The changing risk of infant mortality by gestation, plurality, and race: 1989-1991 versus 1999-2001

Analysis of perinatal risk factors for massive pulmonary hemorrhage in very low birth weight infant: A nationwide large cohort database

OBJECTIVE

To determine perinatal risk factors for Massive pulmonary hemorrhage (MPH) and MPH-caused mortality to guide clinicians in implementing preventive measures at the beginning of life for improving the survival of very low birth weight infant (VLBWIs).

STUDY DESIGN

A total of 13,826 VLBWIs born between 2013 and 2020 in the Korean Neonatal Network database were included.

RESULTS

MPH occurred in 870 (6.3 %) VLBWIs. Among infants with MPH, 162 (18.6 %) VLBWIs died due to MPH. In the multivariate logistic regression analysis, independent risk factors for MPH were identified as small for gestational age, multiple gestation, high CRIB-II score, use of surfactant, and symptomatic patent ductus arteriosus (sPDA) in VLBIWs. Independent risk factors for MPH-caused mortality were identified as multiple gestation in VLBWIs. Receiving a complete course of antenatal corticosteroids (ACS) was found to be a significant independent protective factor for MPH-caused mortality in VLBWIs.

CONCLUSION

Proactive managements for reducing unnecessary use of pulmonary surfactant and for decreasing the risk of sPDA at the beginning of life could be recommended as preventive strategies to reduce the risk of MPH in extremely preterm infants. ACS therapy is highly recommended for women with a high likelihood of giving birth preterm to reduce the risk of mortality caused by MPH.

Emergency Cesarean Section in a Dichorionic Diamniotic Twin Pregnancy With Hydrops Fetalis: A Report of a Critical Case

This case report describes the emergent scenario of a 41-year-old primipara at 31.2 weeks of gestation, presenting with abdominal and back pain in the context of a dichorionic diamniotic twin pregnancy complicated by hydrops fetalis. The patient, with a history of hypertension, hyperthyroidism, and a cervical stitch in place, underwent an emergency lower segment cesarean section. The ultrasound revealed an intrauterine left footling in one twin, contributing to the suspected hydrops fetalis. Neonatal complications arose, particularly with Baby B, necessitating immediate resuscitation and intensive care. Successful outcomes were achieved through a well-coordinated multidisciplinary approach involving obstetricians, neonatologists, and anesthesiologists. This case underscores the importance of prompt recognition, timely interventions, and collaborative care in managing complex pregnancies, shedding light on the challenges associated with dichorionic diamniotic twin pregnancies and emphasizing the need for ongoing research to refine perinatal strategies.

A conditional standard for the customized fetal growth trajectory in twin pregnancy

BACKGROUND

The difference in the birth weights between twins and singletons grows with advancing gestation. Although many fetal weight standards based on ultrasonographic measurements have been created for tracking fetal growth in twin pregnancies, their applicability to other groups is limited by the fact that they are population specific.

OBJECTIVE

This study aimed to generate conditional centiles for growth assessment of twin fetuses and to compare them with other population-based growth standards for singleton and twin fetuses.

STUDY DESIGN

This was a retrospective, longitudinal study of ultrasound-based estimated fetal weight data of normal twin fetuses delivered after 34 weeks of gestation. Linear mixed effects models that adjusted for maternal characteristics, fetal gender, and chorionicity were used to evaluate the relationship between estimated fetal weight and gestational age. The estimated fetal weight reference values were calculated using conditional centile based on the estimated fetal weight at an earlier gestational age. To compare our results with previous studies, fetal growth curves were generated using a formula we created that included maternal characteristics and the estimated fetal weight at 24 weeks of gestation in these studies. In a subgroup analysis of our low-risk twin babies born at full term, we calculated the number of fetuses who were reclassified as being in the bottom 10th percentile using each of the previous population-based standard.

RESULTS

A total of 2644 ultrasounds with a median of 4 scans per fetus from 572 twin pregnancies were included in this analysis. In the cohort, 36% of the fetuses were monochorionic. Maternal age, body mass index, and the interaction between fetal gender and chorionicity were significantly associated with estimated fetal weight. The predicted growth curves matched the growth standard for twins. In our low-risk group, when the singleton standard was used, the incidence of estimated fetal weight <10th percentile was above 20% from gestational week 24 to 38, and this incidence varied when reclassified using other population-based twin standards.

CONCLUSION

This conditional growth chart was specifically designed to assess fetal growth in twin pregnancies, but it is generalizable to other populations.

Epidemiology and factors associated with preterm births in multiple pregnancy: a retrospective cohort study

OBJECTIVE

Multiple pregnancies carry an increased risk of maternal and perinatal complications, notably prematurity. Few studies have evaluated the risk factors for preterm births in multiple pregnancies within the Thai population. This study aims to ascertain maternal and perinatal outcomes and identify factors linked to preterm births in multiple pregnancies.

METHODS

This study was carried out at Khon Kaen University, Faculty of Medicine, Department of Obstetrics and Gynecology in Thailand. We reviewed the medical records of women with multiple pregnancies who delivered at a gestational age of more than 20 weeks between January 1, 2012 and December 31, 2021. We excluded patients with incomplete data or those for whom data were missing.

RESULTS

Out of 21,400 pregnancies, 427 were multiple pregnancies, constituting approximately 1.99%. Over the ten-year period, 269 multiple pregnancies (65.1%) resulted in preterm births. Of these, 173 (64.3%) were monochorionic twins, and 96 (35.7%) were dichorionic twins. Monochorionic twins had a notably higher rate of preterm delivery (AOR, 2.06; 95%CI 1.29-3.30). Vaginal delivery was observed in 7.9% of the cases, while cesarean sections were performed for both twins in 91.5% of cases. In 0.5% of the cases, only the second twin was delivered by cesarean section. In terms of neonatal outcomes, 160 infants (19.4%) weighed less than 1,500 g at birth, and there were 78 perinatal deaths (9.4%). Birth asphyxia was noted in 97 cases (20.2%) among monochorionic twins and in 28 cases (8.1%) for dichorionic twins.

CONCLUSION

The prevalence of multiple pregnancies was 1.99%, with 65.1% resulting in preterm births. Neonatal complications were notably more frequent in monochorionic twins. Monochorionic placenta and antepartum complications emerged as significant risk factors for preterm birth.

National Trends in Preterm Infant Mortality in the United States by Race and Socioeconomic Status, 1995-2020

Importance

Inequalities in preterm infant mortality exist between population subgroups within the United States.

Objective

To characterize trends in preterm infant mortality by maternal race and socioeconomic status to assess how inequalities in preterm mortality rates have changed over time.

Design, Setting, and Participants

This was a retrospective longitudinal descriptive study using the US National Center for Health Statistics birth infant/death data set for 12 256 303 preterm infant births over 26 years, between 1995 and 2020. Data were analyzed from December 2022 to March 2023.

Exposures

Maternal characteristics including race, smoking status, educational attainment, antenatal care, and insurance status were used as reported on an infant's US birth certificate.

Main Outcomes and Measures

Preterm infant mortality rate was calculated for each year from 1995 to 2020 for all subgroups, with a trend regression coefficient calculated to describe the rate of change in preterm mortality.

Results

The average US preterm infant mortality rate (IMR) decreased from 33.71 (95% CI, 33.71 to 34.04) per 1000 preterm births per year between 1995-1997, to 23.32 (95% CI, 23.05 to 23.58) between 2018-2020. Black non-Hispanic infants were more likely to die following preterm births than White non-Hispanic infants (IMR, 31.09; 95% CI, 30.44 to 31.74, vs 21.81; 95% CI, 21.43 to 22.18, in 2018-2020); however, once born, extremely prematurely Black and Hispanic infants had a narrow survival advantage (IMR rate ratio, 0.87; 95% CI, 0.84 to 0.91, in 2018-2020). The rate of decrease in preterm IMR was higher in Black infants (-0.015) than in White (-0.013) and Hispanic infants (-0.010); however, the relative risk of preterm IMR among Black infants compared with White infants remained the same between 1995-1997 vs 2018-2020 (relative risk, 1.40; 95% CI, 1.38 to 1.44, vs 1.43; 95% CI, 1.39 to 1.46). The rate of decrease in preterm IMR was higher in nonsmokers compared with smokers (-0.015 vs -0.010, respectively), in those with high levels of education compared with those with intermediate or low (-0.016 vs - 0.010 or -0.011, respectively), and in those who had received adequate antenatal care compared with those who did not (-0.014 vs -0.012 for intermediate and -0.013 for inadequate antenatal care). Over time, the relative risk of preterm mortality widened within each of these subgroups.

Conclusions and Relevance

This study found that between 1995 and 2020, US preterm infant mortality improved among all categories of prematurity. Inequalities in preterm infant mortality based on maternal race and ethnicity have remained constant while socioeconomic disparities have widened over time.

Examining Twitter-Derived Negative Racial Sentiment as Indicators of Cultural Racism: Observational Associations With Preterm Birth and Low Birth Weight Among a Multiracial Sample of Mothers, 2011-2021

BACKGROUND

Large racial and ethnic disparities in adverse birth outcomes persist. Increasing evidence points to the potential role of racism in creating and perpetuating these disparities. Valid measures of area-level racial attitudes and bias remain elusive, but capture an important and underexplored form of racism that may help explain these disparities. Cultural values and attitudes expressed through social media reflect and shape public norms and subsequent behaviors. Few studies have quantified attitudes toward different racial groups using social media with the aim of examining associations with birth outcomes.

OBJECTIVE

We used Twitter data to measure state-level racial sentiments and investigate associations with preterm birth (PTB) and low birth weight (LBW) in a multiracial or ethnic sample of mothers in the United States.

METHODS

A random 1% sample of publicly available tweets from January 1, 2011, to December 31, 2021, was collected using Twitter's Academic Application Programming Interface (N=56,400,097). Analyses were on English-language tweets from the United States that used one or more race-related keywords. We assessed the sentiment of each tweet using support vector machine, a supervised machine learning model. We used 5-fold cross-validation to assess model performance and achieved high accuracy for negative sentiment classification (91%) and a high F1 score (84%). For each year, the state-level racial sentiment was merged with birth data during that year (~3 million births per year). We estimated incidence ratios for LBW and PTB using log binomial regression models, among all mothers, Black mothers, racially minoritized mothers (Asian, Black, or Latina mothers), and White mothers. Models were controlled for individual-level maternal characteristics and state-level demographics.

RESULTS

Mothers living in states in the highest tertile of negative racial sentiment for tweets referencing racial and ethnic minoritized groups had an 8% higher (95% CI 3%-13%) incidence of LBW and 5% higher (95% CI 0%-11%) incidence of PTB compared to mothers living in the lowest tertile. Negative racial sentiment referencing racially minoritized groups was associated with adverse birth outcomes in the total population, among minoritized mothers, and White mothers. Black mothers living in states in the highest tertile of negative Black sentiment had 6% (95% CI 1%-11%) and 7% (95% CI 2%-13%) higher incidence of LBW and PTB, respectively, compared to mothers living in the lowest tertile. Negative Latinx sentiment was associated with a 6% (95% CI 1%-11%) and 3% (95% CI 0%-6%) higher incidence of LBW and PTB among Latina mothers, respectively.

CONCLUSIONS

Twitter-derived negative state-level racial sentiment toward racially minoritized groups was associated with a higher risk of adverse birth outcomes among the total population and racially minoritized groups. Policies and supports establishing an inclusive environment accepting of all races and cultures may decrease the overall risk of adverse birth outcomes and reduce racial birth outcome disparities.

Racial disparities in the development of comorbid conditions after preterm birth: A narrative review

Despite recognition and attempts to reduce racial disparities in perinatal outcomes, Black infants are still disproportionately represented among those who are born preterm. Postnatal investigations of racial disparities in comorbidities and outcomes after preterm birth are increasing, although their results and interpretations are conflicting. In the present review, we 1.) identify important methodological limitations of that literature 2.) summarize the conflicting literature investigating racial disparities, specifically Black-white differences, in postnatal comorbidities and outcomes after preterm birth 3.) describe mechanisms by which racism operates to contextualize our understanding to inform future work to actively reduce disparities in preterm birth and subsequently, its complications.

Child mortality of twins and singletons among late preterm and term birth: a study of national linked birth and under-five mortality data of Korea

Twins involve a higher risk of perinatal complications compared to singletons. We compared the risk of under five mortality between twins and singletons among late preterm and term births. The national birth data of South Korea pertaining to the years 2010-2014 linked with the mortality record of children aged under 5 years in 2010-2019 was analyzed. The final study population was 2,199,632 singletons and 62,351 twins. We conducted a survival analysis of under-five mortality with adjustment for neonatal and familial factors. Overall under-five mortality rates during the study period were 3.6 and 2.0 for twins and singletons, respectively. Although the unadjusted overall under-five mortality was higher in twins (hazard ratio [HR] = 1.80, 95% confidence interval [CI]: 1.57, 2.06, overall risk), twin birth was associated with comparable or lower risk (HR = 0.70, 95% CI: 0.58, 0.85, overall; 0.70, 95% CI: 0.56, 0.87, excluding neonatal mortality; 0.59, 95% CI: 0.40, 0.86, excluding infant mortality) after controlling for both neonatal and familial factors. Twins born at a gestational age of 34-35 weeks showed a generally lower risk of under-five mortality than their singleton counterparts, regardless of model specification.Conclusion: Among late preterm and term birth, under-5-year mortalities for twins were lower than singleton births when adjusted for neonatal and familial risk factors. This highlights the differential implication of gestational age at birth between twin and singleton in the child mortality.

Arabin pessary to prevent adverse perinatal outcomes in twin pregnancies with a short cervix: a multicenter randomized controlled trial (PESSARONE)

BACKGROUND

The number of twin pregnancies continues to increase worldwide as both the number of pregnancies obtained by medically assisted reproduction and age at first pregnancy keep rising. Preterm delivery is the major complication associated with twin pregnancies. The effectiveness of preventive treatments such as progesterone or cervical cerclage for women with a short cervix is doubtful in twin pregnancies. The effectivity of cervical pessaries in preventing preterm birth and its associated morbidity and mortality is also controversial.

OBJECTIVE

We sought to investigate if the Arabin pessary reduces adverse neonatal outcomes in twin pregnancies with a short cervix.

STUDY DESIGN

This open-label, multicenter, randomized controlled trial on twin pregnancies with a cervical length of <35 mm compared pessary placement at 16+0 to 24+0 weeks' gestation with standard care alone. The primary endpoint was a composite of adverse neonatal outcomes, namely peripartum or neonatal death or significant neonatal morbidity before hospital discharge, defined as at least 1 of the following complications: bronchopulmonary dysplasia, intraventricular hemorrhage grade III to IV, periventricular leukomalacia, necrotizing enterocolitis grade II or higher, culture-proven sepsis, and retinopathy requiring treatment. A sample size of 308 pregnancies was planned to ensure 80% power to compare the proportions of women with at least 1 infant with an adverse neonatal outcome. The intention-to-treat analysis after multiple imputation of missing data, was supplemented with a secondary analysis that controlled for gestational age and cervical length, both at inclusion. The primary endpoint was also compared between randomization groups in the per-protocol population, which excluded patients with prespecified major protocol violations (mostly cervical cerclage and/or progesterone after inclusion). Secondary endpoints included preterm birth, spontaneous preterm birth, and pessary side effects.

RESULTS

In total, 315 women were randomized to either receive a pessary (n=157) or standard management (n=158). Overall, 10.8% (34 women) of participants had a missing value for the primary endpoint, mostly (79%) because of the lack of paternal consent for neonatal data collection. In the intention-to-treat analysis, the adverse neonatal outcome occurred in 16.8% of the pessary group vs in 22.5% of the control group (risk ratio, 0.69; 95% confidence interval, 0.39-1.23; P=.210). The per-protocol analysis did not show any significant difference between groups (risk ratio, 0.78; 95% confidence interval, 0.47-1.28; P=.320). The occurrence of preterm birth or spontaneous preterm birth did not differ significantly between groups. No serious side effects were associated with pessary use.

CONCLUSION

Pessary use in our study did not significantly reduce adverse neonatal outcomes in twin pregnancies with a short cervix.

Exploring association between place of delivery and newborn care with early-neonatal mortality in Bangladesh

Objective

Bangladesh achieved the fourth Millennium Development Goal well ahead of schedule, with a significant reduction in under-5 mortality between 1990 and 2015. However, the reduction in neonatal mortality has been stagnant in recent years. The purpose of this study is to explore the association between place of delivery and newborn care with early neonatal mortality (ENNM), which represents more than 80% of total neonatal mortality in Bangladesh.

Methods

In this study, 2014 Bangladesh Demographic and Health Survey data were used to assess early neonatal survival in children born in the three years preceding the survey. The roles of place of the delivery and newborn care in ENNM were examined using multivariable logistic regression models adjusted for clustering and relevant socio-economic, pregnancy, and newborn characteristics.

Results

Between 2012 and 2014, there were 4,624 deliveries in 17,863 sampled households, 39% of which were delivered at health facilities. The estimated early neonatal mortality rate during this period was 15 deaths per 1,000 live births. We found that newborns who had received at least 3 components of essential newborn care (ENC) were 56% less likely to die during the first seven days of their lives compared to their counterparts who received 0–2 components of ENC (aOR: 0.44; 95% CI: 0.24–0.81). In addition, newborns who had received any postnatal care (PNC) were 68% less likely to die in the early neonatal period than those who had not received any PNC (aOR: 0.32; 95% CI: 0.16–0.64). Facility delivery was not significantly associated with the risk of early newborn death in any of the models.

Conclusion

Our study findings highlight the importance of newborn and postnatal care in preventing early neonatal deaths. Further, findings suggest that increasing the proportion of women who give birth in a healthcare facility is not sufficient to reduce ENNM by itself; to realize the theoretical potential of facility delivery to avert neonatal deaths, we must also ensure quality of care during delivery, guarantee all components of ENC, and provide high-quality early PNC. Therefore, sustained efforts to expand access to high-quality ENC and PNC are needed in health facilities, particularly in facilities serving low-income populations.

Conjoined twins in dichorionic diamniotic triplet pregnancy: a report of three cases and literature review

Background

Conjoined twins are a rare and serious complication of monochorionic twins. The total incidence is 1.5 per 100,000 births, and about 50% are liveborn. Prenatal screening and diagnosis of conjoined twins is usually performed by ultrasonography. Magnetic resonance imaging can be used to assist in the diagnosis if necessary. Conjoined twins in dichorionic diamniotic triplet pregnancy are extremely rare.

Case presentation

We reported three cases of dichorionic diamniotic triplet pregnancy with conjoined twins. Due to the poor prognosis of conjoined twins evaluated by multidisciplinary teams, selective termination of conjoined twins was performed in three cases. In case 1, selective reduction of the conjoined twins was performed at 16 gestational weeks, and a healthy female baby weighing 3270 g was delivered at 37 weeks. In case 2, the conjoined twins were selectively terminated at 17 weeks of gestation, and a healthy female baby weighing 2760 g was delivered at 37 weeks and 4 days. In case 3, the conjoined twins were selectively terminated at 15 weeks and 2 days, and a healthy female baby weighing 2450 g was delivered at 33 weeks and 6 days. The babies of all three cases were followed up and are in good health.

Conclusion(s)

Surgical separation is the only treatment for conjoined twins after birth. Early determination of chorionicity and antenatal diagnosis of conjoined twins in triplet gestations are critical for individualized management options and the prognosis of normal triplets. Expecting parents should be extensively counseled by multidisciplinary teams. If there are limitations in successful separation after birth, early selective termination of the conjoined twins by intrathoracic injection of potassium chloride may be a procedure in dichorionic diamniotic triplet pregnancy to improve perinatal outcomes of the normal triplet.

Doppler Velocimetry of the Ophthalmic Artery Behavior in Twin Pregnancy

Our main objective was to evaluate the ophthalmic artery Doppler behavior in twin pregnancies and compare with singleton pregnancies. We studied 64 healthy twin pregnant women between 12 to 38 weeks of gestation. Resistance index (RI), pulsatility index (PI), and peak ratio (PR) were determined. The control group consisted of 289 singletons. Linear regression analysis was performed to evaluate the association between gestational age and the ophthalmic indexes. Student t test was used to compare the means and standard deviation of the Doppler indexes. There was a decrease in RI and PI and an increase in PR with advancing gestational age (ρ < 0.0001, 0.0052, and 0.0033). The means ± SDs for RI, PI, and PR were 0.77 ± 0.07, 1.79 ± 0.46, and 0.53 ± 0.12, in women with twin pregnancies and 0.75 ± 0.05, 1.88 ± 0.43, and 0.52 ± 0.10 in singletons. No significant difference was found between the PI and PR values, but significant difference was found in the RI values between the groups (P = 0.0332). We concluded that there are no significant differences in ophthalmic artery behavior in twins and the same reference values established in singleton pregnancies can be applied for PI and PR indexes in the evaluation of twin pregnancies. These indexes were the best to evaluate twin pregnancies.

Fetal growth standards for Chinese twin pregnancies

Background

The common use of singleton fetal growth standard to access twin growth might lead to over-monitoring and treatment. We aimed to develop fetal growth standards for Chinese twins based on ultrasound measurements, and compare it with Zhang’s and other twin fetal growth charts.

Methods

A cohort of uncomplicated twin pregnancies were prospectively followed in 2014–2017. Smoothed estimates of fetal growth percentiles for both monochorionic (MC) and dichorionic (DC) twins were obtained using a linear mixed model. We also created growth charts for twins using a model-based approach proposed by Zhang et al. Our twin standards were compared with Hadlock’s (singleton) in predicting adverse perinatal outcomes.

Results

A total of 398 twin pregnancies were included, with 214 MC and 582 DC live-born twins. The MC twins were slightly lighter than the DC twins, with small differences throughout the gestation. Our ultrasound-based fetal weight standards were comparable to that using Zhang’s method. Compared with previous references/standards from the US, Brazil, Italy and UK, our twins had very similar 50th percentiles, but narrower ranges between the 5th and 95th or 10th and 90th percentiles. Compared with the Hadlock’s standard, the risks of neonatal death and adverse perinatal outcomes for small for gestational age (SGA) versus non-SGA were substantially elevated using our standards.

Conclusions

A normal fetal growth standard for Chinese twins was created. The differences between MC and DC twins were clinically insignificant. The 50th weight percentiles of the Chinese twins were identical to those in other races/ethnicities but the ranges were markedly narrower. Our standard performed much better than the Hadlock’s in predicting low birth weight infants associated with adverse perinatal outcomes in twin pregnancies. The present study also indicated that Zhang’s method is applicable to Chinese twins, and other areas may use Zhang’s method to generate their own curves for twins if deemed necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03926-y.

Effect of monochorionicity on perinatal outcome and growth discordance in triplet pregnancy: collaborative multicenter study in England, 2000-2013

OBJECTIVES

To compare perinatal outcome and growth discordance between trichorionic triamniotic (TCTA) and dichorionic triamniotic (DCTA) or monochorionic triamniotic (MCTA) triplet pregnancies.

METHODS

This was a multicenter cohort study using population-based data on triplet pregnancies from 11 Northern Survey of Twin and Multiple Pregnancy (NorSTAMP) maternity units and the Southwest Thames Region of London Obstetric Research Collaborative (STORK) multiple pregnancy cohort, for 2000-2013. Perinatal outcomes (from ≥ 24 weeks' gestation to 28 days of age), intertriplet fetal growth and birth-weight (BW) discordance and neonatal morbidity were analyzed in TCTA compared with DCTA/MCTA pregnancies.

RESULTS

Monochorionic placentation of a pair or trio in triplet pregnancy (n = 72) was associated with a significantly increased risk of perinatal mortality (risk ratio, 2.7 (95% CI, 1.3-5.5)) compared with that in TCTA pregnancies (n = 68), due mainly to a much higher risk of stillbirth (risk ratio, 5.4 (95% CI, 1.6-18.2)), with 57% of all stillbirth cases resulting from fetofetal transfusion syndrome, while there was no significant difference in neonatal mortality (P = 0.60). The associations with perinatal mortality and stillbirth persisted when considering only pregnancies not affected by a major congenital anomaly. DCTA/MCTA triplets had lower BW and demonstrated greater BW discordance than did TCTA triplets (P = 0.049). Severe BW discordance of > 35% was 2.5-fold higher in DCTA/MCTA compared with TCTA pregnancies (26.1% vs 10.4%), but this difference did not reach statistical significance (P = 0.06), presumably due to low numbers. Triplets in both groups were delivered by Cesarean section in over 95% of cases, at a similar gestational age (median, 33 weeks' gestation). The rate of respiratory (P = 0.28) or infectious (P = 0.08) neonatal morbidity was similar between the groups.

CONCLUSIONS

Despite close antenatal surveillance, monochorionic placentation of a pair or trio in triamniotic triplet pregnancy was associated with a significantly increased stillbirth risk, mainly due to fetofetal transfusion syndrome, and with greater size discordance. In liveborn triplets, there was no adverse effect of monochorionicity on neonatal outcome. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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

OBJECTIVES

To investigate racial/ethnic differences in rehospitalization and mortality rates among premature infants over the first year of life.

STUDY DESIGN

A retrospective cohort study of infants born in California from 2011 to 2017 (n = 3,448,707) abstracted from a California Office of Statewide Health Planning and Development database. Unadjusted Kaplan-Meier tables and logistic regression controlling for health and sociodemographic characteristics were used to predict outcomes by race/ethnicity.

RESULTS

Compared to White infants, Hispanic and Black early preterm infants were more likely to be readmitted; Black late/moderate preterm (LMPT) infants were more likely to be readmitted and to die after discharge; Hispanic and Black early preterm infants with BPD were more likely to be readmitted; Black LMPT infants with RDS were more likely to be readmitted and die after discharge.

CONCLUSIONS

Racial/ethnic disparities in readmission and mortality rates exist for premature infants across several co-morbidities. Future studies are needed to improve equitability of outcomes.

The Association Between State-Level Racial Attitudes Assessed From Twitter Data and Adverse Birth Outcomes: Observational Study

Background

In the United States, racial disparities in birth outcomes persist and have been widening. Interpersonal and structural racism are leading explanations for the continuing racial disparities in birth outcomes, but research to confirm the role of racism and evaluate trends in the impact of racism on health outcomes has been hampered by the challenge of measuring racism. Most research on discrimination relies on self-reported experiences of discrimination, and few studies have examined racial attitudes and bias at the US national level.

Objective

This study aimed to investigate the associations between state-level Twitter-derived sentiments related to racial or ethnic minorities and birth outcomes.

Methods

We utilized Twitter’s Streaming application programming interface to collect 26,027,740 tweets from June 2015 to December 2017, containing at least one race-related term. Sentiment analysis was performed using support vector machine, a supervised machine learning model. We constructed overall indicators of sentiment toward minorities and sentiment toward race-specific groups. For each year, state-level Twitter-derived sentiment data were merged with birth data for that year. The study participants were women who had singleton births with no congenital abnormalities from 2015 to 2017 and for whom data were available on gestational age (n=9,988,030) or birth weight (n=9,985,402). The main outcomes were low birth weight (birth weight ≤2499 g) and preterm birth (gestational age <37 weeks). We estimated the incidence ratios controlling for individual-level maternal characteristics (sociodemographics, prenatal care, and health behaviors) and state-level demographics, using log binomial regression models.

Results

The accuracy for identifying negative sentiments on comparing the machine learning model to manually labeled tweets was 91%. Mothers living in states in the highest tertile for negative sentiment tweets referencing racial or ethnic minorities had greater incidences of low birth weight (8% greater, 95% CI 4%-13%) and preterm birth (8% greater, 95% CI 0%-14%) compared with mothers living in states in the lowest tertile. More negative tweets referencing minorities were associated with adverse birth outcomes in the total population, including non-Hispanic white people and racial or ethnic minorities. In stratified subgroup analyses, more negative tweets referencing specific racial or ethnic minority groups (black people, Middle Eastern people, and Muslims) were associated with poor birth outcomes for black people and minorities.

Conclusions

A negative social context related to race was associated with poor birth outcomes for racial or ethnic minorities, as well as non-Hispanic white people.

Racial/Ethnic Disparities Among Extremely Preterm Infants in the United States From 2002 to 2016

IMPORTANCE

Racial/ethnic disparities in quality of care among extremely preterm infants are associated with adverse outcomes.

OBJECTIVE

To assess whether racial/ethnic disparities in major outcomes and key care practices were changing over time among extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

This observational cohort study used prospectively collected data from 25 US academic medical centers. Participants included 20 092 infants of 22 to 27 weeks' gestation with a birth weight of 401 to 1500 g born at centers participating in the National Institute of Child Health and Human Development Neonatal Research Network from 2002 to 2016. Of these infants, 9316 born from 2006 to 2014 were eligible for follow-up at 18 to 26 months' postmenstrual age (excluding 5871 infants born before 2006, 2594 infants born after 2014, and 2311 ineligible infants including 64 with birth weight >1000 g and 2247 infants with gestational age >26 6/7 weeks), of whom 745 (8.0%) did not have known follow-up outcomes at 18 to 26 months.

MAIN OUTCOMES AND MEASURES

Rates of mortality, major morbidities, and care practice use over time were evaluated using models adjusted for baseline characteristics, center, and birth year. Data analyses were conducted from 2018 to 2019.

RESULTS

In total, 20 092 infants with a mean (SD) gestational age of 25.1 (1.5) weeks met the inclusion criteria and were available for the primary outcome: 8331 (41.5%) black infants, 3701 (18.4%) Hispanic infants, and 8060 (40.1%) white infants. Hospital mortality decreased over time in all groups. The rate of improvement in hospital mortality over time did not differ among black and Hispanic infants compared with white infants (black infants went from 35% to 24%, Hispanic infants went from 32% to 27%, and white infants went from 30% to 22%; P = .59 for race × year interaction). The rates of late-onset sepsis among black infants (went from 37% to 24%) and Hispanic infants (went from 45% to 23%) were initially higher than for white infants (went from 36% to 25%) but decreased more rapidly and converged during the most recent years (P = .02 for race × year interaction). Changes in rates of other major morbidities did not differ by race/ethnicity. Death before follow-up decreased over time (from 2006 to 2014: black infants, 14%; Hispanic infants, 39%, white infants, 15%), but moderate-severe neurodevelopmental impairment increased over time in all racial/ethnic groups (increase from 2006 to 2014: black infants, 70%; Hispanic infants, 123%; white infants, 130%). Rates of antenatal corticosteroid exposure (black infants went from 72% to 90%, Hispanic infants went from 73% to 83%, and white infants went from 86% to 90%; P = .01 for race × year interaction) and of cesarean delivery (black infants went from 45% to 59%, Hispanic infants went from 49% to 59%, and white infants went from 62% to 63%; P = .03 for race × year interaction) were initially lower among black and Hispanic infants compared with white infants, but these differences decreased over time.

CONCLUSIONS AND RELEVANCE

Among extremely preterm infants, improvements in adjusted rates of mortality and most major morbidities did not differ by race/ethnicity, but rates of neurodevelopmental impairment increased in all groups. There were narrowing racial/ethnic disparities in important care practices, including the use of antenatal corticosteroids and cesarean delivery.

Ethnic and socioeconomic variation in cause-specific preterm infant mortality by gestational age at birth: national cohort study

OBJECTIVE

To describe ethnic and socioeconomic variation in cause-specific infant mortality of preterm babies by gestational age at birth.

DESIGN

National birth cohort study.

SETTING

England and Wales 2006-2012.

SUBJECTS

Singleton live births at 24-36 completed weeks' gestation (n=256 142).

OUTCOME MEASURES

Adjusted rate ratios for death in infancy by cause (three groups), within categories of gestational age at birth (24-27, 28-31, 32-36 weeks), by baby's ethnicity (nine groups) or area deprivation score (Index of Multiple Deprivation quintiles).

RESULTS

Among 24-27 week births (5% of subjects; 47% of those who died in infancy), all minority ethnic groups had lower risk of immaturity-related death than White British, the lowest rate ratios being 0.63 (95% CI 0.49 to 0.80) for Black Caribbean, 0.74 (0.64 to 0.85) for Black African and 0.75 (0.60 to 0.94) for Indian. Among 32-36 week births, all minority groups had higher risk of death from congenital anomalies than White British, the highest rate ratios being 4.50 (3.78 to 5.37) for Pakistani, 2.89 (2.10 to 3.97) for Bangladeshi and 2.06 (1.59 to 2.68) for Black African; risks of death from congenital anomalies and combined rarer causes (infection, intrapartum conditions, SIDS and unclassified) increased with deprivation, the rate ratios comparing the most with the least deprived quintile being, respectively, 1.54 (1.22 to 1.93) and 2.05 (1.55 to 2.72). There was no evidence of socioeconomic variation in deaths from immaturity-related conditions.

CONCLUSIONS

Gestation-specific preterm infant mortality shows contrasting ethnic patterns of death from immaturity-related conditions in extremely-preterm babies, and congenital anomalies in moderate/late-preterm babies. Socioeconomic variation derives from congenital anomalies and rarer causes in moderate/late-preterm babies. Future research should examine biological origins of extremely preterm birth.

Intertwin birthweight discordance and parental race: a retrospective cohort study

Objectives: Previous studies examined the association of maternal race with pregnancy outcomes. The study aimed to examine the effects of maternal, paternal, and parental race on intertwin birth weight discordance.Methods: We used the 2011-2015 multiple birth files of the USA for this study. The exposure variable of this study was parental race and intertwin birthweight discordance >25% was the outcome. In addition to separately analyzing maternal and paternal races, we assessed the effect of the combined race after grouping the participants into nine groups based on the race of both parents.Results: A total of 203,872 pairs of twins were included in the final analysis. The overall incidence of intertwin birthweight discordance in this population was 7.8%. Birthweight discordance was significantly associated with maternal, paternal, and parental races. Twins born to Black parents had significant risks of developing birthweight discordance than twins born to White parents (adjusted OR = 1.11, 95% CI: 1.06-1.17 for Black mothers and Black fathers). Combined parental race showed that compared to twins born to both parents Whites, twins born to both parents Blacks had a significantly elevated risk of developing birthweight discordance (adjusted OR = 1.13, 95% CI: 1.07-1.18). No significant difference in the risk of developing birthweight discordance was found for other parental race groups, same race or different race parents.Conclusions: Twins born to Black mothers, fathers, or both parents had significant risks of developing intertwin birthweight discordance than twins born to White mothers, fathers, or both parents.

Does Gestational Diabetes Cause Additional Risk in Twin Pregnancy?

It has been suggested that the risk of adverse perinatal outcomes in twin pregnancies is exacerbated by concomitant gestational diabetes mellitus (GDM). This study aimed to assess the risk incurred by twin pregnancy and by a diagnosis of GDM, separately, on the development of poor perinatal outcomes. A retrospective cohort study was conducted on all pregnant women at a tertiary center between 2016 and 2017. The impact of GDM and twin pregnancies on perinatal outcomes — birth weight above the 90th centile for gestational age, cesarean delivery, clinical neonatal hypoglycemia, and premature delivery (before 37 weeks’ gestation) — was assessed using univariate and multivariate analyses. Overall, 13,527 women were eligible for the study; 11,915 were uncomplicated singleton pregnancies; 1379 of these had GDM; 194 were twin pregnancies, and 39 of these had GDM. Univariate analyses showed that twin pregnancies were associated with a higher risk of all perinatal outcomes except macrosomia. In the multivariate analyses, twin pregnancy was a much higher predictor of cesarean delivery (OR 8.40, 95% CI [6.25, 11.49], p < .0001) and preterm birth (OR 58.82, 95% CI [31.25, 125], p < .0001) compared to GDM but GDM was a higher predictor of neonatal hypoglycemia (OR 4.87, 95% CI [3.74, 6.29], p < .0001). Twin pregnancy is more strongly associated with all adverse perinatal outcomes except macrosomia. GDM does not increase risk of adverse perinatal outcomes except for neonatal hypoglycemia.

Twitter-derived measures of sentiment towards minorities (2015-2016) and associations with low birth weight and preterm birth in the United States

INTRODUCTION

The objective of this study was to investigate the association between state-level publicly expressed sentiment towards racial and ethnic minorities and birth outcomes for mothers who gave birth in that state.

METHODS

We utilized Twitter's Streaming Application Programming Interface (API) to collect 1,249,653 tweets containing at least one relevant keyword pertaining to a racial or ethnic minority group. State-level derived sentiment towards racial and ethnic minorities were merged with data on all 2015 U.S. births (N=3.99 million singleton births).

RESULTS

Mothers living in states in the lowest tertile of positive sentiment towards racial/ethnic minorities had greater prevalences of low birth weight (+6%), very low birth weight (+9%), and preterm birth (+10%) compared to mothers living in states in the highest tertile of positive sentiment, controlling for individual-level maternal characteristics and state demographic characteristics. Sentiment towards specific racial/ethnic groups showed a similar pattern. Mothers living in states in the lowest tertile of positive sentiment towards blacks had an 8% greater prevalence of low birth weight and very low birth weight, and a 16% greater prevalence of preterm birth, compared to mothers living in states in the highest tertile. Lower state-level positive sentiment towards Middle Eastern groups was also associated with a 4-13% greater prevalence of adverse birth outcomes. Results from subgroup analyses restricted to racial/ethnic minority mothers did not differ substantially from those seen for the full population of mothers.

CONCLUSIONS

More negative area-level sentiment towards blacks and Middle Eastern groups was related to worse individual birth outcomes, and this is true for the full population and minorities.

The color of child survival in Colombia, 1955-2005

OBJECTIVE(S)

Colombia has the third largest black population in the Americas after Brazil and the USA. In 2005 mortality rate under 5 in Colombia was 21.5 per 1000, with a reduction of 82% between 2005 and 1955. That rate is not in line with rates for Cuba (6.8), Chile (9.1) or Costa Rica (10.4). Here we aim to provide evidence that a further reduction of child mortality relates to the unspoken racial gap in a pioneering country in family planning and praised in the 2000 WHO report as having the world's fairest health care reform in terms of coverage and financial access.

DESIGN

The lack of nationally representative data to estimate black/white differences in child mortality is overcome by using the ratio of children born and alive as the measure of mortality and the 2005 census data from IPUMS-I, which provides racial categories based on self-identification. The working sample contains 617,985 mothers between 15 and 49 years of age, of whom 7.7% have experienced the death of at least one child. Using individual weights, a logistic regression is regressed on race, individual and community socio-economic status (SES), and demographic variables. Second, a model by cohort is regressed to capture the evolution of the racial gap over time. Third, interactions are run to examine the racial gap across SES groups.

RESULTS

The chances of losing a child are over 25% higher among black mothers relative to white mothers after controlling for individual and community SES characteristics. The racial gap remains stagnant and high for the period 1955-2005. The racial gap also is robust to changes in education and income levels.

CONCLUSION

Failing to account for race slows down the improvement of child survival in Colombia relative to other countries of the region.

Racial and Ethnic Disparities in Preterm Infant Mortality and Severe Morbidity: A Population-Based Study

BACKGROUND

Disparities exist in the rates of preterm birth and infant mortality across different racial/ethnic groups. However, only a few studies have examined the impact of race/ethnicity on the outcomes of premature infants.

OBJECTIVE

To report the rates of mortality and severe neonatal morbidity among multiple gestational age (GA) groups stratified by race/ethnicity.

METHODS

A retrospective cohort study utilizing linked birth certificate, hospital discharge, readmission, and death records up to 1 year of life. Live-born infants ≤36 weeks born in the period 2007-2012 were included. Maternal self-identified race/ethnicity, as recorded on the birth certificate, was used. ICD-9 diagnostic and procedure codes captured neonatal morbidities (intraventricular hemorrhage, retinopathy of prematurity, periventricular leukomalacia, bronchopulmonary dysplasia, and necrotizing enterocolitis). Multiple logistic regression was performed to evaluate the impact of race/ethnicity on mortality and morbidity, adjusting for GA, birth weight, sex, and multiple gestation.

RESULTS

Our cohort totaled 245,242 preterm infants; 26% were white, 46% Hispanic, 8% black, and 12% Asian. At 22-25 weeks, black infants were less likely to die than white infants (odds ratio [OR] 0.76; 95% confidence interval [CI] 0.62-0.94). However, black infants born at 32-34 weeks (OR 1.64; 95% CI 1.15-2.32) or 35-36 weeks (OR 1.57; 95% CI 1.00-2.24) were more likely to die. Hispanic infants born at 35-36 weeks were less likely to die than white infants (OR 0.66; 95% CI 0.50-0.87). Racial disparities at different GAs were also detected for severe morbidities.

CONCLUSIONS

The impact of race/ethnicity on mortality and severe morbidity varied across GA categories in preterm infants. Disparities persisted even after adjusting for important potential confounders.

Racial/ethnic differences in preterm perinatal outcomes

BACKGROUND

Racial disparities in preterm birth and infant death have been well documented. Less is known about racial disparities in neonatal morbidities among infants who are born at <37 weeks of gestation.

OBJECTIVE

The purpose of this study was to determine whether the risk for morbidity and death among infants who are born preterm differs by maternal race.

STUDY DESIGN

A retrospective cohort design included medical records from preterm deliveries of 19,325 black, Hispanic, and white women in the Consortium on Safe Labor. Sequentially adjusted Poisson models with generalized estimating equations estimated racial differences in the risk for neonatal morbidities and death, controlling for maternal demographics, health behaviors, and medical history. Sex differences between and within race were examined.

RESULTS

Black preterm infants had an elevated risk for perinatal death, but there was no difference in risk for neonatal death across racial groups. Relative to white infants, black infants were significantly more likely to experience sepsis (9.1% vs 13.6%), peri- or intraventricular hemorrhage (2.6% vs 3.3%), intracranial hemorrhage (0.6% vs 1.8%), and retinopathy of prematurity (1.0% vs 2.6%). Hispanic and white preterm neonates had similar risk profiles. In general, female infants had lower risk relative to male infants, with white female infants having the lowest prevalence of a composite indicator of perinatal death or any morbidity across all races (30.9%). Differences in maternal demographics, health behaviors, and medical history did little to influence these associations, which were robust to sensitivity analyses of pregnancy complications as potential underlying mechanisms.

CONCLUSION

Preterm infants were at similar risk for neonatal death, regardless of race; however, there were notable racial disparities and sex differences in rare, but serious, adverse neonatal morbidities.

Early-life mortality risks in opposite-sex and same-sex twins: a Danish cohort study of the twin testosterone transfer hypothesis

PURPOSE

To investigate the twin testosterone transfer (TTT) hypothesis by comparing early-life mortality risks of opposite-sex (OS) and same-sex (SS) twins during the first 15 years of life.

METHODS

We performed a population-based cohort study to compare mortality in OS and SS twins. We included 68,629 live-born Danish twins from 1973 to 2009 identified through the Danish Twin Registry and performed piecewise stratified Cox regression and log-binomial regression.

RESULTS

Among 1933 deaths, we found significantly higher mortality for twin boys than for twin girls. For both sexes, OS twins had lower mortality than SS twins; the difference persisted for the first year of life for boys and for the first week of life for girls.

CONCLUSIONS

Although the mortality risk for OS boys was in the expected direction according to the TTT hypothesis, the results for OS girls pointed in the opposite direction, providing no clear evidence for the TTT hypothesis.

Risk-profiles and outcomes of multi-foetal pregnancies in adolescent mothers

In this retrospective review of 468 mothers with a multi-foetal pregnancy in Detroit, we describe the risk-profiles and the obstetrical, maternal and foetal outcomes of multi-foetal pregnancy in 59 (13%) adolescents. Overall, most mothers were African American, did not have private insurance and all were unmarried. For most mothers, this was their first pregnancy (59.3%) and their first delivery (69.5%). Almost 50% presented to triage at least once during their pregnancy. Anaemia (78%) and hypertensive disorders (18.6%) were common in this age group. The majority of adolescents delivered preterm as 81.4% were <37 weeks and 49% were <34 weeks. Furthermore, the majority of infants (79%) had low birth weights (median: 1975 g, range: 365-3405 g). This contemporary report emphasises the need for multidisciplinary prenatal management and specialist supervision, as multi-foetal pregnancies in adolescents pose real risks and impact obstetrical, maternal and neonatal outcomes.

Birthweight percentiles for twin birth neonates by gestational age in China

Localized birthweight references for gestational ages serve as an essential tool in accurate evaluation of atypical birth outcomes. Such references for twin births are currently not available in China. The aim of this study was to construct up-to-data sex specific birth weight references by gestational ages for twin births in China. We conducted a population-based analysis on the data of 22,507 eligible living twin infants with births dated between 8/01/2006 and 8/31/2015 from all 95 hospitals within the Wuhan area. Gestational ages in complete weeks were determined using a combination of last-menstrual-period based (LMP) estimation and ultrasound examination. Smoothed percentile curves were created by the Lambda Mu Sigma (LMS) method. Reference of the 3(rd), 10(th), 25(th), 50(th), 75(th), 90(th), 97(th) percentiles birth weight by sex and gestational age were made using 11,861 male and 10,646 female twin newborns with gestational age 26-42 weeks. Separate birthweight percentiles curves for male and female twins were constructed. In summary, our study firstly presents percentile curves of birthweight by gestational age for Chinese twin neonates. Further research is required for the validation and implementation of twin birthweight curves into clinical practice.

Dichorionic twin trajectories: the NICHD Fetal Growth Studies

BACKGROUND

Systematic evaluation and estimation of growth trajectories in twins require ultrasound measurements across gestation that are performed in controlled clinical settings. Currently, there are few such data for contemporary populations. There is also controversy about whether twin fetal growth should be evaluated with the use of the same benchmarks as singleton growth.

OBJECTIVES

Our objective was to define the trajectory of fetal growth in dichorionic twins empirically using longitudinal 2-dimensional ultrasonography and to compare the fetal growth trajectories for dichorionic twins with those based on a growth standard that was developed by our group for singletons.

STUDY DESIGN

A prospective cohort of 171 women with twin gestations was recruited from 8 US sites from 2012-2013. After an initial sonogram at 11 weeks 0 days-13 weeks 6 days of gestation during which dichorionicity was confirmed, women were assigned randomly to 1 of 2 serial ultrasonography schedules. Growth curves and percentiles were estimated with the use of linear mixed models with cubic splines. Percentiles were compared statistically at each gestational week between the twins and 1731 singletons, after adjustment for maternal age, race/ethnicity, height, weight, parity, employment, marital status, insurance, income, education, and infant sex. Linear mixed models were used to test for overall differences between the twin and singleton trajectories with the use of likelihood ratio tests of interaction terms between spline mean structure terms and twin-singleton indicator variables. Singleton standards were weighted to correspond to the distribution of maternal race in twins. For those ultrasound measurements in which there were significant global tests for differences between twins and singletons, we tested for week-specific differences using Wald tests that were computed at each gestational age. In a separate analysis, we evaluated the degree of reclassification in small for gestational age, which was defined as <10th percentile that would be introduced if fetal growth estimation for twins was based on an unweighted singleton standard.

RESULTS

Women underwent a median of 5 ultrasound scans. The 50th percentile abdominal circumference and estimated fetal weight trajectories of twin fetuses diverged significantly beginning at 32 weeks of gestation; biparietal diameter in twins was smaller from 34-36 weeks of gestation. There were no differences in head circumference or femur length. The mean head circumference/abdominal circumference ratio was progressively larger for twins compared with singletons beginning at 33 weeks of gestation, which indicated a comparatively asymmetric growth pattern. At 35 weeks of gestation, the average gestational age at delivery for twins, the estimated fetal weights for the 10th, 50th, and 90th percentiles were 1960, 2376, and 2879 g for dichorionic twins, respectively, and 2180, 2567, and 3022 g for the singletons, respectively. At 32 weeks of gestation, the initial week when the mean estimated fetal weight for twins was smaller than that of singletons, 34% of twins would be classified as small for gestational age with the use of a singleton, non-Hispanic white standard. By 35 weeks of gestation, 38% of twins would be classified as small for gestational age.

CONCLUSION

The comparatively asymmetric growth pattern in twin gestations, initially evident at 32 weeks of gestation, is consistent with the concept that the intrauterine environment becomes constrained in its ability to sustain growth in twin fetuses. Near term, nearly 40% of twins would be classified as small for gestational age based on a singleton growth standard.

Risk Factors for Cause-specific Mortality of Very-Low-Birth-Weight Infants in the Korean Neonatal Network

This study attempted to assess the risk factors for mortality of very-low-birth-weight (VLBW) infants in the neonatal intensive care unit (NICU, n=2,386). Using data from the Korean Neonatal Network, we investigated infants with birth weights <1,500 g and gestational ages (GAs) of 22-31 weeks born between January 2013 and June 2014. Cases were defined as death at NICU discharge. Controls were randomly selected from live VLBW infants and frequency matched to case subjects by GA. Relevant variables were compared between the cases (n=236) and controls (n=236) by Cox proportional hazards regression to determine their associations with cause-specific mortality (cardiorespiratory, neurologic, infection, gastrointestinal, and others). In a Cox regression analysis, cardiorespiratory death were associated with a foreign mother (hazard ratio, HR, 4.33; 95% confidence interval, CI, 2.08-9.02), multiple gestation (HR, 1.65; 95% CI, 1.07-2.54), small for gestational age (HR, 2.06; 95% CI, 1.25-3.41), male gender (HR, 1.69; 95% CI, 1.10-2.60), Apgar score ≤3 at 5 min (HR, 1.97; 95% CI, 1.18-3.31), and delivery room resuscitation (HR, 2.60; 95% CI, 1.53-4.40). An Apgar score ≤3 at 5 min was also associated with neurological death (HR, 2.95; 95% CI, 1.29-6.73). Death due to neonatal infection was associated with outborn delivery (HR, 5.09; 95% CI, 1.46-17.74). Antenatal steroid and preterm premature rupture of membranes reduced risk of cardiorespiratory death (HR, 0.43; 95% CI, 0.27-0.67) and gastrointestinal death (HR, 0.30; 95% CI, 0.13-0.70), respectively. In conclusion, foreign mother, multiple gestation, small gestation age, male gender, Apgar score ≤3 at 5 min, and resuscitation in the delivery room are associated with cardiorespiratory mortality of VLBW infants in NICU. An Apgar score ≤3 at 5 min and outborn status are associated with neurological and infection mortality, respectively.

Nationwide Twin Birth Weight Percentiles by Gestational Age in Taiwan

BACKGROUND

Nationwide birth weight norms for twins have been reported in several countries across different ethnicities, but such data have not been established in Taiwan. The purpose of this study was to develop reference growth charts that are population-based and contain the information of birth weight percentiles by gestational age for twin neonates in Taiwan.

METHODS

In this study, we collected nationwide birth weight data for twins by sex and gestational age through the Taiwan Birth Registry. Percentiles, means, and standard deviations of birth weight for each 1-week increment of gestational age from 21 weeks of gestation were estimated and smoothed using weighted polynomial models.

RESULTS

The 10(th), 50(th), and 90(th) percentiles of birth weight born at the 37(th) gestational week were 2174 g, 2580 g, and 3125 g for male twins, respectively, and they were 2100 g, 2500 g, and 3000 g for female twins, respectively. The 10(th), 50(th), and 90(th) percentiles of birth weight born at the 40(th) gestational week were 2326, 3285, and 3790 g for male twins, respectively, and they were 2200 g, 2770 g, and 3690 g for female twins, respectively.

CONCLUSION

This is the first nationwide birth weight norm for twins in Taiwan, which is particularly useful for investigation into the predictors and outcomes of altered fetal growth through twin studies in the Taiwanese population.

Influence of gestational diabetes mellitus on neonatal weight outcome in twin pregnancies

AIMS

To evaluate the influence of gestational diabetes mellitus on neonatal birthweight, macrosomia and weight discrepancy in twin neonates.

METHODS

An observational retrospective study was performed. One hundred and six women with gestational diabetes and twin pregnancy and 166 twin controls who delivered viable fetuses > 24 weeks were included. Impact of maternal pre-pregnancy BMI, smoking habit, method of conception, chorionicity, gestational age at delivery, mode of delivery and hypertensive complications were also analysed. The effect of maternal hyperglycaemia and metabolic control in gestational diabetes pregnancies was assessed.

RESULTS

Gestational hypertension and pre-eclampsia were significantly higher in the group with gestational diabetes (21.5% vs. 6.3%, P = 0.007 and 6.2% vs. 0%, P = 0.025). There were no differences in the incidence of macrosomia (5.7% vs. 7.2%, P = 0.803), large for gestational age (10.3% vs. 13.2%, P = 0.570), small for gestational age (10.3% vs. 12.0%, P = 0.701), severely small for gestational age (6.6% vs. 7.8%, P = 0.814) or weight discrepancy (20.6% vs. 15.2%, P = 0.320) in the group with gestational diabetes compared with twin pregnancies without diabetes. There were no differences when comparing insulin-requiring gestational diabetes pregnancies and twins without diabetes for any of the neonatal weight outcomes. There was no relationship between third trimester HbA1c and neonatal birthweight or infant birthweight ratio.

CONCLUSION

Gestational diabetes did not increase the risk of macrosomia or weight discrepancy of twin newborns. Furthermore, glycaemic control did not influence the rate of any of the weight outcomes in our study population. In twin pregnancies, gestational diabetes was associated with a higher risk of gestational hypertension and pre-eclampsia.

Perinatal outcome after fetal reduction from twin to singleton: to reduce or not to reduce?

OBJECTIVE

To determine whether reduction of twin gestation to singleton pregnancy is associated with improved perinatal outcome.

DESIGN

A retrospective cohort study.

SETTING

Single tertiary care medical center.

PATIENT(S)

A cohort of 63 singleton pregnancies after reduction from dichorionic-diamniotic twins gestation and 62 dichorionic-diamniotic nonreduced twins.

INTERVENTION(S)

Fetal reduction between 11 and 14 weeks of gestation.

MAIN OUTCOME MEASURE(S)

Obstetric outcome.

RESULT(S)

The rates of preterm delivery at <34 weeks (1.6% in pregnancies after reduction vs. 11.7% in nonreduced twins) and at <37 weeks of gestation (9.5% vs. 56.7%) were significantly lower in patients whose pregnancies were reduced to singletons. The rates of miscarriage of one twin (0% vs. 4.8%) and early pregnancy loss before 24 weeks of gestation as well as the rates of gestational diabetes (11.1% vs. 10%), hypertensive diseases of pregnancy (6.3% vs. 15%), and intrauterine growth restriction (0% vs. 3.3%) were similar in both groups.

CONCLUSION(S)

Fetal reduction of twins to singleton is associated with a lower risk of prematurity and superior perinatal outcome compared with nonreduced twins. Therefore, the option of fetal reduction should be considered in certain cases of twin pregnancies, where the risk for adverse outcome seems exceptionally high.

Disparities in mortality rates among US infants born late preterm or early term, 2003-2005

The purpose of this study was to identify disparities in neonatal, post-neonatal, and overall infant mortality rates among infants born late preterm (34-36 weeks gestation) and early term (37-38 weeks gestation) by race/ethnicity, maternal age, and plurality. In analyses of 2003-2005 data from US period linked birth/infant death datasets, we compared infant mortality rates by race/ethnicity, maternal age, and plurality among infants born late preterm or early term and also determined the leading causes of death among these infants. Among infants born late preterm, infants born to American Indian/Alaskan Native, non-Hispanic black, or teenage mothers had the highest infant mortality rates per 1,000 live births (14.85, 9.90, and 11.88 respectively). Among infants born early term, corresponding mortality rates were 5.69, 4.49, and 4.82, respectively. Among infants born late preterm, singletons had a higher infant mortality rate than twins (8.59 vs. 5.62), whereas among infants born early term, the rate was higher among twins (3.67 vs. 3.15). Congenital malformations and sudden infant death syndrome were the leading causes of death among both late preterm and early term infants. Infant mortality rates among infants born late preterm or early term varied substantially by maternal race/ethnicity, maternal age, and plurality. Information about these disparities may help in the development of clinical practice and prevention strategies targeting infants at highest risk.

The changing character of the Black-White infant mortality gap, 1983-2004

OBJECTIVES

We examined how changes in demographic, geographic, and childbearing risk factors were related to changes in the Black-White infant mortality rate (IMR) gap over 2 decades.

METHODS

Using 1983-2004 Vital Statistics, we applied inverse probability weighting methods to examine the relationship between risk factors and 3 outcomes: the overall IMR gap, its birth weight component, and its conditional (on birth weight) IMR component.

RESULTS

The unexplained IMR gap (the part not related to observed risk factors) was stable, changing from 5.0 to 5.3 deaths per 1000 live births. By contrast, the explained gap declined from 4.6 to 1.9. The decline in the explained gap was driven by the changing relationship between risk factors and IMR. Further analysis revealed that most of the unexplained gap occurred among infants weighing less than 1000 grams at birth, whereas most of the explained gap occurred among infants weighing more than 1000 grams.

CONCLUSIONS

The unexplained gap was stable over the last 2 decades, but the explained gap declined markedly. If the stability of the unexplained gap continues, even complete convergence of risk factors would reduce the Black-White IMR gap by only one quarter.

Impact of fetal death reporting requirements on early neonatal and fetal mortality rates and racial disparities

OBJECTIVE

Racial disparities in infant and neonatal mortality vary substantially across the U.S. with some states experiencing wider disparities than others. Many factors are thought to contribute to these disparities, but state differences in fetal death reporting have received little attention. We examined whether such reporting requirements may explain national variation in neonatal and fetal mortality rates and racial disparities.

METHODS

We used data on non-Hispanic white and non-Hispanic black infants from the U.S. 2000-2002 linked birth/infant death and fetal death records to determine the degree to which state fetal death reporting requirements explain national variation in neonatal and fetal mortality rates and racial disparities. States were grouped depending upon whether they based the lower limit for fetal death reporting on birthweight alone, gestational age alone, both birthweight and gestational age, or required reporting of all fetal deaths. Traditional methods and the fetuses-at-risk approach were used to calculate mortality rates, 95% confidence intervals, and relative and absolute racial disparity measures in these four groups.

RESULTS

States with birthweight-alone fetal death thresholds substantially underreported fetal deaths at lower gestations and slightly overreported neonatal deaths at older gestations. This finding was reflected by these states having the highest neonatal mortality rates and disparities, but the lowest fetal mortality rates and disparities.

CONCLUSIONS

Using birthweight alone as a reporting threshold may promote some shift of fetal deaths to newborn deaths, contributing to racial disparities in neonatal mortality. The adoption of a uniform national threshold for reporting fetal deaths could reduce systematic differences in live birth and fetal death reporting.

Preterm preeclampsia: 32 to 37 weeks gestation

OBJECTIVE

To evaluate neonatal outcomes in late preterm infants delivered due to preeclampsia.

METHODS

A retrospective cohort of 3580 infants delivered at 32 0/7 to 36 6/7 weeks gestation was examined. Neonatal outcomes of infants delivered due to preeclampsia were compared with outcomes of infants delivered prematurely due to other etiologies. Multivariate logistic regression was used to analyze the association between preeclampsia and the neonatal outcomes.

RESULTS

Infants of women with preeclampsia were more likely to be SGA (26.8% vs. 8.4%). They were also more likely to be admitted to the ICN (54.3% versus 39.0%); however, they were less likely to suffer a neonatal death (2.2% vs. 3.4%). Infants born to women with preeclampsia had similar rates of RDS (19.8% vs. 14.2%).

DISCUSSION

Neonatal outcomes in late preterm infants born to preeclamptic mothers are significantly different from outcomes in late preterm neonates delivered due to other indications.

Prematurity and low birth weight as potential mediators of higher stillbirth risk in mixed black/white race couples

OBJECTIVE

Although births of multiracial and multiethnic infants are becoming more common in the United States, little is known about birth outcomes and risks for adverse events. We evaluated risk of fetal death for mixed race couples compared with same race couples and examined the role of prematurity and low birth weight as potential mediating risk factors.

METHODS

We performed a retrospective cohort analysis using data from the 1998-2002 California Birth Cohort to evaluate the odds of fetal death, low birth weight, and prematurity for couples with a mother and father who were categorized as either being of same or different racial groups. Risk of prematurity (birth prior to 37 weeks gestation) and low birth weight (<2500 g) were also tested to see if the model could explain variations among groups.

RESULTS

The analysis included approximately 1.6 million live births and 1749 stillbirths. In the unadjusted model, compared with two white parents, black/black and black/white couples had a significantly higher risk of fetal death. When all demographic, social, biological, genetic, congenital, and procedural risk factors except gestational age and birth weight were included, the odds ratios (OR) were all still significant. Black/black couples had the highest level of risk (OR 2.11, CI 1.77-2.51), followed by black mother/white father couples (OR 2.01, CI 1.16-3.48), and white mother/black father couples (OR 1.84, CI 1.33-2.54). Virtually all of the higher risk of fetal death was explainable by higher rates of low birth weight and prematurity.

CONCLUSIONS

Mixed race black and white couples face higher odds of prematurity and low birth weight, which appear to contribute to the substantially higher demonstrated risk for stillbirth. There are likely additional unmeasured factors that influence birth outcomes for mixed race couples.

Acceptance rates in state-federal vocational rehabilitation of clients with brain injury: Is racial disparity an issue?

PRIMARY OBJECTIVE

To utilize Aday and Andersen's Framework for the Study of Access to examine racial disparity within the State-Federal vocational rehabilitation system, among clients with brain injury. Research questions included: Do pre-disposing characteristics such as age, race, ethnicity, gender, marital status and education influence vocational rehabilitation acceptance rates in the US? Do enabling characteristics such as referral source, insurance coverage and primary source of support at application influence vocational rehabilitation acceptance rates in the US? Is there a difference, based on race, in the reason for case closure for vocational rehabilitation services?

METHODS AND PROCEDURES

Exhaustive CHAID analysis was conducted with acceptance for rehabilitation as the criterion variable and pre-disposing characteristics as predictor variables. Chi-square analysis was calculated with regard to reason for closure.

MAIN OUTCOMES AND RESULTS

Descriptive findings are presented. Of the pre-disposing factors, the most significant predictor of acceptance rate was education level. Pearson Chi-square analyses revealed significant differences between White and non-White clients with brain injury with regard to reason for closure.

CONCLUSIONS

The data indicate that racial differences were only a small part of the overall equation and again that distinct disparity by race is not evidenced in the RSA-911 data for persons with a primary or secondary diagnosis of brain injury.

Racial disparities in stillbirth risk across gestation in the United States

OBJECTIVE

We sought to determine factors associated with racial disparities in stillbirth risk.

STUDY DESIGN

Stillbirth hazard was analyzed using 5,138,122 singleton gestations from the National Center of Health Statistics perinatal mortality and birth files, 2001-2002.

RESULTS

Black women have a 2.2-fold increased risk of stillbirth compared with white women. The black/white disparity in stillbirth hazard at 20-23 weeks is 2.75, decreasing to 1.57 at 39-40 weeks. Higher education reduced the hazard for whites more than for blacks and Hispanics. Medical, pregnancy, and labor complications accounted for 30% of the hazard in blacks and 20% in whites and Hispanics. Congenital anomalies and small for gestational age contributed more to preterm stillbirth risk among whites than blacks. Pregnancy and labor conditions contributed more to preterm stillbirth risk among blacks than whites.

CONCLUSION

The excess stillbirth risk for blacks was greatest at preterm gestations, and factors contributing to stillbirth risk vary by race and gestational age.

From paradox to disparity: trends in neonatal death in very low birth weight non-Hispanic black and white infants, 1989-2004

OBJECTIVES

To examine temporal trends in race-specific neonatal death in California to determine whether the overall decline in mortality attenuated the paradoxical survival advantage of very low birth weight (VLBW; birth weight < 1500 g) non-Hispanic black infants relative to VLBW non-Hispanic white infants.

STUDY DESIGN

The data set comprised the California birth cohort file on non-Hispanic black and non-Hispanic white VLBW neonatal mortality for 1989-2004. Logistic regression methods were used to control for potentially confounding maternal characteristics.

RESULTS

In 1989 and 1990, non-Hispanic black VLBW infants demonstrated a paradox of lower neonatal mortality (adjusted odds ratio [aOR] = 0.84; 95% confidence interval [CI] = 0.75-0.94). This survival advantage disappeared after 1991, however. In 2003 and 2004, the incidence of neonatal mortality increased in non-Hispanic black VLBW infants but decreased in non-Hispanic white VLBW infants, resulting in a racial disparity (aOR = 1.34; 95% CI = 1.14-1.56).

CONCLUSIONS

An initial survival paradox transformed into a disparity. The magnitude of this non-Hispanic black/non-Hispanic white VLBW disparity rose to its highest levels in the last 2 years of the study period. Moreover, the steady mortality increase in VLBW non-Hispanic black VLBW infants since 2001 reversed the secular decline in neonatal mortality in this population. Our findings underscore the need to augment strategies to improve the health trajectory of gestation in non-Hispanic black women.

The challenge of infant mortality: have we reached a plateau?

OBJECTIVES

Infant mortality is a major indicator of the health of a nation. We analyzed recent patterns and trends in U.S. infant mortality, with an emphasis on two of the greatest challenges: (1) persistent racial and ethnic disparities and (2) the impact of preterm and low birthweight delivery.

METHODS

Data from the national linked birth/infant death datasets were used to compute infant mortality rates per 100,000 live births by cause of death (COD), and per 1,000 live births for all other variables. Infant mortality rates and other measures of infant health were analyzed and compared. Leading and preterm-related CODs, and international comparisons of infant mortality rates were also examined.

RESULTS

Despite the rapid decline in infant mortality during the 20th century, the U.S. infant mortality rate did not decline from 2000 to 2005, and declined only marginally in 2006. Racial and ethnic disparities in infant mortality have persisted and increased, as have the percentages of preterm and low birthweight deliveries. After decades of improvement, the infant mortality rate for very low birthweight infants remained unchanged from 2000 to 2005. Infant mortality rates from congenital malformations and sudden infant death syndrome declined; however, rates for preterm-related CODs increased. The U.S. international ranking in infant mortality fell from 12th place in 1960 to 30th place in 2005.

CONCLUSIONS

Infant mortality is a complex and multifactorial problem that has proved resistant to intervention efforts. Continued increases in preterm and low birthweight delivery present major challenges to further improvement in the infant mortality rate.