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Biomedical subjects

Isaac Blickstein

Publications and source records attributed to Isaac Blickstein.

At least 19 recordsLinked to original sources
PubMed2006

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.

Adult↗
PubMed2006

Plurality-dependent risk of severe intraventricular hemorrhage among very low birth weight infants and antepartum corticosteroid treatment.

OBJECTIVE: This study was undertaken to compare the effect of antenatal corticosteroid therapy on the risk for severe intraventricular hemorrhage (IVH grade III-IV) in preterm singleton and multiple very low birth weight (VLBW) infants. STUDY DESIGN: The occurrence of severe IVH was recorded in 5022 singleton, 2032 twin, and 582 triplet infants, delivered at 24 to 32 weeks' gestation, registered in the Israeli National VLBW infant database. Antenatal corticosteroid therapy was defined as complete, partial, or none. RESULTS: The incidence of IVH grade III-IV ranged from 6.8% among singletons receiving complete course to 29.3% in triplets without antenatal corticosteroid treatment. Complete treatment significantly reduced the incidence of IVH in all plurality groups. The adjusted risk for IVH among multiple infants who received a complete course compared with singletons was not significantly different, odds ratio (OR) 1.3, 95% CI 1.0-1.7 for twins and OR 1.5, 95% CI 0.9-2.3 for triplets. CONCLUSION: Complete course of antenatal corticosteroid therapy was independently associated with decreased risk for severe IVH in singleton and in multiple preterm VLBW infants.

Betamethasone↗
PubMed2006

Diagnosis and management of heterokaryotypic monochorionic twins.

The diagnosis, management, and outcome of six consecutive heterokaryotypic monochorionic twins were evaluated. All suspected cases, based on discordant ultrasound findings, underwent amniocentesis of both sacs. Two cases also had chorionic villous sampling (CVS). Dual amniocentesis was superior to CVS in diagnosing heterokaryotypic monochorionic twins. In four cases, the X-chromosome was involved and autosomal aneuploidy was noted in the others. In five cases, the anomalous twin was selectively reduced by cord coagulation. All pregnancies ended with a phenotypically normal liveborn and all children are developing normally at 1-7 years of age.

Adult↗
PubMed2006

The association between small-for-gestational age triplet pregnancies and neonatal mortality: a novel approach to growth assessment in multiple gestations.

It is customary to estimate the uteroplacental function in singletons by defining appropriateness of birth weight by gestational age. Such a measure, however, is not available for the entire multiple pregnancy set. We evaluate a new index, total triplet birth weight, expressed as multiples of the median (MOM) birth weight of singleton gestations. We categorized triplet sets as small-, appropriate-, and large-for-gestational age pregnancies (SGA, AGA, and LGA, respectively), defined as <1 SD, +/-1 SD, and >1 SD from the mean MOM birth weight of singleton gestations. We used the 1995-1998 US matched multiple dataset to evaluate this index and to explore the association between the three categories in terms of risk of neonatal mortality. The mean +/- SD MOM value was 2.3 +/- 0.4. There was an inverse correlation between mean MOM and gestational age. LGA pregnancy status was associated with multiparity, race (being white), and high social status (education). Maternal age did not influence MOM scores. Compared with the LGA pregnancy category, the risk for neonatal mortality was more than doubled in the AGA pregnancy group and more than 9-fold in the SGA pregnancy category. We propose that this new measure could be a useful proxy for the uteroplacental efficiency in a similar way that the SGA designation works for singleton infants.

Adult↗
PubMed2006

Induction of labor with oral misoprostol in nulliparous mothers of twins.

The efficacy and safety of oral misoprostol for labor induction of twins is unknown. We conducted a retrospective case-control study to evaluate the use of oral misoprostol in near term (> or =35 weeks) twin pregnancies in nulliparas. Eligible cases were given 100 mcg oral misoprostol, which was repeated after 6 h if labor did not start. Either a third dose or diluted oxytocin infusion were given in intractable cases. Diluted oxytocin infusion was used for augmentation. Controls were nulliparas delivered at > or =35 weeks by elective cesarean section. The two groups were comparable in most aspects, except for fetal malpresentation, which was the major reason for avoiding induction. Of the 69 patients in whom labor was induced, 53 (76.8%) had a vaginal birth, 3 (4.3%) had a combined twin delivery, and 13 (18.8%) had a cesarean during labor. The mean length of stay of the neonates was significantly shorter among study cases, without significant difference in the frequency of delayed discharges as an overall proxy for neonatal complications. Labor induction with oral misoprostol could be offered to patients in whom near term vaginal twin delivery is unequivocally permitted and wish to deliver by the vaginal route.

Administration, Oral↗
PubMed2006

The Northwestern twin chorionicity study: testing the 'placental crowding' hypothesis.

OBJECTIVE: To evaluate the relation between placental proximity and frequency of birth weight discordance and small-for-gestational age (SGA) infants. STUDY DESIGN: Retrospective three-tier chorionicity analysis of 1155 twin placentas comparing birth weight characteristics of the twins in different placental types. RESULTS: Dichorionic-separate, but not dichorionic-fused twins, are heavier than monochorionic-diamniotic and monoamniotic twins (2376+/-721 vs. 2274+/-770, P < 0.006, and 2376+/-721 vs. 2166+/-782, P < 0.04). SGA twins are less frequent among dichorionic twins (OR 0.4; 95% CI 0.3, 0.6). Fewer sets with two SGA infants are present among dichorionic-separate compared to monochorionic-diamniotic pairs (OR 0.3; 95% CI 0.1, 0.8). The same trends are found when comparing all dichorionic to all monochorionic twins. Twins of all placental types have similar gestational ages and discordance values. CONCLUSIONS: Dichorionic-separate placentas are least likely to experience 'placental crowding' and thus are associated with heavier twins and fewer sets with one or two SGA infants.

Adult↗
PubMed2005

Plurality-dependent risk of respiratory distress syndrome among very-low-birth-weight infants and antepartum corticosteroid treatment.

OBJECTIVE: The purpose of this study was to determine the effect of antenatal corticosteroids on the incidence of respiratory distress syndrome in singleton infants and multiple infants who weigh <1500 g and are delivered at 24 to 32 weeks of gestation. STUDY DESIGN: The incidence of respiratory distress syndrome was established in 4754 singleton infants, 2460 twin infants, and 906 triplet infants. RESULTS: The incidence of respiratory distress syndrome ranged from 58.2% among singleton infants who received a complete course of antenatal corticosteroid to 81.5% in triplets without any treatment. Complete treatment significantly reduced the incidence of respiratory distress syndrome, compared with partial or no treatment (odds ratio, 0.2-0.6). The adjusted risk for respiratory distress syndrome among infants who received a complete course of antenatal corticosteroids compared with singleton infants increased with plurality (odds ratio, 1.4 and 1.8 for twins and triplets, respectively). CONCLUSION: The effect of corticosteroids decreased with increasing plurality. Irrespective of plurality, a complete course of antenatal corticosteroids significantly reduced the incidence of respiratory distress syndrome, whereas partial treatment had the same effect as no treatment.

Adrenal Cortex Hormones↗
PubMed2005

Estimation of iatrogenic monozygotic twinning rate following assisted reproduction: Pitfalls and caveats.

The true incidence of monozygosity after assisted reproduction is unknown. Proxy estimations, such as counting the number of monochorionic twins, using Weinberg's differential rule, and counting cases where the number of fetuses exceeds the number of transferred embryos, are less accurate than zygosity assessment in all twins. These methods commonly underestimate the true frequency of zygotic splitting because they disregard like-sexed monozygotic-dichorionic twins, consider twin births rather than twin pregnancies, and do not count the number of higher-order multiples with a monozygotic pair. Because zygotic splitting following assisted reproduction is of biological interest as well as of clinical significance, efforts should be directed to increase the accuracy of zygosity determination. This will improve understanding of the zygotic splitting phenomenon and its relation to pathologic processes.

Embryo Transfer↗
PubMed2005

The decreased rates of triplet births: temporal trends and biologic speculations.

Recent data from the US and from England and Wales demonstrate decreasing rates of higher-order multiple births and represent, for the first time, a striking change in trend when compared with the previous steep 4-fold increase since the early 1980s. However, the incidence of other multiples--twins--continued to escalate. The most probable reasons for this change are new embryo transfer guidelines and availability of multi-fetal pregnancy reduction procedures. Because actual numbers of higher-order multiples are by far lower than the number of twins, and because twins are predictably associated with significant perinatal morbidity and mortality, the implications of the ever-increasing multiple birth rates are no less alarming. As long as the incidence of twins is not reduced, the decreasing incidence of higher-order multiples, per se, does not herald the end of the epidemic of multiple births.

Embryo Transfer↗
PubMed2005

Spontaneous embryonic loss rates in twin and singleton pregnancies after transfer of top- versus intermediate-quality embryos.

OBJECTIVE: To determine whether embryo quality is associated with early spontaneous loss rates in twin and singleton pregnancies after IVF/intracytoplasmic sperm injection (ICSI). DESIGN: Retrospective, single center analysis. SETTING: The Center of Reproductive Medicine, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy. PATIENT(S): Women undergoing IVF/ICSI and two- or three-embryo transfer of intermediate- and top-quality embryos. INTERVENTION(S): First-trimester sonography at 6 to 7 weeks to determine number of embryos with positive heartbeat. Number of embryos lost was calculated from a second-trimester sonogram. MAIN OUTCOME MEASURE(S): Rates of total pregnancy loss, as related to embryo quality, initial number of embryos, maternal age <35 or > or =35 years, and IVF procedure. RESULTS: A total of 94 losses (23.1% of 407 pregnancies) were counted, with similar proportions in pregnancies after transfer of intermediate- or top-quality embryos. Neither the mode of IVF procedure nor the number of transferred embryos affected the loss rate. In contrast, the loss rate was significantly higher in older mothers after transfer of intermediate-quality embryos (odds ratio [OR 2.4], 95% confidence interval [CI] 1.1-5.5). Losses among singletons were significantly higher compared with losses among twins (OR 2.5, 95% CI 1.1-6.0), but this was observed in top-quality embryos only. CONCLUSION(S): Top-quality but not intermediate-quality ETs are associated with lower early spontaneous loss rates among twin pregnancies after IVF/ICSI.

Abortion, Spontaneous↗
PubMed2005

Down syndrome screening in multiple pregnancies.

First or second trimester screening in twin pregnancies is feasible and still efficacious by using either a combination of ultrasound and maternal serum biochemistry in the first trimester or maternal serum biochemistry in the second trimester. Special care, however, should be emphasized in what concerns biochemical screening, since it is much less sensitive in multiples. These "pseudo-risks" have been challenged for their scientific and clinical validity, however. Until more data are available from larger studies on the distribution of markers in concordant or discordant twins, nuchal translucency estimated for each fetus should be the predominant factor by which women who present with increased risk should be counseled regarding invasive testing. In dizygotic pregnancies, pregnancy-specific risk should be calculated by summing the individual risk estimates for each fetus. In monozygotic twins, the risk should be calculated based on the geometric mean of both nuchal translucency measurements, not forgetting that the false-positive rate of nuchal translucency screening is expectantly higher than in singletons.

Biomarkers↗
PubMed2005

Growth aberration in multiple pregnancy.

Growth of twins and higher-order multiples is an exceptional metabolic challenge for the expecting mother. She is doing much more than a mother of a singleton in terms of nurturing, however. Metabolic requirements need adequate dietary intervention in the form of increased weight gain during early pregnancy. It is normal for multiples to be smaller than singletons. Being smaller than singletons does not necessarily mean that multiples are pathologically growth restricted. It is important to remember that twins and triplets have different growth patterns, and their growth should not be considered by using singleton standards. When a small-for-gestational-age fetus is suspected in a multiple pregnancy, it is advisable to follow or to treat the pregnancy as if it was an SGA singleton.

Birth Weight↗
PubMed2005

En route to an "instant family": psychosocial considerations.

Societal and cultural norms require that a worthwhile person engage in reproduction and formation of a family. Young adults who postpone childbearing may presume that fertility is granted. When all other measures fail, the use of assisted reproductive technologies is considered the ultimate salvation for these couples. It is highly stressful and may lead to significant negative psychological consequences (loss of self-esteem, confidence, health, close relationships, security, and hope). Assisted reproductive technology may produce multiple pregnancy, which is frequently overlooked or underappreciated by infertile couples. Despite the real risks associated with a multiple pregnancy and birth, infertile patients often express a desperate wish to have twins or triplets, thereby accomplishing an instant family. It is necessary to provide these couples with detailed information on the risks of multiple pregnancy and birth.

Female↗
PubMed2005

Characteristics of mothers who delivered the heaviest, average-weight, and lightest triplet sets.

We analyzed a cohort of 2850 live-born triplet sets to compare age, parity, stature, pre-gravid body mass index (BMI), and weekly weight gain in mothers who delivered triplets with a total weight in the 10th, 5th, and 1st deciles corresponding to the heaviest, average-weight, and lightest triplet sets, respectively. Mothers who delivered the heaviest triplets were significantly older, multiparous, taller, heavily built, and gained more weight compared with mothers of average-weight triplets. In contrast, except for higher parity, mothers of average-weight sets were not significantly different compared with mothers who delivered the lightest triplet sets. We concluded that parity was the only significant factor for increased total triplet weight in the first five deciles. However, the presence of other factors in addition to parity is needed for a triplet pregnancy to be included in the 10th decile.

Adolescent↗
PubMed2005

Gestational age-specific distribution of twin birth weight discordance.

AIM: To examine the gestational age-specific distribution of twin birth weight discordance. METHODS: We analyzed all liveborn twin sets between 28 and 40 weeks' gestation from the United States 1995-1998 Multiple Matched Birth Data Set compiled by the National Center for Health Statistics. We calculated the 50th and 95th percentiles of birth weight discordance at each gestational age. Neonatal mortality rates were calculated for discordant twins at the 95th percentile of birth weight discordance for each gestational age. RESULTS: At older gestational ages, the 95th percentile of birth weight discordance resulted in an inter-twin birth weight difference of approximately 25%, a value often used to define twins as birth weight discordant. However, at earlier gestational ages, the 95th percentile of birth weight discordance was greater, reaching nearly 50% at 28 weeks. CONCLUSIONS: The inter-twin birth weight difference at the 95th percentile is greater at lower gestational ages, possibly illustrating the different nature or severity of twin birth weight discordance at an earlier gestational age.

Birth Weight↗
PubMed2005

Early adequate maternal weight gain is associated with fewer small for gestational age triplets.

OBJECTIVE: To examine whether the recommended weight gain during the first 24 weeks reduces the frequency of SGA triplets. STUDY DESIGN: We used data collected by the Women's Health Division of Matria Healthcare, Inc (Marietta, GA). We studied the frequency of SGA triplets (birth weight <10th percentile by triplet standards) by weight gain, parity, and pregravid BMI category. Adequate weight gain was defined as >16.2 kg at 24 weeks and BMI categories were defined as underweight (<19.8), normal (19.8-26), and obese (BMI>26). RESULTS: We studied 2890 triplet sets. Adequate weight gain reduces the frequency of SGA triplets, irrespective of pregravid BMI category and parity, except for obese nulliparous women. However, the reduced frequency of SGA infants was significant only in underweight nulli-paras (OR 0.3, 95% CI 0.1, 0.9). CONCLUSION: Higher pregravid BMI and parity seem to reduce the occurrence of SGA triplets. However, lean mothers, especially nulliparas, may be the most important target population for nutritional intervention in triplet pregnancies.

Adult↗
PubMed2005

[Psychosocial aspects of the direct path from infertility to the "instant family": are all risks known].

Infertility is invariably described as a crisis event. Couples who encounter infertility are further challenged with the accompanied sense of profound losses: loss of health, sexuality, status and prestige, relationship, self-confidence, self-esteem, security, and the fantasy for biological parenthood. Fertility treatments (ART) create hope and cure for the problem on one hand, but place a tremendous burden on the couple's resources on the other. Assisted Reproductive Technologies (ART), carry potential risks for both the infant and for the mother, in addition to diverse negative psychosocial consequences for the couple. However, it seems that couples either ignore these risks or are unaware of them, and therefore, wish to accomplish the "instant family" (more than one child) via a shortcut (one pregnancy). Although it is impossible to ignore the numerous children born with the aid of ART, it is crucial that professionals inform the couple about the medical as well as the psychological consequences that accompany fertility treatments, to enable couples to make more realistic decisions.

Family↗