The question addressed in the present report is whether the large birth weight differences in dizygotic twin pairs of opposite sex (DZos), especially in 'male first' couples--observed by Blickstein and Weissman (Blickstein I, Weissman A. Birth weight discordancy in male-first and female-first pairs of unlike-sexed twins. Am J Obstet Gynecol 1990;162:661-663) and replicated in the present study-...

Evidence of a positive association between birthweight and IQ has been established in several studies. Analyses of within twin pair differences in birthweight and IQ have been used to shed light on the basis of the association. The strength of this approach is the possibility of controlling for both unmeasured common childhood-environmental factors as well as genetic factors shared by the co-tw...

In order to evaluate the influence of the time interval on the second twin in twin deliveries, we have used more precise criteria than have been used in the literature to date. In the period from July 1, 1970 to December 31, 1974, 35 twin deliveries in our hospital were analyzed, in which both twins fulfilled the following criteria: 1. vertex presentation 2. vaginal deliveries 3. birth weight a...

STUDY QUESTION Does the intergenerational influence on birthweight and birth length remain within female dizygotic and monozygotic twin pairs? SUMMARY ANSWER The intergenerational influence on birthweight and birth length remained within dizygotic but not within monozygotic twin pairs. WHAT IS KNOWN ALREADY Low birthweight is associated with increased morbidity and mortality in both the sho...

Twin pregnancies are becoming common as a result of increased assisted reproduction. Studies have shown that the smaller twin of a pair is at greater risk of morbidity and mortality. Our aim was to determine if there is a relation between birth-weight discordancy and neonatal morbidity and mortality and to test the occurrence of respiratory distress syndrome (RDS) in discordant twins. For 5 yea...

AIM To assess the relative effect of birth weight and gestational age on retinopathy of prematurity (ROP) using preterm twin pairs discordant for birth weigh in a tertiary neonatal intensive care unit in China. METHODS Fifty-six discordant twin pairs of 112 preterm infants were retrospectively analyzed. The twin pairs were divided into two subgroups based on birth weight in each pair. The occ...

The study of discordant monozygotic twins may identify important developmental risk factors for adult psychiatric disorder. Differential experience in utero is one candidate environmental risk factor that may distinguish monozygotic twins. In this report, we examine whether intra-pair differences in birth weight predicts discordance for adult psychiatric disorders in 527 female monozygotic twin...

In Multipregnancies, The careful control of Number of follicles in stimulation cycles and Number of embryos transferred in ART cycles is so important. Just twin pregnancies are reason for racial death (12- 15%). The risk for CP in twin pregnancies is 8 times more and for Triple is 47 times more than simple ones.Approximately all prenatal problems increase in multiple pregnancies and therefore t...

OBJECTIVES We aimed to determine the accuracy of sonographic formulas for estimating birth weight in twin pregnancies. METHODS We conducted a retrospective cohort study of consecutive twin pregnancies undergoing sonography at within 1 week of delivery. Pregnancies were included if biometric measurements and birth weight were available and excluded if anomalies were present. Estimated fetal we...

lamb survival is one of the major factors affecting overall sheep productivity. lamb survival affected by environmental effect such as management, birth-type, year, season of birth, dam-age, maternal behavior, genotype of parents, and birth-weight. the data comprised 9989 records were collected from 1989 to 2009 in iranian baluchi sheep at abbasabad sheep breeding station. four binary traits cr...