Objectives: The performance of noninvasive prenatal screening (NIPS) for fetal aneuploidy in twin pregnancies is dependent on the amount of placentally derived cell-free DNA, the "fetal fraction (FF)," present in maternal plasma. We report FF values in monozygotic (MZ) and dizygotic (DZ) pregnancies.
Methods: We reviewed FF in pregnancies at 10 to 20 completed weeks gestational age based on single-nucleotide polymorphism (SNP)-based NIPS where zygosity was routinely established in twin pregnancies. The cohort included 121 446 (96.3%) singleton, 1454 (1.2%) MZ, and 3161 (2.5%) DZ pregnancies. For DZ twins, individual FFs were measured.
Results: Combined FF for DZ and MZ fetuses were 35% and 26% greater than singletons, respectively. The individual FF contributions from each fetus in DZ twins were, on average, 32% less than singletons. FF in DZ twin pairs were moderately correlated (Pearson correlation coefficient.66). When a threshold of 2.8% FF was applied to define uninterpretable results, 1.7% (2102/121 446) of singletons, 0.8% (11/1454) of MZ pairs, and 5.6% (178/3161) of DZ pairs were uninterpretable.
Conclusion: For optimal aneuploidy NIPS in twin pregnancies, zygosity should be established and in DZ twins FF for both fetuses should be determined to identify those cases where results can be reliably interpreted.
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http://dx.doi.org/10.1002/pd.5609 | DOI Listing |
Prenat Diagn
January 2025
Department of Preventive Medicine, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.
Introduction: Fetoscopic laser surgery (FLS) is the gold standard treatment for monochorionic (MC) twin pregnancies complicated by twin-twin transfusion syndrome (TTTS). The aim of our study was to evaluate the rate and risk factors for cord entanglement in the presence of iatrogenic monoamnioticity (iMA), a consequence of inadvertent septostomy during FLS.
Methods: This is a retrospective analysis of two consecutive cohorts of FLS performed either using the selective technique from January 2004 to January 2012, or with the Solomon technique, from that date onwards.
J Nutr Biochem
January 2025
Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University.; Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Sichuan 610041, China.. Electronic address:
Zinc is an essential trace element. The regulatory mechanism of zinc and its transporters in fetal growth in monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (MCDA-sIUGR) is unclear. A total of 45 MCDA twins were divided into two groups, MCDA (n=37) and MCDA-sIUGR (n=8), to investigate their possible effects on fetal growth.
View Article and Find Full Text PDFMidwifery
January 2025
School of Health, Education, Policing and Sciences, University of Staffordshire, UK.
Problem: Tongue tie is an added complication when breastfeeding, but little is known about the role tongue tie might play when breastfeeding twins.
Background: Twins are much less likely to be breastfed than singleton babies due to added complications regarding pregnancy, birth and ongoing care. Tongue tie can cause breastfeeding barriers including poor latch, inefficient milk transfer and nipple pain.
Anim Reprod Sci
January 2025
Agrotecnio Center, Department of Animal Sciences, University of Lleida, Lleida 25198, Spain.
The objectives of this study were: (i) to evaluate the associations between postpartum health disorders, relative increase in walking activity (RIWA) and expression of behavioral estrus intensity captured by pedometers; (ii) to assess associations between RIWA and pregnancy in cows submitted to timed artificial insemination (TAI). Lactating dairy cows (n = 881) were enrolled in the study. Cows were submitted to a 5d TAI protocol with insertion of a progesterone device.
View Article and Find Full Text PDFHum Reprod
January 2025
Next Fertility GynePro, Bologna, Italy.
In recent years, the transfer of more than one embryo has become less frequent to diminish multiple pregnancies. Even so, there is still a risk of one embryo splitting into two or even three. This report presents the case of a triamniotic monochorionic gestation in a 35-year-old woman, obtained after the transfer of a single day 5 embryo that had been previously hatched with a laser and subsequently transferred in a fresh IVF cycle.
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