Placentation in Multiple Births

Effect of Parity on Placental Histopathology Features in Singleton Live Births Following IVF

The aim of this study was to evaluate the effect of parity (primipara vs multipara) on the histopathology of the placenta in singleton live births following in vitro fertilization. We conducted a retrospective cohort study evaluating data of all IVF resulted live births from one university affiliated hospital during 2009-2017. All patients had the placenta sent for pathological evaluation. Exclusion criteria were history of miscarriage or elective termination of pregnancy, abnormal uterine cavity findings, previous uterine surgery, in vitro maturation cycles, gestational carrier cycles, oocyte recipient cycles, preimplantation genetic diagnosis cycles, and multiple pregnancies. The outcomes measured included anatomical, inflammation, vascular malperfusion, and villous maturation placental features. A multivariate analysis was conducted to adjust the results for factors potentially associated with placental pathology features. A total of 395 live births were included in the final analysis and were allocated to the study groups according to parity: primipara (n = 273) and multipara (n = 122). After adjustment for potential confounding factors, multiparity was found to be significantly associated with delayed villous maturation (OR 4.9; 95% CI 1.2-19.8) and primiparity was significantly associated with maternal vascular malperfusion (OR 0.6; 95% CI 0.3-0.8). We showed that parity has an impact on placental histopathological changes which in turn may affect perinatal outcome.

Twin-to-Twin Transfusion Syndrome: Definition, Staging, and Ultrasound Assessment

Objective: The purpose of this article is to review the definition of twin-to-twin transfusion syndrome (TTTS) and the sonographic diagnostic assessment of these cases prior to therapy.

Materials and Methods: The article addresses the terminology used to refer to the condition and describes the systematic ultrasound assessment of the condition, including the ultrasound diagnosis, the staging of the disease, cervical assessment and pre-operative mapping.

Results: From an etymologic and medical point of view, the term ‘fetofetal transfusion’ is more appropriate than ‘TTTS’. However, as the latter, and its attendant acronym TTTS, have been widely adopted in the English language, it is impractical to change at this point. TTTS is defined sonographically in the combined presence of a maximum vertical pocket (MVP) of 8 cm or greater in one sac and 2 cm or less in the other sac, regardless of the gestational age at diagnosis. Staging of the condition using the Quintero staging system is practical, reproducible, and accepted. Transvaginal cervical length assessment should be an integral part of the ultrasound evaluation. Pre-operative mapping to anticipate the location of the placental vascular anastomoses and avoid injuring the dividing membrane is also discussed.

Conclusions: The term ‘TTTS’ can continue to be used in the English medical literature. The condition can be diagnosed and assessed following a systematic ultrasound methodology. The use of such ultrasound methodology breaks the examination into a distinct set of components, assuring a comprehensive examination and proper communication among caregivers.

The Personalities of Twins: Just Ordinary Folks

Twin studies have demonstrated that personality traits show moderate genetic influence. The conclusions drawn from twin studies rely on the assumptions that twins are representative of the population at large and that monozygotic and dizygotic twins are comparable in every way that might have bearing on the traits being studied. To evaluate these assumptions, we used Multidimensional Personality Questionnaire (MPQ) data from three samples drawn from the Minnesota Twin Registry (totaling 12,971 respondents) to examine the effect sizes associated with mean differences on the 11 MPQ scales and 3 higher-order MPQ factors for singletons versus twins and MZ twins versus DZ twins. The singletons in the samples were family members of the participating twins. We also used ratios of scale variances to examine the significance of variance differences. The only mean or variance difference replicated across all three samples was greater Social Closeness (about .1 standard deviation) for twins than for singletons. This difference was obtained for both males and females. It would appear that, with respect to personality, twins are not systematically different from other people. Our results also highlight the importance of replication in psychological research because each of our large samples showed differences not replicated in other samples.

Estimation of the stillbirth rate in twin pairs according to zygosity

It is common opinion that the stillbirth rate is higher among monozygotic (MZ) than among dizygotic (DZ) twins. This is supported by the fact that stillbirth rates are higher among same-sexed than among opposite-sexed twins, and the relatively high stillbirth rates among twins of young mothers. In this study we present a method to estimate the stillbirth rates for MZ and DZ twins and identify the difference. We performed analyses based on the assumptions of (a) Weinberg's differential rule, including the assumption that the secondary sex ratio is 100, (b) the stillbirth rates among opposite-sexed twins hold for all DZ twins, and (c) the stillbirth rates estimated for MZ and DZ male and female twins yield for both sexes the observed total number of stillborn twins. Our methods are applied to data from Sweden, 1869-1967, the Aland Islands, 1750-1949, Saxony, 1881-1900, and England and Wales, 1996-2003. We observed that the ratio between the estimated stillbirth rates among MZ and DZ twins were on average 1.75, and the ratio among same-sexed and DZ (opposite-sexed) twins were on average 1.31. For Sweden and Saxony similar values were obtained, but for England and Wales the values were higher and for Aland lower. With exception of Aland, the estimated stillbirth rates were in all populations the lowest for DZ, medium for same-sexed and highest for MZ twins.

Pattern of twin placentation in Ghana

A 2-year study involving macroscopic examination of twin placentae was conducted at the Korle Bu Teaching Hospital in Accra, Ghana to determine the proportions of the various types of twin placentation, cord insertions and number of cord vessels and their relationships. Of 765 twin-pair placentae examined, 398 (52%, 95% confidence interval [CI] 48.4%–55.6%) had fused dichorionic, 247 (32.3%, 95% CI 29.0%–35.7%) had separate dichorionic, and 119 (15.6%, 95% CI 13.1%–18.4%) had monochorionic diamniotic placentae; only one (0.1%, 95% CI 0.0%–0.8%) had monochorionic monoamniotic placentation. Of 1529 cords whose insertion could be determined, 1285 (84%) had disc, 172 (11.2%) marginal and 72 (4.7%) velamentous insertions. Only 10 (0.65%) cords had two vessels (i.e., single umbilical artery). Abnormal cord insertions (marginal and velamentous) were significantly more likely to occur in monochorionic than in dichorionic placentation (odds ratio [OR] 3.56, 95% CI 2.62–4.84), and in two-vessel than in three-vessel cords (OR 5.79, 95% CI 1.44–24.5). The prevalence of two-vessel cord in monochorionic was not significantly different from that in dichorionic placentation (OR = 0.60, 95% CI 0.10–2.67). Zygosity could be determined in 53.3% of twins from placental examination and babies' sex-pair combinations. In conclusion the most common twin placentation in Ghana is fused dichorionic. Abnormal cord insertion is more common in monochorionic than dichorionic placentation. Monoamniotic twins and single umbilical artery are less common than have been reported in other centers. Modern methods of DNA analysis are needed to establish zygosity in almost half of twin pairs.

High frequency of iatrogenic monozygotic twins with administration of clomiphene citrate and a change in chorionicity

The data of the population-based, prospective survey of multiple births in East Flanders, Belgium, show that a greater proportion of monozygotic twins is observed with clomiphene citrate as sole treatment compared with other ovulatory drugs. Among iatrogenic monozygotic twins, the ratio of monochorionic versus dichorionic pairs is higher compared with spontaneous twins.

Antenatal Detection of Arterio-Arterial Anastomoses by Doppler Placental Assessment in Monochorionic Twin Pregnancies

OBJECTIVES

To evaluate the reproducibility of Doppler antenatal detection of arterio-arterial anastomoses (AAA) in monochorionic (MC) twin pregnancies.

METHODS

Between October 2002 and February 2004, 21 MC diamniotic twin pregnancies and one dichorionic triamniotic triplet seen at the Twin Clinic at the University of Brescia were recruited. After routine ultrasonographic assessment, AAA were searched using Color or Power and spectral Doppler. The presence of AAA was confirmed postnatally by placental injection studies.

RESULTS

Data of 19 patients were available for the analysis. AAA were detected in 12 cases (63%) antenatally and in 16 (84.2%) at injection study. Sensitivity and specificity of Doppler for detecting AAA were 75 and 100%, respectively. Detection rates increased at advanced gestations and with anterior/fundal placentae. The incidence of twin-twin transfusion syndrome was higher in the group with no AAA detected in vivo compared to the group with AAA found with Doppler (28.5 vs. 16.6%), but the difference was not statistically significant (p = 0.5).

CONCLUSION

This study confirmed the feasibility of AAA Doppler detection in vivo in MC pregnancies.

Genetic and environmental influences on human psychological differences

Psychological researchers typically distinguish five major domains of individual differences in human behavior: cognitive abilities, personality, social attitudes, psychological interests, and psychopathology (Lubinski, 2000). In this article we: discuss a number of methodological errors commonly found in research on human individual differences; introduce a broad framework for interpreting findings from contemporary behavioral genetic studies; briefly outline the basic quantitative methods used in human behavioral genetic research; review the major criticisms of behavior genetic designs, with particular emphasis on the twin and adoption methods; describe the major or dominant theoretical scheme in each domain; and review behavioral genetic findings in all five domains. We conclude that there is now strong evidence that virtually all individual psychological differences, when reliably measured, are moderately to substantially heritable.