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.

Recurrence Risk of Pregnancy Complications in Twin and Singleton Deliveries.

OBJECTIVE: This study aimed to estimate and compare the recurrence risk of preterm birth (PTB), gestational diabetes mellitus (GDM), gestational hypertension (GH), and preeclampsia and eclampsia (PE and E) in subsequent pregnancy groups (index-subsequent) of singleton-singleton (n = 49,868), twin-singleton (n = 448), and singleton-twin (n = 723) pregnancies. STUDY DESIGN: Birthing individuals from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Consecutive Pregnancy Study (2002-2010) with ≥ 2 singleton or twin deliveries were examined. Adjusted relative risks (aRR) and 95% confidence intervals (CI) for recurrent PTB, GDM, GH, and PE and E were estimated using Poisson regression models with robust variance estimators. RESULTS: The aRR of PTB and GDM ranged from 1.4 to 5.1 and 5.2 to 22.7, respectively, with the greatest recurrence relative risk for both conditions in singleton-singleton subsequent pregnancies (PTB: aRR = 5.1 [95% CI: 4.8-5.5], GDM: aRR = 22.7 [95% CI: 20.8-24.8]). The aRR of GH and PE and E ranged from 2.8 to 7.6 and 3.2 to 9.2, respectively, with the greatest recurrence relative risk for both conditions in twin-singleton subsequent pregnancies (GH: aRR = 7.6 [95% CI: 2.8-20.5], PE and E: aRR = 9.2 [95% CI: 2.9-28.6]). CONCLUSION: Recurrence relative risk was increased for PTB, GDM, GH, and PE and E in all subsequent pregnancy groups, which varied in magnitude based on the birth number of the index and subsequent pregnancy. This information provides insight into risk management for subsequent pregnancies including multiples. KEY POINTS: · Recurrence risk for all conditions is persistent in all subsequent pregnancy groups.. · The magnitude of risk varies by the presence of multiples in the index or subsequent pregnancy.. · Singleton-singleton pregnancies are at the greatest risk of PTB.. · Singleton-singleton pregnancies are at the greatest risk of GDM.. · Twin-singleton pregnancies are at the greatest risk of hypertensive disorders..

When a baby is born, so is a parent: Understanding the effects of preterm birth on Black parents through the lens of the NIMHD framework.

BACKGROUND: The rate of preterm birth (PTB) is high in the United States and Black infants remain disproportionately affected, with the disparity between Black and White infant deaths greater today than it was under antebellum slavery. PURPOSE: The National Institute on Minority Health and Disparities Research Framework reflects a unique set of determinants relevant to the understanding and promotion of minority health. METHODS: We have applied this framework to better understand the effects of PTB on Black parents and the distribution of the social determinants of health, including structural determinants and root causes of inequities. DISCUSSION: This adaptation shows the intersection in maternal and infant health that shapes individuals' experiences, drives disparities and impacts perinatal outcomes in critical periods over the lifecourse. CONCLUSION: In our efforts to achieve health equity, it is imperative that we study the underlying mechanisms and recognize that policies, institutional structures, and social factors are drivers of racism.

Dual Barriers: Examining Digital Access and Travel Burdens to Hospital Maternity Care Access in the United States, 2020.

Policy Points The White House Blueprint for Addressing the Maternal Health Crisis report released in June 2022 highlighted the need to enhance equitable access to maternity care. Nationwide hospital maternity unit closures have worsened the maternal health crisis in underserved communities, leaving many birthing people with few options and with long travel times to reach essential care. Ensuring equitable access to maternity care requires addressing travel burdens to care and inadequate digital access. Our findings reveal socioeconomically disadvantaged communities in the United States face dual barriers to maternity care access, as communities located farthest away from care facilities had the least digital access. CONTEXT: With the increases in nationwide hospital maternity unit closures, there is a greater need for telehealth services for the supervision, evaluation, and management of prenatal and postpartum care. However, challenges in digital access persist. We examined associations between driving time to hospital maternity units and digital access to understand whether augmenting digital access and telehealth services might help mitigate travel burdens to maternity care. METHODS: This cross-sectional study used 2020 American Hospital Association Annual Survey data for hospital maternity unit locations and 2020 American Community Survey five-year ZIP Code Tabulation Area (ZCTA)-level estimates of household digital access to telecommunication technology and broadband. We calculated driving times of the fastest route from population-weighted ZCTA centroids to the nearest hospital maternity unit. Rural-urban stratified generalized median regression models were conducted to examine differences in ZCTA-level proportions of household lacking digital access equipment (any digital device, smartphones, tablet), and lacking broadband subscriptions by spatial accessibility to maternity units. FINDINGS: In 2020, 2,905 (16.6%) urban and 3,394 (39.5%) rural ZCTAs in the United States were located >30 minutes from the nearest hospital maternity units. Regardless of rurality, these communities farther away from a maternity unit had disproportionally lower broadband and device accessibility. Although urban communities have greater digital access to technology and broadband subscriptions compared to rural communities, disparities in the percentage of households with access to digital devices were more pronounced within urban areas, particularly between those with and without close proximity to a hospital maternity unit. Communities where nearest hospital maternity units were >30 minutes away had higher poverty and uninsurance rates than those with <15-minute access. CONCLUSIONS: Socioeconomically disadvantaged communities face significant barriers to maternity care access, both with substantial travel burdens and inadequate digital access. To optimize maternity care access, ongoing efforts (e.g., Affordable Connectivity Program introduced in the 2021 Infrastructure Act), should bridge the gaps in digital access and target communities with substantial travel burdens to care and limited digital access.

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.

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 Overtime in Perinatal Management and Outcomes of Extremely Preterm Infants in One Tertiary Care Romanian Center.

Background and Objectives: Extremely preterm infants were at increased risk of mortality and morbidity. The purpose of this study was to: (1) examine changes over time in perinatal management, mortality, and major neonatal morbidities among infants born at 250-286 weeks' gestational age and cared for at one Romanian tertiary care unit and (2) compare the differences with available international data. Material and Methods: This study consisted of infants born at 250-286 weeks in one tertiary neonatal academic center in Romania during two 4-year periods (2007-2010 and 2015-2018). Major morbidities were defined as any of the following: severe intraventricular hemorrhage (IVH), severe retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), and bronchopulmonary dysplasia (BPD). Adjusted logistic regression models examined the association between the mortality and morbidity outcome and the study period. Results: The two cohorts differed with respect to antenatal antibiotics and rates of cesarean birth but had similar exposure to antenatal steroids and newborn referral to the tertiary care center. In logistic regression analyses, infants in the newer compared to the older cohort had a lower incidence of death (OR: 0.19; 95% CI: 0.11-0.35), a lower incidence of IVH (OR: 0.26; 95% CI: 0.15-0.46), and increased incidence of NEC (OR: 19.37; 95% CI: 2.41-155.11). Conclusions: Changes over time included higher use of antenatal antibiotics and cesarean delivery and no change in antenatal steroids administration. Overall mortality was lower in the newer cohort, especially for infants 250-266 weeks' gestation, NEC was higher while BPD and ROP were not different.

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.

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.

Admission Temperature and Associated Mortality and Morbidity among Moderately and Extremely Preterm Infants.

OBJECTIVE: To evaluate the temperature distribution among moderately preterm (MPT, 29-33 weeks) and extremely preterm (EPT, <29 weeks) infants upon neonatal intensive care unit (NICU) admission in 2012-2013, the change in admission temperature distribution for EPT infants between 2002-2003 and 2012-2013, and associations between admission temperature and mortality and morbidity for both MPT and EPT infants. STUDY DESIGN: Prospectively collected data from 18 centers in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network were used to examine NICU admission temperature of inborn MPT and EPT infants. Associations between admission temperature and mortality and morbidity were determined by multivariable logistic regression. EPT infants from 2002-2003 and 2012-2013 were compared. RESULTS: MPT and EPT cohorts consisted of 5818 and 3213 infants, respectively. The distribution of admission temperatures differed between the MPT vs EPT (P < .01), including the percentage <36.5°C (38.6% vs 40.9%), 36.5°C-37.5°C (57.3% vs 52.9%), and >37.5°C (4.2% vs 6.2%). For EPT infants in 2012-2013 compared with 2002-2003, the percentage of temperatures between 36.5°C and 37.5°C more than doubled and the percentage of temperatures >37.5°C more than tripled. Admission temperature was inversely associated with in-hospital mortality. CONCLUSIONS: Low and high admission temperatures are more frequent among EPT than MPT infants. Compared with a decade earlier, fewer EPT infants experience low admission temperatures but more have elevated temperatures. In spite of a change in distribution of NICU admission temperature, an inverse association between temperature and mortality risk persists.

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.

Examining the Prevalence Rates of Preexisting Maternal Medical Conditions and Pregnancy Complications by Source: Evidence to Inform Maternal and Child Research.

Objectives We sought to examine whether there are systematic differences in ascertainment of preexisting maternal medical conditions and pregnancy complications from three common data sources used in epidemiologic research. Methods Diabetes mellitus, chronic hypertension, gestational diabetes mellitus (GDM), gestational hypertensive disorders (GHD), placental abruption and premature rupture of membranes (PROM) among 4821 pregnancies were identified via birth certificates, maternal self-report at approximately 4 months postpartum and by discharge codes from the Statewide Planning and Research Cooperative System (SPARCS), a mandatory New York State hospital reporting system. The kappa statistic (k) was estimated to ascertain beyond chance agreement of outcomes between birth certificates with either maternal self-report or SPARCS. Results GHD was under-ascertained on birth certificates (5.7 %) and more frequently indicated by maternal report (11 %) and discharge data (8.2 %). PROM was indicated more on birth certificates (7.4 %) than maternal report (4.5 %) or discharge data (5.7 %). Confirmation across data sources for some outcomes varied by maternal age, race/ethnicity, prenatal care utilization, preterm delivery, parity, mode of delivery, infant sex, use of infertility treatment and for multiple births. Agreement between maternal report and discharge data with birth certificates was generally poor (kappa < 0.4) to moderate (0.4 ≤ kappa < 0.75) but was excellent between discharge data and birth certificates for GDM among women who underwent infertility treatment (kappa = 0.79, 95 % CI 0.74, 0.85). Conclusions for Practice Prevalence and agreement of conditions varied across sources. Condition-specific variations in reporting should be considered when designing studies that investigate associations between preexisting maternal medical and pregnancy-related conditions with health outcomes over the life-course.

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.

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.

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.

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 ß = 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 ß = 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.

Interpregnancy interval and adverse perinatal outcomes: A within-individual comparative method.

Background and Aim: Previously observed associations between interpregnancy interval (IPI) and perinatal outcomes using a between-individual method may be confounded by unmeasured maternal factors. This study aims to examine the association between IPI and adverse perinatal outcomes using within-individual comparative analyses. Methods: We studied 10,647 individuals from the National Institute of Child Health and Human Development Consecutive Pregnancies Study in Utah with ≥3 liveborn singleton pregnancies. We matched two IPIs per individual and used conditional logistic regression to examine the association between IPI and adverse perinatal outcomes, including preterm birth (PTB, <37 weeks' gestation), small-for-gestational-age (SGA, <10th percentile of sex-specific birthweight for gestational age), low birthweight (LBW, <2,500 g), and neonatal intensive care unit (NICU) admission. Point and 95% confidence interval (CI) estimates were adjusted for factors that vary across pregnancies within individuals. Results: CIs did not unequivocally support either an increase or a decrease in the odds of PTB (adjusted odds ratio [aOR]: 1.31, 95% CI: 0.87, 1.96), SGA (aOR: 0.81, 95% CI: 0.51, 1.28), LBW (aOR: 1.59, 95% CI: 0.90, 2.80), or NICU admission (aOR: 0.96, 95% CI: 0.66, 1.40) for an IPI <6 months compared to 18-23-months IPI (reference), and neither did the CIs for the aOR of IPIs of 6-11 and 12-18 months compared to the reference. In contrast, an IPI ≥24 months was associated with increased odds of LBW (aOR: 1.66, 95% CI: 1.03, 2.66 for 24-29 months; aOR: 2.27, 95% CI: 1.21, 4.29 for 30-35 months; and aOR: 2.09, 95% CI: 1.17, 3.72 for ≥36 months). Conclusions: Using a within-individual comparative method, we did not find evidence that a short IPI compared to the recommended IPI of 18-23 months was associated with increased odds of PTB, SGA, LBW, and NICU admission. IPI ≥ 24 months was associated with increased odds of delivering an LBW infant.