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PubMed1990

Twinning in families of triplets.

A study was conducted on twinning in relatives of consecutive triplet sets in the Aland Islands in the years 1740-1939. The incidence of twinning in sibships of triplets was extremely high, 80/1000 (56/1000 before and 143/1000 after the triplet maternity). In Finland as a whole, 1905-1954, the twinning rate was among mothers of triplets 38/1000, ie, about 2.6 times the rate in general population, and was higher after (48/1000) than before the triplet maternity (34/1000). In the sibships of fathers of triplets there was a low rate of twinning (below 10/1000) both of same-sexed (SS) and of opposite-sexed (OS) triplets. Among sibships of mothers of OS triplets the twinning rate was 18/1000 and among mothers' sibships of SS triplets 26/1000. The series of triplet families from both Aland and Finland as a whole indicate a considerably higher frequency of twinning on the maternal than on the paternal side. The sibships of OS triplets in Finland have higher twinning rates than sibships of SS triplets (50/1000 vs 27/1000). In sibships of triplets, not only the DZ but also the MZ twinning rates were approximately twice as high as those in the general population. The triplet rates in Finland were increasingly strong with maternal age and were in the last century among mothers of 30-39 years of age considerably higher than among mothers from this century. This, in combination with higher mean parity, may explain the high rates of multiple maternities in sibships of triplets in the past. The rate of triplet maternities seems to be more sensitive to sociodemographic changes than the rate of twin maternities. Mothers of triplets in Finland had a high frequency (more than 40%) of prenuptially conceived firstborn children. This, and a short protogenesic interval indicate that triplet-prone mothers are more fecundable, ie, they conceive with greater ease and/or may have a better physical condition than other women for completing a gestation with multiple embryos.

Adult↗
PubMed2005

Mean arterial pressure in concordant and discordant triplets during the first week of life.

OBJECTIVE: To retrospectively determine mean arterial pressure (MAP) for stable concordant and discordant triplets during the first 7 days of life. BACKGROUND: Morbidity and mortality for prematurely born triplets is high, therefore, MAP monitoring during the first day of life is important for their clinical management. MAP reference values for special populations such as triplets have not been published. Recently, we reported that in stable discordant twins MAP values during the first day of life were significantly lower in the smaller than in their larger siblings. Comparable information for triplets is not available. DESIGN: Retrospective cohort study. METHODS: We studied 30 sets of concordant and 29 sets of discordant (birth weight difference > or =20%) consecutively born triplets. Stable patients were defined as those having umbilical cord hemoglobin > or =13 g/dl, normal blood gases, who were never treated for hypotension, and survived at least 7 days. MAP (torr) were measured by oscillometry in 3410, and by transducer via an umbilical arterial catheter in 1251 instances. RESULTS: Concordant and discordant triplets were similar in demographics, history of preterm labor (63 and 63%), chorioamnionitis (10 and 10%), pre-eclampsia (53 and 48%), cesarean delivery (100 and 100%), antenatal steroids (77 and 73%), cord hemoglobin (16 and 16 g/dl), combined triplets birth weight (4922 and 4732 g), gestational age (32 and 33 weeks), normal head ultrasounds or Grade I intracranial hemorrhage (96 and 100%) and neonatal mortality (2 and 1%), but were different in the number of infants requiring mechanical ventilation (57 and 31%). A total of 80 (89%) concordant triplets and 77 (88%) discordant triplets were stable according to our definition. Concordant stable triplets, whether small, medium or large, had similar MAP at birth. Their MAP values increased noticeably from birth to 24 hours and more subtlely to 7 days. Triplets of < or =32 weeks GA had lower MAP throughout than those of > or =33 weeks GA. Discordant stable triplets were divided into 27 small (1382 g), 26 medium (1683 g) and 27 large (1969 g); during the first 24 hours, medium and smaller triplets had MAP values that were lower than those of their larger siblings. From the second to the seventh day of life, all MAP values and trends were similar. Among discordant triplets, 86% of the smallest, 13% of the medium and 13% of the largest infants had asymmetrical intrauterine growth restriction. CONCLUSION: In stable concordant and stable discordant triplets, MAP correlates with birth weight, gestational age and postnatal age. MAP values increase noticeably during the first 24 hours and more subtlely during the next 7 days. Concordant or discordant, small, medium, and large triplets have similar MAP values and trends to that of their siblings. Small and medium discordant triplets have lower MAP values during the first day of life than their larger siblings but by the second day there MAP trends and values were no longer different.

Age Factors↗
PubMed1980

Carotenoid triplet yields in normal and deuterated Rhodospirillum rubrum.

Quantum yields of carotenoid triplet formation in Rhodospirillum rubrum wild type and fully deuterated cells and chromatophores were determined in weak laser flashes for excitation wavelength lambda i = 530 nm (mainly absorbed by the carotenoid spirilloxanthin) and for lambda i = 608 nm (mainly absorbed by bacteriochlorophyll) in the presence and absence of magnetic fields. All experiments were performed at room temperature and in the absence of oxygen. The quantum yield of reaction center bacteriochlorophyll oxidation in wild type preparations, in which all reaction centers are in state PIX, at lambda i = 608 nm is close to unity, whereas the quantum yield of antenna carotenoid triplet formation is low (about 5%); P is the primary electron donor, a bacteriochlorophyll dimer, I the primary acceptor, a bacteriopheophytin, and X the secondary acceptor, an iron-ubiquinone complex. In cells in which the reaction centers are in the state P+IX(-), the antenna carotenoid triplet yield is about 0.2. In contrast, at lambda i = 530 nm, the quantum yield of P+ formation is relatively low (0.3) and the yield of the antenna carotenoid triplet state in state PIX unusually high (0.3). At increasing light intensities of 530 nm only about 3 carotenoids per reaction center of the 15 carotenoids present are efficiently photoconverted into the triplet state, which indicates that there are two different pools of carotenoids, one with a low efficiency for transfer of electronic excitation to bacteriochlorophyll and a high yield for triplet formation, the other with a high transfer efficiency and a low triplet yield. The absorption difference spectrum of the antenna carotenoid triplet, excited by 608 or 530 nm light in the state P+IX(-) does not show the peak at 430 nm, that is present in the difference spectrum of the reaction center carotenoid triplet, mainly observed at lambda i = 608 nm with weak flashes. The yield of the reaction center carotenoid triplet, generated in chromatophores in the state PIX(-), is decreased by about 10% by a magnetic field of 0.6 T. In a magnetic field of 0.6 T the yield of the carotenoid triplet, formed by 530 nm excitation in chromatophores at ambient redox potential, is decreased by about 45%. The high quantum yield of formation and the pronounced magnetic field effect for the carotenoid triplet generated by direct excitation at 530 nm can be explained by assuming that this triplet is not formed by intersystem crossing, but by fission of the singlet excitation into two triplet excitations and subsequent annihilation (triplet pair mechanism), or by charge separation and subsequent recombination (radical pair mechanism). Fully deuterated bacteria give essentially the same triplet yields, both in the reaction center and in the antenna carotenoids and show the same magnetic field effects as non-deuterated samples. This indicates that hyperfine interactions do not play a major role in the dephasing of the spins in the radical pair P+I- nor in the formation of the antenna carotenoid triplet.

Carotenoids↗
PubMed1976

Triplet states of bacteriochlorophyll and carotenoids in chromatophores of photosynthetic bacteria.

Chromatophores from photosynthetic bacteria were excited with flashes lasting approx. 15 ns. Transient optical absorbance changes not associated with the photochemical electron-transfer reactions were interpreted as reflecting the conversion of bacteriochlorophyll or carotenoids into triplet states. Triplet states of various carotenoids were detected in five strains of bacteria; triplet states of bacteriochlorophyll, in two strains that lack carotenoids. Triplet states of antenna pigments could be distinguished from those of pigments specifically associated with the photochemical reaction centers. Antenna pigments were converted into their triplet states if the photochemical apparatus was oversaturated with light, if the primary photochemical reaction was blocked by prior chemical oxidation of P-870 or reduction of the primary electron acceptor, or if the bacteria were genetically devoid of reaction centers. Only the reduction of the electron acceptor appeared to lead to the formation of triplet states in the reaction centers. In the antenna bacteriochlorophyll, triplet states probably arise from excited singlet states by intersystem crossing. The antenna carotenoid triplets probably are formed by energy transfer from triplet antenna bacteriochlorophyll. The energy transfer process has a half time of approx. 20 ns, and is about 1 X 10(3) times more rapid than the reaction of the bacteriochlorophyll triplet states with O2. This is consistent with a role of carotenoids in preventing the formation of singlet O2 in vivo. In the absence of carotenoids and O2, they decay half times of the triplet states are 70 mus for the antenna bacteriochlorophyll and 6-10 mus for the reaction center bacteriochlorophyll. The carotenoid triplets decay with half times of 2-8 mus. With eak flashes, the quantum yields of the antenna triplet states are in the order of 0.02. The quantum yields decline severely after approximately one triplet state is formed per photosynthetic unit, so that even extremely strong flashes convert only a very small fraction of the antenna pigments into triplet states. The yield of fluorescence from the antenna bacteriochlorophyll declines similarly. These observations can be explained by the proposal that single-triplet fusion causes rapid quenching of excited single states in the antenna bacteriochlorophyll.

Bacterial Chromatophores↗
PubMed2005

Time-resolved resonance Raman and density functional theory study of hydrogen-bonding effects on the triplet state of p-methoxyacetophenone.

Picosecond and nanosecond time-resolved resonance Raman spectroscopy combined with density functional theory calculations have been performed to characterize the structure, dynamics, and hydrogen-bonding effects on the triplet state of the phototrigger model compound p-methoxyacetophenone (MAP) in cyclohexane, MeCN, and 50% H2O/50% MeCN (v:v) mixed solvent. Analogous work has also been done to study the corresponding ground state properties. The ground and triplet states of MAP were both found to be associated strongly with the water solvent molecules in the 50% H2O/50% MeCN solvent system. A hydrogen-bond complex model involving one or two water molecules bonded with the oxygen atoms of the MAP carbonyl and methoxy moieties has been employed to explore the hydrogen-bond interactions and their influence on the geometric and electronic properties for the ground and triplet states of MAP. Among the various hydrogen-bond configurations examined, the carbonyl hydrogen-bond configuration involving one water molecule was calculated to lead to the most stable hydrogen-bond complex for both the ground and the triplet states with the strength of the hydrogen-bond interaction being stronger in the triplet state than the ground state. The increased carbonyl located hydrogen-bond strength in the triplet state results in substantial modification of both the electronic and the structural conformation so that the triplet of the hydrogen-bond complex can be considered as a distinct species from the free MAP triplet state. This provides a framework to interpret the differences observed in the TR3 spectral and triplet lifetime obtained in the neat MeCN solvent (attributed to the free MAP triplet state) and the 50% H2O/50% MeCN solvent (due to the triplet of the hydrogen-bond complex). Temporal evolution at early picosecond times indicates rapid ISC conversion, and subsequent relaxation of the excess energy of the initially formed energetic triplets occurs for both the free MAP and the hydrogen-bond complex. The triplet of the carbonyl hydrogen-bond complex appears to be generated directly from the corresponding ground state complex and it does not dissociate back to the free triplet state within the triplet state lifetime. We briefly discuss the influence of the carbonyl hydrogen-bond effect on the pi pi* triplet reactivity for MAP and closely related compounds.

Acetophenones↗
PubMed2004

The ponderal index in triplets: III. Association with birth weight discordance.

Our objective was to determine the association of the ponderal index with birth weight discordance in triplets. We analyzed data from triplets delivered at 28-37 weeks for birth weight discordance (>25% difference between the heaviest and lightest triplet). Three categories of discordance (low skew, symmetrical, and high skew) were classified according to the relative position of the middle triplet. Birth weights and the ponderal index (birth weight/[length]3) of all concordant and discordant triplet groups were compared. Of 752 triplet sets included, 184 (24.5%) were discordant. Total triplet birth weight was higher in the concordant compared to all discordant categories. As opposed to birth weight, where only the middle triplet differed according to discordance pattern, the ponderal index for the largest triplet was significantly higher in the low skew discordant group compared to the concordant and other discordant triplet groups. In contrast, the ponderal index for the smallest and middle triplets were similar among the discordant groups. We concluded that discordance in triplet pregnancies exhibits different patterns of mass (birth weight) versus size (ponderal index). Our findings suggest that it may be the size of largest triplet that determines the presence or absence or discordance in triplet gestations.

Adult↗
PubMed1979

Quenching of fluorescence by triplet excited states in chloroplasts.

The fluorescence quantum yield in spinach chloroplasts at room temperature has been studied utilizing a 0.5-4.0 mus duration dye laser flash of varying intensities as an excitation source. The yield (phi) and carotenoid triplet concentration were monitored both during and following the laser flash. The triplet concentration was monitored by transient absorption spectoscopy at 515 nm, while the yield phi following the laser was probed with a low intensity xenon flash. The fluorescence is quenched by factors of up to 10-12, depending on the intensity of the flash and the time interval following the onset of the flash. This quenching is attributed to a quencher Q whose concentration is denoted by Q. The relative instantaneous concentration of Q was calculated from phi utilizing the Stern-Volmer equation, and its buildup and decay kinetics were compared to those of carotenoid triplets. At high flash intensities (greater than 10(16) photon . cm-2) the decay kinetics of Q are slower than those of the carotenoid triplets, while at lower flash intensities they are similar. Q is sensitive to oxygen and it is proposed that Q, at the higher intensities, is a trapped chlorophyll triplet. This hypothesis accounts well for the continuing rise of the carotenoid triplet concentration for 1-2 mus after the cessation of the laser pulse by a slow detrapping mechanism, and the subsequent capture of the triplet energy by carotenoid molecules. At the maximum laser intensities, the carotenoid triplet concentration is about one per 100 chlorophyll molecules. The maximum chlorophyll ion concentration generated by the laser pulses was estimated to be below 0.8 ions/100 chlorophyll molecules. None of the observations described here were altered when a picosecond pulse laser train was substituted for the microsecond pulse. A simple kinetic model describing the generation of singlets and triplets (by intersystem crossing), and their subsequent interaction leading to fluorescence quenching, accounts well for the observations. The two coupled differential equations describing the time dependent evolution of singlet and triplet excited states are solved numerically. Using a single-triplet bimolecular rate constant of gammast = 10(-8) cm3 . s-1, the following observations can be accounted for: (1) the rapid initial drop in phi and its subsequent levelling off with increasing time during the laser pulse, (2) the buildup of the triplets during the pulse, and (3) the integrated yield of triplets per pulse as a function of the energy of the flash.

Carotenoids↗
PubMed2006

Triplet correlation in sheared suspensions of Brownian particles.

Triplet microstructure of sheared concentrated suspensions of Brownian monodisperse spherical particles is studied by sampling realizations of a three-dimensional unit cell subject to periodic boundary conditions obtained in accelerated Stokesian dynamics simulations. Triplets are regarded as a bridge between particle pairs and many-particle clusters thought responsible for shear thickening. Triplet-correlation data for weakly sheared near-equilibrium systems display an excluded volume effect of accumulated correlation for equilateral contacting triplets. As the Peclet number increases, there is a change in the preferred contacting isosceles triplet configuration, away from the "closed" triplet where the particles lie at the vertices of an equilateral triangle and toward the fully extended rod-like linear arrangement termed the "open" triplet. This transition is most pronounced for triplets lying in the plane of shear, where the open triplets' angular orientation with respect to the flow is very similar to that of a contacting pair. The correlation of suspension rheology to observed structure signals onset of larger clusters. An investigation of the predictive ability of Kirkwood's superposition approximation (KSA) provides valuable insights into the relationship between the pair and triplet probability distributions and helps achieve a better and more detailed understanding of the interplay of the pair and triplet dynamics. The KSA is seen more successfully to predict the shape of isosceles contacting triplet nonequilibrium distributions in the plane of shear than for similar configurations in equilibrium hard-sphere systems; in the sheared case, the discrepancies in magnitudes of distribution peaks are attributable to two interaction effects when pair average trajectories and locations of particles change in response to real, or "hard," and probabilistically favored ("soft") neighboring excluded volumes and, in the case of open triplets, due to changes in the correlation of the farthest separated pair caused by the fixed presence of the particle in the middle.

Journal Article↗
PubMed1998

Preliminary experience with a prospective protocol for planned vaginal delivery of triplet gestations.

OBJECTIVE: The objective of the study was to evaluate a protocol for vaginal delivery of triplet gestations. STUDY DESIGN: All women with triplet gestations managed between January 1, 1995, and December 31, 1997, by University Medical Center's perinatal practice were offered enrollment in our vaginal delivery protocol. Our protocol offered attempt of vaginal delivery if triplet A was in vertex presentation, fetal monitoring was possible, and there were no other obstetric contraindications. Twenty-three triplet gestations were identified; 8 achieved vaginal delivery. Outcome parameters investigated included neonatal mortality, Apgar scores, neonatal intracranial hemorrhage, arterial cord pH, neonatal weight, and length of postpartum hospital stays of mother and neonates. All parameters were analyzed with analysis of variance and the Student t test as appropriate with the JMP 3.1 statistics program (Cary, NC). RESULTS: Twenty-three sets of triplets were enrolled. Eight sets were delivered vaginally. Eight of 9 patients (88.9%) who attempted trial of labor were delivered vaginally, 1 of which was a vaginal birth after cesarean section. The remaining triplet gestation failed to progress at 4-cm dilation. Twelve sets of triplets had a nonvertex-presenting triplet and were delivered by the cesarean route. The remaining 2 triplet gestations were delivered by the cesarean route because of inadequate fetal monitoring. Neonatal survivals were 100% for both groups. No significant differences in neonatal mortality, Apgar scores, intracranial hemorrhage, arterial cord blood pH, hospital or neonatal intensive care unit stay of neonate, neonatal weight, and change in maternal or neonatal blood cell count were noted. There were no cases of grade III or IV intraventricular hemorrhage in either group. A significant reduction in postpartum hospital stay of mother was noted in the vaginal delivery group (2.8 vs 4.5 days, P <.001). The mean gestational age at delivery was significantly lower for the vaginal delivery group (31.3 vs 34.0 weeks, P <.02). The mean neonatal weight for the vaginal delivery group was significantly lower (1758 +/- 473 vs 2022 +/- 407 g, P <.02). There were no significant differences in outcome parameters for the first, second, and third triplets within each group when compared with each other or with the other study group. One patient who underwent vaginal delivery had retained products of conception and required curettage. A single fetal death occurred at 22 weeks' gestation from twin-twin transfusion, with the remaining triplets being delivered vaginally at 35 weeks' gestation. Cesarean hysterectomy was required in 1 case for uncontrollable bleeding at the time of cesarean delivery. Perinatal complications occurred in a large number of patients, with the incidence of premature labor 47. 8% (n = 11), that of preterm premature rupture of membranes 26.1% (n = 6), and that of preeclampsia 34.8% (n = 8). CONCLUSION: In selected cases vaginal delivery of triplet gestations can be accomplished without increased maternal or neonatal morbidity and mortality and may significantly decrease maternal hospital stay and postoperative morbidity.

Cesarean Section↗
PubMed2006

An experience of laser surgery for feto-fetal transfusion syndrome complicated with unexpected feto-fetal hemorrhage in a case of monochorionic triamniotic triplets.

Feto-fetal transfusion syndrome (FFTS) in monochorionic triplets is a rare clinical entity which may share the principal adverse perinatal outcomes of twin-twin transfusion syndrome. Recently, favorable prognoses regarding morbidity and mortality in twins after selective laser photocoagulation of placental communicating vessels (SLPCV) have been described. But descriptions of this procedure in monochorionic triplet cases are limited. This is the case report of an experience of SLPCV applied to monochorionic triamniotic triplets with FFTS. Triplet A had polyhydramnios, while absent end-diastolic flow in the umbilical artery of triplet B, the triplet with anhydramnios, was persistent. Triplet C looked normal, vertical amniotic pocket and Doppler studies yielding normal results. At the beginning of the SLPCV procedure, feto-fetal hemorrhage, subsequent to the fetal death of the donor triplet, occurred. Both surviving cofetuses showed persistent bradycardia; and 1 fetus died while the other recovered from the fetal bradycardia. All vascular anastomoses between the 3 triplets could be identified and obliterated, requiring two trocars. Our fetoscopic observation revealed feto-fetal hemorrhage after demise of monochorionic triplet, which led to injury of other fetuses due to hypovolemia in an instant. In conclusion, SLPCV might be a valid option for FFTS in triplet cases, while further experience is required in order to evaluate the risks and benefits of this procedure in triplet cases.

Adult↗
PubMed1998

Neonatal morbidity and mortality associated with triplet pregnancy.

OBJECTIVE: To compare neonatal morbidity and mortality in a large cohort of triplet pregnancies with singleton and twin neonates managed at a single tertiary center over a short time. METHODS: Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for neonatal outcome data. Pregnancies delivered before 20 weeks' gestation and neonates with lethal congenital anomalies were excluded. The comparison group comprised all singleton and twin neonates managed in the same neonatal intensive care unit (NICU) during the same period. RESULTS: During the 5-year period, 55 triplet pregnancies and their resulting 165 neonates were managed and delivered at this center. Their outcomes were compared with those of 959 singleton and 357 twin neonates born at similar gestational ages. The median gestational age at delivery for triplets was 32.1 weeks, and 149 of the 165 infants were admitted. Sixteen triplet neonates were not admitted to our neonatal intensive care unit, 12 because of previable gestational age, three because of stillbirth, and one because of a lethal congenital anomaly. The crude perinatal mortality rate in triplets was 121 per 1000 births, and there was no significant difference in outcome based on triplet birth order. There were no significant differences in survival rates between singleton, twin, and triplet neonates, with an overall neonatal survival of 95%, 95%, and 97%, respectively. The only significant differences in morbidity were an increased incidence of mild intraventricular hemorrhage (relative risk [RR] 6.20; 95% confidence interval [CI] 2.64, 14.61), mild retinopathy of prematurity (RR 20.05; 95% CI 3.59, 111.79), and severe retinopathy of prematurity (RR 46.69; 95% CI 6.25, 348.85) in triplets compared with singletons, and severe retinopathy of prematurity (RR 6.83; 95% CI 1.24, 37.56) in triplets compared with twins. CONCLUSION: When stratified by gestational age, triplet neonates delivered at 24-34 weeks' gestation have similar outcomes as singleton and twin neonates, with the only clinically significant difference being an increased incidence of retinopathy of prematurity in triplets.

Female↗
PubMed2002

Cleavage-arrested cell triplets from ascidian embryo differentiate into three cell types depending on cell combination and contact timing.

During early ascidian development, which is a prototype of early vertebrate development, anterior neuroectoderm cells (a4.2) from the eight-cell embryo are destined to become anterior neural structures including the brain vesicle, while presumptive notochordal neural cells (A4.1) become larval posterior neural structures including motoneurons. Whereas, an anterior quadrant cell (A3) of the four-cell embryo, from which both anterior neuroectoderm (a4.2) and notochordal neural cells (A4.1) are derived, has both fates. Cleavage-arrested cell triplets were prepared from the anterior quadrant cell and a pair of anterior neuroectoderm cells (A3-aa triplet) or a pair of presumptive notochordal neural cells (A3-AA triplet), and cultured in contact. Differentiation of cells in the triplet was determined electrophysiologically by observing cell type-specific currents. In the A3-aa triplet, when two neuroectoderm cells and an anterior quadrant cell were prepared from the same batch of embryos, all three cells in the triplet developed into neuronal cells in 60 % of cases, but in 40 % of cases all of them differentiated into epidermal cells. However, when the batch of embryos from which neuroectoderm cells were prepared was fertilized 3 h later than that from which the anterior quadrant cell was prepared all three cells in the triplet consistently became neuronal cells. In contrast, when the batch of embryos from which neuroectoderm cells were prepared was fertilized 3 h earlier, all three cells became epidermal. In the A3-AA triplet no switching of differentiation occurred and all three cells in the triplet differentiated into neuronal cells, although the amplitude of inward current was often small. In neuralized A3-aa triplets the spikes in the anterior quadrant cell were characteristically small in amplitude and brief in duration, suggesting the presence of A-currents, which is a characteristic feature of posterior neuronal differentiation. In contrast, the spikes in the anterior neuroectoderm cells were large in amplitude and long in duration, chracteristic to the anterior neuronal type. The majority of single isolated anterior quadrant cells became non-excitable. However, the minority was apparently autonomously neuralized to become the posterior neuronal type. In neuralized A3-AA triplets, the majority of anterior quadrant cells was induced to become the anterior neuronal type. When isolated anterior quadrant cells were neuralized with subtilisin, a protease, they also predominantly became the anterior neuronal type. While, in medium containing a fibroblast growth factor posterior neuralization of isolated anterior quadrant cells was facilitated, but the anterior neuronal type, although minor, appeared anew. These observations indicate that the multiple fates of the anterior quadrant cell expressed in vivo were effectively reproduced in this experimental condition at the single cell level. Interactive differentiation in this triplet system recapitulates not only fundamental neural induction of ascidian neuroectoderm cells, but also functional and positional specificity within the neuronal group.

Animals↗
PubMedDate not supplied

Reduction of soft tissue deposition in normal triplets.

In a previous study, birth weight projections obtained with Rossavik growth models were systematically greater than actual birth weights in triplets but not in singletons. To investigate the cause of this overestimation, average mean percent deviations for head circumference (HC), abdominal circumference (AC), thigh circumference (ThC), and weight (WT) at different times in the third trimester were studied in 13 normal triplet and 20 normal singleton fetuses using individual growth curve standards. Average mean percent deviation values for HC in both singletons and triplets were close to zero throughout the third trimester. Average mean percent deviation values for AC in both singletons and triplets were similar, and remained relatively constant. Average mean percent deviation values for ThC in triplets decreased toward the end of the third trimester, but those for singletons increased. Average mean percent deviation values for estimated weight did not change during the third trimester in singletons whereas those in triplets decreased. The difference in average mean percent deviation values for estimated weight between singletons and triplets in the 32- to 36-week interval was statistically significant. There were no significant differences between actual and predicted measurements for HC in both singletons and triplets at birth. However, actual birth measurements were systematically less than predicted birth measurements for AC and ThC in singletons, and for AC, ThC, and WT for triplets. These systematic differences were significantly larger in triplets for ThC and WT. Nutrition Score values, direct measures of subcutaneous tissue, were significantly lower in triplets compared to singletons.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1997

A triplet pregnancy after in vitro fertilization is a procedure-related complication that should be prevented by replacement of two embryos only.

OBJECTIVE: To investigate whether the incidence and obstetric outcome of triplet pregnancies after IVF treatment justify strict limitation of the number of embryos to be replaced to two. DESIGN: Retrospective analysis. SETTING: A transport IVF program. PATIENT(S): All patients who had more than one embryo replaced. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Obstetric outcome, pregnancy. RESULT(S): High-order pregnancies occurred in 24 cases (23 triplets and 1 quadruplet). Three patients opted for selective embryo reduction (12.5%). Three triplet pregnancies spontaneously reduced to twins. Comparison of 18 triplets, reaching at least 20 weeks' gestation, with 54 twin pregnancies shows a higher perinatal mortality in the triplet group, causing 6 out of 18 patients to be confronted with at least one perinatal death. Triplets were born at a lower gestational age, had a lower birth weight, and a higher hospital admission rate of longer duration. Replacement of two, three, or four embryos did not lead to differences in pregnancy rates in the population studied. When a pregnancy occurred after replacement of three embryos, the risk of having a triplet pregnancy was 7.5%. CONCLUSION(S): The obstetric outcome of triplet pregnancies in our population indicates that triplet pregnancies after IVF treatment have to be prevented. Selective embryo reduction is acceptable for few patients only and can therefore not be seen as a solution. Replacement of three embryos results in triplet pregnancy in an unacceptably high percentage. Replacement of two embryos only gives acceptable IVF results and is the method chosen in the IVF program in Rotterdam to prevent triplet pregnancies.

Birth Weight↗
PubMed1995

[Handicaps in twins and triplets].

This study was conducted to investigate the prevalence rates of handicaps in twins and triplets. The subjects were 252 twins and 287 triplets. The following results were obtained. 1) The prevalence rates of the handicapped were 8.7 per 100 triplets, and 4.4 per 100 twins. The risk of producing at least one handicapped child was approximately 22% in triplet pregnancy and 9% in twin pregnancy. This means that one in 4 or 5 sets of triplets had at least one handicapped child, as did one in 11 pairs of twins. 2) Cerebral palsy was the most frequent handicap in twins and triplets. The risks of producing a child with cerebral palsy were 2.0% and 3.1% in twins and triplets, respectively. 3) The prevalence rates of congenital anomalies (congenital heart disease, limb anomalies, and others) were 2.4% in twins and 4.5% in triplets. Approximately 45% of the handicaps in twins and triplets resulted from congenital anomalies. 4) The prevalence rate of the handicapped in twins and triplets was not associated with maternal age, but was associated with the years of delivery in triplets, and was higher in babies with shorter gestation periods.

Adult↗
PubMed1999

Trends in twin and triplet births: 1980-97.

This report presents data from U.S. birth certificates on the numbers and rates of twin and triplet and other higher order multiple births for 1980-97. Over the study period, the number of twin births rose 52 percent (from 68,339 to 104,137) and triplet and other higher order multiple births (heretofore referred to as "triplet/+") climbed 404 percent (from 1,337 to 6,737 births). Comparable but less pronounced rises were observed in twin and triplet/+ birth rates. Growth in twin and triplet/+ birth rates was most marked among women aged 30 years and over. Between 1980-82 and 1995-97, the twin rate rose 63 percent for women aged 40-44 years, and soared nearly 1,000 percent for women 45-49 years. (As one result, there were more twins born to women 45-49 years of age in 1997, than during the entire decade of the 1980's.) The triplet/+ birth rate rose nearly 400 percent for women in their thirties and exploded by more than 1,000 percent for women in their forties. The extraordinary rise in multiple births resulted in a shift in age-specific patterns, and the highest twin and triplet/+ birth rates now are for women 45-49 years of age. Historical differences in twinning rates between non-Hispanic white and black mothers have been largely eliminated (28.8 per 1,000 non-Hispanic white compared with 30.0 for black women). Non-Hispanic white women were more than twice as likely as non-Hispanic black or Hispanic women to have a triplet/+ birth. Rates of low birthweight, very low birthweight, and infant mortality were 4 to 33 times higher for twins and triplet/+ compared with singleton births. The risk for these adverse outcomes was lowest for twins and triplet/+ born to women 35-44 years of age. Twin birth rates for Massachusetts and Connecticut were at least 25 percent higher than the U.S. rate; triplet/+ rates for Nebraska and New Jersey were twice the national level.

Adult↗
PubMed1995

[Childcare problems and maternal fatigue symptoms in families with twins and triplets].

A mailed questionnaire survey was conducted on a population of 123 mothers of twins and 96 mothers of triplets to study problems in the families and maternal fatigue symptoms. The following results were obtained. 1) The prevalence rate of handicap was 9.7 per 100 for triplets, and 4.9 per 100 for twins. The risk of handicap in triplet pregnancy was approximately 25%, and in twin pregnancy was approximately 10%. Therefore 1 in 4 mothers with triplets and 1 in 10 mothers with twins had one and more handicapped children. 2) Mothers with triplets aged 0-11 months reported significantly poorer sleep quality than mothers with triplets aged one year or more with shorter sleeping time, greater frequency of awakening during the night, and more complaints of inadequate sleep. Mothers with twins aged 0-11 months showed a greater tendency for poor sleep quality than mothers with twins aged one year or more. 3) Approximately 70% of mothers with twins and triplets aged up to two reported lack of time to care for the other children. When the age of twin was 3 or more, lack of time to take care of other children was reported by only 13.3% of mothers, while it was 41.7% for mothers with triplets. 4) Mothers of twins and triplets who did not receive assistance from others for childcare reported severe physical fatigue, compared to mothers who received assistance from others. Mothers of twins and triplets aged 3 or more showed a tendency of less physical fatigue, compared to mothers of twins and triplets aged up to two.

Child Care↗
PubMed1997

Triplet births: trends and outcomes, 1971-94.

OBJECTIVES: This report describes changes in the number and ratio of live births in triplet and other higher order multiple deliveries from 1971 to 1994 by maternal race, age, education, and marital status. The report also examines the birth outcomes of triplets compared with singletons, including overall gestation specific, and birthweight specific infant mortality rates. METHODS: Birth data are obtained from the U.S. certificates of live birth. Mortality data were obtained from the Linked Birth and Infant Death Data Sets for the 1983-91 birth cohorts. Most analyses are based on triplet and other higher-order multiple births (quadruplet and quintuplet and greater births) in the aggregate. (Triplet births comprise about 92 percent of all higher order multiple births.) Triplet and other higher order birth ratios for most variables are computed by combining data for years 1982-84 and 1992-94, and for infant mortality by combining birth cohorts for years 1987-91. FINDINGS: Between 1971 and 1994 the number and ratio of triplet births quadrupled, rising from 1,034 to 4,594, and from 29.1 to 116.2 per 100,000 live births. Most of the increase was among births to white mothers, particularly among married and more educated mothers. Only about one-third of the increase in triplet birthing among white mothers between 1989 and 1994 could be attributed to changes in the maternal age distribution. Massachusetts reported the highest triplet birth ratio (215.9), more than twice the U.S. ratio (105.5). Other States with comparatively high ratios were New Hampshire, New Jersey, and Iowa. Nine of 10 triplets were born preterm compared with 1 of 10 singletons. The average triplet weighed 1,698 grams at birth, one-half that of the average singleton (3,358 grams). Triplets were about 12 times more likely to die during the first year of life as singletons, but had a survival advantage over singletons at lower gestations and birthweights.

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