Are Twin Pregnancies at Higher Risk for Iron and Calcium Deficiency than Singleton Pregnancies?

The aim of this study was to compare the iron and calcium status in singleton and twin pregnancies and to assess whether there is an increased risk for iron and calcium deficiency in twin gestation. The study included 105 singleton and 9 twin pregnancies at or above 35 weeks of gestation. Information on prenatal supplementation with iron or calcium was acquired, and adverse perinatal outcomes were recorded. Biosamples from all 114 mothers and 73 newborns (61 singleton and 12 twin newborns) were finally analyzed. Total iron and calcium concentrations in serum were measured through total reflection X-ray fluorescence analysis. The results indicated no significant differences in maternal serum iron and calcium concentrations between singleton and twin pregnancies. Similarly, iron and calcium concentrations in newborn umbilical cord serum samples were not different between singleton and twin pregnancies. The comparison of total iron and calcium between mothers and umbilical cord serum indicated significantly lower concentrations in the mothers, with the differences being not homogenous but rather pair-specific. A significant positive correlation between maternal serum and umbilical cord serum calcium concentration was noticed. Prenatal iron supplementation was associated with higher iron concentrations in both mothers and newborns, supporting the efficiency of supplementation and the quality of the study methods. Collectively, the data indicate no significant differences in serum iron and calcium concentrations with regard to singleton or twin pregnancies and the efficiency of iron supplementation during pregnancy for increasing iron status.

Review of Dietary Recommendations for Twin Pregnancy: Does Nutrition Science Keep Up with the Growing Incidence of Multiple Gestations?

Recommendations for nutrition and the use of dietary supplements for pregnant women are updated on regular basis but it remains to be seen to what extent they may be applicable in twin pregnancies. The aim of this narrative review is to present the current state of knowledge about the energy and nutrient demand in twin pregnancy. There is general consensus in literature that the energy demand is higher than in a singleton pregnancy, but there is a lack of position statements from scientific societies on specific energy intake that is required. In turn, recommended maternal weight gain, which favors the normal weight of the neonate, has been determined. There is even a larger knowledge gap when it comes to vitamins and minerals, the body stores of which are theoretically used up faster. The greatest number of studies so far focused on vitamin D, and most of them concluded that its concentration in maternal blood is lower in twin as compared to singleton pregnancy. Few randomized studies focus on iron supplementation and there are no other studies that would assess dietary interventions. In light of a growing incidence of multiple pregnancies, more studies are necessary to establish the nutritional demands of the mother and the course of action for adequate supplementation.

Heritability of tea drinking and its relationship with cigarette smoking in the Chinese male adult twins.

The aims of this study are to estimate the contributions of genetic factors to the variation of tea drinking and cigarette smoking, to examine the roles of genetic factors in their correlation and further to investigate underlying causation between them. We included 11 625 male twin pairs from the Chinese National Twin Registry (CNTR). Bivariate genetic modelling was fitted to explore the genetic influences on tea drinking, cigarette smoking and their correlation. Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) was further used to explore the causal relationship between them. We found that genetic factors explained 17% and 23% of the variation in tea drinking and cigarette smoking, respectively. A low phenotypic association between them was reported (rph = 0.21, 95% confidence interval [CI]: [0.19, 0.24]), which was partly attributed to common genetic factors (rA = 0.45, 95% CI [0.19, 1.00]). In the ICE FALCON analysis with current smoking as the exposure, tea drinking was associated with his own (ßself = 0.39, 95% CI [0.23, 0.55]) and his co-twin's smoking status (ßco-twin = 0.25, 95% CI [0.10, 0.41]). Their association attenuated with borderline significance conditioning on his own smoking status (p = 0.045), indicating a suggestive causal effect of smoking status on tea drinking. On the contrary, when we used tea drinking as the predictor, we found familial confounding between them only. In conclusion, both tea drinking and cigarette smoking were influenced by genetic factors, and their correlation was partly explained by common genetic factors. In addition, our finding suggests that familial confounders account for the relationship between tea drinking and cigarette smoking. And current smoking might have a causal effect on weekly tea drinking, but not vice versa.

Maternal and Perinatal Factors Associated With Twin Pregnancies in Ecuador.

There are few studies on twins in Ecuador and Latin America. It requires a better understanding of perinatal conditions, especially from an ethnic perspective. This work aims to assess perinatal factors related to twin pregnancy in Ecuadorian Mestizo individuals. We performed an epidemiological, observational and cross-sectional study at the Hospital San Francisco and Hospital Nueva Aurora in Quito, Ecuador, from November 2019 to January 2020. It included 203 newborns from twin pregnancies, including mothers with and without pathological history. The average gestational age was 31 weeks, and the APGAR score at first minute was 6.86, with significant differences. Regarding the metabolic balance, the mean pH was 6.14; and bicarbonate was 11.57, with significant differences. Twins had intrauterine growth restriction in 6.9% of cases, with significant differences (p = .003); 81.4% required supplemental oxygen, with significant differences (p = .002); 93% required noninvasive mechanical ventilation (NIMV), with significant differences (p = . 003); 93% required inotropic and sedation, with substantial differences; 69% required antibiotics (≥21 days), with significant differences (p = .014); and 17.2% needed between 8 to 14 days of hospitalization, and 51% more than 28 days, with significant differences. The studied mothers' demographic profile was mostly Mestizos, with an average age of 32 years, and 93% had a poverty status. Most of the twins were diamniotic monochorial and were discordant twins. It found jaundice, premature anemia and sepsis in 100% of twins and hyaline membrane disease in 89.66% of twins. Twins of women with relevant prenatal care had more premature births (30.4 ± 2.6 weeks), more acid-base imbalance, APGAR at ≥7 min in 90% of cases, and patent ductus arteriosus in all. There was also a greater need for double intensive phototherapy than twins of healthy women.

Associations Between Anxiety Symptoms and Health-Related Quality of Life: A Population-Based Twin Study in Sri Lanka.

Anxiety not only concerns mental wellbeing but also negatively impacts other areas of health. Yet, there is limited research on (a) the genetic and environmental aetiology of such relationships; (b) sex differences in aetiology and (c) non-European samples. In this study, we investigated the genetic and environmental variation and covariation of anxiety symptoms and eight components of health-related quality of life (QoL), as measured by the short form health survey (SF-36), using genetic twin model fitting analysis. Data was drawn from the Colombo Twin and Singleton Study (COTASS), a population-based sample in Sri Lanka with data on twins (N = 2921) and singletons (N = 1027). Individual differences in anxiety and QoL traits showed more shared environmental (family) effects in women. Men did not show familial effects. Anxiety negatively correlated with all eight components of QoL, mostly driven by overlapping unique (individual-specific) environmental effects in both sexes and overlapping shared environmental effects in women. This is the first study in a South Asian population supporting the association between poor mental health and reduced QoL, highlighting the value of integrated healthcare services. Associations were largely environmental, on both individual and family levels, which could be informative for therapy and intervention.

Conduct disorder and somatic health in children: a nationwide genetically sensitive study.

BACKGROUND: Conduct disorder (CD), a serious behavioral and emotional disorder in childhood and adolescence, characterized by disruptive behavior and breaking societal rules. Studies have explored the overlap of CD with neurodevelopmental problems (NDP). The somatic health of children with NDP has been investigated; however, the prevalence of these problems in children with CD has not been sufficiently studied. Holistic assessment of children with CD is required for establishing effective treatment strategies. AIMS: (1) Define the prevalence of selected neurological problems (migraine and epilepsy) and gastrointestinal problems (celiac disease, lactose intolerance, diarrhea, and constipation) in a population of twins aged 9 or 12; (2) Compare the prevalence of somatic problems in three subpopulations: (a) children without CD or NDP, (b) children with CD, and (c) children with both CD and NDP; (3) Select twin pairs where at least one child screened positive for CD but not NDP (proband) and map both children's neurological and gastrointestinal problems. METHOD: Telephone interviews with parents of 20,302 twins in a cross-sectional, nationwide, ongoing study. According to their scores on the Autism-Tics, AD/HD, and Comorbidities inventory, screen-positive children were selected and divided into two groups: (1) children with CD Only, (2) children with CD and at least one NDP. RESULTS: Children with CD had an increased prevalence of each neurological and gastrointestinal problem (except celiac disease), and the prevalence of somatic problems was further increased among children with comorbid CD and NDP. The presence of CD (without NDP) increased the odds of constipation for girls and the odds of epilepsy for boys. Girls with CD generally had more coexisting gastrointestinal problems than boys with CD. Female co-twins of probands with CD were strongly affected by gastrointestinal problems. Concordance analyses suggested genetic background factors in neurological and gastrointestinal problems, but no common etiology with CD could be concluded. CONCLUSION: Co-occurring NDP could explain most of the increased prevalence of somatic problems in CD. Our results raise a new perspective on CD in children and adolescents; their CD seems to be linked to a number of other health problems, ranging from neurodevelopmental and psychiatric disorders to somatic complaints.

Twin Block in Myogenous Orofacial Pain: Applied Anatomy, Technique Update, and Safety.

The twin block, introduced in 2014, has proven to be more advantageous for the management of myogenous orofacial pain than the masseteric nerve block, which was introduced in 2009. The twin block is an extraoral nerve block injection which passes through the temporal fossa to anesthetize both the masseteric and the deep temporal nerves as they exit the infratemporal fossa at the infratemporal crest. Similar to the masseteric nerve block, the twin block has demonstrated efficacy with expeditious and sustained relief of myogenous face pain originating from the masseter muscle. Furthermore, in a 6-month prospective treatment study, that has been accepted for publication, the twin block has been demonstrated as comparable to trigger point injections in the management of chronic myofascial pain of masseteric origin. The twin block's ability to mitigate myogenous pain from both the masseter and temporalis muscles and its ease of administration are the key advantages over the masseteric nerve block. Since its inception, we have refined the technique for administering the twin block and our clinical experience corroborates its safety and efficacy. This review describes the refined technique and its safety in the context of the region's applied anatomy.

Plasma metabolomic profiles associated with infant food allergy with further consideration of other early life factors.

BACKGROUND: Fatty acids have been implicated in early life immune development. Food allergy provides a clear phenotype of early allergic disease. Fish oil and vitamin D have immune-modulating properties. We aimed to identify the metabolomic profile of (i) infant food allergy and (ii) factors linked to food allergy in past studies such as fish oil supplementation and serum 25OHD3 levels in early life. METHODS: NMR was used to quantify 73 metabolites in plasma of 1 year old infants from the Barwon Infant Study (n=485). Logistic regression models were used to examine associations between infant metabolome and food allergy in infants. Linear regression models were used to describe associations between maternal fish oil supplementation and 25OHD3 levels with infant metabolites. RESULTS: A higher linoleic acid: total fatty acid (FA) ratio and phenylalanine level were associated with higher odds of food allergy. Antenatal fish oil supplementation was positively associated with docosahexaenoic acid (DHA) and omega-3 related metabolite levels. Postnatal 25OHD3 levels at 1 year of age were positively associated with several FA measures and creatinine and inversely with the saturated FA: total FA ratio. Only the postnatal 25OHD3 patterns persisted after adjustment for multiple comparisons. CONCLUSIONS: Infants with food allergy had altered fatty acid profiles at one year. Fish oil supplementation in pregnancy was associated with higher DHA and omega-3 related metabolites at 1 year of age. Associations were modest and the most robustly altered metabolomic profiles were with postnatal 25OHD3 levels.

[The association between the frequency of prenatal care in childbearing aged women and risk of small for gestational age among neonatal twins in Shaanxi Province].

Objective: To explore the association between the frequency of prenatal care in childbearing aged women and risk of small for gestational age (SGA) among neonatal twins in Shaanxi Province. Methods: From July to December 2013, a total of 30 027 childbearing aged women, who were pregnant from January 2010 to November 2013 and had definite outcomes, were selected from 30 districts (counties) of Shaanxi Province by using the multi-stage random sampling method. The questionnaires with a face-to-face survey method were used to retrospectively collect demographic information, pregnancy history, lifestyle during pregnancy, disease history, nutritional supplements, and health care during pregnancy. Information on the gestational age and birth weight of the newborn were obtained by consulting the medical certificate of birth and were registered as twin A and twin B by birth order. Finally, 356 childbearing aged women and their twin babies with complete data were included in the analysis. A generalized estimation equation model was used to analyze the association between the frequency of prenatal care and the risk of SGA among neonatal twins. Results: The age of childbearing aged women was (27.44±4.68) years old, of which 79.49% (283 women) were rural residents and 44.38% (158 women) had seven or more times prenatal care. The gestational age and birth weight were (37.64±2.51) weeks and (2 510±497) g, respectively. The prevalence of SGA was 51.40% (183/356) for twin A and 53.37% (190/356) for twin B, respectively. The prevalence of SGA was 44.30% (70/158) for twin A with seven or more times prenatal care and 42.41% (67/158) for twin B with seven or more times prenatal care, which was lower than that for twins with less than seven times prenatal care, respectively [57.07% (113/198) and 62.12% (123/198)] (P values were 0.017 and <0.001). The results of generalized estimation equation model suggested that compared to those with less than seven times prenatal care, after adjusting for parity, birth order, place of residence, maternal age, occupation, education, family wealth index, passive smoking, pregnancy-induced hypertension syndrome, folic acid, and iron supplement during perinatal period, and gender of the newborn, the OR (95%CI) of risk of SGA among childbearing aged women with seven or more times prenatal care was 0.60 (0.40-0.91). Conclusion: Seven or more times prenatal care could reduce the risk of SGA among neonatal twins in Shanxi Province.

Case report of sudden death in a twin infant given melatonin supplementation: A challenging interpretation of postmortem toxicology.

Melatonin (MEL) is a neurohormone in humans produced in a number of locations. Starting with the amino acid tryptophan, MEL is produced through a number of enzymatic steps that includes serotonin as an intermediate compound. The primary production of MEL is in the pineal gland located in the brain. It is directly associated with the the suprachiasmatic nucleus (SCN) located in the hypothalamus. In young and adult humans, the blood levels of MEL are typically in the picogram levels and produced in a cyclic schedule highly regulated by light detected in the retina by intrinsically photosensitive retinal ganglion cells (ipRGCs), resulting in production primarily during periods of darkness. During periods of light, MEL levels are typically very low or undetectable. Basal levels of MEL in infants have been observed to be either undetectable or also in the picogram levels, although some medical treatment has involved administration of exogenous MEL resulting in peak levels in the nanogram range. MEL is considered to be well tolerated and there have been limited reports of toxicity. In this case, an infant was found unresponsive and cause of death was ruled as Undetermined. Melatonin was detected in the peripheral blood at a concentration of 1,400ng/mL.

The role of the IPL in person identification.

We investigate the brain activations when identifying a newly encountered individual as being the same as a person previously perceived, a fundamental but seldom acknowledged process. In an identity condition, two faces had to be identified as the same person in contrast to a control condition, in which two faces had to be recognised as belonging to similar looking twins. Our results demonstrate an increase of neural activation in frontal as well as in parietal areas including the left inferior parietal lobe and the precuneus during identification. We introduce mental files theory to model this process as a linking of co-referential files and identify important connections to other domains in neurological and cognitive science (e.g., delusional misidentification syndromes, theory of mind).

Mindfulness and associations with symptoms of insomnia, anxiety and depression in early adulthood: A twin and sibling study.

This study investigated associations between mindfulness and symptoms of insomnia, depression and anxiety. Mindfulness was disaggregated into five subscales: 'nonreactivity to inner experience', 'observing', 'acting with awareness', 'describing' and 'nonjudging of inner experience'. Twin models were used to examine genetic and environmental influences on mindfulness, symptoms of insomnia, depression and anxiety and on their associations. Data came from a longitudinal twin/sibling study (G1219) comprising 862 individuals (age range 22-32 years, 66% females). Less mindfulness was associated with greater symptoms of insomnia, depression and anxiety (r = .22-.48). Of the mindfulness subscales, 'nonjudging of inner experience' was most strongly associated with the other traits. Overall mindfulness was largely influenced by non-shared environmental factors (E = .72) although familial influences played a role for overall mindfulness, as well as for the 'acting with awareness' and 'describing' subscales. The genetic correlations between overall mindfulness and symptoms of insomnia, depression and anxiety ranged from .32 to .75 (but were non-significant), while the shared environmental correlations ranged from -.78 to .79 (also non-significant). The non-shared environmental influences between these three variables were moderately, significantly correlated (rE = .21-.55).

Unusual cause of severe neonatal hyperbilirubinaemia: a twin case.

We present twins born to the 31-year-old, multigravida mother, who were referred to our centre at 90 hours of life for severe hyperbilirubinaemia. Twin 1 had already received two double volume exchange transfusions at 55 and 83 hours of life, in view of the persistent rise in bilirubin despite receiving phototherapy. Twin 2 had received phototherapy and 1 packed red blood cell transfusion in view of the fall in haematocrit. Mother's blood group was B positive and that of both twins was O positive. Both the twins were started on intensive phototherapy and their serum bilirubin and haematocrit were evaluated. On investigation, a minor blood incompatibility was found. Double volume exchange transfusion was done for twin 2 at 100 hours of life in view of the rapid rise in serum bilirubin. Both the babies were monitored for their serum bilirubin and treated for sepsis and discharged after 15 days.

Parenteral administration of l-arginine to twin-bearing Romney ewes during late pregnancy is associated with reduced milk somatic cell count during early lactation.

Maternal milk is the primary source of nutrition for suckling mammals, and its yield and composition are important determinants of survival during the early neonatal period. The objective of this study was to examine whether parenteral administration of l-Arg to twin-bearing ewes, during mid to late pregnancy, influenced prepartum maternal mammary gland development and subsequent lactation performance in the early postpartum period (14 d). At 80 d of pregnancy, multiparous Romney ewes were housed indoors in group pens, split into 2 cohorts, and fed a lucerne-based pellet diet, formulated to meet 100% of National Research Council-recommended requirements for twin-bearing pregnant ewes, once a day. Cohort 1 was administered l-Arg (72.7 mg/kg of live weight via i.v, 3 times a day) from d 100 of pregnancy until d 140. At d 140, ewes were euthanized and maternal mammary tissues were collected for analysis of the biochemical indices total DNA, RNA, protein, protein synthetic efficiency (protein:RNA), cell size (protein:DNA), transcriptional efficiency (RNA:DNA), and the abundance of mammalian target of rapamycin (mTOR) and mTORSer2448 protein. Cohort 2 was administered an identical l-Arg regimen as cohort 1, but from d 100 until parturition. Milk was collected over a 14-d period (d 1, 4, 7, 10, and 14) to assess milk yield and composition. In cohort 1, total mammary DNA (cell number) tended to be higher in l-Arg ewes, with no change in total mammary RNA or protein content, biochemical indices of protein synthetic efficiency, cell size or transcriptional efficiency, or mTOR protein abundance or phosphorylation. In cohort 2, milk composition analysis from l-Arg ewes showed lower (d 7-14) milk somatic cell counts, greater crude protein percentage from d 7 to 10 but lower at d 14, and altered absolute concentrations of some free AA (d 7 and 14) compared with controls. We propose that parenteral administration of l-Arg during late pregnancy is associated with increased mammary gland cellular content and decreased somatic cell counts during early lactation.

Running in the Family? Structural Brain Abnormalities and IQ in Offspring, Siblings, Parents, and Co-twins of Patients with Schizophrenia.

Structural brain abnormalities and cognitive deficits have been reported in patients with schizophrenia and to a lesser extent in their first-degree relatives (FDRs). Here we investigated whether brain abnormalities in nonpsychotic relatives differ per type of FDR and how these abnormalities are related to intelligent quotient (IQ). Nine hundred eighty individuals from 5 schizophrenia family cohorts (330 FDRs, 432 controls, 218 patients) were included. Effect sizes were calculated to compare brain measures of FDRs and patients with controls, and between each type of FDR. Analyses were repeated with a correction for IQ, having a nonpsychotic diagnosis, and intracranial volume (ICV). FDRs had significantly smaller ICV, surface area, total brain, cortical gray matter, cerebral white matter, cerebellar gray and white matter, thalamus, putamen, amygdala, and accumbens volumes as compared with controls (ds < -0.19, q < 0.05 corrected). Offspring showed the largest effect sizes relative to the other FDRs; however, none of the effects in the different relative types survived correction for multiple comparisons. After IQ correction, all effects disappeared in the FDRs after correction for multiple comparisons. The findings in FDRs were not explained by having a nonpsychotic disorder and were only partly explained by ICV. FDRs show brain abnormalities that are strongly covarying with IQ. On the basis of consistent evidence of genetic overlap between schizophrenia, IQ, and brain measures, we suggest that the brain abnormalities in FDRs are at least partly explained by genes predisposing to both schizophrenia risk and IQ.

Major Issues of Care in Thalassemia Major Children Refugees.

Beta thalassemia major (ßTM) is the most common inherited hemoglobinopathy. Management essentially focuses on preventing and treating complications. Conventional treatment is based on a regular blood transfusion program, and chelation therapy. Management essentially focuses on preventing and treating complications. Severe complications of ßTM are very rarely seen in children in Europe. In the context of the migrant crisis, pediatricians will be confronted with the challenge of managing severe complicated ßTM. We report the case of 2 Syrian 10-year-old twin girls who arrived to France with numerous and severe complications of ßTM: hemochromatosis, alloimmunization, hypopituitarism, osteopenia… Their clinical management, which led to successful vital and functional improvement, is reported in this article.

Source and Quality of Enteral Nutrition Influences Oxidative Stress in Preterm Infants: A Prospective Cohort Study.

BACKGROUND: Preterm infants are at risk of oxidative stress from neonatal intensive care interventions. 8-Oxo-2'-deoxyguanosine (8-oxodG), generated by oxygen radical attack on DNA, is a potential marker of oxidative stress. The aim of the present study was to investigate the impact of quality and source of enteral nutrition (EN) on renal excretion of 8-oxodG in preterm infants. METHODS: Spontaneous urine samples were collected on postnatal days 26-31 in 33 preterm infants. Infants were fed either breast milk (BM), formula (FM), or BM/FM mixtures. Daily iron (Fe) supplementation was started day 28 ± 1 postnatally. 8-oxodG was determined by highperformance liquid chromatography-electrochemical detection (HPLC-EC). RESULTS: The 8-oxodG/creatinine ratio was significantly higher in infants fed FM vs FM/BM (38.7 ± 28.7 vs 16.7 ± 12.2 nmol 8-oxodG/mmol creatinine, P < 0.0001) or BM (11.6 ± 10.4 nmol 8-oxodG/mmol creatinine, P < 0.0001). There was no significant effect of Fe supplementation (P = 0.547). 8-OxodG excretion showed significant interindividual variation but was similar within pairs of twins. CONCLUSION: Quality and source of EN seem to influence oxidative stress in preterm infants. The underlying pathophysiological mechanism is unclear and needs further investigation. It may be speculated that other mechanisms than Fe supplementation contribute to oxidative stress, such as cow's milk protein-mediated up-regulation of the intestinal inflammatory cascade.

Iron Supplementation in Twin Pregnancy - The Benefit of Doubling the Iron Dose in Iron Deficient Pregnant Women: A Randomized Controlled Trial.

OBJECTIVE: To assess the efficacy of doubling the daily dose of iron supplement in iron-deficient women with twin pregnancies. STUDY DESIGN: Using a prospective randomized controlled trial, iron-deficient women with twin gestations were randomized to receive a single or a double dose of daily iron from 16 weeks of gestation until 6 weeks postpartum. The primary outcome was hemoglobin at 32 weeks. Secondary outcomes included ferritin at 32 weeks, hemoglobin during pregnancy and postpartum, birth weights, preterm birth rate, gastrointestinal side effects, intravenous iron administration, and compliance with treatment. RESULTS: Eighty-five and 87 women were randomized to receive one capsule (group A) or two capsules (group B) of 34 mg of ferrous sulfate, respectively. Mean hemoglobin (9.6 g/dL and 9.7 g/dL) and ferritin (8.6 ng/ml and 8.5 ng/ml) were similar in both groups A and B, respectively, at allocation. Hemoglobin in group B was significantly higher from 32 weeks onward, until 6 weeks postpartum. There were no significant differences in any of the secondary outcomes examined. CONCLUSIONS: In twin pregnancies complicated by iron deficiency anemia, doubling the dose of iron increases hemoglobin and ferritin without worsening gastrointestinal side effects.

Comparison of perinatal outcomes in late preterm birth between singleton and twin pregnancies

OBJECTIVE: To determine whether late preterm twin neonates have a more favorable perinatal outcome than singleton late preterm neonates. METHODS: We studied 401 late preterm births between 34+0 and 36+6 weeks of gestation, from January 2011 to December 2014 in our institution. We compared the maternal and neonatal characteristics and perinatal outcomes between singleton and twin pregnancies. Perinatal outcomes included Apgar score, admission to the neonatal intensive care unit (NICU) or special care nursery, duration of NICU stay, and the rate of composite morbidity (antibiotic use, hypoglycemia, hypocalcemia, hyperbilirubinemia requiring phototherapy, respiratory support, and respiratory distress syndrome). RESULTS: A total of 289 neonates were in the singleton group and 112 in the twin group. The twin group showed smaller mean birth weight despite of longer gestational age at delivery. In addition, there were significant differences in the indication of delivery and cesarean section rate between the 2 groups. Overall, the risk of composite morbidity was similar between 2 groups (odds ratio, 1.4; 95% confidence interval, 0.8 to 2.4). CONCLUSION: Our findings suggest that late preterm twins do not show a more favorable outcome than singleton late preterm births.