Stillbirths: Contribution of preterm birth and size-for-gestational age for 125.4 million total births from nationwide records in 13 countries, 2000-2020.

OBJECTIVE: To examine the contribution of preterm birth and size-for-gestational age in stillbirths using six 'newborn types'. DESIGN: Population-based multi-country analyses. SETTING: Births collected through routine data systems in 13 countries. SAMPLE: 125 419 255 total births from 22+0 to 44+6 weeks' gestation identified from 2000 to 2020. METHODS: We included 635 107 stillbirths from 22+0 weeks' gestation from 13 countries. We classified all births, including stillbirths, into six 'newborn types' based on gestational age information (preterm, PT, <37+0 weeks versus term, T, ≥37+0 weeks) and size-for-gestational age defined as small (SGA, <10th centile), appropriate (AGA, 10th-90th centiles) or large (LGA, >90th centile) for gestational age, according to the international newborn size for gestational age and sex INTERGROWTH-21st standards. MAIN OUTCOME MEASURES: Distribution of stillbirths, stillbirth rates and rate ratios according to six newborn types. RESULTS: 635 107 (0.5%) of the 125 419 255 total births resulted in stillbirth after 22+0 weeks. Most stillbirths (74.3%) were preterm. Around 21.2% were SGA types (PT + SGA [16.2%], PT + AGA [48.3%], T + SGA [5.0%]) and 14.1% were LGA types (PT + LGA [9.9%], T + LGA [4.2%]). The median rate ratio (RR) for stillbirth was highest in PT + SGA babies (RR 81.1, interquartile range [IQR], 68.8-118.8) followed by PT + AGA (RR 25.0, IQR, 20.0-34.3), PT + LGA (RR 25.9, IQR, 13.8-28.7) and T + SGA (RR 5.6, IQR, 5.1-6.0) compared with T + AGA. Stillbirth rate ratios were similar for T + LGA versus T + AGA (RR 0.7, IQR, 0.7-1.1). At the population level, 25% of stillbirths were attributable to small-for-gestational-age. CONCLUSIONS: In these high-quality data from high/middle income countries, almost three-quarters of stillbirths were born preterm and a fifth small-for-gestational age, with the highest stillbirth rates associated with the coexistence of preterm and SGA. Further analyses are needed to better understand patterns of gestation-specific risk in these populations, as well as patterns in lower-income contexts, especially those with higher rates of intrapartum stillbirth and SGA.

Neonatal mortality risk of large-for-gestational-age and macrosomic live births in 15 countries, including 115.6 million nationwide linked records, 2000-2020.

OBJECTIVE: We aimed to compare the prevalence and neonatal mortality associated with large for gestational age (LGA) and macrosomia among 115.6 million live births in 15 countries, between 2000 and 2020. DESIGN: Population-based, multi-country study. SETTING: National healthcare systems. POPULATION: Liveborn infants. METHODS: We used individual-level data identified for the Vulnerable Newborn Measurement Collaboration. We calculated the prevalence and relative risk (RR) of neonatal mortality among live births born at term + LGA (>90th centile, and also >95th and >97th centiles when the data were available) versus term + appropriate for gestational age (AGA, 10th-90th centiles) and macrosomic (≥4000, ≥4500 and ≥5000 g, regardless of gestational age) versus 2500-3999 g. INTERGROWTH 21st served as the reference population. MAIN OUTCOME MEASURES: Prevalence and neonatal mortality risks. RESULTS: Large for gestational age was common (median prevalence 18.2%; interquartile range, IQR, 13.5%-22.0%), and overall was associated with a lower neonatal mortality risk compared with AGA (RR 0.83, 95% CI 0.77-0.89). Around one in ten babies were ≥4000 g (median prevalence 9.6% (IQR 6.4%-13.3%), with 1.2% (IQR 0.7%-2.0%) ≥4500 g and with 0.2% (IQR 0.1%-0.2%) ≥5000 g). Overall, macrosomia of ≥4000 g was not associated with increased neonatal mortality risk (RR 0.80, 95% CI 0.69-0.94); however, a higher risk was observed for birthweights of ≥4500 g (RR 1.52, 95% CI 1.10-2.11) and ≥5000 g (RR 4.54, 95% CI 2.58-7.99), compared with birthweights of 2500-3999 g, with the highest risk observed in the first 7 days of life. CONCLUSIONS: In this population, birthweight of ≥4500 g was the most useful marker for early mortality risk in big babies and could be used to guide clinical management decisions.

Neonatal mortality risk for vulnerable newborn types in 15 countries using 125.5 million nationwide birth outcome records, 2000-2020.

OBJECTIVE: To compare neonatal mortality associated with six novel vulnerable newborn types in 125.5 million live births across 15 countries, 2000-2020. DESIGN: Population-based, multi-country study. SETTING: National data systems in 15 middle- and high-income countries. METHODS: We used individual-level data sets identified for the Vulnerable Newborn Measurement Collaboration. We examined the contribution to neonatal mortality of six newborn types combining gestational age (preterm [PT] versus term [T]) and size-for-gestational age (small [SGA], <10th centile, appropriate [AGA], 10th-90th centile or large [LGA], >90th centile) according to INTERGROWTH-21st newborn standards. Newborn babies with PT or SGA were defined as small and T + LGA was considered as large. We calculated risk ratios (RRs) and population attributable risks (PAR%) for the six newborn types. MAIN OUTCOME MEASURES: Mortality of six newborn types. RESULTS: Of 125.5 million live births analysed, risk ratios were highest among PT + SGA (median 67.2, interquartile range [IQR] 45.6-73.9), PT + AGA (median 34.3, IQR 23.9-37.5) and PT + LGA (median 28.3, IQR 18.4-32.3). At the population level, PT + AGA was the greatest contributor to newborn mortality (median PAR% 53.7, IQR 44.5-54.9). Mortality risk was highest among newborns born before 28 weeks (median RR 279.5, IQR 234.2-388.5) compared with babies born between 37 and 42 completed weeks or with a birthweight less than 1000 g (median RR 282.8, IQR 194.7-342.8) compared with those between 2500 g and 4000 g as a reference group. CONCLUSION: Preterm newborn types were the most vulnerable, and associated with the highest mortality, particularly with co-existence of preterm and SGA. As PT + AGA is more prevalent, it is responsible for the greatest burden of neonatal deaths at population level.

Vulnerable newborn types: Analysis of population-based registries for 165 million births in 23 countries, 2000-2021.

OBJECTIVE: To examine the prevalence of novel newborn types among 165 million live births in 23 countries from 2000 to 2021. DESIGN: Population-based, multi-country analysis. SETTING: National data systems in 23 middle- and high-income countries. POPULATION: Liveborn infants. METHODS: Country teams with high-quality data were invited to be part of the Vulnerable Newborn Measurement Collaboration. We classified live births by six newborn types based on gestational age information (preterm <37 weeks versus term ≥37 weeks) and size for gestational age defined as small (SGA, <10th centile), appropriate (10th-90th centiles), or large (LGA, >90th centile) for gestational age, according to INTERGROWTH-21st standards. We considered small newborn types of any combination of preterm or SGA, and term + LGA was considered large. Time trends were analysed using 3-year moving averages for small and large types. MAIN OUTCOME MEASURES: Prevalence of six newborn types. RESULTS: We analysed 165 017 419 live births and the median prevalence of small types was 11.7% - highest in Malaysia (26%) and Qatar (15.7%). Overall, 18.1% of newborns were large (term + LGA) and was highest in Estonia 28.8% and Denmark 25.9%. Time trends of small and large infants were relatively stable in most countries. CONCLUSIONS: The distribution of newborn types varies across the 23 middle- and high-income countries. Small newborn types were highest in west Asian countries and large types were highest in Europe. To better understand the global patterns of these novel newborn types, more information is needed, especially from low- and middle-income countries.

Global resilience and new strategies needed for antimicrobial stewardship during the COVID-19 pandemic and beyond.

Resilience is having the ability to respond to adversity proactively and resourcefully. The coronavirus disease 2019 (COVID-19) pandemic's profound impact on antimicrobial stewardship programs (ASP) requires clinicians to call on their own resilience to manage the demands of the pandemic and the disruption of ASP activities. This article provides examples of ASP resilience from pharmacists and physicians from seven countries with different resources and approaches to ASP-The United States, The United Kingdom, Canada, Nigeria, Lebanon, South Africa, and Colombia. The lessons learned pertain to providing ASP clinical services in the context of a global pandemic, developing new ASP paradigms in the face of COVID-19, leveraging technology to extend the reach of ASP, and conducting international collaborative ASP research remotely. This article serves as an example of how resilience and global collaboration is sustaining our ASPs by sharing new "how to" do antimicrobial stewardship practices during the COVID-19 pandemic.

Assessing the Risk of Having Small for Gestational Age Newborns Among Lebanese Underweight and Normal Pre-pregnancy Weight Women.

Introduction It has been established that underweight women with low gestational weight gain (GWG) are at a higher risk of having Small for Gestational Age (SGA) newborns. However, the association remains poorly studied in Middle Eastern societies exhibiting different ethnic groups, genetic predisposing factors along with differences in nutritional food intake during pregnancy. The aim of this study is to assess the risk of having a SGA newborn among underweight and normal weight BMI women while studying the role of GWG in this association. Methods This is a retrospective cross-sectional study of 62,351 singleton pregnancies from the National Collaborative Perinatal Neonatal Network between 2001 and 2009 from 27 hospitals across Lebanon. Women who had underweight and normal pre-pregnancy BMI were included. Results A total of 8.6% newborns were SGA and 6.6% of women were underweight. Among women with normal and underweight pre-pregnancy BMI, 8.6 and 12.4% had SGA births respectively. Overall, the adjusted OR of having SGA newborns was significantly higher among underweight women (OR = 1.448; 95%CI = 1.287-1.630) compared to normal pre-pregnancy BMI. Below normal weight gain significantly increased the odds of SGA for both normal and underweight pre-pregnancy BMI women, with adjusted ORs of 1.535 (95% CI = 1.418-1.661) and 1.970 (95%CI = 1.515-2.560) respectively. Discussion Higher risks of SGA newborns in underweight and normal BMI women with low GWG were observed. In addition, normal weight gain couldn't protect underweight women of having risk for SGA newborns. Hence, all pregnant women should be encouraged to maintain healthy BMI before pregnancy and attain adequate GWG.

Association of Pre-Pregnancy Body Mass Index and Gestational Weight Gain with Preterm Births and Fetal Size: an Observational Study from Lebanon.

BACKGROUND: Pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) are reported to impact the preterm birth (PTB) rate and newborn size. Most studies have been conducted in developed countries, although PTB and adverse pregnancy outcomes are more frequent in the developing world. The aim of this study is to elucidate the association of pre-pregnancy BMI and GWG on the occurrence of PTB and sub-optimal fetal size in Lebanon. METHODS: This is a retrospective cohort study using a hospital-based register covering 35% of births in Lebanon between 2001 and 2012. Data were collected on 170 428 pregnancies from 32 hospitals using medical records and interviews. RESULTS: After adjusting for confounders, underweight women had increased odds of having very preterm [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.16, 2.14], preterm (OR 1.42, 95% CI 1.28, 1.58), and small for gestational age (SGA) (OR 1.50, 95% CI 1.37, 1.63) neonates. When BMI was analysed with GWG, only SGA remained significant in underweight women with low GWG. For all BMI groups, low GWG was protective against large for gestational age (LGA) and high GWG increased the odds of LGA. GWG, both low (OR 1.25, 95% CI 1.15, 1.35) and high (OR 1.43, 95% CI 1.32, 1.55) increased the risk of PTB in normal weight women. The same result was obtained for overweight women. CONCLUSIONS: High GWG increased the risk of LGA for all groups and PTB in normal weight and overweight women, whereas low GWG increased the risk of SGA and PTB. Given that there are not many studies from middle income/developing countries on patterns of weight gain during pregnancy, findings from this study may help with pre-conception counselling with emphasis on the importance of an optimal pre-pregnancy BMI and appropriate weight gain during pregnancy.

Consanguinity: a risk factor for preterm birth at less than 33 weeks' gestation.

Consanguinity promotes homozygosity of recessive susceptibility gene variants and can be used to investigate a recessive component in diseases whose inheritance is uncertain. The objective of this study was to assess the association between consanguinity and preterm birth (PTB), stratified by gestational age and clinical presentation (spontaneous vs. medically indicated). Data were collected on 39,745 singleton livebirths without major birth defects, admitted to 19 hospitals in Lebanon, from September 2003 to December 2007. Deliveries before completed 33 weeks' gestation and deliveries at 33-36 weeks' gestation were compared, with respect to cousin marriage, with those after completed 36 weeks' gestation by using multinomial multiple logistic regression. Overall, infants of consanguineous parents had a statistically significant 1.6-fold net increased risk of being born at less than 33 weeks' gestation compared with infants of unrelated parents. This association was statistically significant only with spontaneous PTB. There was no increased risk of being born at 33-36 weeks' gestation associated with consanguinity for both clinical presentations of PTB. Our findings support a genetic contribution to early onset PTB and suggest that early PTB should be targeted in future genetic studies rather than the classic lumping of all births less than 37 weeks' gestation.

Correlation between Group B Streptococcal Genotypes, Their Antimicrobial Resistance Profiles, and Virulence Genes among Pregnant Women in Lebanon.

The antimicrobial susceptibility profiles of 76 Streptococcus agalactiae (Group B Streptococci [GBS]) isolates from vaginal specimens of pregnant women near term were correlated to their genotypes generated by Random Amplified Polymorphic DNA analysis and their virulence factors encoding genes cylE, lmb, scpB, rib, and bca by PCR. Based on the distribution of the susceptibility patterns, six profiles were generated. RAPD analysis detected 7 clusters of genotypes. The cylE gene was present in 99% of the isolates, the lmb in 96%, scpB in 94.7%, rib in 33%, and bca in 56.5% of isolates. The isolates demonstrated a significant correlation between antimicrobial resistance and genotype clusters denoting the distribution of particular clones with different antimicrobial resistance profiles, entailing the practice of caution in therapeutic options. All virulence factors encoding genes were detected in all seven genotypic clusters with rib and bca not coexisting in the same genome.

Predictors of breast-feeding in a developing country: results of a prospective cohort study.

OBJECTIVE: Data on the prevalence and predictors of breast-feeding remain scarce in Lebanon. Moreover, no study has previously addressed the effect of the paediatrician's sex on breast-feeding. The present study aimed to assess the prevalence and predictors of breast-feeding at 1 and 4 months of infant age while exploring the potential role of the sex of the paediatrician. DESIGN: Prospective cohort study. Predictors of breast-feeding significant at the bivariate level were tested at 1 and 4 months through two stepwise regression models. SETTING: Infants were enrolled through the clinics and dispensaries of 117 paediatricians located in Beirut, Lebanon, and its suburbs. SUBJECTS: A total of 1,320 healthy newborn infants born between August 2001 and February 2002 were prospectively followed during the first year. FINDINGS: Breast-feeding rates at 1 and 4 months were 56.3 % and 24.7 %, respectively. Early discharge, high parity and religion were significantly associated with higher breast-feeding rates at 1 and 4 months of age. Maternal age proved significant only at 1 month, while maternal working status and sex of the paediatrician were significant at 4 months. A novel finding of our study was the positive effect of female paediatricians on breast-feeding continuation until 4 months of age (OR = 1.49; 95 % CI 1.03, 2.15). CONCLUSIONS: Breast-feeding rates are low at 1 and 4 months of infant age in Beirut. Further research to investigate the interactions between female physicians and lactating mothers in maintaining breast-feeding in other populations is warranted. The results constitute the basis for designing interventions targeting policy makers, health professionals and mothers.

Intrauterine growth standards in a developing country: a study of singleton livebirths at 28-42 weeks' gestation.

This study aimed to develop fetal growth charts for the population of Greater Beirut, Lebanon, and compare them with previously established references. A survey of consecutive singleton livebirths admitted to normal nurseries and neonatal intensive care units of major hospitals, through the database project of the National Collaborative Perinatal Neonatal Network was used as a design. The study was conducted in nine major healthcare institutions serving the population of Beirut and its suburbs. A total of 24 767 singleton livebirths delivered between 28 and 42 weeks' gestation, with known data on gender, gestational age and anthropometric characteristics were recorded between 1 April 1999 and 31 March 2002. Growth charts were developed by plotting birthweight, length and head circumference percentiles against gestational age for male and female infants separately. Overall, 1348 (5.4%) pregnancies were delivered before 37 weeks' gestation and 1227 (4.9%) were low birthweight. Male infants were delivered slightly earlier than their female counterparts and the mean birthweight, length and head circumference were consistently higher in males. A total of 2247 (9.1%) infants were small-for-gestational-age, with a male-to-female sex ratio of 1.03. Using previously established growth references that overestimated small-for-gestational-age prevalence resulted in a greater proportion of false positives. The opposite was true for growth references that underestimated small-for-gestational-age prevalence. The current growth charts present useful tools for assessing the general health status of newborn infants delivered at sea level in the urban areas of Lebanon and other East Mediterranean countries.

Cesarean delivery among nulliparous women in Beirut: assessing predictors in nine hospitals.

BACKGROUND: Obstetric practice has witnessed a worldwide trend of increasing cesarean section rates in recent years. Similar trends have been observed in Lebanon, according to 2 studies conducted in 1996 and 1999. The objective of the present study was to assess the differences in predictors of cesarean delivery among nulliparous women in a "control hospital" with a low cesarean delivery rate (12.5%) and the rest of the National Collaborative Perinatal Neonatal Network (NCPNN) "study hospitals" with a higher cesarean delivery rate (31.4%). METHODS: Data were collected by the NCPNN database, which covers deliveries at 9 major hospitals located in the Greater Beirut area. Data analysis was performed on the 6,668 consecutive deliveries occurring between January 1, 2001, and December 31, 2002, at the NCPNN participating centers. The questionnaires included items that cover parental sociodemographic characteristics and maternal and newborn health characteristics. Sources of data included direct interviews with mothers after delivery and before hospital discharge and reviews of obstetric and nursery medical charts. Chi-square tests and t tests were performed for categorical and continuous clinical predictors of cesarean section. Logistic regression was performed to determine the odds of having a cesarean section for the study hospitals when compared with the control hospital. Odds ratios and 95% confidence intervals are reported. RESULTS: Variables in the study hospitals that correlated with a higher cesarean delivery rate were male obstetricians, day of the week, and mode of payment compared with the control hospital. CONCLUSIONS: In a country with a high cesarean section rate, 1 hospital met World Health Organization criteria for acceptable cesarean section rates, with no compromise in neonatal outcome. Further studies are needed to investigate potential policies to decrease the high cesarean section rate.

Effect of consanguinity on birth weight for gestational age in a developing country.

Consanguinity, the marriage between relatives, has been associated with adverse child health outcomes because it increases homozygosity of recessive alleles. The objective of this study was to assess the effect of consanguinity on the birth weight of newborns in Greater Beirut, Lebanon. Cross-sectional data were collected on 10,289 consecutive liveborn singleton newborns admitted to eight hospitals belonging to the National Collaborative Perinatal Neonatal Network during the years 2000 and 2001. Birth weight was modeled by use of the fetal growth ratio, defined as the ratio of the observed birth weight to the median birth weight for gestational age. A mixed-effect multiple linear regression model was used to predict the net effect of first- and second-cousin marriage on the birth weight for gestational age, accounting for within-hospital clustering of data. After controlling for medical and sociodemographic covariates, the authors found a statistically significant negative association between consanguinity and birth weight at each gestational age. No significant difference was observed in the decrease in birth weight between the first- and second-cousin marriages. Overall, consanguinity was associated with a decrease in birth weight for gestational age by 1.8% (beta = -0.018, 95% confidence interval: -0.027, -0.008). The largest effects on fetal growth were seen with lower parity and smoking during pregnancy.

Aortic dissection in a neonate: case report and review of the literature.

We report a case of aortic dissection causing hypertension in a neonate, which occurred following iatrogenic intimal injury during umbilical arterial cannulation. The intimal flap was diagnosed by color Doppler sonography, and treated by conservative management with complete spontaneous healing of the intimal injury.

Predicting neonatal outcomes: birthweight, body mass index or ponderal index?

AIMS: To compare birthweight (BW), body mass index (BMI) and ponderal index (PI) as predictors of selected short-term (ST) outcomes, namely Neonatal Intensive Care Unit (NICU) admission and prolonged hospitalization (PH), among newborn (NB) infants. METHODS: Data was collected prospectively on 9,226 infants born during one year at nine tertiary care hospitals in Greater Beirut, Lebanon. The predictive abilities of BW, BMI and PI were compared using the area under the receiver operator characteristic (ROC) curves and sensitivity analysis was performed at the optimal cut-off points for the best anthropometric measurement. RESULTS: The area under the ROC curve suggested superior discriminative power for BW as compared to BMI or PI, as a predictor of NICU admission (ROC area = 0.73) and PH (ROC area = 0.74). The optimal BW cut-off point was 2750 g (sensitivity: 0.49; specificity: 0.89) and 2950 g (sensitivity: 0.62; specificity: 0.78) for NICU admission and PH, respectively. CONCLUSION: In our population of NB infants, BW--a crude measure of fetal growth--is a better predictor than either BMI--a measure of adiposity in adults and children--or PI--a measure of thinness at birth--for selected ST outcomes in NB infants.

Risk factors for term or near-term fetal growth restriction in the absence of maternal complications.

The objective of this study was to examine risk factors for term or near-term fetal growth restriction (FGR) in the absence of pregnancy complications. We completed a survey of uncomplicated single live births delivered in Greater Beirut, Lebanon. FGR cases were defined as below the 10th percentile of expected weight at gestational age. Multivariate logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CIs). Main predictors of FGR were female gender (OR, 1.94; 95% CI, 1.46 to 2.59), nulliparity (Or, 1.66; 95% CI, 1.25 ton 2.20), low prepregnancy weight (OR, 2.52; 95% CI, 1.58 to 4.01), short stature (OR, 2.59; 95% CI, 1.57 to 4.28), and low pregnancy weight gain (OR, 1.75; 95% CI, 1.21 to 2.55). Anthropometric characteristics of mothers are important modifiable determinants of fetal size in our developing urban population of uncomplicated births.

Bone mineralization in newborns whose mothers received magnesium sulphate for tocolysis of premature labour.

Prolonged maternal magnesium sulphate infusion therapy for tocolysis of premature labour may result in secondary fetal hypermagnesaemia, which has been associated with bony abnormalities in the newborn. We report on four infants, members of two twin pregnancies, who were exposed to prolonged fetal hypermagnesaemia. Three of the infants, all appropriate for gestational age, showed abnormal radiological findings consisting of abnormal mineralisation of long-bone metaphyses owing to fetal hypermagnesaemia. The fourth infant, who was growth retarded, had normal bones. Intrauterine growth restriction appears to be protective against magnesium sulphate-induced abnormal bone mineralisation in the newborn.

Caesarean route of delivery and hyaline membrane disease: a hospital-based case-control study in Greater Beirut.

A hospital-based case-control study was conducted to examine the relationship between hyaline membrane disease (HMD) and caesarean route of delivery, in light of sociodemographic, obstetric and perinatal confounders and risk modifying factors. The study population consisted of 78 HMD cases and a control group of 803 infants delivered at 25-36 weeks' gestation and admitted over a 16-month period to nine hospitals in Greater Beirut, Lebanon. The likelihood of delivery by caesarean section was nearly twice as high among newborn infants diagnosed with HMD as compared with the non-HMD control group (OR = 2.02, [95% CI 1.04, 3.92], after adjusting for fetal growth ratio, one-minute Apgar score, maternal age, antenatal steroid administration and pregnancy-related complications. The impact of caesarean section on HMD was considerably more important in infants delivered < or = 32 weeks' gestation (OR = 2.10, [95% CI 0.79, 5.52]) as compared with those delivered afterwards (OR = 1.13, [95% CI 0.40, 3.21]).

Perinatal outcome of vaginally delivered twin gestations with a larger twin B.

OBJECTIVE: To study the perinatal outcome of vaginally delivered twins when twin B is more than 250 g larger than twin A. STUDY DESIGN: Maternal and neonatal charts of live-born, nonanomalous twins, >25 weeks' gestation and vaginally delivered over a period of 17 years were reviewed. The results of this review were distributed among two groups: (1). those with twin B more than 250 g larger than twin A (DeltaBW>250) and (2). those where the difference was <250 g (DeltaBW<250). For vaginally delivered twin gestations, the perinatal outcome of twin B in the group DeltaBW>250 was compared to that of its co-twin, and to that of twin B in the group DeltaBW<250. RESULTS: Of the 679 twin gestations reviewed, 138 (20.6%) were in the group DeltaBW>250, of whom 73 (52.9%) delivered vaginally despite malpresentation in 39.7%. The vaginally delivered twin pregnancies in the groups DeltaBW>250 (n=73) and DeltaBW<250 (n=303) had similar demographics, parity, presentation, gestational age at delivery, and duration of the first stage of labor. Discordant twins were more frequent in the group DeltaBW>250 (26.0 versus 9.5%, p=0.001). Twin B in the group DeltaBW<250 was smaller, with higher incidence of growth restriction, low 5 min Apgar score, and hyperbilirubinemia compared to twin B in the group DeltaBW>250. There was no difference in the incidence of intraventricular hemorrhage, seizures, sepsis, neonatal death, and median nursery stay. Except for a lower median Apgar score at 1 min in twin B and a longer median nursery stay in twin A, twins A and B in the group DeltaBW>250 were similar regarding all other neonatal outcome variables. CONCLUSIONS: When twin B is more than 250 g larger than A, and both are delivered vaginally, the perinatal outcome is similar to its co-twin as well as to that of twin B of all other vaginally delivered twins. That twin B is larger than A is not itself a contraindication to attempted vaginal delivery.