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Biomedical subjects

N Fries

Publications and source records attributed to N Fries.

12 recordsLinked to original sources
PubMed2006

French fetal biometry: reference equations and comparison with other charts.

OBJECTIVES: To construct new reference charts and equations for fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), using a large sample of fetuses examined at 15-40 weeks in France, and to compare them with previous references. METHODS: The study data were obtained over a continuous 1-year period from a population of pregnant women undergoing ultrasound examination. Excluded were those with a known abnormal karyotype or congenital malformation, multiple pregnancies, and those with no first-trimester dating based on crown-rump length. No fetuses were excluded on the basis of abnormal biometry or birth weight. For each measurement, separate regression models were fitted to estimate both the mean and the SD at each gestational age. RESULTS: Full biometric measurements were obtained for 19 647 fetuses. New charts and reference equations are reported for BPD, HC, AC and FL. Prediction intervals for the new reference charts were similar to those of previous ones, whereas there were some differences in predicted centiles. CONCLUSION: We present new French reference charts and equations for fetal biometry. They can be used easily to compute centiles and Z-scores to control the quality of biometric assessments and to evaluate their performance relative to other references.

Abdomen↗
PubMed1988

Evidence for an adverse effect of elevated serum estradiol concentrations on embryo implantation.

Multiple follicular stimulation for IVF may be associated with greatly elevated serum E2 concentrations that are presumed to be antinidatory. This factor was analyzed in 825 consecutive embryo transfer cycles. The pregnancy rate decreased significantly after the transfer of one and two embryos in association with preovulatory E2 levels greater than the 90th percentile for the group (2320 pg/ml). The pregnancy rate did not vary with preovulatory E2 concentration following the transfer of three embryos. Highly significant correlations were noted between preovulatory E2 and early luteal phase concentrations of E2 and P. In a subgroup of 245 cycles, there were no significant relationships between implantation and early luteal phase levels of P or the ratio of E2/P. There was a small but nonsignificant tendency for the pregnancy rate to decrease in association with raised luteal E2. It is concluded that excessive E2 levels at the time of ovulation induction with hCG had an adverse effect on implantation when one or two embryos are transferred, but this may be overcome by the transfer of three embryos. The consequences for embryo transfer are discussed.

Embryo Implantation↗
PubMed1988

Improvements in ovarian stimulation for in vitro fertilization.

What are the major improvements in stimulation over recent years? The stimulated cycle has completely superseded the natural cycle since this is the only method of obtaining several embryos. In conventional stimulation, despite an enormous body of literature, no single treatment modality has emerged as superior to other forms of therapy. Undoubtedly it is the experience and habits of individual IVF teams that determine the success of one or another method. Therefore programmed stimulation is an improvement in that it introduces the factors of convenience and simplicity while retaining the clinical efficacy of stimulation by conventional treatment. The analogues of LHRH are still in an early phase of development, but they appear to be associated with a low cancellation rate even in previous poor-responders. Furthermore, preliminary results seem to indicate that this is the first development since the widespread adoption of follicular stimulation, which is associated with an increased pregnancy rate. We are currently involved in trying to associate programmed stimulation and analogue treatment in a bid to combine the advantages of both therapies. Finally, embryo cryopreservation must be mentioned. There is no point in refining our stimulation protocols to obtain many embryos if those surplus to immediate requirement are disposed of. Cryopreservation offers the means of maximizing the pregnancy potential of a single IVF cycle while reducing the possibility of multiple pregnancy.

Embryo, Mammalian↗
PubMed1987

The effect of dydrogesterone supplementation in an IVF programme.

Various treatments are given during the luteal phase by most IVF programmes, without any proof of their efficacy. We have performed a double-blind, randomized study with dydrogesterone (125 transfers) against placebo (133 transfers). The pregnancy rate was 21.6 versus 15.0% per transfer cycle with dydrogesterone or placebo, respectively. There was no significant difference between these figures, but taking into account the usual success rate in IVF programmes (15-20%) a difference of 5% would be significant only with two groups of 1500 subjects. This paper discusses the question of how we can come to a definite conclusion on the efficacy of hormonal supplementation during the luteal phase.

Adult↗
PubMed1987

One year's experience with programmed oocyte retrieval for IVF.

We have previously described a simplified form of ovulation stimulation for IVF in which the day of presumed oocyte retrieval is determined several weeks in advance. This paper retrospectively analyses this technique in 296 unselected patients over a one year period to assess if the method is suitable for routine use in an IVF programme. Oocyte retrieval was performed on the predetermined day in 70% of patients commencing stimulation. In the remainder, the presumptive day of oocyte retrieval was modified, or the cycle was cancelled. Compared with 356 patients undergoing a comparable classically monitored IVF stimulation during the same period, there was no significant difference in the cancellation rate of cycles prior to oocyte recovery, in the numbers of oocytes or embryos obtained or in the pregnancy rate between the two populations. It is concluded that programmed oocyte retrieval does not have a deleterious effect on the success rate of IVF compared with classical clomiphene citrate/HMG stimulation and it considerably facilitates the administration of an IVF programme.

Clomiphene↗
PubMed1986

An obstetric assessment of the first 100 births from the in vitro fertilization program at Clamart, France.

From April, 1981, to July, 1984, 142 pregnancies have been attained after in vitro fertilization and embryo transfer. They are divided into 22 biochemical pregnancies (human chorionic gonadotropin greater than or equal to 20 mU/ml but remaining below 1000 mU/ml), 27 spontaneous abortions, three ectopic pregnancies, and 90 ongoing pregnancies, of which 11 were twin pregnancies. The 90 women in whom the pregnancies progressed were compared with the 52 women having nonprogressive pregnancies. The two populations did not differ either in age, in the indication for in vitro fertilization and embryo transfer, or in the quality of ovulation or results of semen analysis. The 90 ongoing pregnancies were compared with those pregnancies occurring in the same obstetrics department during this period. We found that the in vitro fertilization group had a higher proportion of arterial hypertension (16.5% versus 8.5%, p less than 0.05), breech presentations (13.9% versus 4.3%, p less than 0.001), and caesarean sections (46.8% versus 15.5%, p less than 0.001) but the sex ratio did not differ.

Abortion, Spontaneous↗
PubMed1975

[Studies on cerebrospinal fluid diffusion of trimethoprim in children].

Full quantitative fluorometric analysis of TMP in serum and cerebrospinal fluid in 91 infants and children (all anyhow designed for lumbar puncture for other reasons) 1/2 - 12 hours after i. v. injection of TMP in a single dose of 4 mg/kg (73 cases, tab. 1-2, fig. 1) or 12 mg/kg (18 cases, tab. 3, fig. 2). TMP in serum and cerebrospinal fluid showed regularly high plateaus for the whole time investigated, i.e. 12 hours after i. v. injection (fig. 1-2). The c.s.f./serum ratio for TMP (2-12 hours after injection) was 30-40%(fig. 1). After a dose of 12 mg/kg the ratio was even 50% and more (fig. 2). There were - in our material - no differences of the ratio according to c.s.f. state (normal - tab. 1, or pathological-tab. 2), or age. Considerating published data on enteral resorption of trimethoprim-sulfamethoxazole and c.s.f. diffussion of SMZ together with our results, we can expect a very intensifying proportion TMP: SMZ near 1:10 in cerebrospinal fluid after intake of officinal TMP-SMZ (Co-trimoxazol). This might have diagnostic and therapeutic consequences.

Child↗