regressed hospital quality scores on birth year to estimate the linear temporal slope by BHS-serving status for hospitals within each Census division.

RESULTS

Hospital quality improved similarly over time for BHS and NBHS hospitals across all divisions except West South Central where a mean change in the composite score was -18.8 (95% CI: -24.1, -13.5) for NBHS and -9.3 (95% CI: -14.1, -4.6) for BHS hospitals (p-value = 0.009).

CONCLUSION

Hospital quality improved similarly for BHS and NBHS hospitals across most divisions. Variation within and between divisions should be a focus for quality improvement.

Performance of a validated spontaneous preterm delivery predictor in South Asian and Sub-Saharan African women: a nested case control study

OBJECTIVES

To address the disproportionate burden of preterm birth (PTB) in low- and middle-income countries, this study aimed to (1) verify the performance of the United States-validated spontaneous PTB (sPTB) predictor, comprised of the IBP4/SHBG protein ratio, in subjects from Bangladesh, Pakistan and Tanzania enrolled in the Alliance for Maternal and Newborn Health Improvement (AMANHI) biorepository study, and (2) discover biomarkers that improve performance of IBP4/SHBG in the AMANHI cohort.

STUDY DESIGN

The performance of the IBP4/SHBG biomarker was first evaluated in a nested case control validation study, then utilized in a follow-on discovery study performed on the same samples. Levels of serum proteins were measured by targeted mass spectrometry. Differences between the AMANHI and U.S. cohorts were adjusted using body mass index (BMI) and gestational age (GA) at blood draw as covariates. Prediction of sPTB < 37 weeks and < 34 weeks was assessed by area under the receiver operator curve (AUC). In the discovery phase, an artificial intelligence method selected additional protein biomarkers complementary to IBP4/SHBG in the AMANHI cohort.

RESULTS

The IBP4/SHBG biomarker significantly predicted sPTB < 37 weeks (n = 88 vs. 171 terms ≥ 37 weeks) after adjusting for BMI and GA at blood draw (AUC= 0.64, 95% CI: 0.57-0.71, p < .001). Performance was similar for sPTB < 34 weeks (n = 17 vs. 184 ≥ 34 weeks): AUC = 0.66, 95% CI: 0.51-0.82, p = .012. The discovery phase of the study showed that the addition of endoglin, prolactin, and tetranectin to the above model resulted in the prediction of sPTB < 37 with an AUC= 0.72 (95% CI: 0.66-0.79, p-value < .001) and prediction of sPTB < 34 with an AUC of 0.78 (95% CI: 0.67-0.90, p < .001).

CONCLUSION

A protein biomarker pair developed in the U.S. may have broader application in diverse non-U.S. populations.

Quantile contours and allometric modelling for risk classification of abnormal ratios with an application to asymmetric growth-restriction in preterm infants

We develop an approach to risk classification based on quantile contours and allometric modelling of multivariate anthropometric measurements. We propose the definition of allometric direction tangent to the directional quantile envelope, which divides ratios of measurements into half-spaces. This in turn provides an operational definition of directional quantile that can be used as cutoff for risk assessment. We show the application of the proposed approach using a large dataset from the Vermont Oxford Network containing observations of birthweight (BW) and head circumference (HC) for more than 150,000 preterm infants. Our analysis suggests that disproportionately growth-restricted infants with a larger HC-to-BW ratio are at increased mortality risk as compared to proportionately growth-restricted infants. The role of maternal hypertension is also investigated.

Racial and Ethnic Differences Over Time in Outcomes of Infants Born Less Than 30 Weeks' Gestation

OBJECTIVES

To examine changes in care practices over time by race and ethnicity and whether the decrease in hospital mortality and severe morbidities has benefited infants of minority over infants of white mothers.

METHODS

Infants 22 to 29 weeks' gestation born between January 2006 and December 2017 at a Vermont Oxford Network center in the United States were studied. We examined mortality and morbidity rate differences and 95% confidence intervals for African American and Hispanic versus white infants by birth year. We tested temporal differences in mortality and morbidity rates between white and African American or Hispanic infants using a likelihood ratio test on nested binomial regression models.

RESULTS

Disparities for certain care practices such as antenatal corticosteroids and for some in-hospital outcomes have narrowed over time for minority infants. Compared with white infants, African American infants had a faster decline for mortality, hypothermia, necrotizing enterocolitis, and late-onset sepsis, whereas Hispanic infants had a faster decline for mortality, respiratory distress syndrome, and pneumothorax. Other morbidities showed a constant rate difference between African American and Hispanic versus white infants over time. Despite the improvements, outcomes including hypothermia, mortality, necrotizing enterocolitis, late-onset sepsis, and severe intraventricular hemorrhage remained elevated by the end of the study period, especially among African American infants.

CONCLUSIONS

Racial and ethnic disparities in vital care practices and certain outcomes have decreased. That the quality deficit among minority infants occurred for several care practice measures and potentially modifiable outcomes suggests a critical role for quality improvement initiatives tailored for minority-serving hospitals.

Associations of maternal gestational weight gain with the risk of offspring obesity and body mass index Z scores beyond the mean

PURPOSE

We examined the association of meeting the 2009 Institute of Medicine gestational weight gain (GWG) guidelines with offspring obesity and body mass index Z score (BMIZ) at age six overall and by maternal weight status.

METHODS

Data were from the Infant Feeding Practices Survey II Study (2005-2007) and their Year Six Follow-Up Study (2012). Logistic regression and quantile regression models were used.

RESULTS

Eleven percent of children were obese. Children born to mothers who gained excessive weight during pregnancy had an increased risk of obesity as compared with those born to mothers who gained adequate weight (adjusted odds ratio: 1.67). The association was stronger among normal-weight mothers (adjusted odds ratio: 3.50). Inadequate GWG was not associated with offspring obesity overall or in subsamples by maternal prepregnancy BMI. Children born to mothers who gained excessive weight had higher BMIZ. This distributional association was more pronounced among normal-weight mothers. Children born to obese mothers who gained inadequate weight had lower BMIZ at some percentiles of the BMIZ distribution.

CONCLUSIONS

Excessive GWG was associated with increased risk of offspring obesity and higher BMIZ at age six, whereas inadequate GWG was protective of high BMIZ among children born to obese mothers.

Sex Differences in Mortality and Morbidity of Infants Born at Less Than 30 Weeks' Gestation

OBJECTIVE

To examine whether changes in mortality and morbidities have benefited male more than female infants.

METHODS

Infants of gestational ages 22 to 29 weeks born between January 2006 and December 2016 at a Vermont Oxford Network center in the United States were studied. We examined mortality and morbidity rate differences and 95% confidence intervals by sex and birth year. We tested temporal differences in mortality and morbidity rates between boys and girls by means of a likelihood ratio test (LRT) on nested binomial regression models with log links.

RESULTS

A total of 205 750 infants were studied; 97 048 (47.2%) infants were girls. The rate for mortality and chronic lung disease decreased over time faster for boys than for girls (LRT P < .001 for mortality; P = .006 for lung disease). Restricting to centers that remained throughout the entire study period did not change all the above but additionally revealed a significant year-sex interaction for respiratory distress syndrome, with a faster decline among boys (LRT P = .04). Morbidities, including patent ductus arteriosus, necrotizing enterocolitis, early-onset sepsis, late-onset sepsis, severe intraventricular hemorrhage, severe retinopathy of prematurity, and pneumothorax, revealed a constant rate difference between boys and girls over time.

CONCLUSIONS

Compared with girls, male infants born at <30 weeks' gestation experienced faster declines in mortality, respiratory distress syndrome, and chronic lung disease over an 11-year period. Future research should investigate which causes of death declined among boys and whether their improved survival has been accompanied by a change in their neurodevelopmental impairment rate.

Body mass index trajectories during the first year of life and their determining factors

OBJECTIVE

The purpose of this study was to examine the trajectories of body mass index (BMI) in the first year of life and their determining factors.

METHODS

We used data from the Infant Feeding Practices Survey II restricted to children with 2 or more time points of BMI data during follow-up visits within the first year of life (n = 2320). Latent class growth analysis was used to identify distinct BMI trajectories. Using multinomial logistic regression, we examined the prenatal and early life determinants of the identified trajectories.

RESULTS

Three BMI trajectories were identified during the first year of life: "low-stable" (81.6%), "high-stable" (15.6%), and "rising" (2.8%) trajectories. Boys, preterm infants, infants born to overweight mothers, Hispanic mothers, non-Hispanic Black mothers, and mothers who smoked during pregnancy were significantly more likely to have high-stable versus low-stable trajectories. Infants born to non-Hispanic Black mothers were more likely to have a rising versus a low-stable trajectory. Household income ≥350% of the federal poverty level and full adherence to the guidelines of the American Academy of Pediatrics for both breastfeeding exclusivity and duration reduced the likelihood of infants being in the rising versus the low-stable trajectory.

CONCLUSION

Distinct BMI trajectories were evident as early as infancy. The predictors of these trajectories offer information about high-risk groups, and important and preventable prenatal and postnatal risk factors for future intervention programs.

Neonatal and fetal growth charts to identify preterm infants <30 weeks gestation at risk of adverse outcomes

BACKGROUND

It is unclear whether a neonatal or a fetal growth standard is a better predictor of adverse in-hospital newborn infant outcomes.

OBJECTIVE

We aimed to evaluate and compare the power of birthweight for gestational age to predict adverse neonatal outcomes using neonatal and fetal growth charts. Gestational age-specific birthweight was examined either as a percentile score or as a binary indicator for birthweight <10th percentile (small for gestational age) with the use of 3 fetal growth charts (National Institute of Child Health and Human Development, World Health Organization, and Intergrowth-21st) and 1 neonatal sex-specific birthweight chart.

STUDY DESIGN

Inborn singleton infants from 2006-2014 with gestational age between 22 and 29 weeks and who were enrolled at 1 of the 852 US centers that were participating in the Vermont Oxford Network were studied. Outcomes included death, necrotizing enterocolitis, severe intraventricular hemorrhage, severe retinopathy of prematurity, and chronic lung disease. Receiver operating characteristic curve analysis was used to assess the predictive power of birthweight for gestational age, either as a score or as a small-for-gestational-age indicator, with the use of the 4 charts. We also examined the relative risks of the outcomes by comparing small-for-gestational-age and non-small-for-gestational-age infants with the use of the 4 charts.

RESULTS

The percentage of small-for-gestational-age newborn infants ranged from 25.9-29.7% when with used the fetal growth charts. In contrast, the percentage was 10% when we used the neonatal charts. The areas under the receiver operating characteristic curves were similar across the 4 classification methods and were all <0.60, which suggests a poor predictive power. Small-for-gestational-age status, as classified by the neonatal chart, showed stronger associations with death, necrotizing enterocolitis, severe retinopathy of prematurity, and chronic lung disease, compared with those associations that were based on the other classification methods.

CONCLUSION

Neither the neonatal nor the fetal growth charts are predictive of adverse infant in-hospital outcomes. In contrast to fetal charts, the use of the neonatal charts results in stronger associations between small-for-gestational-age and adverse outcomes.

In-Hospital Outcomes in Large for Gestational Age Infants at 22-29 Weeks of Gestation

OBJECTIVE

To estimate the risks of mortality and morbidities in large for gestational age (LGA) infants relative to appropriate for gestational age infants born at 22-29 weeks of gestation.

STUDY DESIGN

Data on 156 587 infants were collected between 2006 and 2014 in 852 US centers participating in the Vermont Oxford Network. We defined LGA as sex-specific birth weight above the 90th centile for gestational age measured in days. Generalized additive models with smoothing splines on gestational age by LGA status were fitted on mortality and morbidity outcomes to estimate adjusted relative risks and their 95% CIs.

RESULTS

Compared with appropriate for gestational age infants, being born LGA was associated with decreased risks of mortality, respiratory distress syndrome, patent ductus arteriosus, necrotizing enterocolitis, late-onset sepsis, severe retinopathy of prematurity, and chronic lung disease. Early onset sepsis and severe intraventricular hemorrhage were increased among LGA infants, but these risks were not homogeneous across the gestational age range.

CONCLUSIONS

Being born LGA was associated with lower risks for all the examined outcomes except for early onset sepsis and severe intraventricular hemorrhage.

Morbidity and Mortality in Small for Gestational Age Infants at 22 to 29 Weeks' Gestation

OBJECTIVES

To identify the relative risks of mortality and morbidities for small for gestational age (SGA) infants in comparison with non-SGA infants born at 22 to 29 weeks' gestation.

METHODS

Data were collected (2006-2014) on 156 587 infants from 852 US centers participating in the Vermont Oxford Network. We defined SGA as sex-specific birth weight <10th centile for gestational age (GA) in days. Binomial generalized additive models with a thin plate spline term on GA by SGA were used to calculate the adjusted relative risks and 95% confidence intervals for outcomes by GA.

RESULTS

Compared with non-SGA infants, the risk of patent ductus arteriosus decreased for SGA infants in early GA and then increased in later GA. SGA infants were also at increased risks of mortality, respiratory distress syndrome, necrotizing enterocolitis, late-onset sepsis, severe retinopathy of prematurity, and chronic lung disease. These risks of adverse outcomes, however, were not homogeneous across the GA range. Early-onset sepsis was not different between the 2 groups for the majority of GAs, although severe intraventricular hemorrhage was decreased among SGA infants for only gestational week 24 through week 25.

CONCLUSIONS

SGA was associated with additional risks to mortality and morbidities, but the risks differed across the GA range.

Rare copy number variants identified in prune belly syndrome

Prune belly syndrome (PBS), also known as Eagle-Barrett syndrome, is a rare congenital disorder characterized by absence or hypoplasia of the abdominal wall musculature, urinary tract anomalies, and cryptorchidism in males. The etiology of PBS is largely unresolved, but genetic factors are implicated given its recurrence in families. We examined cases of PBS to identify novel pathogenic copy number variants (CNVs). A total of 34 cases (30 males and 4 females) with PBS identified from all live births in New York State (1998-2005) were genotyped using Illumina HumanOmni2.5 microarrays. CNVs were prioritized if they were absent from in-house controls, encompassed ≥10 consecutive probes, were ≥20 Kb in size, had ≤20% overlap with common variants in population reference controls, and had ≤20% overlap with any variant previously detected in other birth defect phenotypes screened in our laboratory. We identified 17 candidate autosomal CNVs; 10 cases each had one CNV and four cases each had two CNVs. The CNVs included a 158 Kb duplication at 4q22 that overlaps the BMPR1B gene; duplications of different sizes carried by two cases in the intron of STIM1 gene; a 67 Kb duplication 202 Kb downstream of the NOG gene, and a 1.34 Mb deletion including the MYOCD gene. The identified rare CNVs spanned genes involved in mesodermal, muscle, and urinary tract development and differentiation, which might help in elucidating the genetic contribution to PBS. We did not have parental DNA and cannot identify whether these CNVs were de novo or inherited. Further research on these CNVs, particularly BMP signaling is warranted to elucidate the pathogenesis of PBS.

Maternal Obesity, Gestational Weight Gain, and Asthma in Offspring

INTRODUCTION

Obesity is common among women of childbearing age; intrauterine exposure to maternal obesity or gestational weight gain may influence the development of asthma in early childhood. We examined the relationships of maternal obesity and gestational weight gain with asthma in offspring.

METHODS

We used data from the Early Childhood Longitudinal Study-Birth Cohort, which has a nationally representative sample of children followed from birth in 2001 through age 4 (n = 6,450). Asthma was based on parental report of a medical professional's diagnosis. We used generalized estimating equation binomial models to compute adjusted odds ratios (ORs) of childhood asthma with maternal obesity and 4 measures of gestational weight gain.

RESULTS

Compared with children of normal-weight mothers, children of obese mothers had increased risk of asthma (adjusted OR, 1.63; 95% confidence interval [CI], 1.26-2.12) by age 4, and children born to overweight mothers had similar risk (adjusted OR, 1.25; 95% CI, 0.99-1.59). Extreme-low weight gain (<5 kg) and extreme-high weight gain (≥25 kg) were associated with increased risk of asthma; however, the following measures were not significant predictors of asthma: meeting gestational weight gain recommendations of the Institute of Medicine, total gestational weight gain, and weekly rate of weight gain in the second and third trimesters.

CONCLUSION

Extreme-low or extreme-high gestational weight gain and maternal obesity are risk factors for early childhood asthma, further evidence of the long-term impact of intrauterine exposure on children and the need to target preconception care to improve child health indicators.

Interpregnancy weight change and adverse maternal outcomes: a retrospective cohort study

PURPOSE

Examine associations between interpregnancy body mass index (BMI) change (difference in the pre-pregnancy BMIs of two consecutive pregnancies) and gestational diabetes mellitus (GDM), pre-eclampsia (PE), gestational hypertension (GHtn), primary cesarean delivery, and vaginal birth after cesarean delivery (VBAC).

METHODS

Modified Poisson regression models estimated adjusted associations.

RESULTS

Every 1-unit increase in interpregnancy BMI increased risks of GDM (relative risk [RR]: 1.09; 95% confidence interval [CI], 1.07-1.11), PE (RR: 1.06; 95% CI, 1.04-1.09), GHtn (RR: 1.08; 95% CI, 1.06-1.10), and primary cesarean delivery (RR: 1.03; 95% CI, 1.01-1.05) and decreased the risk of a successful VBAC (RR: 0.98; 95% CI: 0.97-0.997) in the second pregnancy. A BMI increase of ≥3 units increased risks of GDM (RR: 1.71, 95% CI, 1.52-1.93), PE (RR: 1.60, 95% CI, 1.33-1.94), GHtn (RR: 1.66, 95% CI, 1.42-1.94), and primary cesarean delivery (RR: 1.29, 95% CI, 1.12-1.49) and decreased the risk of a successful VBAC (RR: 0.89; 95% CI, 0.80-0.99) compared to women with interpregnancy BMI change within -1 and +1 unit. GDM was also increased among women increasing their BMI by ≥2 but <3 units (RR: 1.40; 95% CI, 1.21-1.61) and among those gaining ≥1 but <2 units (RR: 1.23; 95% CI, 1.08-1.40).

CONCLUSION

An interpregnancy BMI increase of ≥3 units is associated with an increased risk of all outcomes. These findings emphasize the importance of interpregnancy weight management.

Anthropometric Charts for Infants Born Between 22 and 29 Weeks' Gestation

OBJECTIVES

Using a large, racially diverse US dataset, we aimed primarily to: (1) fit and validate sex-specific birth weight and head circumference for gestational age charts for infants born at 22 to 29 weeks' gestation; and (2) fit race-specific birth weight and head circumference for gestational age charts.

METHODS

We used data collected between 2006 and 2014 on 183 243 singleton infants without congenital malformations with gestational age between 22 weeks, 0 days and 29 weeks, 6 days from 852 US members of the Vermont Oxford Network. For the sex-specific charts, the final sample size included 156 587 infants who survived hospital discharge. From these 156 587, we abstracted a subset of 47 005 infants to fit sex-specific charts separately for white, black, and Asian infants. For all charts, we applied quantile regression models to predict infants' birth weight and head circumference percentiles from gestational age expressed in days.

RESULTS

We successfully validated the overall sex-specific charts. Over most of the gestational age range, black infants, either girls or boys, had the lowest predicted birth weight as compared with white and Asian infants for many percentiles.

CONCLUSIONS

We fitted and validated new sex-specific charts using a recent, large, and racially diverse dataset. Future steps include using these charts to examine associations of weight and head circumference at birth with mortality and morbidity.

Association of Antenatal Corticosteroids With Mortality, Morbidity, and Neurodevelopmental Outcomes in Extremely Preterm Multiple Gestation Infants

IMPORTANCE

Little is known about the effects of antenatal corticosteroids (ANS) on extremely preterm multiples.

OBJECTIVE

To examine if use of ANS is associated with improvement in major outcomes in extremely preterm multiples.

DESIGN, SETTING, AND PARTICIPANTS

Infants with a gestational age between 22 and 28 weeks born at a National Institute of Child Health and Human Development Neonatal Research Network center were studied between January 1998 and December 2013. Generalized estimating equation models were used to generate adjusted relative risks (aRR) controlling for important maternal and neonatal variables.

EXPOSURE

Antenatal corticosteroids.

MAIN OUTCOMES AND MEASURES

In-hospital mortality and the composite outcome of neurodevelopmental impairment at 18 to 22 months' corrected age or death before assessment.

RESULTS

A total of 6925 multiple-birth infants were studied; 5775 of 6925 (83.4%) were twins, and 4276 (61.7%) were white. Of the total study population, 6094 (88%) were born to women who received ANS. In-hospital mortality was lower among infants with exposure to ANS vs no exposure (aRR = 0.87; 95% CI, 0.78-0.96). Neurodevelopmental impairment or death was not significantly lower among those exposed to ANS vs no exposure (aRR = 0.93; 95% CI, 0.84-1.03). Other adverse outcomes that occurred less frequently among infants of women receiving ANS included severe intraventricular hemorrhage (aRR = 0.68; 95% CI, 0.58-0.78) and the combined outcomes of necrotizing enterocolitis or death and severe intraventricular hemorrhage or death. Subgroup analyses indicated that exposure to ANS was associated with a lower risk of mortality and a lower composite of neurodevelopmental impairment or mortality among nonsmall for gestational age multiples (aRR = 0.82; 95% CI, 0.74-0.92; and aRR = 0.89; 95% CI, 0.80-0.98, respectively) and a higher risk among small for gestational age multiples (aRR = 1.40; 95% CI, 1.02-1.93; and aRR = 1.62; 95% CI, 1.22-2.16, respectively). Antenatal corticosteroids were associated with higher neurodevelopmental impairment or mortality among multiple-birth infants of mothers with diabetes (aRR = 1.55; 95% CI, 1.00-2.38) but not among infants of mothers without diabetes (aRR = 0.91; 95% CI, 0.83-1.01).

CONCLUSIONS AND RELEVANCE

Compared with no exposure, exposure to ANS was associated with a lower risk of mortality in extremely preterm multiples, with no significant differences in the composite of neurodevelopmental impairment or death. Future research should investigate the increased risks of mortality and the composite of neurodevelopmental impairment or death associated with exposure to corticosteroids among small for gestational age multiples.

Outcomes of Extremely Preterm Infants Born to Insulin-Dependent Diabetic Mothers

BACKGROUND AND OBJECTIVE

Little is known about in-hospital morbidities and neurodevelopmental outcomes among extremely preterm infants born to women with insulin-dependent diabetes mellitus (IDDM). We examined risks of mortality, in-hospital morbidities, and neurodevelopmental outcomes at 18 to 22 months' corrected age between extremely preterm infants of women with insulin use before pregnancy (IBP), with insulin use started during pregnancy (IDP), and without IDDM.

METHODS

Infants 22 to 28 weeks' gestation born or cared for at a Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network center (2006-2011) were studied. Regression models compared the association between maternal IDDM and timing of insulin use and the outcomes of the 3 groups.

RESULTS

Of 10 781 infants, 536 (5%) were born to women with IDDM; 58% had IBP, and 36% had IDP. Infants of mothers with IBP had higher risks of necrotizing enterocolitis (adjusted relative risk [RR] = 1.55 [95% confidence interval (CI) 1.17-2.05]) and late-onset sepsis (adjusted RR = 1.26 [95% CI 1.07-1.48]) than infants of mothers without IDDM. There was some indication of higher in-hospital mortality risk among infants of mothers with IBP compared with those with IDP (adjusted RR = 1.33 [95% CI 1.00-1.79]). Among survivors evaluated at 18 to 22 months' corrected age, average head circumference z score was lower for infants of mothers with IBP compared with those without IDDM, but there were no differences in risk of neurodevelopmental impairment.

CONCLUSIONS

In this cohort of extremely preterm infants, infants of mothers with IBP had higher risks of necrotizing enterocolitis, sepsis, and small head circumference.

Rare copy number variants implicated in posterior urethral valves

The cause of posterior urethral valves (PUV) is unknown, but genetic factors are suspected given their familial occurrence. We examined cases of isolated PUV to identify novel copy number variants (CNVs). We identified 56 cases of isolated PUV from all live-births in New York State (1998-2005). Samples were genotyped using Illumina HumanOmni2.5 microarrays. Autosomal and sex-linked CNVs were identified using PennCNV and cnvPartition software. CNVs were prioritized for follow-up if they were absent from in-house controls, contained ≥ 10 consecutive probes, were ≥ 20 Kb in size, had ≤ 20% overlap with variants detected in other birth defect phenotypes screened in our lab, and were rare in population reference controls. We identified 47 rare candidate PUV-associated CNVs in 32 cases; one case had a 3.9 Mb deletion encompassing BMP7. Mutations in BMP7 have been associated with severe anomalies in the mouse urethra. Other interesting CNVs, each detected in a single PUV case included: a deletion of PIK3R3 and TSPAN1, duplication/triplication in FGF12, duplication of FAT1--a gene essential for normal growth and development, a large deletion (>2 Mb) on chromosome 17q that involves TBX2 and TBX4, and large duplications (>1 Mb) on chromosomes 3q and 6q. Our finding of previously unreported novel CNVs in PUV suggests that genetic factors may play a larger role than previously understood. Our data show a potential role of CNVs in up to 57% of cases examined. Investigation of genes in these CNVs may provide further insights into genetic variants that contribute to PUV.

Delivery Blood Pressure and Other First Pregnancy Risk Factors in Relation to Hypertensive Disorders in Second Pregnancies

BACKGROUND

First pregnancy characteristics and blood pressure (BP) measures may be associated with second pregnancy hypertensive disorder risk. We examined the association between first pregnancy risk factors and second pregnancy hypertensive disorders.

METHODS

Electronic medical records of nulliparas (n = 26,787) delivering at least twice in Utah (2002-2010) were used. Polychotomous logistic regression models estimated the association of first pregnancy risk factors with second pregnancy hypertensive disorders (gestational hypertension, preeclampsia, or chronic hypertension) stratified by first pregnancy hypertensive status and adjusted for second characteristics.

RESULTS

Among normotensive women in their first pregnancy, preterm birth (<34 weeks) and elevated BP at delivery admission in the first pregnancy increased odds of all incident hypertensive disorders in the second. Even borderline admission BP (either systolic or diastolic BP: 130-139 or 85-89 mm Hg, respectively) was associated with a doubling of hypertensive disorder risk in a subsequent pregnancy. First pregnancy BP was also associated with recurrence risks for hypertensive disorders, but the relation was stronger for women with gestational hypertension in their first pregnancy with more than 2-fold elevated risk across all BP categories (odds ratios range: 2.32-12.6). However, the majority of women (75%) with a hypertensive disorder in the first pregnancy do not repeat this outcome in the second pregnancy.

CONCLUSION

Delivery admission BP of a first pregnancy was strongly related to hypertensive disorder incidence and recurrence in the subsequent pregnancy. Although crude, these measures may prove useful as a predictor of long-term maternal health and future pregnancy risk.

Risk factors differ between recurrent and incident preeclampsia: a hospital-based cohort study

PURPOSE

To examine whether risk factors, including prepregnancy body mass index (BMI), differ between recurrent and incident preeclampsia.

METHODS

Data included electronic medical records of nulliparas (n = 26,613) delivering 2 times or more in Utah (2002-2010). Modified Poisson regression models were used to examine (1) adjusted relative risks (RR) of preeclampsia and 95% confidence intervals (CI) associated with prepregnancy BMI; (2) maternal risk factor differences between incident and recurrent preeclampsia among primiparous women.

RESULTS

In the first pregnancy, compared with normal weight women (BMI: 18.5-24.9), preeclampsia risks for overweight (BMI: 25-29.9), obese class I (BMI: 30-34.9), and obese class II/III (BMI: ≥ 35) women were 1.82 (95% CI = 1.60-2.06), 2.10 (95% CI = 1.76-2.50), and 2.84 (95% CI = 2.32-3.47), respectively, whereas second pregnancy-incident preeclampsia risks were 1.66 (95% CI = 1.27-2.16), 2.31 (95% CI = 1.67-3.20), and 4.29 (95% CI = 3.16-5.82), respectively. Recurrent preeclampsia risks associated with BMI were highest among obese class I women (RR = 1.60; 95% CI = 1.06-2.42) without increasing in a dose-response manner. Nonwhite women had higher recurrence risk than white women (RR = 1.70; 95% CI = 1.16-2.50), whereas second pregnancy-incident preeclampsia risk did not differ by race.

CONCLUSION

Prepregnancy BMI appeared to have stronger associations with risk of incident preeclampsia either in the first or second pregnancy, than with recurrence risk. Nonwhite women had higher recurrence risk.

Newborn Adipokines and Birth Outcomes

BACKGROUND

Adipokines can serve as a measure of adipose tissue activity. Although birthweight correlates with neonatal adiposity, findings for cord blood levels of adipokines and birth outcomes have been conflicted. Therefore, we determined the cross-sectional associations between adipokines measured in newborn dried blood spots (DBS) and birth outcomes.

METHODS

The Upstate KIDS study enrolled mothers and infants from 2008 to 2010. Among infants whose parents consented to the use of residual DBS from newborn screening, 2397 singletons and 1240 twins had adipokine measurements from the Human Obesity Panel (R&D Systems) by Luminex. Odds ratios were estimated by multivariable logistic regression for risk of birth outcomes of preterm delivery (<37 weeks for singletons, <32 for twins) and small-for-gestational age (SGA <10th for singletons and <3rd for twins age- and sex-specific percentiles) by adipokine quintiles. Generalised estimating equations were applied to account for correlations between twins.

RESULTS

Singletons in the lowest compared with the highest quintile of adiponectin were more likely preterm (adjusted odds ratio 3.26; 95% confidence interval [CI] 1.99, 5.34) and SGA (1.81; [95% CI 1.18, 2.77]). Similar associations were observed among twins. Resistin was associated with preterm birth (Q1 vs. Q5: 2.08; [95% CI 1.20, 3.62]) only among singletons. Adipsin had inconsistent associations after adjustment.

CONCLUSIONS

This large population-based study demonstrates that newborn DBS-measured adipokines are associated with birth outcomes, particularly preterm birth and SGA among those with lower adiponectin levels regardless of plurality.

Changes in diabetes status between pregnancies and impact on subsequent newborn outcomes

OBJECTIVE

Pregnancies complicated by gestational diabetes mellitus (GDM) or preexisting diabetes mellitus (DM) are at high risk for adverse newborn outcomes. Whether GDM history, recurrence, or transition to DM modifies such risks is unknown.

STUDY DESIGN

Medical record data on 62,013 repeat singleton pregnancies were collected retrospectively from women who delivered at least twice in Utah (2002 through 2010). Poisson regression models with robust variance estimators were used to estimate relative risks (RR) and 95% confidence intervals (CI) associated with GDM/DM status at the previous and/or current pregnancy relative to those without GDM/DM at either. Large for gestational age (LGA), shoulder dystocia, preterm birth (<37 weeks), respiratory distress syndrome, and other neonatal morbidities were examined adjusting for study site, maternal age, race, parity, interpregnancy interval, prepregnancy body mass index, and smoking status.

RESULTS

GDM in the previous pregnancy alone increased the risk of LGA in the current pregnancy (RR, 1.20; 95% CI, 1.05-1.38). Recurrent GDM increased the risks of LGA (RR, 1.76; 95% CI, 1.56-1.98), shoulder dystocia (RR, 1.98; 95% CI, 1.46-2.70), and preterm birth (RR, 1.68; 95% CI, 1.44-1.96) beyond that observed for pregnancies with current GDM alone. Women with GDM in a previous pregnancy that transitioned to DM in the current pregnancy and women with DM prior to the previous pregnancy had increased risks of all above outcomes.

CONCLUSION

GDM in a previous pregnancy alone without recurrence may still confer an increased LGA risk. Pregnancies complicated by GDM that transition to DM and those with DM prior to the previous pregnancy have the highest risks of adverse newborn outcomes.

Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study

OBJECTIVE

Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth.

DESIGN

Hospital-based cohort study.

SETTING

Utah, USA.

POPULATION

Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010).

METHODS

Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference).

MAIN OUTCOME MEASURES

Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference.

RESULTS

SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence.

CONCLUSION

There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.

The association between parity and birthweight in a longitudinal consecutive pregnancy cohort

BACKGROUND

Nulliparity is associated with lower birthweight, but few studies have examined how within-mother changes in risk factors impact this association.

METHODS

We used longitudinal electronic medical record data from a hospital-based cohort of consecutive singleton live births from 2002-2010 in Utah. To reduce bias from unobserved pregnancies, primary analyses were limited to 9484 women who entered nulliparous from 2002-2004, with 23,380 pregnancies up to parity 3. Unrestricted secondary analyses used 101,225 pregnancies from 45,212 women with pregnancies up to parity 7. We calculated gestational age and sex-specific birthweight z-scores with nulliparas as the reference. Using linear mixed models, we estimated birthweight z-score by parity adjusting for pregnancy-specific sociodemographics, smoking, alcohol, prepregnancy body mass index, gestational weight gain, and medical conditions.

RESULTS

Compared with nulliparas', infants of primiparas were larger by 0.20 unadjusted z-score units [95% confidence interval (CI) 0.18, 0.22]; the adjusted increase was similar at 0.18 z-score units [95% CI 0.15, 0.20]. Birthweight continued to increase up to parity 3, but with a smaller difference (parity 3 vs. 0 β = 0.27 [95% CI 0.20, 0.34]). In the unrestricted secondary sample, there was significant departure in linearity from parity 1 to 7 (P < 0.001); birthweight increased only up to parity 4 (parity 4 vs. 0 β = 0.34 [95% CI 0.31, 0.37]).

CONCLUSIONS

The association between parity and birthweight was non-linear with the greatest increase observed between first- and second-born infants of the same mother. Adjustment for changes in weight or chronic diseases did not change the relationship between parity and birthweight.

Mortality and morbidity of VLBW infants with trisomy 13 or trisomy 18

OBJECTIVE

Little is known about how very low birth weight (VLBW) affects survival and morbidities among infants with trisomy 13 (T13) or trisomy 18 (T18). We examined the care plans for VLBW infants with T13 or T18 and compared their risks of mortality and neonatal morbidities with VLBW infants with trisomy 21 and VLBW infants without birth defects.

METHODS

Infants with birth weight 401 to 1500 g born or cared for at a participating center of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network during the period 1994-2009 were studied. Poisson regression models were used to examine risk of death and neonatal morbidities among infants with T13 or T18.

RESULTS

Of 52,262 VLBW infants, 38 (0.07%) had T13 and 128 (0.24%) had T18. Intensity of care in the delivery room varied depending on whether the trisomy was diagnosed before or after birth. The plan for subsequent care for the majority of the infants was to withdraw care or to provide comfort care. Eleven percent of infants with T13 and 9% of infants with T18 survived to hospital discharge. Survivors with T13 or T18 had significantly increased risk of patent ductus arteriosus and respiratory distress syndrome compared with infants without birth defects. No infant with T13 or T18 developed necrotizing enterocolitis.

CONCLUSIONS

In this cohort of liveborn VLBW infants with T13 or T18, the timing of trisomy diagnosis affected the plan for care, survival was poor, and death usually occurred early.

Ten-year review of major birth defects in VLBW infants

OBJECTIVE

Birth defects (BDs) are an important cause of infant mortality and disproportionately occur among low birth weight infants. We determined the prevalence of BDs in a cohort of very low birth weight (VLBW) infants cared for at the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) centers over a 10-year period and examined the relationship between anomalies, neonatal outcomes, and surgical care.

METHODS

Infant and maternal data were collected prospectively for infants weighing 401 to 1500 g at NRN sites between January 1, 1998, and December 31, 2007. Poisson regression models were used to compare risk of outcomes for infants with versus without BDs while adjusting for gestational age and other characteristics.

RESULTS

A BD was present in 1776 (4.8%) of the 37 262 infants in our VLBW cohort. Yearly prevalence of BDs increased from 4.0% of infants born in 1998 to 5.6% in 2007, P < .001. Mean gestational age overall was 28 weeks, and mean birth weight was 1007 g. Infants with BDs were more mature but more likely to be small for gestational age compared with infants without BDs. Chromosomal and cardiovascular anomalies were most frequent with each occurring in 20% of affected infants. Mortality was higher among infants with BDs (49% vs 18%; adjusted relative risk: 3.66 [95% confidence interval: 3.41-3.92]; P < .001) and varied by diagnosis. Among those surviving >3 days, more infants with BDs underwent major surgery (48% vs 13%, P < .001).

CONCLUSIONS

Prevalence of BDs increased during the 10 years studied. BDs remain an important cause of neonatal morbidity and mortality among VLBW infants.

Late-onset sepsis in very low birth weight infants from singleton and multiple-gestation births

OBJECTIVES

To describe and compare the incidence of late-onset sepsis (LOS) and demographic and clinical characteristics associated with LOS in very low birth weight (VLBW) infants from singleton and multiple births, and to examine the heritability of susceptibility to LOS among VLBW twins by comparing same-sex and unlike-sex twin pairs.

STUDY DESIGN

The study group comprised infants with birth weight 401-1500 g seen at clinical centers of the Eunice Kennedy Shriver National Institute of Child and Human Development Neonatal Research Network between 2002 and 2008. Only the first episode of LOS was included in our analysis. Stepwise logistic regression models were fitted separately for singleton and multiple pregnancies to examine the maternal and neonatal factors associated with LOS. LOS due solely to gram-negative bacteria in singleton and multiple pregnancies was also examined in separate models. The heritability of LOS was estimated by examining the concordance of LOS in twins from same-sex and unlike-sex pairs.

RESULTS

LOS occurred in 25.0% (3797 of 15,178) of singleton and 22.6% (1196 of 5294) of multiple-birth VLBW infants. Coagulase-negative staphylococci were the most common infecting organisms, accounting for 53.2% of all LOS episodes in singletons and 49.2% in multiples. Escherichia coli and Klebsiella species were the most commonly isolated gram-negative organisms, and Candida albicans was the most commonly isolated fungus. Concordance of LOS did not differ significantly between same-sex and unlike-sex twin pairs.

CONCLUSION

LOS remains a common problem in VLBW infants. The incidence of LOS is similar for singleton and multiple-birth infants. The similar concordance of LOS in same-sex and unlike-sex twin pairs provides no evidence that susceptibility to LOS among VLBW infants is genetically determined.

Dietary patterns in association with postpartum weight retention

BACKGROUND

Postpartum weight retention (PPWR) can contribute to obesity development in women of reproductive age. Few studies have examined the association between postnatal diet and PPWR.

OBJECTIVE

We examined both PPWR and substantial PPWR (≥4.55 kg) in association with the following dietary patterns: the alternate Mediterranean Diet Score (aMED) and the Alternative Healthy Eating Index-2010 (AHEI-2010).

DESIGN

Women (n = 1136) in the Infant Feeding Practices Study II (2005-2007) self-reported their prepregnancy and postpartum weights at ~4, 7, 10, and 14 mo. Dietary patterns were calculated from a food-frequency questionnaire administered ~4 mo postpartum. Linear mixed models and generalized estimating equations for repeated measurements were used to examine PPWR and substantial PPWR, respectively, in association with the dietary patterns with adjustment for energy intake, breastfeeding, age, education, smoking, and marital status.

RESULTS

At 14 mo postpartum, the mean (±SD) PPWR was 1.1 ± 6.7 kg, and 22.4% of women had substantial PPWR. Although the change in PPWR over time seemed to differ by diet quality 4-7 mo postpartum, no differences were ultimately observed in the total mean PPWR or probability of substantial PPWR across aMED and AHEI-2010 categories during the rest of the follow-up (P > 0.12). Instead, PPWR and substantial PPWR were associated with total energy intake (at ~7-14 mo postpartum: 0.97 kg/1000 kcal (95% CI: 0.40, 1.55 kg/1000 kcal); OR: 1.25/1000 kcal (95% CI: 1.03, 1.52/1000 kcal), respectively].

CONCLUSIONS

Postpartum diet quality assessed by 2 patterns was not associated with weight retention. Total energy intake, regardless of the diet composition, plays a more important role in weight retention.

Outcome of extremely preterm infants (<1,000 g) with congenital heart defects from the National Institute of Child Health and Human Development Neonatal Research Network

Little is known about the outcomes of extremely low birth weight (ELBW) preterm infants with congenital heart defects (CHDs). The aim of this study was to assess the mortality, morbidity, and early childhood outcomes of ELBW infants with isolated CHD compared with infants with no congenital defects. Participants were 401-1,000 g infants cared for at National Institute of Child Health and Human Development Neonatal Research Network centers between January 1, 1998, and December 31, 2005. Neonatal morbidities and 18-22 months' corrected age outcomes were assessed. Neurodevelopmental impairment (NDI) was defined as moderate to severe cerebral palsy, Bayley II mental or psychomotor developmental index <70, bilateral blindness, or hearing impairment requiring aids. Poisson regression models were used to estimate relative risks for outcomes while adjusting for gestational age, small-for-gestational-age status, and other variables. Of 14,457 ELBW infants, 110 (0.8 %) had isolated CHD, and 13,887 (96 %) had no major birth defect. The most common CHD were septal defects, tetralogy of Fallot, pulmonary valve stenosis, and coarctation of the aorta. Infants with CHD experienced increased mortality (48 % compared with 35 % for infants with no birth defect) and poorer growth. Surprisingly, the adjusted risks of other short-term neonatal morbidities associated with prematurity were not significantly different. Fifty-seven (52 %) infants with CHD survived to 18-22 months' corrected age, and 49 (86 %) infants completed follow-up. A higher proportion of surviving infants with CHD were impaired compared with those without birth defects (57 vs. 38 %, p = 0.004). Risk of death or NDI was greater for ELBW infants with CHD, although 20 % of infants survived without NDI.

Major chromosomal anomalies among very low birth weight infants in the Vermont Oxford Network

OBJECTIVE

To examine prevalence, characteristics, interventions, and mortality of very low birth weight (VLBW) infants with trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), or triploidy.

STUDY DESIGN

Infants with birth weight 401-1500 g admitted to centers of the Vermont Oxford Network during 1994-2009 were studied. A majority of the analyses are presented as descriptive data. Median survival times and their 95% CIs were estimated using the Kaplan-Meier approach.

RESULTS

Of 539 509 VLBW infants, 1681 (0.31%) were diagnosed with T21, 1416 (0.26%) with T18, 435 (0.08%) with T13, and 116 (0.02%) with triploidy. Infants with T18 were the most likely to be growth restricted (79.7%). Major surgery was reported for 30.4% of infants with T21, 9.2% with T18, 6.4% with T13, and 4.8% with triploidy. Hospital mortality occurred among 33.1% of infants with T21, 89.0% with T18, 92.4% with T13, and 90.5% with triploidy. Median survival time was 4 days (95% CI, 3-4) among infants with T18 and 3 days (95% CI, 2-4) among both infants with T13 and infants with triploidy.

CONCLUSION

In this cohort of VLBW infants, survival among infants with T18, T13, or triploidy was very poor. This information can be used to counsel families.

Anthropometric charts for infants with trisomies 21, 18, or 13 born between 22 weeks gestation and term: the VON charts

Data on birth weight for gestational age (GA) are not well described for infants with trisomy 21 (T21), trisomy 18 (T18), or trisomy 13 (T13). We report on anthropometric charts of infants with these conditions using data from the Vermont Oxford Network (VON). Data from a total of 5,147 infants with T21 aged 22-41 weeks, 1,053 infants with T18 aged 22-41 weeks, and 613 infants with T13 aged 22-40 weeks were used to create birth weight for GA charts. Head circumference for GA charts were created for infants with T21 only. Combined-sex charts were generated for infants with T18 or T13 while sex-specific charts were generated for infants with T21. Smoothed centiles were created using LmsChartMaker Pro 2.3. Among the three examined groups, infants with T18 were the most likely to be growth restricted while infants with T21 were the least likely to be growth restricted. The new charts for infants with T21 were also compared to the Lubchenco and Fenton charts and both show frequent misclassification of infants with T21 as small or large for GA. The new charts should prove to be useful, especially for infants with T21, to assist in medical management and guide nutrition care decisions.

Survival and morbidity outcomes for very low birth weight infants with Down syndrome

OBJECTIVE

Our objective was to compare survival and neonatal morbidity rates between very low birth weight (VLBW) infants with Down syndrome (DS) and VLBW infants with non-DS chromosomal anomalies, nonchromosomal birth defects (BDs), and no chromosomal anomaly or major BD.

METHODS

Data were collected prospectively for infants weighing 401 to 1500 g who were born and/or cared for at one of the study centers participating in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network in 1994-2008. Risk of death and morbidities, including patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC), late-onset sepsis (LOS), retinopathy of prematurity, and bronchopulmonary dysplasia (BPD), were compared between VLBW infants with DS and infants in the other groups.

RESULTS

Infants with DS were at increased risk of death (adjusted relative risk: 2.47 [95% confidence interval: 2.00-3.07]), PDA, NEC, LOS, and BPD, relative to infants with no BDs. Decreased risk of death (relative risk: 0.40 [95% confidence interval: 0.31-0.52]) and increased risks of NEC and LOS were observed when infants with DS were compared with infants with other non-DS chromosomal anomalies. Relative to infants with nonchromosomal BDs, infants with DS were at increased risk of PDA and NEC.

CONCLUSION

The increased risk of morbidities among VLBW infants with DS provides useful information for counseling parents and for anticipating the need for enhanced surveillance for prevention of these morbidities.