A spare or an individual? Cloning and the implications of monozygotic twinning.
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The creation of Dolly, the cloned sheep, raises the scenario of cloning in humans. Neither the case for, nor against, the ethics of cloning in humans is discussed in this paper. Instead, it considers the neglected issue of the likely happiness or otherwise of the resulting children if they are born as monozygotic twins or triplets. The advantages and disadvantages of twinship are discussed in detail, and it is concluded that recognized medical risks, and incompletely understood psychological effects, should be given serious consideration. (+info)
Early prenatal diagnosis of cord entanglement in monoamniotic multiple pregnancies.
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OBJECTIVES: Cord entanglement is a severe complication in monoamniotic multiple pregnancies. Three cases were reviewed to determine how early ultrasound diagnosis might improve counselling and management. METHODS: In two monoamniotic twin and one dichorionic diamniotic triplet pregnancies, cord entanglement was detected between 10 and 18 gestational weeks by color Doppler and pulsed Doppler velocimetry. Pregnancies were followed up on a weekly basis with special observation of fetal behavior and use of color Doppler velocimetry. RESULTS: In Case 1, a monoamniotic twin pregnancy with cord entanglement close to the umbilical insertions was diagnosed at 10 weeks. Longitudinal follow-up showed intrauterine death of both twins at 15 weeks. In Case 2, entanglement of the umbilical cords of two monoamniotic triplets within a dichorionic diamniotic triplet pregnancy was diagnosed at 10 weeks. The pregnancy continued uneventfully until 35 weeks when cord entanglement was confirmed at Cesarean section. All triplets have since developed normally. In Case 3, monoamniotic twins were diagnosed at 18 weeks. Color Doppler detected side-by-side insertion of the umbilical cords and Doppler velocimetry suggested an entanglement at the chorionic plate. The pregnancy was complicated by polyhydramnios. Cesarean section at 36 weeks confirmed cord entanglement at the chorionic plate. Postnatal computer angiography and morphological examination of the placenta showed the presence of superficial artery-to-artery and vein-to-vein anastomoses and of deep arteriovenous shunts. The development of the twins was uneventful. CONCLUSIONS: Diagnosis of cord entanglement is feasible early in gestation. Future protocols are proposed to document the gestational age at detection, the location, and the Doppler flow patterns and to facilitate the assessment of short- and long-term development. (+info)
Perinatal outcome after in-vitro fertilization-surrogacy.
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The perinatal outcome of pregnancies (both single and multiple) established after in-vitro fertilization (IVF)-surrogacy was evaluated and compared to the outcome of pregnancies that resulted from standard IVF. Analysis of medical records and a telephone interview with physicians, IVF-surrogates, and commissioning mothers were conducted to assess prenatal follow up and delivery care in several hospitals. 95 IVF-surrogates delivered 128 liveborn (65 singletons, 27 sets of twins and two sets of triplets). The commissioning mothers and the IVF-surrogates average ages were 37.7 +/- 5.0 and 30.4 +/- 4.7 years old respectively. IVF-surrogates carrying twin and triplet gestations delivered substantially earlier than those who gestated singleton pregnancies (36.2 +/- 0.4 versus 35.5 versus 38.7 +/- 0.3 weeks gestation respectively; P < 0.001). Twin newborns were significantly lighter than singleton infants born through IVF-surrogacy (2.7 +/- 0.06 versus 3.5 +/- 0.07 kg; P < 0.001). The incidence of low birth weight infants rose from 3.3% in the single births to 29.6% (P < 0.01) in the twins and to 33.3% in the triplets born through IVF-surrogacy. The incidence of prematurity was significantly greater in both twins delivered by IVF-surrogates (20.4%) and infertile IVF patients (58%). The occurrence of pregnancy-induced hypertension and bleeding in the third trimester was four to five times lower in the IVF-surrogates, independently of whether they were carrying multiples. The incidence of Caesarean section was 21.3% for singleton gestations, while two times higher in the IVF-surrogates carrying multiples (56.3%). Postpartum complications occurred in 6.3% of patients and the incidence of malformation was similar to those reported for the general population. The results provide general reassurance regarding perinatal outcome to couples who wish to pursue IVF-surrogacy. (+info)
Comparison of fetal growth in singleton, twin, and triplet pregnancies.
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The objective of this longitudinal retrospective study was to evaluate differences of the fetal growth and fetal organ growth among singleton small for gestational age (S-SGA), singleton appropriate for gestational age (S-AGA), twin (Tw-AGA), and triplet (Tri-AGA) infants. Ultrasonographic examinations were performed on 35 S-AGA, 18 S-SGA, 52 Tw-AGA and 12 Tri-AGA fetuses. Circumferences of head (HC), abdomen (AC), spleen (SC) and adrenal gland (AGC) and lengths of femur diaphysis (FDL), liver (LL), estimated weight (EWT) were measured every 2 weeks after 15 weeks of menstrual age until delivery. There was no significant difference in predicted HC values in S-AGA, Tw-AGA and Tri-AGA fetuses; these values were lowest in S-SGA fetuses. As the number of fetuses in the uterus increased with advancing menstrual age, the slope of the growth curve for predicted AC value became lower, but there was no significant difference between Tri-AGA and S-SGA fetuses. There was no significant difference in predicted FDL values among Tw-AGA, Tri-AGA and S-SGA fetuses; those values were significantly lower than that in S-AGA fetuses. There was no significant difference in predicted EWT value between Tw-AGA and Tri-AGA fetuses, which were intermediate between those for S-AGA and S-SGA fetuses. There were no significant differences in predicted SC and AGC values between S-AGA and Tw-AGA fetuses, respectively. However, in S-SGA fetuses, the slopes of the growth curve for SC and AGC were lower than those in the other two groups with advancing menstrual age. There were slight differences in predicted LL values between S-AGA, S-SGA and Tw-AGA fetuses. These results suggest that in AGA fetuses, there was a slight difference in growth pattern among singleton, twin, and triplet pregnancies. (+info)
Trisomy 2 in an acardiac twin in a triplet in-vitro fertilization pregnancy.
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A case is reported of twin reversed arterial perfusion (TRAP) sequence in a triamniotic dichorionic triplet pregnancy conceived by in-vitro fertilization which was diagnosed at 25 weeks of gestation by colour Doppler sonography. It highlights the risk of monochorionicity-associated morbidity in multiple pregnancies obtained by assisted conception and stresses the importance of chorionicity determination by early ultrasound examination. Cytogenetic analysis of skin from the acardius showed trisomy 2 in all cells, whereas the karyotype in the monochorionic triplet was normal. This is an example of heterokaryotypic monozygotism where the chromosomal abnormality must have occurred during the early cleavage divisions. Aneuploidy as a possible aetiological factor of TRAP sequence is discussed. (+info)
Incidence and perinatal outcome of multiple pregnancies after intracytoplasmic sperm injection compared to standard in vitro fertilization.
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PURPOSE: Our purpose was to assess the incidence of multiple pregnancies and their obstetric outcome after intracytoplasmic sperm injection. METHODS: The study group comprised women who delivered twins or triplets after intracytoplasmic sperm injection and standard in vitro fertilization. The incidence and main perinatal outcome of 140 multiple pregnancies resulting from intracytoplasmic sperm injection or standard in vitro fertilization treatment were analyzed. RESULTS: A total of 60 multiple pregnancies was obtained after intracytoplasmic sperm injection (3.4 +/- 1.1 embryos/cycle) and 80 after standard in vitro fertilization (3.3 +/- 2.0 embryos/cycle). The incidence of multiple pregnancy, i.e., 22.6 compared to 20.7%, respectively, was calculated. The obstetric outcome of 47 multiple pregnancies after intracytoplasmic sperm injection was 39 twin deliveries at between 27 and 37 weeks of gestation (mean, 36 +/- 3.3) and 8 successful triplet deliveries between 26 and 36 weeks of gestation (mean 32.6 +/- 2.4). The outcome after regular in vitro fertilization was similar. No major malformations were observed. CONCLUSIONS: The results of this study showed that the incidence of multiple pregnancies after intracytoplasmic sperm injection was similar to that after standard, conventional in vitro fertilization. The perinatal outcome did not differ between both groups. (+info)
Triplet pregnancy achieved through intracytoplasmic sperm injection with spermatozoa obtained by prostatic massage of a paraplegic patient: case report.
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Spinal cord-injured men with ejaculation disorders can have children thanks to assisted reproduction techniques. Spermatozoa from these patients are usually obtained through vibratory stimulation, electroejaculation or by puncturing the seminal duct or the testicle. We present the first published case, as far as we are aware, of spermatozoa obtained through prostatic massage of a paraplegic patient. Penile vibratory stimulation was unsuccessful in this patient. In-vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) with spermatozoa obtained through electroejaculation was performed at another centre but pregnancy was not achieved. Through prostatic massage, we obtained a total semen volume of 6 ml containing a total count of 12.32x10(6) spermatozoa (6.24x10(6) with tails), 8% of which had motility (graded + and ++); and 16% of which had normal morphology. The spermatozoa obtained were then used to perform IVF with ICSI and a triplet pregnancy was achieved. Prostatic massage appears to be an easy, non-traumatic and risk-free method to obtain spermatozoa from paraplegic patients. (+info)
Doppler waveform analysis of the intertwin blood flow in acardiac pregnancy: implications for pathogenesis.
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OBJECTIVE: To investigate interfetal hemodynamics in acardiac twins and the implications for pathogenesis. DESIGN: A retrospective study. SUBJECTS: All acardiac twins involved in this study were identified by B-mode ultrasound at a teaching hospital in Taiwan. METHODS: Color Doppler imaging and, in one case, color power angiography were used to assess umbilical blood flow between acardiac twins and their normal co-twins. Placental anastomoses were examined by pathologists after delivery. RESULTS: In total five sets of acardiac twins and their normal co-twins were enrolled. Autonomous cardiac activity in the form of a contractile pocket was detected in two cases. Analysis of the pattern of the Doppler waveforms in each case enabled us to classify the type of hemodynamics into one of three categories: 'collision-summation', typified by a pattern of cyclic alternations of bidirectional flow; 'twin-pulse', which described the simultaneous recordings of two opposite constant flows with different pulsating rates; and the 'pump in' pattern, which indicated pulsatile flow in the reversed direction towards the acardiac mass. In two cases we detected, we believe for the first time, an artery-to-vein placental anastomosis between the acardiac twin and its co-twin. The nature of the vascular connections were confirmed on pathological follow-up. CONCLUSIONS: Our observations suggest that acardiac twins may be not only the result of but also the cause of placental vascular anastomoses, which may involve either artery-to-artery or artery-to-vein anastomoses. (+info)