Preimplantation genetic diagnosis for the treatment of failed in vitro fertilization-embryo transfer and habitual abortion.

Objective: To apply preimplantation genetic diagnosis (PGD) for the treatment of patients with a history of failed FVF-ET or habitual aborters. Design: Prospective clinical study. Setting: Tertiary center for assisted reproduction. Patient(s): Ninety-four couples with failed IVF-ET after >2 F/F cycles and 64 couples with >2 spontaneous abortions. Intervention(s): Patients were prepared for oocyte retrieval using standard controlled ovarian hyperstimulation protocols after standard laboratory techniques. Blastomeres from 6- to 8-cell embryos were analysed using fluorescence in situ hybridization with commercial chromosomal probes, and normoploid embryos were transferred on day 3 after fertilization. Main Outcome Measure(s): Pregnancy and implantation rates and live births. Result(s): Both 3- and 5-probe PGD resulted in a significantly higher outcome than controls for failed IVF-ET. Five-probe PGD appeared to be more suitable for habitual aborters. Conclusion(s): This pilot study suggests that 3-probe PGD is a valid option for failed IVF-ET patients. The use of five or more probes is indicated for habitual aborters

Amino acids for the neonate: Search for the ideal dietary composition

Amino acids play crucial roles as precursors for proteins and neurotransmitters, as transport molecules, and in cell signaling. In this review, we describe the unique functions of the individual amino acids and conclude that the amino acid requirements of parenterally fed neonates are inadequately defined. Parenterally fed neonates are at risk of amino acid deficiency or toxicity because the intestines serve as an important site of metabolism, regulating systemic availability of individual amino acids

Phenylalanine requirements of enterally fed term and preterm neonates

Background: Phenylalanine, which is an essential aromatic amino acid, is either used for protein synthesis or irreversibly hydroxylated to tyrosine. The provision of optimal amounts of dietary phenylalanine is not only important for growth and development but might also influence catecholamine synthesis and release rates. The current recommended aromatic amino acid requirement for infants aged 0-6 mo is based on the amino acid content of human milk. Objective: We quantified the requirements for phenylalanine in the presence of excess tyrosine (166 or 177 mg/kg per day for term and preterm infants, respectively) for term and preterm neonates by using the indicator amino acid oxidation method with L-[1-C-13]lysine 2HCl as an indicator. Hence, we determined the minimum obligatory phenylalanine requirement. Design: Fully enterally fed term and preterm infants received randomly graded amounts of phenylalanine (5-177 mg/kg per day) as part of an elemental formula. Data are expressed as means +/- SDs. Results: Twenty term (birth weight: 3.19 +/- 0.34 kg; gestational age: 38.9 +/- 1 wk) and 16 preterm (birth weight: 1.75 +/- 0.17 kg; gestational age: 32.5 +/- 0.6 wk) Asian infants participated at a postnatal age of 17 +/- 8 d. In total, 44 studies were performed. The minimum obligatory phenylalanine requirement was 58 mg/kg per day (95% CI: 38-78 mg/kg per day) and 80 mg/kg per day (95% CI: 40-119 mg/kg per day) for term and preterm infants, respectively. Conclusion: The determined mean phenylalanine-requirement estimates are lower than the contents of term and preterm formulas currently on the market. This trial was registered at www. trialregister.nl as NTR1610