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Dive into the research topics where Olaf G.J. Naether is active.

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Featured researches published by Olaf G.J. Naether.


Fertility and Sterility | 1993

Morphometric characteristics of endometrial biopsies after different types of ovarian stimulation for infertility treatment

Annette Bonhoff; Olaf G.J. Naether; Elisabeth Johannisson; Heinz G. Bohnet

OBJECTIVE To investigate whether various types of ovarian stimulation induce differences in endometrial development at the midluteal phase in infertile women. DESIGN Assessment of stromal and glandular compartments in endometrial biopsies using morphometric criteria. SETTING Institute for Hormone and Fertility Research, Hamburg, Germany. PATIENTS The study included 18 women after treatment with human menopausal gonadotropin (hMG)/human chorionic gonadotropin (hCG) (group I), 23 women after clomiphene citrate (CC)/hMG/hCG treatment (group II), and 12 women after CC stimulation (group III). INTERVENTIONS Endometrial biopsies and blood samples were taken simultaneously in the early to midluteal phase. To assess the time of ovulation, hormone analysis and regular checks by ultrasonography were performed. MAIN OUTCOME MEASURES Morphometric evaluation of glandular and stromal structures revealed an impaired endometrial development after various treatment protocols. CONCLUSION Ovarian stimulation in infertile women results in most cases in an elevation of steroid levels; however, the occurrence of an inadequate endometrial development might have an unfavorable influence on the outcome of implantation. Therefore, these findings may be of importance to the choice of treatment for infertility.


Fertility and Sterility | 1994

24-Hour profiles of salivary progesterone

Torsten Delfs; Susann Klein; Patrick Fottrell; Olaf G.J. Naether; Freimut A. Leidenberger; Ralf C. Zimmermann

OBJECTIVES To assess whether the known pulsatility of P secretion by the corpus luteum, which is detected in blood by P measurements, translates into fluctuations of saliva P concentrations, and to determine how well saliva P measurements reflect plasma P concentration. A second objective was to see whether there is a window in the luteal phase, where P secretion has reached its maximum capacity, but the amplitude is not very accentuated, which would be an ideal time to measure P. DESIGN Twenty-one ovulatory women were randomly assigned to be studied on day 5, 7, or 8 after the luteinizing hormone surge. Blood samples were drawn every 20 minutes, and saliva samples were obtained hourly over a 24-hour period. Comparison between saliva plasma P was performed, and pulse analysis of plasma P was done. RESULTS The percent variation of saliva P concentration over a 24-hour period was much higher when compared with the percent variation of plasma P concentration over the same time period (saliva P: 149%; plasma P: 107%). Also, the ratio of saliva to plasma P varied significantly between individuals (range: 0.0050 to 0.0148). A single plasma P concentration (8:00 A.M.) correlated better with the 24-hour mean plasma concentration than the respective single saliva value or the mean of two or three saliva samples (8:00 A.M. and 12:00 P.M.; 8:00 A.M., 12:00 P.M., and 8:00 P.M.). Plasma pulse frequency, mean pulse interval, pulse width, pulse amplitude, and 24-hour mean P level did not differ between the 3 study days. CONCLUSIONS A single plasma P determination reflects more accurately 24-hour P secretion than repeated saliva P samples measured in the same individual. We could not identify a window in the luteal phase when P measurements are more representative of corpus luteum function.


Drug, Healthcare and Patient Safety | 2015

Individualized recombinant human follicle-stimulating hormone dosing using the CONSORT calculator in assisted reproductive technology: a large, multicenter, observational study of routine clinical practice

Olaf G.J. Naether; Andreas Tandler-Schneider; Wilma Bilger

Purpose This postmarketing surveillance survey was conducted to investigate the utility of the CONsistency in r-FSH Starting dOses for individualized tReatmenT (CONSORT) calculator for individualizing recombinant human follicle-stimulating hormone (r-hFSH) starting doses for controlled ovarian stimulation (COS) in routine clinical practice. Methods This was a 3-year, open-label, observational study evaluating data from women undergoing COS for assisted reproductive technology at 31 German fertility centers. Physicians stated their recommended r-hFSH starting dose, then generated a CONSORT-recommended r-hFSH starting dose. Physicians could prescribe any r-hFSH starting dose. The primary objective was to compare the r-hFSH starting dose recommended by the physician with the CONSORT-calculated dose and that prescribed. Statistical analyses were conducted post hoc. Results Data were collected from 2,579 patients; the mean (standard deviation [SD]) age was 30.5 (2.93) years (range: 19–40 years). The mean (SD) CONSORT-calculated r-hFSH starting dose was significantly lower than the physician-recommended dose (134.5 [38.0] IU versus 164.6 [47.1] IU; P<0.0001); the mean (SD) starting dose prescribed was 162.2 (48.4) IU. CONSORT-calculated doses were prescribed for 27.3% (number [n] =677) of patients, and non-CONSORT-calculated doses prescribed for 72.7% (n=1,800). The mean (SD) number of oocytes retrieved per patient was 10.6 (6.15) and 11.4 (6.66) in the CONSORT and non-CONSORT groups, respectively; the mean (SD) number of embryos transferred per patient was 1.98 (0.41) and 2.03 (0.45), respectively. Clinical pregnancy rates per COS cycle were 38.8% (CONSORT) and 34.8% (non-CONSORT) (P=0.142); clinical pregnancy rates per embryos transferred were 45.0% and 39.5%, respectively (P=0.049). Miscarriage occurred in 14.8% of all clinical pregnancies (CONSORT: 12.5%; non-CONSORT: 15.3%). The rate of grade 3 ovarian hyperstimulation syndrome (OHSS) was 0.3% (n=2) in the CONSORT group and 0.6% (n=11) in the non-CONSORT group. OHSS led to hospitalization in 0.81% (n=21) of cases (CONSORT group: 0.74% [n=5]; non-CONSORT group: 0.83% [n=15]). Conclusion Physician-recommended r-hFSH starting doses were generally higher than those calculated by CONSORT; most patients were prescribed a higher starting dose than that recommended by CONSORT.


Obstetrical & Gynecological Survey | 1994

Laparoscopic Electrocoagulation of the Ovarian Surface in Infertile Patients With Polycystic Ovarian Disease

Olaf G.J. Naether; Robert Fischer; Hans Christoph Weise; Linda Geiger-Kötzler; Torstea Delfs; Klaus Rudolf

OBJECTIVE To assess the endocrinologic and clinical outcome after laparoscopic ovarian electrocautery because of polycystic reaction to ovarian stimulation in anovulatory infertility patients. DESIGN Between 1986 and 1989, 133 patients with polycystic ovarian disease underwent laparoscopic electrocoagulation of the ovarian surface in an outpatient clinic after conventional ovarian stimulation had led to polycystic reaction. SETTING All patients were referred to our outpatient clinic affiliated with the university hospital. RESULTS The reduction of androgen levels and normalization of cycle length were highly significant. The overall pregnancy rate was 70% (73 of 104), ranging from 27% in smokers to 94% in nonsmoking couples. In 26 second-look operations de novo adhesions were found in 26.9% of the patients. CONCLUSION Laparoscopic coagulation of the ovarian surface is an effective tool to reduce elevated androgen levels and to improve the intraovarian mechanism of selecting a dominant follicle. A postoperative complication may be adhesion formation.


Fertility and Sterility | 1990

Patterns of serum-luteinizing hormone surges in stimulated cycles in relation to injections of human chorionic gonadotropin**Supported by Serono Diagnostics, Freiburg, FRG.

Vera Baukloh; Robert Fischer; Olaf G.J. Naether; Heinz-G. Bohnet

Endogenous-luteinizing hormone (LH) surges may complicate the management of in vitro fertilization cycles. To investigate the effects of LH surges after hormonal stimulation 53 IVF cycles were analyzed by assessing LH levels three times daily until egg collection. In 43% the LH rise started before the planned exogenous trigger for ovulation was given, in 11% the rise occurred simultaneously with and in 45% after the injection of human chorionic gonadotropin. Three main patterns of serum LH surges were identified: (A) low-LH tonus with straight increase to maximum; (B) low tonus with elevation before straight increase; (C) high tonus with large variations but no prominant peak. These patterns were not related to the follicular estradiol increase, luteal steroid concentrations or resulting pregnancy rates.


Fertility and Sterility | 1993

Laparoscopic electrocoagulation of the ovarian surface in infertile patients with polycystic ovarian disease

Olaf G.J. Naether; Robert Fischer; Hans Christoph Weise; Linda Geiger-Kötzler; Torsten Delfs; Klaus Rudolf


Human Reproduction | 1994

Surgery:Long-term follow-up in 206 infertility patients with polycystic ovarian syndrome after laparoscopic electrocautery of the ovarian surface

Olaf G.J. Naether; V. Baukloh; Robert Fischer; T. Kowalczyk


Fertility and Sterility | 1993

Adhesion formation after laparoscopic electrocoagulation of the ovarian surface in polycystic ovary patients

Olaf G.J. Naether; Robert Fischer


Human Reproduction | 1996

Effects of clomiphene citrate stimulation on endometrial structure in infertile women

Annette Bonhoff; Olaf G.J. Naether; Elisabeth Johannisson


Fertility and Sterility | 1990

Patterns of serum-luteinizing hormone surges in stimulated cycles in relation to injections of human chorionic gonadotropin *

Vera Baukloh; Robert Fischer; Olaf G.J. Naether; Heinz-G. Bohnet

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Elisabeth Johannisson

Katholieke Universiteit Leuven

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