First-born Twins Research Articles

Neonatal Respiratory Morbidity in Twins according to Birth Order and Mode of Delivery

Objective: To compare neonatal respiratory morbidity of twins according to birth order related to gestational age and mode of delivery. Methods: We performed the retrospective research of the medical records of 3,224 neonates (1,612 twin pairs) born in a single center from January 2011 to December 2015. Subjects were classified into four gestational age groups: very (<32 weeks), moderate (32-33 weeks), late (34-36 weeks) preterm, and term (≥37 weeks) groups. We investigated clinical characteristics and respiratory morbidity according to birth order related to gestational age group and mode of delivery. Results: We found increased risk of respiratory morbidity in second-born twin than first-born twin (P=0.039). Second-born twin was associated with increased risk of respiratory distress syndrome (RDS) in late preterm group (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.30-5.95), and transient tachypnea of newborn in term group (OR 1.4, 95% CI 1.03-1.81). In vaginal delivery mode, there was no difference of respiratory morbidity between first and second-born twin in each group, but in cases of Cesarean delivery, second-born twin was related with a greater risk of RDS in late preterm group (OR 2.3, 95% CI 1.07-5.09). Birth order and Cesarean section independently increased the risk of RDS (adjusted OR [aOR] 1.69, 95% CI 1.12-2.54; aOR 2.14, 95% CI 1.25-3.66, respectively). Conclusion: Second-born twin and Cesarean delivery are associated with increased risk of RDS, especially in late preterm twins.

Spontaneous emotional coordination of first-born dizygotic twins and singletons with their mothers in early infancy

We compare matching of facial expressions of emotion, completion of the positive valence of emotional expression, attunement of emotional intensity, and non-matching of emotion, in engagements with their mothers of firstborn dizygotic twins and of singletons. Nine twins and nine singletons were video-recorded at home in spontaneous face-to-face interactions from the second to the sixth month after birth. Microanalysis of infant and maternal facial expressions of emotion revealed qualitative and quantitative differences that indicate that engagements with twins had more frequent and more accurate emotional matching and attunements compared to those with singletons. Singletons displayed more emotional completion and non-matching reactions. Expressions of matching for pleasure and interest followed different developmental patterns in the two kinds of dyads. These results are discussed in relation to the theory of innate affective intersubjectivity. Differences may shed light on the relationship between sharing early life with a twin, and development of self-other awareness.

HIV transmission in twin pregnancy: Maternal and perinatal outcomes

Background: Despite over two decades of studies of mother-to-child transmission (MTCT) of HIV, very little data is available on HIV transmission in twin pregnancies in Africa.Objective: To determine transmission rates of the HIV virus between twins and the maternal and perinatal outcomes in HIV positive twin pregnancies.Methods: An audit involving 186 sets of twin pregnancies delivered at two hospitals in KwaZulu-Natal, South Africa was conducted over a one year period. Relevant data included maternal age, parity, obstetric history, foetal presentation, gestational age at delivery, Apgar scores, birth weight and pregnancy complications.Results: Of 9521 deliveries, 186 (1.95%) women were identified with a twin pregnancy; 80 (43%) of these mothers were HIV infected. One twin was HIV infected giving an incidence of 0.9%. The infected twin was the first-born twin (or twin 1) and was delivered by Caesarean delivery. Based on mode of delivery, there was no transmission for twin 1 or twin 2 via vaginal delivery, but a 1.4% transmission for twin 1 and 0% for twin 2 following Caesarean delivery.Conclusion: Twin pregnancies are at low risk of MTCT of HIV provided the mother is on highly active antiretroviral therapy (HAART) or has taken effective antiretroviral (ARV) treatment (dual therapy) in the antenatal period.

Left ventricular rotational mechanics in identical twins with juvenile idiopathic arthritis (from the MAGYAR-Twin study).

We report the case of a 21-year-old Hungarian genetically identical monozygotic female pair of twins who were involved in Motion Analysis of the heart and Great vessels bY three-dimensionAl (3D) speckle tRacking echocardiography in Twins (MAGYAR-Twin) study. Small joints of the first-born twin (twin A) were affected by early onset seronegative juvenile idiopathic arthritis (JIA) at the age of 10 years (1,2).

Maternal behaviour of Awassi sheep and behaviour of thelambs during the first hour after parturition

Data from sixty-one 2-5-year-old Awassi ewes (38 single and 23 twin births) were evaluated in order to determine behaviour at parturition and the following first hour. Observations were subjected to Kolmogorov-Smirnov and Shapiro-Wilk tests, Pearson-s chi-square test, independent samples t-test, and ANOVA. The Awassi sheep exhibited sniffing action after parturition as the initial behaviour, choosing the back part of the lamb. First licking and sniffing times were found to decrease with maternal age; calculated average data for these characteristics were 138.3 - 15.39 and 118.3 - 26.48 s for singlets, and 147.7 - 15.12 and 123.6 - 29.54 s for twins, respectively (P < 0.05). Total mean licking time was found to be 27.9 - 0.81 min in single births and 26.2 - 0.90 min in twin births. The mean first successful standing-up time was determined to be 23.2 - 1.83 min in single births, 21.1 - 1.63 min in the firstborn twin, and 20.2 - 2.96 min in the second-born twin (P < 0.05). In the same order, the average suckling time of lambs was specified as 34.3 - 2.27 min, 34.3 - 2.50 min, and 29.2 - 3.70 min (P < 0.05), respectively. In conclusion, Awassi ewes showed good maternal behaviour and encouraged their lambs in standing up and suckling.

Učestalost i izbor metoda porođaja kod terminskih i preterminskih blizanaca u Opštoj bolnici Novi Pazar tokom 2009-2013.

The aim of this paper is to analyze the method of term and preterm deliveries of twin pregnancies and vitality of twins at birth. The development of two fetuses in the uterine cavity at the same time is considered a twin pregnancy. Today, due to more often examination and proper treatment, 50% of twin pregnancies end in preterm delivery. We used retrospective study to analyze the delivery method and vitality of twins born term and preterm at Gynecology and Obstetrics Department of General hospital Novi Pazar in the five-year period, from 2009 to 2013. There were 10.489 deliveries in the said five-year period. Out of this number, 118 pregnancies were twin pregnancies and they amount to 1.12% of all deliveries which is in line with world's standards. About 73% of deliveries were term and 27% were preterm twin deliveries. The analysis of twin vitality showed that first-born twins at both term and preterm deliveries are more vital and in better condition. Second-born twins are generally born with lower Apgar score. Due to liberalization for caesarean section indication, a great number of twin deliveries end in caesarean section.

Identifying Children at Risk of High Myopia Using Population Centile Curves of Refraction.

PurposeTo construct reference centile curves of refraction based on population-based data as an age-specific severity scale to evaluate their efficacy as a tool for identifying children at risk of developing high myopia in a longitudinal study.MethodsData of 4218 children aged 5–15 years from the Guangzhou Refractive Error Study in Children (RESC) study, and 354 first-born twins from the Guangzhou Twin Eye Study (GTES) with annual visit were included in the analysis. Reference centile curves for refraction were constructed using a quantile regression model based on the cycloplegic refraction data from the RESC. The risk of developing high myopia (spherical equivalent ≤ -6 diopters [D]) was evaluated as a diagnostic test using the twin follow-up data.ResultsThe centile curves suggested that the 3rd, 5th, and 10th percentile decreased from -0.25 D, 0.00 D and 0.25 D in 5 year-olds to -6.00 D, -5.65D and -4.63 D in 15 year-olds in the population-based data from RESC. In the GTES cohort, the 5th centile showed the most effective diagnostic value with a sensitivity of 92.9%, a specificity of 97.9% and a positive predictive value (PPV) of 65.0% in predicting high myopia onset (≤-6.00D) before the age of 15 years. The PPV was highest (87.5%) in 3rd centile but with only 50.0% sensitivity. The Mathew’s correlation coefficient of 5th centile in predicting myopia of -6.0D/-5.0D/-4.0D by age of 15 was 0.77/0.51/0.30 respectively.ConclusionsReference centile curves provide an age-specific estimation on a severity scale of refractive error in school-aged children. Children located under lower percentiles at young age were more likely to have high myopia at 15 years or probably in adulthood.

Haemoglobin discordances in twins: due to differences in timing of cord clamping?

ObjectiveOur objective was to study the differences in haemoglobin (Hb) at birth in dichorionic (DC) versus monochorionic (MC) twins in relation to birth order and mode of delivery.MethodsAll consecutive DC...

HIV transmission in twin pregnancy: Maternal and perinatal outcomes

Background: Despite over two decades of studies of mother-to-child transmission (MTCT) of HIV, very little data is available on HIV transmission in twin pregnancies in Africa.Objective: To determine transmission rates of the HIV virus between twins and the maternal and perinatal outcomes in HIV positive twin pregnancies.Methods: An audit involving 186 sets of twin pregnancies delivered at two hospitals in KwaZulu-Natal, South Africa was conducted over a one year period. Relevant data included maternal age, parity, obstetric history, foetal presentation, gestational age at delivery, Apgar scores, birth weight and pregnancy complications.Results: Of 9521 deliveries, 186 (1.95%) women were identified with a twin pregnancy; 80 (43%) of these mothers were HIV infected. One twin was HIV infected giving an incidence of 0.9%. The infected twin was the first-born twin (or twin 1) and was delivered by Caesarean delivery. Based on mode of delivery, there was no transmission for twin 1 or twin 2 via vaginal delivery,...

Patterns in longitudinal growth of refraction in Southern Chinese children: cluster and principal component analysis.

In the present study we attempt to use hypothesis-independent analysis in investigating the patterns in refraction growth in Chinese children, and to explore the possible risk factors affecting the different components of progression, as defined by Principal Component Analysis (PCA). A total of 637 first-born twins in Guangzhou Twin Eye Study with 6-year annual visits (baseline age 7–15 years) were available in the analysis. Cluster 1 to 3 were classified after a partitioning clustering, representing stable, slow and fast progressing groups of refraction respectively. Baseline age and refraction, paternal refraction, maternal refraction and proportion of two myopic parents showed significant differences across the three groups. Three major components of progression were extracted using PCA: “Average refraction”, “Acceleration” and the combination of “Myopia stabilization” and “Late onset of refraction progress”. In regression models, younger children with more severe myopia were associated with larger “Acceleration”. The risk factors of “Acceleration” included change of height and weight, near work, and parental myopia, while female gender, change of height and weight were associated with “Stabilization”, and increased outdoor time was related to “Late onset of refraction progress”. We therefore concluded that genetic and environmental risk factors have different impacts on patterns of refraction progression.

Fertility, Migration, and Maternal Wages: Evidence from Brazil

In this paper, I examine whether child rearing curbs women’s geographic mobility. Using first-born twins as an instrument for fertility, I find that, in Brazil, an additional child reduces the migration rate by 6 percent. The effect is stronger among women with younger children: a 20 percent reduction in the migration rate. Consistent with previous studies, fertility has a negative impact on women’s labor supply and wages. Finally, two-stage least squares estimates reveal that migrant women are more likely to work and earn more than nonmigrant women, suggesting that the migration-deterrent effects of fertility might be one of the explanations for the inverse fertility-income relationship.

Predictors and outcomes of low birth weight in Lusaka, Zambia

ObjectiveTo determine factors associated with low birth weight (LBW) in an urban Zambian cohort and investigate risk of adverse outcomes for LBW neonates. MethodsThe present retrospective cohort analysis used data recorded between February 2006 and December 2012 for singletons and first-born twins delivered in the public health system of Lusaka, Zambia. Routine clinical data and generalized estimating equations were used to examine covariates associated with LBW (<2500 g) and describe outcomes of LBW. ResultsIn total, 200 557 neonates were included, 21 125 (10.5%) of whom were LBW. Placental abruption, delivery before 37 weeks, and twin pregnancy were associated with LBW in multivariable analysis (P<0.01 for all). Compared with neonates weighing more than 2500 g, LBW neonates were at higher risk of stillbirth (adjusted odds ratio [AOR] 8.6, 95% confidence interval [CI] 6.5–11.5), low Apgar score (AOR 5.7, 95% CI 4.6–7.2), admission to the neonatal intensive care unit (AOR 5.4, 95% CI 3.5–8.3), and very early neonatal death (AOR 6.2, 95% CI 3.7–10.3). ConclusionLBW neonates are at increased risk of adverse outcomes, including stillbirth and neonatal death, independent of pregnancy duration at delivery and multiple pregnancy. These findings underscore the need for early, comprehensive, and high-quality prenatal care.

Hemoglobin Differences in Uncomplicated Monochorionic Twins in Relation to Birth Order and Mode of Delivery.

To determine the differences in hemoglobin (Hb) levels in the first 2 days after birth in uncomplicated monochorionic twins in relation to birth order and mode of delivery. All consecutive uncomplicated monochorionic pregnancies with two live-born twins delivered at our center were included in this retrospective study. We recorded Hb levels at birth and on day 2, and analyzed Hb levels in association with birth order, mode of delivery, and time interval between delivery of twin 1 and 2. A total of 290 monochorionic twin pairs were analyzed, including 171 (59%) twins delivered vaginally and 119 (41%) twins born by cesarean section (CS). In twins delivered vaginally, mean Hb levels at birth and on day 2 were significantly higher in second-born twins compared to first-born twins: 17.8 versus 16.1 g/dL and 18.0 versus 14.8 g/dL, respectively (p < .01). Polycythemia was detected more often in second-born twins (12%, 20/166) compared to first-born twins (1%, 2/166; p < .01). Hb differences within twin pairs delivered by CS were not statistically or clinically significant. We found no association between inter-twin delivery time intervals and Hb differences. Second-born twins after vaginal delivery have higher Hb levels and more often polycythemia than their co-twin, but not when born by CS.

Effect of breed and litter size on the display of maternal perinatal and offspring postnatal behavior in dairy sheep

Abstract A preliminary study was conducted to examine the effects of breed and litter size on the expression of ewes' maternal and lambs' neonatal behavior in 3 Greek dairy breeds. Animal observations were carried out on 7 Karagouniko (3 single- and 4 twin-bearing ewes), 7 Chios (4 single- and 3 twin-bearing ewes), and 7 Orini Epirus (4 single- and 3 twin-bearing ewes) multiparous ewes during 12 hours before and after parturition of each lamb. Overall, labor was not significantly different among the 3 breeds, although was shorter for first-born twin lambs compared to singletons ( P P P P P P = 0.120). The time standing during the first hour after birth was significantly higher in Karagouniko compared with Chios lambs ( P

Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project.

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.

The value of children: Inter-generational support, fertility, and human capital

This paper offers robust empirical evidence of a Darwinian pro-natalist mechanism: parents can improve their old-age support with an additional child. Using the incidence of first-born twins as an instrument for fertility outcomes, I find that Chinese senior parents with more children receive more financial transfers and are more likely to co-reside with an adult child. They are also less likely to work past retirement age. The estimated effects are large, despite the evidence that adult children from larger families are less educated and earn significantly less. Interestingly, the effect of an increase in the number of children on old-age support does not depend on the child's gender.

Perinatal mortality in second- vs firstborn twins: a matter of birth size or birth order?

Second-born twins on average weigh less than first-born twins and have been reported at an elevated risk of perinatal mortality. Whether the risk differences depend on their relative birth size is unknown. The present study aimed to evaluate the association of birth order with perinatal mortality by birth order-specific weight difference in twin pregnancies. In a retrospective cohort study of 258,800 twin pregnancies without reported congenital anomalies using the US matched multiple birth data 1995-2000 (the available largest multiple birth dataset), conditional logistic regression was applied to estimate the odds ratio (OR) of perinatal death adjusted for fetus-specific characteristics (sex, presentation, and birthweight for gestational age). Comparing second vs first twins, the risks of perinatal death were similar if they had similar birthweights (within 5%) and were increasingly higher if second twins weighed progressively less (adjusted ORs were 1.37, 1.90, and 3.94 if weighed 5.0-14.9%, 15.0-24.9%, and ≥25.0% less, respectively), and progressively lower if they weighed increasingly more (adjusted ORs were 0.67, 0.63, and 0.36 if weighed 5.0-14.9%, 15.0-24.9%, and ≥25.0% more, respectively) (all P < .001). The perinatal mortality rates were not significantly different in cesarean deliveries or preterm (<37 weeks) vaginal deliveries but were significantly higher in second twins in term vaginal deliveries (3.1 vs 1.8 per 1000; adjusted OR, 2.15; P < .001). Perinatal mortality risk differences in second vs first twins depend on their relative birth size. Vaginal delivery at term is associated with a substantially greater risk of perinatal mortality in second twins.

Acute peripartum twin–twin transfusion syndrome: Incidence, risk factors, placental characteristics and neonatal outcome

The aim of this study was to examine the incidence, placental characteristics and outcome in acute peripartum twin-twin transfusion syndrome (TTTS). All consecutive cases of monochorionic (MC) twins admitted to our center were included in the study. We excluded cases with chronic TTTS or twin anemia polycythemia sequence. Acute peripartum TTTS was defined when the inter-twin hemoglobin difference at birth was >8 g/dL. A total of 241 MC twin pregnancies were included in the study. Acute peripartum TTTS was detected in six cases (2.5%, 6/241). Vaginal delivery occurred more often in the acute peripartum TTTS group compared to the control group of uncomplicated MC pregnancies, 100% (6/6) versus 57% (135/235) (P = 0.002), respectively. Acute anemia was detected only in firstborn twins. Placental angioarchitecture in acute peripartum TTTS was similar to the placentas in the control group. The incidence of acute peripartum TTTS is low (2.5%). Birth order and mode of delivery appear to be associated with increased risk of acute peripartum TTTS.

Cesarean Section for the Second Twin: A Population‐Based Study of Occurrence and Outcome

Although management of twin deliveries has been a topic of discussion for decades, a consensus on how to deliver twins is lacking. The objective of this study was to examine short-term neonatal outcome of the second twin delivered by cesarean section after vaginal delivery of the first-born twin (combined delivery) and to identify predictors of combined delivery. This study was a 3-year, population-based, retrospective cohort investigation of 1,254 twin births in Denmark. The twin births were divided into three groups: vaginal deliveries, planned cesarean deliveries, and combined deliveries. Data were extracted from medical records, a fetal medicine software program (Astraia), and the National Birth Registry. Short-term poor neonatal outcome was measured as a 5-minute Apgar score ≤ 7, umbilical cord pH ≤ 7.10, and admission to neonatal intensive care unit for more than 3 days. Vertex-nonvertex fetal presentations were more prevalent in combined deliveries than vaginal deliveries (OR 4.4, 2.5-7.8). Nonvertex second twins born by combined delivery had a higher risk of Apgar score ≤ 7 and umbilical cord pH ≤ 7.10 compared with vaginal delivery, unadjusted OR 6.2 (2.1-18), and unadjusted OR 3.9 (1.6-9.5). Prenatal ultrasound scans were evaluated in combined deliveries, of which 48 percent were vertex-vertex at the last ultrasound scan in pregnancy (mean gestational age 34 + 0) and 37 percent were vertex-vertex at birth. Vertex-nonvertex presenting twins have an increased risk of combined delivery. Combined deliveries are associated with increased neonatal morbidity for the second twin.

Study of the substructure in nanometer copper thin films treated by laser shock processing

We study nanometer copper thin films prepared by magnetron sputtering and treated with laser shock processing (LSP). We observe the formation of firstborn twin crystals and some complete twin crystals in the copper thin films. After LSP, scanning electron microscope (SEM) images show obvious plastic deformation of the copper grain on the film surface, dramatically increased grain size, and the appearance of a large number of twin crystals. Moreover, the width of the crystals is a few dozen nanometers, and the cross angle is more than or close to 90o. Many vacancy defects appear during the sliding of atomic plane, which leads to a faulty structure; however, no obvious dislocation is observed. These substructures play a significant role in improving the mechanical performance of nanometer copper thin films.