Prospective Risk of Intrauterine Death of Monochorionic-Diamniotic Twins

OBJECTIVE: The purpose of this study was to calculate the prospective risk of fetal death in monochorionic-diamniotic twins. STUDY DESIGN: We evaluated 193 monochorionic diamniotic twin pregnancies that were followed and delivered after 24 weeks. Surveillance included cardiotocography and sonography performed at least once weekly. The prospective risk of fetal death was calculated as the total number of deaths at the beginning of the gestational period divided by the number of continuing pregnancies at or beyond that period. RESULTS: The fetal death rate was 5 of 193 pregnancies (2.6%; 95% CI, 1.1, 5.9); the prospective risk of stillbirth per pregnancy after 32 weeks of gestation was 1.2% (95% CI, 0.3% - 4.2%). CONCLUSION: Under intensive surveillance, the prospective risk of fetal death in monochorionic-diamniotic pregnancies after 32 weeks of gestation is much lower than reported and does not support a policy of elective preterm delivery

Puerperal Complications Following Elective Cesarean Sections for Twin Pregnancies

OBJECTIVE: To estimate the maternal puerperal morbidity in elective and emergent cesareans in twins. STUDY DESIGN: We evaluated postpartum complications among patients who underwent elective cesarean birth for twin pregnancy. This group was compared to matched singletons and to emergent cesareans in twins. RESULTS: During the period September 1994-March 2006 there were 299 (47.4%) elective and 80 (12.7%) emergent cesarean sections in twin pregnancies, for a total of 379 (60.1%) cesarean births for both twins. Controls included 299 cases of elective cesareans in singletons. The comparison between elective and emergent cesareans and between elective cesareans in twins and in singletons found no significant differences in postpartum fever, scar infection, and postpartum hemorrhage. Venous thromboembolism occurred in two twin pregnancies, one in the elective and one in the emergent cesarean group. Postpartum hysterectomy was required in a singleton pregnancy following an elective cesarean birth. CONCLUSION: At present, no data exist to show a disadvantage for a planned cesarean birth for twins.info:eu-repo/semantics/publishedVersio

Perinatal Outcome and Change in Body Mass Index in Mothers of Dichorionic Twins: a Longitudinal Cohort Study

We used a prospective cohort to analyze the effect of change in BMI rather than change in weight, in mothers carrying dichorionic twins from a population that did not receive any dietary intervention. A total of 269 mothers (150 nulliparas and 119 multiparas) were evaluated. The average change (%) from the pre-gravid BMI was 7.2+/-6.1, 17.4+/-8.2, and 28.7+/-10.8, at 12-14, 22-25, and 30-34 weeks, respectively, without difference between nulliparas and multiparas. The comparison between maternities below or above the average change from the pregravid BMI failed to demonstrate an advantage (in terms of total twin birthweight and gestational age) of an above average change from the pregravid BMI, even when the lower versus upper quartiles were compared. Our observations reached different conclusions regarding the recommended universal dietary intervention in twin gestations. A cautious approach is advocated towards seemingly harmless excess weight gain, as normal weight women may turn overweight, or even obese, by the end of pregnancy, and be exposed to the untoward effects of obesity on future health and body image

Birth weight in a large series of triplets

Background: Triplets are often born premature and with a low birth weight. Because the incidence of triplet births is rare, there are relatively few studies describing triplet birth weight characteristics. Earlier studies are often characterized by small sample sizes and lack information on important background variables such as zygosity. The objective of this study is to examine factors associated with birth weight in a large, population-based sample of triplets registered with the Netherlands Twin Register (NTR).Methods: In a sample of 1230 triplets from 410 families, the effects of assisted reproductive techniques, zygosity, birth order, gestational age, sex, maternal smoking and alcohol consumption during pregnancy on birth weight were assessed. The resemblance among triplets for birth weight was estimated as a function of zygosity. Birth weight discordance within families was studied by the pair-wise difference between triplets, expressed as a percentage of the birth weight of the heaviest child. We compare data from triplets registered with the NTR with data from population records, which include live births, stillbirths and children that have deceased within days after birth.Results: There was no effect of assisted reproductive techniques on triplet birth weight. At gestational age 24 to 40 weeks triplets gained on average 130 grams per week; boys weighed 110 grams more than girls and triplets of smoking mothers weighted 104 grams less than children of non-smoking mothers. Monozygotic triplets had lower birth weights than di- and trizygotic triplets and birth weight discordance was smaller in monozygotic triplets than in di- and trizygotic triplets. The correlation in birth weight among monozygotic and dizygotic triplets was 0.42 and 0.32, respectively. In nearly two-thirds of the families, the heaviest and the lightest triplet had a birth weight discordance over 15%. The NTR sample is representative for the Dutch triplet population that is still alive 28 days after birth.Conclusion: Birth weight is an important determinant of childhood development. Triplet status, gestational age, sex, zygosity and maternal smoking affect birth weight. The combined effects amount to a difference of 364 grams between monozygotic girl triplets of smoking mothers compared to dizygotic boy triplets of non-smoking mothers of the same gestational age. Birth weight in triplets is also influenced by genetic factors, as indicated by a larger correlation in monozygotic than in di- and trizygotic triplets

Предварительные результаты датирования нижнепалеолитических стоянок Украины (Меджибож 1 и Меджибож А, Хмельницкая область) методом электронного спинового резонанса

In the West of Ukraine, the Medzhibozh site complex includes two multi-layered open-air Lower Paleolithic sites sitting at 49°35′ N 27°42′ E, 270 m amsl. In Medzhibozh I’s lower alluvial cycle, Layer 16a yielded Paleolithic artefacts, mainly choppers, chopping tools, and flakes with little secondary modification, associated with likely fireplaces and bones with cutmarks left by early hominids inhabiting an ancient shoreline. Ursus deningeri, Stephanorhinus kirchbergensis, and other Middle Pleistocene fossils, as well as microtheriofauna, pollen, paleopedology data suggest that Layers 13—16 must predate 200 ka, but only one TL date has been done here.  About 500 m away from Medzhibozh I, Medzhibozh A’s six archaeological layers were intercalated with sterile gravels, with analogous stone products, fauna, hearth relics .  Since ESR can date mammalian enamel up to 2—4 Ma with 2—5 % precision, three cervid teeth from Layer 16a at Medzhibozh I and one from the Layer 1 in Medzhibozh A were dated by standard and isochron ESR. Sediment samples were analyzed by NAA to measure volumetrically averaged sedimentary dose rates. Using geological criteria, a ramped box model calculated time-averaged cosmic dose rates were determined. From Medzhibozh A, AT29’s standard LU age of 379±27 ka agreed best with ages estimated from the faunal analyses, but the isochron showed diffusional secondary U uptake, suggesting the age could be older. At Medzhibozh I, all teeth had >100 ppm U in their dentine, but enamel U ranged from 2,8 to 11,8 ppm. AT41’s isochron, which did not show secondary U uptake, suggested that the U uptake rate, p~4 was the best uptake rate, yielding an age of 373±17 ka, which correlates with late Marine Isotope Stage (MIS) 11. Meanwhile, AT44’s age likely dates at 399±11 ka with p=4, and AT45’s at 396±13 ka with p=6, both of which correlate with mid MIS 11. Their isochrons suggested secondary diffusional U uptake had affected both teeth. All isochron analyses suggest that one secondary uptake event may have affected the entire site, likely due to immersion in U-rich water. If correct, AT29’s age makes Medzhibozh A’s hearths the oldest in the Ukraine, but more teeth from all the layers must be ESR dated and tested with coupled ESR—230Th/234U to confirm the ages and p’s.Возле пгт Меджибож в Хмельницкой области Украины (49 ° 35 'с.ш., 27 ° 42' в.д., 270 м над уровнем моря) обнаружено два многослойные нижньопалеолитични местонахождение под открытым небом. Слой 16а, связанный с нижним аллювиальным циклом местонахождение Меджибож 1 содержит каменные артефакты, преимущественно Чопры, чопингы, сколы и орудия на них, возможные остатки очага, а также кости с нарезками, засечками и признаками дробления, оставленные здесь ранними гоминидами, которые жили на береговой линии древней водоема. Остатки медведя Денингера (Ursus deningeri), носорога (Stephanorhinus kirchbergensis) и других вымерших млекопитающих эпохи среднего плейстоцена позволяют предполагать, что слои 13-16 должны быть древними за 200 тыс. Лет, что подтверждено имеющейся единичной ТЛ-дате, а также данными о микротериофауны, палеоґрунтив, спорово-пыльцевого анализа. Примерно в 500 м от Меджибожу 1, на местонахождении Меджибож А, обнаружено шесть археологических слоев, разделенных стерильными прослойками, содержащих подобные каменные изделия, остатки фауны, остатки очагов. Для датировки материалов Меджибожу применен метод электронного спинового резонанса (ЕСР), возможности которого по датировке по эмалью зубов млекопитающих достигают 2-4 млн лет, а точность составляет 2-5%. Датированы стандартным и изохронным методами ЕСР оленьи зубы - три из слоя 16а Меджибожу I, один - из слоя 1 Меджибожу А. Образцы содержащих отложений проанализированы в соответствии с методикой нейтронного активационного анализа для измерения уровня усредненной по количеству и объему дозы седиментов. Усредненные во времени показатели мощности космических доз определены в соответствии с моделью изменений, с использованием геологических критериев. Образец AT29 с Меджибожу A со стандартным LU возрастом 379 ± 27 тыс. Лет - лучший с точки зрения датировки слоя, основанный на анализе фауны, но Изохроны показала диффузное вторичное поглощение урана, предполагает более древний возраст. Все зубы с Меджибожу 1 содержали> 100 ppm U в дентине, в эмали его содержание ва риював от 2,8 до 11,8 ppm. Согласно Изохроны образца AT41, не демонстрирует признаков вторичного поглощения урана, можно предполагать, что его поглощения на уровне р ~ 4 наибольший показатель поглощения. При таком уровне г. возраст составляет 373 ± 17 тыс. Лет, коррелирует с поздней фазой морской изотопной стадии 11 (MIS). Предполагаемый возраст образца AT44 - 399 ± 11 тыс. Лет при р = 4, а образца AT45 - 396 ± 13 тыс. Лет при р = 6; обе даты коррелируют с серединой стадии MIS 11. Их изохроны свидетельствуют о влиянии вторичного диффузного поглощения урана на оба зубы. Анализ изохрон допускает, что на всю стоянку мог повлиять один эпизод вторичного поглощения, возможно, связан с погружением в воду с высоким содержанием урана. Согласно датировке, очаги Меджибожу А - древнейшие в Украине, однако для подтверждения возраста и оценка значения р необходимые датировки с помощью метода ЕСР и проверка совмещенными ЕСР-230Th / 234U датами большего количества образцов из разных слоев достопримечательности.Біля смт Меджибіж у Хмельницькій області України (49°35′ пн.ш., 27°42′ сх.д., 270 м н.р.м.) виявлено два багатошарові нижньопалеолітичні місцезнаходження під відкритим небом. Шар 16а, пов’язаний з нижнім алювіальним циклом місцезнаходження Меджибіж 1 містить кам’яні артефакти, переважно чопри, чопінги, сколи й знаряддя на них, вірогідні залишки вогнища, а також кістки з нарізками, зарубками і ознаками дроблення, залишені тут ранніми гомінідами, які мешкали на береговій лінії давньої водойми. Рештки ведмедя Денінгера (Ursus deningeri), носорога (Stephanorhinus kirchbergensis) та інших вимерлих ссавців епохи середнього плейстоцену дають змогу припускати, що шари 13—16 мають бути давнішими за 200 тис. років, що підтверджено наявною одиничною ТЛ-датою, а також даними щодо мікротеріофауни, палеоґрунтів, спорово-пилкового аналізу. Приблизно у 500 м від Меджибожу 1, на місцезнаходженні Меджибіж А, виявлено шість археологічних шарів, розділених стерильними прошарками, що містять подібні кам’яні вироби, рештки фауни, залишки вогнищ. Для датування матеріалів Меджибожу застосовано метод електронного спінового резонансу (ЕСР), можливості якого щодо датування за емаллю зубів ссавців сягають 2—4 млн років, а точність становить 2—5 %. Продатовано стандартним і ізохронним методами ЕСР оленячі зуби — три з шару 16а Меджибожу I, один — з шару 1 Меджибожу А. Зразки вмісних відкладів проаналізовано відповідно до методики нейтронного активаційного аналізу для вимірювання рівня усередненої за кількістю та обсягом дози у седиментах. Усереднені у часі показники потужності космічних доз визначено відповідно до моделі змін, з використанням геологічних критеріїв. Зразок AT29 з Меджибожу A зі стандартним LU віком 379±27 тис. років — найкращий з точки зору датування шару, що ґрунтується на аналізі фауни, але ізохрона показала дифузійне вторинне поглинання урану, що припускає більш давній вік. Усі зуби з Меджибожу 1 містили >100 ppm U у дентині, в емалі його вміст ва ріював від 2,8 до 11,8 ppm. Згідно із ізохроною зразка AT41, що не демонструє ознак вторинного поглинання урану, можна припускати, що його поглинання на рівні р~4 найбільший показник поглинання. За такого рівня р вік становить 373±17 тис. років, що корелює з пізньої фазою морської ізотопной стадії 11 (MIS). Імовірний вік зразка AT44 — 399±11 тис. років при р=4, а зразка AT45 — 396±13 тис. років при р=6; обидві дати корелюють із серединою стадії MIS 11. Їх ізохрони свідчать про вплив вторинного дифузійного поглинання урану на обидва зуби. Аналіз ізохрон допускає, що на всю стоянку міг вплинути один епізод вторинного поглинання, можливо, пов’язаний із зануренням у воду з високим вмістом урану. Згідно з датуванням, вогнища Меджибожу А — найдавніші в Україні, проте для підтвердження віку і оцінювання значення р необхідні датування за допомогою методу ЕСР і перевірка суміщеними ЕСР-230Th/234U датами більшої кількості зразків із різних шарів пам’ятки

Estimation of optimal birth weights and gestational ages for twin births in Japan

BACKGROUND: As multiple pregnancies show a higher incidence of complications than singletons and carry a higher perinatal risk, the calculation of birth weight – and gestational age (GA)-specific perinatal mortality rates (PMR) for multiple births is necessary in order to estimate the lowest PMR for these groups. METHODS: Details of all reported twins (192,987 live births, 5,539 stillbirths and 1,830 early neonatal deaths) in Japan between 1990 and 1999 were analyzed and compared with singletons (10,021,275 live births, 63,972 fetal deaths and 16,862 early neonatal deaths) in the annual report of vital statistics of Japan. The fetal death rate (FDR) and PMR were calculated for each category of birth weight at 500-gram intervals and GA at four-week intervals. The FDR according to birth weight and GA category was calculated as fetal deaths/(fetal deaths + live births) × 1000. The perinatal mortality rate (PMR) according to birth weight and GA category, was calculated as (fetal deaths + early neonatal deaths)/(fetal deaths + live births) × 1000. Within each category, the lowest FDR and PMR were assigned with a relative risk (RR) of 1.0 as a reference and all other rates within each category were compared to this lowest rate. RESULTS: The overall PMR per 1,000 births for singletons was 6.9, and the lowest PMR was 1.1 for birth weight (3.5–4.0 kg) and GA (40- weeks). For twins, the overall PMR per 1,000 births was 36.8, and the lowest PMR was 3.9 for birth weight (2.5–3.0 kg) and GA (36–39 weeks). At optimal birth weight and GA, the PMR was reduced to 15.9 percent for singletons, and 10.6 percent for twins, compared to the overall PMR. The risk of perinatal mortality was greater in twins than in singletons at the same deviation from the ideal category of each plurality. CONCLUSION: PMRs are potentially reduced by attaining the ideal birth weight and GA. More than 90 percent of mortality could be reduced by attaining the optimal GA and birth weight in twins by taking particular care to ensure appropriate pregnancy weight gain, as well as adequate control for obstetric complications

Analysis of factors influencing the ultrasonic fetal weight estimation

Objective: The aim of our study was the evaluation of sonographic fetal weight estimation taking into consideration 9 of the most important factors of influence on the precision of the estimation. Methods: We analyzed 820 singleton pregnancies from 22 to 42 weeks of gestational age. We evaluated 9 different factors that potentially influence the precision of sonographic weight estimation ( time interval between estimation and delivery, experts vs. less experienced investigator, fetal gender, gestational age, fetal weight, maternal BMI, amniotic fluid index, presentation of the fetus, location of the placenta). Finally, we compared the results of the fetal weight estimation of the fetuses with poor scanning conditions to those presenting good scanning conditions. Results: Of the 9 evaluated factors that may influence accuracy of fetal weight estimation, only a short interval between sonographic weight estimation and delivery (0-7 vs. 8-14 days) had a statistically significant impact. Conclusion: Of all known factors of influence, only a time interval of more than 7 days between estimation and delivery had a negative impact on the estimation