No abstract

OBJECTIVE.The

In singleton pregnancies after in-vitro fertilization (IVF), increased rates of obstetric and perinatal complications have been reported. Studies that compared IVF twin pregnancies with spontaneously conceived twins have yielded conflicting results. We compared 96 IVF twin pregnancies to 96 controls after elaborate matching. The design of our study precluded matching by zygosity. The monozygosity rate was higher in the control group and this implies that beforehand the risk for a less favourable outcome in the control group was higher than in the IVF group. However, the average birthweight of the IVF children was less than that of children in the control group (P = 0.04). This was not due to more intrauterine growth retardation in the IVF group. The mean gestational age at birth was 5 days shorter in IVF than control pregnancies, and although this difference was not significant it might explain the lower birthweight in the IVF group. The discordance rate in the IVF group was significantly increased. We found no difference in perinatal mortality and morbidity. We conclude that this study provides further evidence for a different outcome of IVF twin pregnancies in comparison with spontaneously conceived twin pregnancies.

The gonadotrophin-releasing hormone antagonist Cetrorelix is in advanced clinical development for the control of endogenous gonadotrophin secretion during the course of a fertility programme. The aim of the present study was to investigate the pharmacokinetics and pharmacodynamics of Cetrorelix following single and multiple s.c. administration of different doses. Thirty-six healthy female volunteers received either 0.25, 0.50 or 1.00 mg Cetrorelix, in a first menstrual cycle as single dose and in a second cycle as multiple dose (daily between cycle days 3 and 16). Frequent blood samples were collected for determination of Cetrorelix, follicle stimulating hormone (FSH), luteinizing hormone (LH), oestradiol and progesterone concentrations. Follicular growth was measured by transvaginal ultrasonography. After single administration of each dose, maximum Cetrorelix concentrations (Cmax) were reached after 1 h, and Cmax and area under curve (AUC) increased linearly with the dose. The median terminal half-life ranged from 5 to 10 h in the three different dose groups. FSH, LH, oestradiol and progesterone concentrations were suppressed, with a nadir at 6-12 h after Cetrorelix administration. During multiple administration, Cmax and AUC also showed dose-linearity. The median terminal half-life of Cetrorelix varied between 20 and 80 h. A dose-dependent suppression of FSH, LH and oestradiol concentrations was observed during treatment. After multiple administration, ovulation was delayed for 5, 10 and 13 days in the 0.25, 0.50 and 1.00 mg dose groups, respectively. In conclusion, Cetrorelix showed linear pharmacokinetics, and effectively delayed the LH surge.

The aim of this study was to investigate the nature of initial treatment provided by dental practitioners to children aged 1-17 years with various types of traumatic dental injuries at public dental clinics in Tanzania. Questionnaires on initial treatment were mailed to 188 practitioners and returned by 138 (73%). The reported treatments were analyzed in relation to the dental practitioners' qualifications and area of practice. Extraction of injured teeth was frequently reported for 64% of the injuries and prescription of antibiotics was reported by 67%, 48% and 46% of the practitioners for soft tissue injuries, concussion, and alveolar fracture respectively. Practitioners working at the Faculty of Dentistry were less involved in treating dental trauma than those at urban and rural clinics (P = 0.001), while no significant association was found with the level of education of the practitioners. Equal proportions of practitioners, about one-third each, reported correct, unnecessary and wrong treatment options. The quality of the treatments provided could not be explained by background variables. It can be concluded that dental practitioners in Tanzania provide a lot of over-treatment for traumatic dental injuries. Therefore, it is suggested that efforts should be made to improve and standardize treatment methods in Tanzania.