Egg Recovery Rates Research Articles

Use of follicle-stimulating hormone alone (urofollitropin*) to stimulate the ovaries for assisted conception after pituitary desensitization

Analyse outcome of FSH therapy alone after pituitary desensitization for assisted conception to compare with published results of conventional hMG. Descriptive study of complete series of patients undergoing IVF-ET or GIFT treatment using the chosen drug protocol without exception. University private IVF-ET clinic within a comprehensive fertility service. All couples (n = 773), including 10% > or = 40 years old, treated by IVF-ET or GIFT (1,097 cycles started and 1,012 attempted egg recoveries) for mainly tubal pelvic infective damage (36% of cycles), endometriosis (16%), sperm disorders (14%) and prolonged unexplained infertility (34%) during 3 calendar years, 1990 to 1992. Ovarian stimulation using FSH alone (urofollitropin, Metrodin; Serono Laboratories Limited, Welwyn Garden City, United Kingdom) after pituitary desensitization using buserelin acetate nasal spray (Suprefact; Hoechst, Hounslow, United Kingdom) from the previous midluteal phase, monitored by ultrasonography and serum E2 measurements, followed by standard IVF-ET or GIFT treatment methods limited to the transfer of no more than three embryos or eggs. Rates per cycle started of cancellation of egg recovery, failure of egg recovery, clinical pregnancy (ultrasound detection of sac), livebirths, and cumulative pregnancy rates (PR) and birth rates. In women < 40 years old and men with favorable sperm (77% of couples and 84% of cycles) the cycle cancellation rate of egg recovery was 7%; attempted egg recovery was successful in every case. For IVF-ET the clinical PR per started cycle and the livebirth rate were 27% and 23%, respectively, and for GIFT 39% and 33%, respectively. The four-cycle cumulative PR by either treatment was 77% and livebirth rate 68%. In women > 40 years old, the cycle PR and birth rate were 14% and 8%, respectively. In cases of sperm disorder the rates in women < 40 years old were 17% and 14%, respectively, and > 40 years old were 18% and 0, respectively. By comparison with the best worldwide results of assisted conception employing pituitary desensitization, the findings demonstrate that FSH alone to stimulate the ovaries is fully effective and highly successful, and supplementation with LH is not needed.

Effect of active immunization against the amino-terminal peptide (alpha N) of the alpha 43 kDa subunit of inhibin (alpha 43) on fertility of ewes

Immunization against the amino-terminal peptide (alpha N) of the alpha 43 subunit of inhibin was shown previously to reduce fertility in ewes. The aim of this study was to examine the effects of active immunization of ewes against alpha N on egg recovery and fertilization rates. Ewes were immunized against alpha N immunogen, and were given 800 I.U. of pregnant mare's serum gonadotrophin at the end of treatment with intravaginal progesterone to synchronize the oestrous cycles. Control ewes received adjuvant only. The ewes were run with fertile rams, and 4 days after withdrawal of the progesterone device the oviducts were flushed to recover eggs and luteal structures on the ovaries were recorded. Eggs were recovered from 17/19 (90%) control ewes compared with 4/16 treated ewes (25%) (P < 0.01), and the egg recovery rates were 76% (45/59) and 17% (7/42) respectively (P < 0.001). The mean number of corpora lutea (CL) per ewe were similar (3.1 +/- 1.4 v. 2.6 +/- 1.0) but several CL in the treated ewes did not appear to have ruptured, and 2 treated ewes had cystic follicles and no CL. There were no apparent differences in either the fertilization rates or the stages of development of fertilized eggs between treated and control ewes. Antibody binding levels in follicular fluid were approximately half those found in peripheral plasma. It is concluded that immunization of ewes against alpha N leads to lowered fertility by suppressing ovulation, implicating alpha N in the normal ovulatory process.

Fertilization and ovum recovery rates in superovulated ewes following cervical insemination or laparoscopic intrauterine insemination at different times after progestagen withdrawal and in one or both uterine horns

In Exp. 1, 40 ewes were used in a 2 x 2 factorial design to investigate the effects of intrauterine versus cervical insemination and superovulation using pig FSH or PMSG and GnRH on egg recovery and fertilization rate. Cervical inseminations were carried out at 48 and 60 h (N = 20 ewes) and intrauterine insemination at 52 h (N = 20 ewes) after progestagen pessary withdrawal. Eggs were recovered on Day 3 of the oestrous cycle. Ovulation, egg recovery and fertilization rates were independent of the type of superovulatory hormone used. Fertilization rate was high irrespective of insemination site but intrauterine insemination at 52 h was associated with a significant (P less than 0.01) decrease in egg recovery of over 40% compared with cervically inseminated ewes. In Exp. 2 ewes were inseminated at 36 (N = 5), 48 (N = 6) or 60 (N = 6) h after pessary withdrawal to determine the optimum intrauterine insemination time to maximize both fertilization rate and egg recovery. Egg recovery per ewe flushed was 23, 59 and 67% after intrauterine insemination at 36, 48 and 60 h respectively. Correspondingly, 0, 85 and 100% of the eggs recovered were fertilized. The results of Exps 1 and 2 suggest that when intrauterine insemination occurs before or during ovulation it interferes with oocyte collection by the fimbria. In Exp. 3 egg recovery and fertilization rates were determined after cervical insemination at 48 and 60 h (N = 8) or intrauterine insemination at 48 (N = 9) or 60 (N = 8) h after progestagen withdrawal. Ewes in the last two groups were subdivided and inseminated unilaterally or bilaterally. Egg recovery was high after cervical insemination (95%) but only 36% of these eggs were fertilized. Unilateral intrauterine insemination was as effective as bilateral in ensuring high fertilization rates (100 versus 97%). Intrauterine insemination at 48 h compared with 60 h resulted in a significantly lower (P less than 0.05) percentage of eggs recovered (42 versus 90% respectively). However, reducing the degree of interference by adopting unilateral rather than bilateral insemination did not alleviate the detrimental effects of the 48-h insemination time on egg recovery. From these results we advocate the adoption of intrauterine insemination at 60 h after progestagen withdrawal to maximize fertilization rate and egg recovery in superovulated ewes.

Direct intrauterine versus cervical insemination:- effects on egg recovery and fertilization in superovulated ewes

The problem of partial or complete failure of fertilization following cervical insemination in superovulated ewes submitted for embryo transfer can largely be overcome by depositing semen directly into the uterine lumen. However this technique, when carried out by mid-line laparotomy in superovulated ewes is associated with a significant reduction in ovum recovery (Trounson &amp; Moore, 1974; Boland &amp; Gordon, 1978). Although the recent introduction of laparoscopic intrauterine (IU) insemination has now removed the need for major surgery when inseminating superovulated ewes its use in non-superovulated ewes often results in a slight depression in litter size (McKelvey, Robinson, Aitken &amp; Henderson, 1985). Such results imply that it too may reduce embryo recovery rates. Indeed our initial experience with the widespread use of the laparoscopic technique to inseminate superovulated ewes, although devoid of proper conventionally-inseminated controls, gave disappointingly low values for embryo recovery.The present study was carried out therefore to determine the effect of direct intrauterine versus natural cervical insemination on egg recovery and fertilization rates in ewes superovulated using porcine FSH or PMSG and GnRH.

Repeated superovulation and surgical recovery of embryos in the ewe.

Repeated superovulation using three treatments of pFSH at intervals of 45 to 55 days during the same breeding season was carried out in 18 Préalpes ewes. The embryos were recovered by surgery after the first two treatments and by slaughter after the last one at Day 6. Three lots of control ewes (n = 5 or 6) receiving the same superovulation treatment were slaughtered respectively at the same time. The first and third repeated superovulation treatments gave averages of 5.2 +/- 0.6 and 4.5 +/- 0.6 corpora lutea. The second one gave 3.4 +/- 0.4 corpora lutea, which was significantly lower than with treatments 1 and 3, but adhesions did not permit a perfect view of the whole surface of the ovaries. Recovery rates decreased regularly with repeated collection (88.2, 52 and 24%, respectively). The proportion of embryos at the morula/blastocyst stage also decreased from 86 and 93% to 6.7% at the third treatment. The development of post-surgical lesions probably caused variations in the apparent rate of ovulation and a decrease of egg recovery and fertilization rates. In control ewes the mean level of superovulation did not vary significantly during the breeding season and embryonic development was normal when checked at slaughter. Repeated superovulation using pFSH is worthwhile only if the eggs are recovered by perfusion with an appropriate catheter (introduced into the uterus by laparoscopy) instead of by surgery.

Fertilization and early embryonic development in androstenedione-immunized Merino ewes

Ewes were immunized against androstenedione (Fecundin) and assigned to be mated 14 days (179 ewes Group C) or 25 days (174 ewes Group B) after a booster immunization with Fecundin. The anti-androstenedione titres at these times were 6790 and 3240 respectively (P less than 0.01). The remaining 169 ewes were untreated controls (Group A). Ewes were mated to entire rams (12 rams to 180 ewes) at their second oestrus after synchronization of oestrus. Immunization against androstenedione caused a shortening of the time from sponge removal to mating (Day 0) and a decrease in the percentage of ewes mated by the rams. Also, ovulation rate was increased after immunization (P less than 0.01), being 1.42, 2.16 and 1.93 for Groups A, C and B respectively. Egg recovery rates on Day 2 were lower in immunized ewes and there was some indication that fertilization rates were lowered. On Day 13 after mating a higher proportion of blastocysts was recovered from ewes in Group A than from those in Groups B and C. Immunization resulted in lower fertilization rates and smaller blastocysts with lower mitotic indexes (P less than 0.01). At Days 24-32 of pregnancy fetal weight was lower in the immunized ewes. At all sampling stages, the proportion of ewes pregnant (fertility) was lowered in immunized ewes. The results of the present study show that significant reproductive wastage occurs in androstenedione-immunized Merino ewes, with lower rates of embryo recovery and delayed embryonic development being found in comparison to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Repeated recoveries of embryos from ewes by laparoscopy

Eight ewes were synchronised in oestrus and induced to superovulate on three occasions over a period of two months. Eggs a a In this paper the word “egg” is used to include embryos and unfertilized ova. were recovered on Day 7 (Day 0 = oestrus) of each cycle by a laparoscopic technique which avoids the adhesion formation normally associated with the conventional surgical procedure. Egg recovery rates were 35% ( 22 62 ), 76% ( 13 17 ) and 66% ( 21 32 ) for the three consecutive recovery sessions. This technique allows ewes to be used repeatedly as embryo donors and should be valuable to research workers and those involved with commercial embryo transfer in sheep.

The evaluation of a laparoscopic insemination technique in ewes

Following synchronisation of oestrus using FGA and PMSG, ewes were inseminated by either the conventional cervical (CC) method or directly into the uterus by laparoscopy (LI). The CC method was carried out either at 48 and 60 hours following progestagen withdrawal with 480 × 10 6 spermatozoa per inseminate or once only at 56 hours with 600 × 10 6 spermatozoa. The laparoscopic method was performed at 52 hr using 48 × 10 6 spermatozoa per ewe. In the first two trials eggs were recovered at laparotomy. The egg recovery rate was significantly lower (P<0.05) for those ewes which had been inseminated by the LI method (74%) compared with those inseminated by the CC method (85%); fertilization rates were not significantly different (92% and 89% respectively). In the third trial 20 ewes were bled to determine their periovulatory LH concentrations and the timing of peak LH concentrations correlated with the outcome of each insemination. Ewes inseminated using laparoscopy did not conceive when their LH surge occurred >58 hr after progestagen withdrawal. In this and in the final experiment, the combined pregnancy rates and litter sizes (assessed radiographically) were 67% (n = 51) and 2.21 (n = 34) for the CC method and 75% (n = 48) and 1.97 (n = 36) for the LI method (P>0.05).

Influence of reduced litter size and daily litter separation on fertility of sows at 2 to 5 weeks postpartum.

Two experiments were conducted to determine the influence of various lactational treatments on the incidence of estrus and subsequent fertility of sows. Experiment 1 consisted of 60 crossbred (Yorkshire X Duroc) sows assigned to one of four treatment groups. Litter size was reduced (RLS) to two to four nursing pigs/sow at 2 (n = 16), 3 (n = 15) or 4 (n = 15) wk of lactation for 5 d before final weaning or litters were weaned from control sows (n = 14) at 5 wk of age. Reduced litter size resulted in 19 of 43 (44%) sows detected in estrus on the day of weaning. More (P less than .05) RLS sows were in estrus 0 to 3 d after weaning than control sows. Fertility traits (number of corpora lutea, eggs recovered, egg recovery rate, eggs fertilized, fertilization rate, cleaved eggs and cleavage rate) were similar among treatment groups at 4 to 6 d postestrus. Experiment 2 consisted of 59 crossbred (Yorkshire X Duroc) sows assigned to one of four treatment groups. Litters were separated from their dams for 6 (n = 20) or 12 (n = 10) h/d between 2 and 4 wk or litters were weaned at 2 (n = 13) and 4 (n = 15) wk of age. Lactational estrus was detected in 13 of 20 (65%) sows and 5 of 10 (50%) sows that were separated from their litters for 6 or 12 h/d, respectively. Lactational estrus (LE, n = 18) in sows was observed 4 to 8 d after initial separation, while sows remaining anestrus during lactation (LA, n = 12) were in estrus 2 to 7 d postweaning. Average intervals from separation or weaning to estrus for LE and LA sows and for sows whose litters were weaned at 2 or 4 wk were 5.9, 4.4, 4.4 and 4.2 d, respectively, and were longer (P less than .05) for LE sows. Fertility traits were similar among treatment groups. These studies demonstrate that lactations of 2 to 5 wk and lactational treatments of sows, including either litter reduction before weaning or daily separation of sows from their litters, resulted in similar postweaning or post-treatment intervals to estrus and similar fecundity regardless of treatment or lactation length. While 50% of the sows responded to treatments, reasons for the lack of response in the remaining sows is not explained, but it appears that body weight and backfat of sows at weaning, and feed intake during lactation were unrelated to the success of the treatments imposed.

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82,87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients. Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.

Non-surgical recovery of bovine eggs

An improved, non-surgical technique for recovering bovine eggs is described using modified Foley catheters. Egg recovery rates per attempt were, 36 51 (71%), for normal, unsuperovulated donors and 4 38 (11%), for unsuperovulated donors with known fertility problems. For superovulated donors, eggs were collected in 24 26 attempts (92%) averaging 6.9 per recovery.

Effect of vaginally administered 15(S)15-methyl-PGF2alpha on egg transport and fertility in rabbits.

The effects of vaginal suppositories containing 1.0 mg of 15[S]15-methy-PGF2alpha on oviductal motility, egg transport, and fertility were determined in rabbits. Suppository treatment caused a significant increase (P less than 0.02) in the amplitude of oviductal contractions, and a decrease in the frequency of contractractions (P less than 0.04). Altered oviductal motility persisted for an average of 2 hr after treatment. Treatment with 1, 2, or 3 suppositories at various times after ovulation caused a significant reduction in the number of eggs located in the oviducts (P less than 0.025). There was, however, a great deal of variation in egg recovery in treated animals (range 0 to 100%). Treatment of mated rabbits during the time of tubal egg transport caused a significant reduction in the number of Day-12 implants (P less than 0.05). The percentage of corpora lutea represented by Day-12 implants was similar to egg recovery rates in animals similarly treated. The treatment had no effect on fetal survival from Day 12 to 28 of pregnancy. The decrease in fertility caused by these vaginal suppositories is presumably due to the stimulatory effect on oviductal motility which accelerates tubal transport of the embryos into the uterus. Embryos that arrive in the uterus prematurely probably do not implant and degenerate or are expelled.

THE INDUCTION OF OVULATION IN THE CHINCHILLA

SUMMARY Forty-five adult chinchilla (Chinchilla laniger) were used to investigate the ovulatory response to pregnant mare serum (PMS) and human chorionic gonadotrophin (HCG) administered by intraperitoneal injection according to various regimes. Ovulation occurred (even during pregnancy) only when both PMS and HCG were given; 87·5% animals ovulated with a mean number of 3·7 ova, but only 26 out of the 119 ova were recovered. The range of ova ovulated per ovary was 1–7 and the range per animal was 1–12. The reasons for the low recovery rate of eggs and the general efficacy of the hormone regimes are discussed.

An Efficient Concentration Method (AEX) for Detecting Helminthic Ova in Feces (Modification of the Telemann Technic)

Summary 1. A modification of the Telemann hydrochloric acid-ether technic is presented, in which hydrochloric acid with a specific gravity of 1.030 and a mixture of equal parts of ether and xylol, are employed. We refer to this modification as AEX. 2. The use of hydrochloric acid with a specific gravity of 1.030 provides satisfactory acid disintegration of the feces and permits ova of all species to be easily sedimented by centrifugation. 3. The addition of the xylol diminishes the adhesive properties of the coagulum of the fecal debris and prevents foaming common to the use of ether alone. 4. AEX was found to be far superior to both the Telemann and Lane DCF technics in both diagnosis and in egg recovery rates in infection showing hookworm, fertile Ascaris and Trichuris ova, while in infections showing Schistosoma or infertile Ascaris ova AEX was the only procedure which consistently demonstrated them. Diagnostically, all species of parasite eggs occurring in feces should be readily found by AEX. 5. In a helminthic survey made under field conditions AEX has proved a reliable diagnostic procedure.