Within the “Wrocław Longitudinal Twin Study” in a part of the material the liking level of singletons (SIN) to identical twins (TMZ) and of TMZ to SIN was analysed cross-sectionally, in the period of 11th to 18th year of life. In each of the 76 classes of elementary and high schools in Wrocław (Poland), including the investigated in 1976-7 TMZ (64 pairs), were evaluated the relations between school-mates, using the Korczak's five-degree scale of liking. The declared by TMZ and SIN liking decreased with age between pupils of the same sex, and increased between pupils of opposite sex, however, in TMZ with some delay. The liking declared by TMZ of both sexes to SIN was on average lower than that declared by SIN to TMZ. The degree of liking declared by SIN to TMZ of the same sex was average higher than in relation of SIN to SIN particularly among girls. Thus, there occurred the so-called “prima donna effect”. The liking declared to pupils of opposite sex in relation of SIN to TMZ was on average lower than the analogous one in relation of SIN to SIN and in relation TMZ to SIN even worse. The higher contrast in treating pupils of the same and opposite sex in TMZ than in SIN indicates a lower social maturity in TMZ. A diverse influence of socio-economic conditions on the declared toward then liking by boys and girls was found. The low number of separated twins did not allow to make a generalisation on specificity of their position in class. The sending of TMZ to different classes appeared to be in Wrocław elementary schools sporadic (1 repeater), and in high schools observed in 38%, from that 28% of twins went to equivalent classes, usually in different school, and in 10% of pairs one of the twins repeated the class.

This study was performed to examine the main characteristics of the French Romulus twin population: zygosity, chorionicity, sex, term and birthweight. A sample of 104 pairs of twins was distinguished by zygosity, chorionicity and sex, and divided into concordant and discordant birthweight groups. Fifty-three % (n = 55) of the fetus pairs studied were born at “ideal term” (35-38 weeks), and 25% (n = 26) were delivered at “preterm” (28-34 weeks). The very preterm (< 28 weeks), and “postterm” (> 38 weeks) represented altogether 22% (n = 23) of the sample. Of the 104 twin pairs, 68% (n = 71) differ by less than 15% in birthweight, and 32% (n = 33) have a birthweight difference higher than 15%. In dizygotic (DZ) pairs females had more tendency to be in the discordant group (p = 0.01) while in monochorionic-monozygotic (MC-MZ) pairs males were more discordant (p = 0.07). We found a significant interaction between sex and zygosity type (p = 0.02). Males had a birthweight difference significantly weaker than that of females in dichorionic-monozygotic (DC-MZ) and DZ twins whereas it was higher than that of females in MC-MZ twins. There were no MZ twin pairs with DC placentation over than 15% birthweight difference. Log linear analysis demonstrated a three-way interaction (p < 0.05) between term type, zygosity type and hypotrophy. Our data indicate that in the group of twins born between 35 and 38 weeks' gestation the crucial question still remains unsettled on how term and birhweight are related to zygotism and/or chorionicity.

We attempted to define parental anxiety in a population of parents of high-risk premature twins (mean birth weight 1.493 ± 227 kg; mean gestational age 33 ± 3.5 weeks), admitted to III level NICU. We specifically examined the following factors: gestational age of the twins, whether or not the twins had ventilatory support, pulmonary sequelae, major malformations or intra-ventricular hemorrhage, parental gender and highest level of education obtained by the parent. In the immediate pre-discharge period and a month later, a questionnaire (State-Trait Anxiety Inventory) was given to all parents of premature twins presenting for the discharge. The parents of 30 twins entered the study twice, at the discharge of their first twin (mean postnatal age 40 ± 32 days), and one month later. They included 15 mothers and 11 fathers, aged 33 ± 5.5 and 33 ± 4.2 years, and at the second evaluation 11 mothers and 10 fathers, respectively. As case-controls we examined parental anxiety of fifteen consecutive singleton high-risk prematures, with equal gestational age, discharged immediately after. Our results indicate that the parents of high-risk twin and singleton prematures present an elevated, lasting state-trait anxiety level. Pre- and post-discharge parental anxiety is more elevated (not significant) in twinning with respect to the prematurity alone. When assessed separately by parental gender, in both these groups an increased (not significant) anxiety was persistently found in the mothers. We recommend that, although neonatologists generally define the discharge of the high-risk premature based upon the acquired stabilization of vital parameters, they pay special attention to the twin group we have identified which is at increased risk for predischarge parental anxiety.

Twin reversed arterial perfusion (TRAP) syndrome is a rare but severe complication of monozygotic monochorionic twin pregnancies. The outcome is invariably fatal for the abnormal twins and for 50-75% of the normal co-twins. The prenatal diagnosis of the TRAP always has to be presumed in a multiple pregnancy within which a twin pair grows whenever cardiac activity can not be proved echographically. We present discuss – based upon literature research – pathogenic mechanisms, pathologic-anatomic, echographic diagnosis and management of these high-risk pregnancies.

Taking into consideration two facts: that the structure of social life forces twins to part and that the presented roles in a pair are not equal, (one of the twins plays the role of a leader (L) and the other, the subordinate (P.)), one can ask the question — what meaning does the moment of parting have and what are its consequences?

In order to do that, a survey was conducted, (a sample of 31 pairs of twins above the age of 30), in which every pair was asked the question: “Which one of you made the decision about parting?” The answer had two options: A – I, B – brother/sister. Out of 31 pairs of twins, 16 pairs chose the variant different from his brother or sister – that is A, B, admitting that the interpersonal conflict was the result of the parting. In 7 pairs, both twins chose the B variant – they withdrew from the conflict; and in 8 pairs they chose the A variant – looking for a compromise as the means of agreement.

When analyzing the results of the survey, we can state the following:

– in the relationship of twins, there is an interpersonal conflict;

– the decision about parting is difficult with prevalent feelings of sadness and sorrow;

– after parting, at least one of the twins has problems with preserving his identity and integrity of psychological space.

Since the moment of parting is necessary and difficult, specialists and mainly parents are required to consciously change their position towards the relationship of twins. It has to be the result of applied educational methods which aim at creating subjectivity and equality of each of the twins before the moment of parting.

The stillbirth rates decreased to 2/3 for MZ male twins, 1/2 for MZ female twins, and under 1/2 for DZ twins for both sexes during the 19-year period from 1975 in Japan. The stillbirth rate was significantly higher in MZ males than MZ females in each year, whereas stillbirth rates of DZ twins for both sexes indicated similar values during that period. After 1986, stillbirth rates were more than 2 times higher in MZ twins than in singletons and in DZ twins. The higher stillbirth rate of MZ twins as opposed to DZ twins could be related to monochorionic twin pairs in MZ twins. The stillbirth rate decreased more drastically in twins for both zygosities than in singleton births during the 34-year period from 1960. However, declining rates of stillbirths may be attributed to medical care during twin pregnancies. Recommendation of an optimum day to give birth for twin pregnancy is 37-38 weeks for Japanese women.

The aim of this preliminary study was the estimation of renal blood flow in 16 premature newborns from twin pregnancies with mean body weight 1270 g and mean gestational age 29 weeks.

In control group we have 16 singleton newborns with mean gestational age 29 weeks and mean birth weight 1240 g. In both intervention and control group we have the similar clinical symptoms. The renal blood flow was carried out in the first day of life with the Acuson 128 XP Colour Doppler using the 6 and 7 MHz linear transducer. The renal blood flow parameters-PI, RI, Vmax, Vmin Vmean were measured in right and left renal arteries in theirs courses from the aorta to the renal hilus, by color sinal. In the investigation group the mean value of RI in right and left renal artery was 0,88. Mean PI in right vessel was 1,67 and in left 1,56. Mean V min in right and in left artery was 0,03 and mean V max in right artery was 0,34 and in left 0,33. Mean value of mean velocity in right vessels was 0,18 and in left 0,19.

In control group we observed in right artery mean value of PI 1,74 and in left 1,6. Mean RI was 0,86 and 0,86 in right vessel in left vessel. Mean V min was 0,05 in right and 0,04 in left artery. Mean V max was 0,37 in right and 0,34 in left artery. Mean value of V mean was 0,19 in right artery and 0,18 in left artery.

Using the student, Mann-Whitney and Shapiro-Wilk tests we have not observed statistically significant difference of Doppler parameters between control and investigation group and between the left and right artery. Although in newborns with broad PDA we noted significant higher value of RI (0,97, 0,98) than in newborns without PDA (0,78, 0,81).

The cerebral central sulci, seat of the sensorimotor cortex, vary anatomically in form, length and depth among individuals and present a left/right asymmetry. The purpose of this work was to measure central sulcus's lengths, at the surface and in-depth, in each hemisphere of monozygotic twins in order to evaluate the influence of environmental factors on the morphometry and asymmetry of this structure. A measurement technique on MR images of the brains using 3 D software was developed. Two operators applied this technique to measure central sulcus lengths at the surface of the brain and in-depth in each hemisphere. Besides the fact that the technique developed gave high Intraclass Correlation Coefficients (ICC) for the surface lengths (mean value 0.94), and slightly less high for the in-depth length (mean value 0.87), we found a weak (from 0.57 to 0.73 for raw data) but significant ICC between homologous sulci in pairs of twins. In addition, the ICC for asymmetry indices were not significant. Hence, if central sulcus morphometry is in part genetically influenced, these results show that nongenetic factors are nonetheless important in their development.

Race, sex, nutritional status and cultural factors affect craniofacial morphogenesis. Out of these, sex is a major factor in craniofacial differentiation, because it can be stronger in one ethnic group and weaker in another. In this study, sex differences in genetic variance and heritability of 13 craniofacial traits are investigated. The study is based on a sample of 45 MZ and 101 DZ twin pairs and their 125 singleton siblings, 104 fathers and 103 mothers in 146 families drawn from an urban population of Chandigarh. Results of t'-tests for equality of the means reveal association of zygosity with the mean value of bigonial diameter in female twins and for none in males. Heterogeneity of variance is observed in about 50% traits in females as compared to 15% in males. This invalidates conventional within-pair genetic variance estimates for these traits. The revised genetic variance ratios are higher on an average in males than in females. However, there is greater MZ environmental covariance in male twins than their female counterparts. Family data indicate higher maternal effect for ear height, nasal height and frontal breadth, while greater paternal effect is seen in cranial traits. Sex-wise midparent-child regression coefficients show greater heritability in daughters for nasal traits and bigonial breadth, while sons show higher genetic component for head size measures.

Type 1 diabetes mellitus (IDDM) results from a chronic process of autoimmune destruction of ß cells of the Langerhans islets. The presence of autoantibodies (ICA, GADA, anti-IA2, IAA) in serum preceds the clinical onset of the disease. Genetic predisposition for IDDM is connected with HLA, CTLA-4 and insulin gene region.

The aim of the study was the genetic and immunological analysis of a triplet. One of them developed Type 1 diabetes mellitus. We analysed HLA class II, CTLA-4 and insulin gene polymorphisms in the whole family. Besides, we investigated immunological status of three brothers.

All patients present identical genotype for VNTR loci: D1S80, D17S5 and Apo B, as well as for HLA-DRB1, — DQA1, — DQB1, CTLA-4 gene and all studied insulin gene polymorphisms. That proves their monozigosity. The triplet presents strong genetic predisposition for IDDM. The two patients without overt diabetes have increased levels of ICA, GADA, IA2 and IAA.

Secular changes in twinning and triplet rates were analyzed using vital statistics in Austria, the Czech Republic, the Slovak Republic, England and Wales, Germany, the Netherlands, Switzerland, Denmark, Finland, Norway, Sweden, Canada, Australia, Hong Kong, Israel, Japan, and Singapore during the period from 1972 to 1996. Among those 17 countries, the twinning and triplet rates in the Czech Republic and in the Slovak Republic remained constant from 1972 to 1994, whereas these rates increased significantly year by year in the other 15 countries during the examined period in each country. Twinning rates increased from 1.2-fold in Austria to 2-fold in Denmark from 1972 to 1996. As for triplets, the rate increased from 3-fold in Denmark to 9-fold in Norway during that period. With one exception, that being the Slovak Republic, the triplet rate was highest in the Scandinavian countries, followed by the other European and Asian countries. The rising twinning and triplet rates have been attributed to the higher proportion of mothers treated with ovulation-inducing hormones and partially attributed to IVF.

OBJECTIVE. The purpose of this study was to evaluate the relationship between the yolk sacs separated or not separated by septum and chorionicity twin pregnancies scanned early in the first trimester, and the relation between size and morphologic features of the yolk sac and the outcome of twin pregnancies.

RESULTS. In all 38 sets of twins two yolk sacs were identified. During the first trimester of a dichorionic twin pregnancy, the yolk sacs were always separated by a septum and not separated (“Eight” sign) in monochorionic twin pregnancy. In five cases, one of yolk sac was abnormally large (> 8mm) and had thin wall. Four of the five mothers spontaneously aborted during the next 2-3 weeks. In one case of monochorionic twin ectopic pregnancy two yolk sacs were seen normally.

CONCLUSION. The sonographic identification of yolk sacs in multiple pregnancies allows an early and efficient recognition of presence and chorionicity of twin pregnancy, both in intra – and extrauterine. Identification of abnormal yolk sac or yolk sacs suggests death of one or all embryos.

It is generally held that there are genetic factors for dizygotic (DZ) twinning, but the pattern of inheritance is far from clear.

We report on a rare pedigree with three sets of spontaneous DZ female twin births in three successive generations. To our knowledge no similar pedigrees have been reported in literature.

Zygosity determination in three pairs of twins was performed with ABO, MN and Rh blood groups from erythrocytes and with STR analysys from samples of saliva.

In our pedigree, the direct trasmission of the DZ twinning through the maternal line seems show an autosomal dominant pattern of inheritance. We believe that the inheritance of DZ twinning appears to be recessive in most case and autosomal dominant only in rare instances. It is plausible with the hypothesis that the expression of the dizygotic twinning trait in a mother shows a genetic heterogeneity.

Blood and saliva samples of 122 like-sexed twin pairs (65 MZ and 57 DZ) living in Chandigarh (India) were analyzed for ABH polymorphism. The results indicated that ABH secretions were independent of ABO blood groups though there was an indication of higher incidence of non-secretors among ‘O’ blood group twin individuals. No significant differences were observed between twins and singletons in secretor gene frequency estimates. The quantitative data revealed that mean titre scores for H substances were lower than that for A and B substances. F test contrasting intra-pair variance between zygosities for ABH quantitative secretions was highly significant indicating stronger genetic component of variation. The results suggested that quantitative assay of ABH secretions would be a better indicator for zygosity determination than mere qualitative differentiation.

The objective of this study was to answer the question whether there is the relation between the uterine capacity, estimated by the total birth weight of fetuses, and the duration of twin gestation. The material for researches contains data received from the books of births and case records concerning the pregnant who gave births to twins in the Institute of Obstetrics and Gynecology of the Medical University in Lódź between 1970-1998. The final analysis concerned only gestations lasting more than 29 weeks, without any complications (excluding prematurity and the growth-discordant twins), and when gestational age was exactly known. The selected group was finally composed of 188 pairs of twins. The analyses considered relations between total birth weight of twins, the sex of newborn babies, parity, and the duration of gestation. The duration of the analyzed twin pregnancies was 35,6 weeks, including primiparous with 35,8 weeks, and multiparous – 35,1 weeks. In the group of male-male twin pairs the average duration of pregnancy was 35,7 weeks, in unlike-sexed pairs – 35,6 weeks, and in female-female pairs – 35,5. In the group of the primiparous having male-male twin pairs the average duration of pregnancy was 35,1 weeks, unlike-sexed pairs – 36,4 weeks and female female pairs – 36,6 weeks, while in the group of multiparous relatively: 36,4, 35,4, 35,0 weeks. The total birth weight of the specific pairs of twins was from 2270 g to 6900g (average 4794g), while in 92% <5500g. In the primiparous group it was 4908,1 g. and in the multiparous group – 4663,1 g. Analyzing the total twins' weight according to the fetal gender and parity it was found that in primiparous with male-male twins - 4715,3, unlike-sexed – 5271,6 and female-female – 4967,5, whereas in multiparous relatively: 4961,5, 4692,6, 4414,0. The shortening of twin pregnancies was caused by the following factors: total body mass achieved by fetuses was > 5500 g, presence of male sex in twin pregnancies (only in primiparous), and also the multiparity.

A case of de novo mosaic partial trisomy of chromosome 5 (q33-q ter) in a stillborn male fetus with bilateral polycystic kidneys, and atrial septal defect, is reported. Fetal cord blood sampling was carried out at 25 weeks of gestation because of bilateral polycystic kidneys with severe oligohydramnios observed on ultrasound examination of the fetus. The family history was notable for the presence of similar phenotypic abnormality in the mother and sibling. However, no chromosomal abnormality was detected in other family members. Significance of this rare chromosomal abnormality and its association with congenital malformations in the fetus and in the family is being discussed.

A case of monoamniotic monochorionic (MAMC) female twins, with one twin being anencephalic, and the co-twin being normal, is reported. Twin to twin transfusion syndrome was also noted. The reasons for anencephaly in association with monozygotic (MZ) twinning are discussed. The management of such a case is presented.

The aims of the study were as follows: 1. to evaluate the effectiveness of current program to promote breast-feeding in our population of infants from multiple pregnancy; 2. to define factors responsible for failure in early breast-feeding establishing and /or maintaining breastfeed during the hospitalization of the babies in neonatal department. 122 newborn infants (2 sets of triplets and 58 twin pairs) born in the Clinic for Pathology of Pregnancy and Labor in Szczecin, Poland, in the years 1995 (January) – 1999 (May) from multiple pregnancy were included in the study. In the examined material there were estimated neonatal conditions at birth, neonatal complications, which may disturb successful breast-feeding as well as other factors contributing to early breast-feeding, the way of feeding the babies during neonatal period and the mean time of starting breast-feeding. It was found that most of the examined babies were born with the features of prematurity: mean gestational age was 35,6 ± 2,2 weeks and mean birthweight – 2225,3 ± 193,2 grams. Only 57,4% of babies were born in good conditions according to Apgar scores. Factors which influence in a negative way early breast-feeding were as follows: respiratory disturbance (22,1%), temporary oral nutrition intolerance due to sickness of the baby or early onset of infections (27,5%), operative delivery (62,3%), medicine taken by mothers (13,9%) and failure in maternal lactation (8,2%). Factors disturbing a normal course of breast-feeding were: fototherapy due to hyperbilirubinemia (20,5%) and late onset of infections (1,6%). In most cases breast-feeding was started 3-4 days after birth and the most frequent way of feeding was formula followed or in combination with maternal milk (at discharge in 86,9% of babies).

We concluded that exclusive breast-feeding, despite program of promotion, is a rarity in population of newborn babies born from multiple pregnancy; time to start breast-feeding in this population is usually 3-4 days after delivery. Most pre-term and full-term twins are discharged from neonatal department on maternal milk – exclusively or in combination with formula in situation of scarce maternal milk for two or more infants – what should be considered as our professional success.