FERTILITY AND STERILITY

Vol. 56, No.1, July 1991

Copyright C> 1991 The American Fertility Society

Printed on acid·free paper in U.S.A.

In vivo and in vitro maturation of human oocytes: effects on embryo development and polyspermic fertilization*

Mary E. Jamieson, B.Sc.t Richard Fleming, Ph.D. Samad Kader, M.R.C.O.G.

Karen S. Ross Robert W. S. Yates, M.R.C.O.G. John R. T. Coutts, Ph.D.

University Department of Obstetrics and Gynaecology, Glasgow Royal Infirmary, Glasgow, Scotland

Objective: To compare the effects of in vivo and in vitro maturation of human oocytes. Design: Women (n = 60) undergoing follicular stimulation for in vitro fertilization, using longcourse analog therapy to suppress endogenous luteinizing hormone (LH), were randomly allocated to a short (34 hour) or long (39 hour) delay between human chorionic gonadotropin (hCG) administration and oocyte retrievaL Each patient's oocytes were divided into two groups that were either inseminated immediately or after 5 hours. Results: The incidence of polyspermic fertilization was highest in oocytes inseminated immediately after a short hCG/oocyte retrieval interval (17/100) and was significantly (P < 0.05) reduced by preincubation and/or a long hGG/oocyte retrieval intervaL Fertilization rates were higher with 39 hours than with 34 hours in vivo maturation (84.2% versus 76.8%; P < 0.05). The incidence of delayed fertilization was reduced by extending the hCG/oocyte retrieval interval (short, 12.9%; long, 3.9%; P < 0.001). Conclusions: Extension of the in vivo maturation time increased fertilization rates and eliminated the requirement for pre insemination incubation, allowing simplification of laboratory procedures. Fertil Steril 56:93, 1991

In most in vitro fertilization (IVF) programs, the commonly practiced delay between administration of the luteinization stimulus (human chorionic gonadotropin [heG]) and oocyte retrieval is 32 to 36 hours. This was derived from studies on patients in whom follicular growth was induced by clomiphene citrate and/or human menopausal gonadotropin (hMG)1-3 and is essentially a compromise between allowing maximum in vivo maturation of oocytes and their retrieval before there is a significant risk of ovulation. In vitro fertilization methodology usually includes, before insemination, a 4 to 6-hour in vitro oocyte preincubation that minimizes the inReceived October 19, 1990; revised and accepted March 12, 199L * Supported in part by grant TA/GB/W75 from the White Top Foundation, Dundee, Scotland. t Reprint requests: Mary E. Jamieson, B.Sc., University Department of Obstetrics and Gynaecology, Glasgow Royal Infirmary, 10 Alexandra Parade, Glasgow G31 2ER, Scotland.

Vol. 56, No.1, July 1991

cidence of polyspermic fertilization and increases the proportion of oocytes that fertilize and develop into normal embryos.4 In patients stimulated using combined therapy of gonadotropin-releasing hormone analog (GnRH-a) and hMG, in which luteinizing hormone (LH) levels are suppressed, ovulation did not occur before 39 hours, and fertilization rates were higher in cycles with delayed oocyte retrieval. 5 The present study investigated if a prolonged delay between the luteinizing stimulus and oocyte retrieval, using the combined therapy, obviated the requirement for preincubation and compared the effects of in vivo and in vitro oocyte maturation on development of the block to polyspermy, fertilization rates, and embryo development. MATERIALS AND METHODS

(n

Sixty women with tubal (n = 50) or unexplained = 10) infertility, undergoing follicular stimulation

Jamieson et aI.

In vivo/in vitro oocyte maturation

93

r

HCG

1 hCG/OR INTERVAL

Figure 1

/~

/~

PREINCUBATION TOTAL MATURATION TIME

LONG (39 h)

SHORT (34 h)

Oh

Oh

5h

5h

1

1 34 h

39 h

44h

Representation of experimental design.

for IVF were included in the study. Male problems were excluded. Multiple follicular growth was induced by longcourse analog therapy with GnRH-a (buserelin acetate, Suprefact; Hoechst UK Ltd, Milton Keynes, United Kingdom) and hMG (Pergonal; Serono UK Ltd, Welwyn Garden City, United Kingdom).6 Gonadotropin-releasing hormone-analog was initiated in the luteal phase (day 21) of the previous cycle and continued until hCG administration. Three days after menstruation, hMG was initiated at a dose of three ampules per day (225 IU follicle-stimulating hormone and 225 IU LH) and titrated as indicated by monitoring (plasma estradiol [E21 concentrations and serial ovarian ultrasound [US, Sonoline SL-1 with 7.5 MHz vaginal probe; Siemens Limited, Sunbury-on-Thames, United Kingdom]). The ovulatory dose of hCG (5,000 IU, Profasi; Serono UK Ltd) was administered when at least three mature follicles (mean diameter ;;:: 17 mm) were seen on US with concomitant E2 levels (> 1.0 ng/mL and

In vivo and in vitro maturation of human oocytes: effects on embryo development and polyspermic fertilization.

To compare the effects of in vivo and in vitro maturation of human oocytes...
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