Early and late ovarian hyperstimulation syndrome: early pregnancy outcome and profile

BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) in IVF/ICSI cycles may occur either as an early (early onset) or a late pattern (late onset). This observational study was designed to identify whether the onset pattern of OHSS is associated with the occurrence of pregnancy and the early pregnancy outcome. METHODS: Among 4376 consecutive IVF/ICSI cycles, 113 patients were hospitalized for OHSS after IVF/ICSI treatment and were included in the study. The setting was the Dutch-speaking Brussels Free University Hospital, between June 2000 and September 2002. RESULTS: Early OHSS occurred in 53 patients, and late OHSS complicated 60 patients. A total of 96.7% of the late OHSS cases occurred in a pregnancy cycle and were more likely to be severe than the early cases (P < 0.05). Although in the early group there initially was a 41.5% positive HCG rate per cycle, the clinical pregnancy rate fell to 28.3% as a result of a significantly (P < 0.05) increased preclinical pregnancy loss rate compared with the non-OHSS patients (31.8 versus 88.3%, respectively). The ongoing pregnancy rate per cycle was 14.4% in the early and 26.4% in the late group. Multiple pregnancy rates were high in both groups (40 and 45.5%, respectively), but only in the late group did the incidence reach significance compared with the non-OHSS population (45.5 versus 29.1%, P = 0.02). Estradiol levels and number of follicles on the day of HCG were significantly higher in the early OHSS group. However, there was no difference in estradiol values on the day of hospital admittance between the two groups. In addition, the number of follicles on the day of HCG administration appears to be a better prognostic indicator for the occurrence of severe OHSS than the estradiol values (87% of the severe cases had > or = 14 or follicles of a diameter > or = 11 mm, whereas only 50% of them had an estradiol value > or = 3000 ng/l). CONCLUSIONS: The early OHSS pattern is associated with exogenously administered HCG and a higher risk of preclinical miscarriage, whereas late OHSS may be closely associated with the conception cycles, especially multiple pregnancies, and is more likely to be severe. Further clarification of these two different clinical entities could have implications for research protocols as well as for preventive and management strategies for OHSS.     

Luteal phase support and severe ovarian hyperstimulation syndrome.

The incidence and statistical associations of the ovarian hyperstimulation syndrome (OHSS) were studied in 304 egg retrievals with gonadotrophin-releasing hormone agonist suppression, gonadotrophin administration and follicular aspiration. In addition to preserving corpus luteum function, the luteal phase administration of human chorionic gonadotrophin (HCG) was associated with a higher incidence of severe OHSS than was supplementation with progesterone alone (12 versus 0%, P less than 0.001). Severe OHSS occurred in 3.7% and 12% of retrievals without and with pregnancy respectively (P less than 0.01). Stepwise logistic regression showed that the occurrence of moderate or severe OHSS was statistically predicted by the log of the serum oestradiol on the day the initial HCG was given (P less than 0.0001), treatment with luteal phase HCG (P less than 0.0003), and fetal number (P less than 0.0079). In the late luteal phase of cycles without luteal HCG, the serum oestradiol concentration was one-tenth and the serum progesterone concentration was one-fifth of the luteal phase value with HCG support (P less than 0.001). Without luteal phase HCG, oestradiol was two-fold higher (P less than 0.001) and progesterone was 1.4-fold higher (P less than 0.005) in pregnant than in non-pregnant women. With luteal phase HCG, oestradiol was 1.4-fold higher in pregnant than in non-pregnant women (P less than 0.05), and progesterone was 1.7-fold higher (P less than 0.001). Oestradiol upper limits of 4400 and 14,700 pmol/l (1200 and 4000 pg/ml) for cycles with and without luteal phase HCG respectively correspond to approximately 5% risk of moderate or severe OHSS with a singleton pregnancy under these conditions.     

An aggressive philosophy in controlled ovarian stimulation cycles increases pregnancy rates

To assess the effect of timing of human chorionic gonadotrophin(HCG) administration in ovarian stimulation cycles, the serumoestradiol concentration and follicle profile were comparedwith the clinical pregnancy rate in 582 ovarian stimulation— intra-uterine insemination (OS—IUI) cycles and3917 in-vitro fertilization—embryo transfer (IVF—ET)cycles. The pregnancy rates increased exponentially with increasingoestradiol in both OS—IUI and IVF—ET cycles (R²= 0.720, P < 0.001) but then decreased in OS-IUI cycles whenthe oestradiol concentration exceeded 5000 pmol/l (R² = 0.936,P < 0.004) at HCG administration. In OS—IUI cyclesthe percentage of cycles with three or more mature follicles( 18 mm diameter) increased up to an oestradiol concentrationof 5000 pmol/l then declined, mirroring the pregnancy rate (R²= 0.900, P = 0.01). The exponential increase in pregnancy ratewith increasing oestradiol concentration in IVF—ET cyclessuggests that high oestradiol concentration does not have adeleterious effect on endometrial receptivity. The decreasein pregnancy rate in OS-IUI cycles when oestradiol concentrationexceeded 5000 pmol/l reflected fewer mature follicles, resultingfrom premature administration of HCG to avoid severe ovarianhyperstimulation syndrome (OHSS). We recommend that HCG administrationbe delayed until multiple follicles have reached maturity, andreducing the risk of severe OHSS by converting high risk OS—IUIcycles to IVF—ET, or if funds or facilities are unavailable,transvaginally draining all but four or five mature follicles.     

Endocrinology: Induction of pre-ovulatory gonadotrophin surge with gonadotrophin-releasing hormone agonist compared to pre-ovulatory injection of human chorionic gonadotrophins for ovulation induction in intrauterine insemination treatment cycles

The clinical outcome of intrauterine insemination (IUI) treatmentcycles employing a gonadotrophin-releasing hormone agonist [GnRHa,triptorelin (Decapeptyl)] or human chorionic gonadotrophin (HCG)for ovulation induction was compared. A group of 48 patientspresenting with amenorrhoea, oligomenorrhoea or unexplainedinfertility were all treated with human menopausal gonadotrophins(HMG) from day 5 of the cycle, on an individualized schedule.They were then randomly divided into two groups to receive eithera single s.c. injection of 0.1 mg triptorelin or a single i.m.injection of 10 000 IU HCG after follicular maturation. IUIwas performed 24 and 48 h following the injection. A transitoryincrease in serum luteinizing hormone and follicle stimulatinghormone concentrations was achieved following injection of GnRHa.A total of 24 patients received 72 treatment cycles with GnRHa,producing 11 conceptions (15.3%) and two abortions (18.2%),resulting in a term pregnancy rate of 13.6%. There were fourcases of grade 3–4 ovarian hyperstimulation syndrome (OHSS),two of which were conception cycles. In all, 24 patients underwent68 cycles treated with HCG, producing 18 conceptions (26.5%)and six abortions (33.3%), resulting in a term pregnancy rateof 19.0%. There were eight cycles of grade 3–4 OHSS, twoof which were conception cycles. These results show that ans.c. injection of a relatively low dose of GnRHa can be as effectiveas HCG in producing pregnancy in IUI treatment cycles.     

The significance of coasting duration during ovarian stimulation for conception in assisted fertilization cycles

BACKGROUND: Withholding gonadotrophin administration and postponing HCG injection, termed coasting, has been suggested as a treatment modality in cases of impending ovarian hyperstimulation syndrome (OHSS). It presents an opportunity to reduce the risk of OHSS and salvage the treatment, without apparent compromise to outcome. However, the duration of the coasting period, which would maintain the advantage without reducing conception rate, has not been fully established. In this retrospective study, we attempted to define the optimal interval of coasting in patients at risk of developing OHSS. METHODS: Patients were grouped according to the number of days elapsed between cessation of gonadotrophins and administration of HCG. Overall, out of 207 patients (mean age 30.76 +/- 0.33 years) coasting lasted 1 day in 39 cycles (18.8%), 2 days in 61 cycles (29.4%), 3 days in 49 cycles (23.6%) and > or = 4 days in the remaining 58 cycles (28.5%). RESULTS: There was no difference between the groups in patients' age, serum estradiol concentrations at the time of HCG administration, oocyte maturity, fertilization and embryo cleavage rates. However, patients in whom coasting lasted > or = 4 days had significantly reduced implantation (10.5%) and pregnancy (26.7%) rates compared with patients with a shorter coasting interval (ranges 18.4-27.9 and 41-55.7% respectively; P < 0.05). CONCLUSION: Coasting for >3 days appears to reduce implantation and pregnancy rates while in-vitro oocyte and embryo quality do not appear to be affected. We suggest that in patients who need coasting for >3 days, cryopreservation of embryos should be considered.     

Multiple follicular development and ovarian steroidogenesis following subcutaneous administration of a highly purified urinary FSH preparation in pituitary desensitized women undergoing IVF: a multicentre European phase III study

A multicentre, multinational study was carried out between November1990 and February 1992 to assess the safety and efficacy ofa new highly purified urinary human follicle stimulating hormone(FSH; Metrodin HP®) which is practically devoid of luteinizinghormone (LH) activity. Metrodin HP was administered s.c. tostimulate multiple follicular development in women undergoingin-vitro fertilization (IVF) and embryo transfer. A total of139 women were recruited from 10 participatin centres. Of these,135 underwent pituitary desensitization with a long gonadotrophin-releasinghormone (GnRH) agonist protocol and following deter-minationof ovarlan inactivity (mean± SD of 12.9 ± 3.2days), Metrodin Hp s.c. stimulation was started; 122 patientswere fully eligible for efficacy analysios and 118 of these(97%) received up to 10 000 IU human chrionic gonadotrophin(HCG) to induce final folicular maturation and timed oocyterecovey. Mean plasma LH concentrations at the beginning of Metro-dinHP treaement were 1.6 ± 0.8 mIU/ml and by the day ofHCG administration were significantly (p<0.001) reduced (1.2±0.8mIU/ml). The mean plasma oestradiol and inhibin concentrationson the day of HCG were 6173±3567 pmol/l and 8.2 ±4.4IU/ml respectively. There was a positive correlation (r= 0.49,p<0.001) between individual oestradiol and inhibin concentrationson the day of HCG. In the 118 patients who received HCG, themean number of oocytes recovered was 8.4 ± 4.7 followingstimulation with 36 ± 10, 75 IU ampoules of MetrodinHP over 12.2±2.1 days. One-hundred-and-eight patients(89% of 122 eligible) ahd 5.3±3.3 oocyted fertilized,and 105 (86%) had 2.8±1.0 embryos transferred; 28 patients(23% perinitiated cycle) had a clinical pregnancy and subsequently18 of these (15% per initiated cycle) had a live birth. A totalof 135 patients who reveiced Metrodin HP were eligible for safetyanalysis. One patient did not receive HCG because of the riskof developing ovarian hyperstimulation syndrome (OHSS). Sevenpatients (5% of those who received HCG) developed OHSS, onesevere, five moderate and one mild case. Three OHSS patientswere pregnant and hospitalized. The patient with severe OHSSwas found to have an ectopic pregnancy. Local side effects werereported by 24 (18%) patients at the site of s.c injection.The most common compliant was brusing (48.5%). There was nodevelopment of antobodies to FSH. In conclusion Metrodln HP,a urinary gonadotrophin preparation in which>95% of the proteincontent is FSH, was effective in stimulating multiple folliculardevelopment and oestradol synthesis to a similar degree reportedfor other gonadotrophin preparations, even when endogenous LHsecretion was significantly reduced by a GnRH agonist. Thesedata support the concept that only very low concentrations ofLH are required in conjunction with FSH for the stimulationof follicular development and ovarian steroidogenesis. MetrodinHp was well tolerated locvally thus enabling convenient self-adminstrationwithout compromising safety or efficacy     

Accumulation of human chorionic gonadotrophin in the serum of patients during in-vitro fertilization treatment cycles with Pergonal

We examined the possible contribution of human chorionic gonadotrophin(HCG) in Pergonal to the serum luteinizing hormone (LH)-likebioactivity in 10 patients (median age32 years, range 28–38)with tubal infertility who were undergoing in-vitro fertilization(IVF), together with 19 controls (median age30 years, range21–43). IVF patients were treated with clomiphene (50mg twice daily) over days 2–6 and Pergonal (150 IU i.m.)daily from day 5 until at least day 10. Serum LH was measuredby fluoro-immunometric assay (I-LH) and in-vitro Leydig cellbioassay (B-LH). Serum HCG was measured by fluoro-immunometricassay. The data were analysed by paired two-tailed t-test, followinglogarithmic transformation. From days 1–5, there was anincrease in serum B-LH (mean, 95% confidence intervals givenin parentheses) from 8.3 (6.8, 10.2) IU/1 to 11.7 (9.8, 13.9)IU/1 [P= 0.004], and in serum I-LH from 4.5 (3.7, 5.4) IU/1to 5.4 (4.6, 6.3) IU/1 [P= 0.002]. From days 5–8, therewas a rise in B-LH to 16.6 (12.6, 21.9) IU/1 [P= 0.023]. Therise in I-LH to 6.3 (5.1, 7.8) IU/1 [P= 0.081] failed to reachsignificance. Furthermore, serum HCG was <<0.75 IU/1 untilafter Pergonal was administered on day 5, then rose to a plateauon day 8 at 1.2(0.8, 1.6) IU/1. Serum HCG in the controls remained<<0.75 IU/1 throughout. We conclude there is a disproportionateincrease in serum B-LH compared to I-LH from days 5–8,corresponding with a rise in serum HCG and the commencementof treatment with Pergonal. The HCG in Pergonal may be contributingto an undesirable rise in serum LH-like bioactivity, which mightreduce the success rate of IVF.     

Endocrinology: Predictive value of serum oestradiol concentrations and oocyte number in severe ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a serious complicationof gonadotrophin usage but it is difficult to accurately predictits occurrence. Previous investigators have identified the combinationof high oestradiol concentrations and oocyte number as beingpredictive in 80% of cases. In this study we sought to identifythe incidence of severe OHSS in patients with high oestradiolconcentrations and large numbers of oocytes and to evaluatethe importance of pregnancy in the development of OHSS. Between1990 and 1993, we studied 139 cycles using two assisted reproductivetechniques [oocyte donor, n =72; in-vitro fertilization (IVF),n = 67] in which either oestradiol (>4000 pg/ml), oocytenumber (>25), or both were elevated. OHSS was diagnosed bystandard criteria. There were no cases of severe OHSS in theoocyte donor group and six in the IVF group. Among 10 patientswith oestradiol concentration >6000 pg/ml and >30 oocytes,only one had OHSS (10%). The relative risk of OHSS with pregnancywas 12 (confidence interval 2.18–66.14). We conclude thatthe risk of OHSS even at high levels of stimulation is lowerthan previously believed. Secondly, donors have a very low riskof OHSS, probably because of the absence of pregnancy. As such,cryopreservation of all oocytes in IVF cycles is a reasonablealternative to cycle cancellation or use of adjunctive medication.     

The benefits of mid-luteal addition of human chorionic gonadotrophin in in-vitro fertilization using a down-regulation protocol and luteal support with progesterone

Luteal support is essential in in-vitro fertilization (IVF)when long-acting gonadotrophin-releasing hormone agonist (GnRHa)is used. Because progesterone lacks luteotrophic stimulation,it seems to be the drug of choice in cases with an increasedrisk of ovarian hyperstimulation syndrome (OHSS). The aim ofthis study was to assess the beneficial effect of the mid-lutealaddition of human choriomc gonadotrophin (HCG) in IVF, usinga down-regulation protocol and luteal support with progesterone,in a prospective randomized study. The study included 170 IVFcycles down-regulated with long-acting GnRHa which were supportedwith 50 mg/day progesterone i.m. during the luteal phase. Patientswere evaluated in the mid-luteal period. Those without clinicalsigns of OHSS, oestradiol concentrations <1000 pg/ml andprogesterone concentrations <50 mg/ml were randomly allocatedto either the addition of 2500 IU HCG (HCG+ group) or no HCG(HCG– group). End luteal phase progesterone concentrationsamong non-pregnant patients were used to assess the contributionof exogenous progesterone and to categorize pregnancies accordingto their corpus luteum function. Similar low OHSS (2.7 and 1.8%)and pregnancy (30 and 29%) rates were observed in the HCG+ andHCG– groups respectively. Of the 26 pregnancies in theHCG+ cases, there was only one case with reduced corpus luteumfunction, compared with 12 of the 25 pregnancies among HCG–patients. Cases with reduced corpus luteum function requiredcontinuous progesterone support and presented lower HCG concentrationsand a higher rate of adverse pregnancy outcome. We concludethat mid-luteal HCG addition does not affect pregnancy rate,but in fact helps to preserve corpus luteum function and avoidsthe need for further supplementation during early pregnancy.     

Triggering of ovulation in human menopausal gonadotrophin-stimulated cycles: comparison between intravenously administered gonadotrophin-releasing hormone (100 and 500 {micro}g), GnRH agonist (buserelin, 500 {micro}g) and human chorionic gonadotrophin (10 000 IU)

We studied the peri-ovulatory and luteal phases in 38 humanmenopausal gonadotrophin (HMG)-stimulated cycles, in which ovulationwas triggered with four different i.v. bolus ovulation triggers:100 µg gonadotrophin-releasing hormone (GnRH; group A,n = 9), 500 µg GnRH agonist (GnRHa; group B, n = 10),10 000IU human chorionic gonadotrophin (HCG; group C, n = 10)and 500 µg GnRH (group D, n = 9). Endogenous luteinizinghormone (LH) surges occurred in all cycles of groups A, B andD. The rise was slowest but highest in group B (P < 0.0001)and lowest in group A. Although the t₀ serum oestradiol valueswere similar in all groups, day +8 oestradiol and day +4 and+8 progesterone concentrations were higher in group C (P <0.05). At day +4 and +8, serum LH concentrations were lowest(P < 0.01) but follicle stimulating hormone (FSH) concentrationswere higher. Clinically, day +8 luteal scores showed a moreconspicuous degree of ovarian hyperstimulation in the HCG group(P = 0.0292). Luteal insufficiency, defined as cycles with progesteroneconcentrations of <8 ng/ml, occurred much more frequentlyin groups A, B and D than in group C (day +4: P < 0.0003;day +8: P < 0.0001), despite progesterone supplementation.Three pregnancies (one in group C and two in group D) and onemoderate case of ovarian hyperstimulation syndrome (OHSS) (ina non-conceptional group D cycle) occurred. These findings showthat (i) ovulation occurs and pregnancy can be achieved followingan endogenous LH surge induced by GnRH and its agonists, (ii)a high frequency of luteal insufficiency occurs in such cycleseven with luteal supplementation and (iii) OHSS cannot be totallyprevented by this approach, although cycles with an endogenousLH surge in general result in fewer subclinical signs of ovarianhyperstimulation.     

Endocrinology: Comparison of gonadotrophin-releasing hormone analogues and human chorionic gonadotrophin for the induction of ovulation and prevention of ovarian hyperstimulation syndrome: a case-control study

Gonadotrophin-releasing hormone analogue (GnRHa) has been suggestedas an alternative to human chorionic gonadotrophin (HCG) fortriggering ovulation, while preventing ovarian hyperstimulationsyndrome (OHSS). Since a prospective, controlled study wouldbe unethical at this point, we used a retrospective, case-selfcontrol approach to compare GnRHa with HCG in that context.A group of 16 in-vitro fertilization (IVF) patients who hadsevere OHSS in previous cycles, in which HCG was given to triggerovulation, were studied in subsequent cycles in which GnRHawas used. Each GnRHa cycle (case) was compared to a previousHCG cycle that resulted in OHSS (self control). None of thesesubsequent cydes resulted in severe OHSS. The use of GnRHa didnot affect the number of oocytes retrieved or their quality.Serum oestradiol concentrations on the day of ovulation triggeringwere signilicantly (P<0.01) higher in the GnRHa cycles comparedto HCG cycles. Exogenous progesterone and oestra diol were effectivein maintaining relatively constant serum oestradiol and progesteroneserum concentrations during the luteal phase. Pregnancy rateper cycle was similar in the two groups. In conclusion, theuse of GnRHa to induce ovulation in IVF patients, who are athigh risk for developing OHSS, effectively eliminates this riskwithout affecting other parameters of the stimulation cycle.     

Endocrinology: Progesterone alone versus progesterone combined with HCG as luteal support in GnRHa/HMG induced IVF cycles: a randomized clinical trial

Two different regimens of luteal support in gonadotrophin hormone-releasinghormone (GnRH) analoguefhuman menopausal gonadotrophin (GnRHa/HMG)-inducedin-vitro fertilization cycles (IVF) were compared in a randomizedclinical trial. After embryo transfer, either vaginal progesteronealone was administered (n=89, P group), or a combination ofvaginal progesterone and human chorionic gonadotrophin (n=87,P/HCG group). The primary aim of this study was to assess theeffect of the different regimens of luteal support on the pregnancyrate. The secondary aim was to compare oestradiol and progesteroneconcentrations in the luteal phase between the two groups, andassess their effect on the pregnancy rate. A clinical pregnancyrate of 15% was found in the P/HCG group in comparison with26% in the P group (odds ratio 0.49; 99% confidence interval:0.18–1.3). The luteal serum oestradiol and progesteronevalues in the P/HCG group were significantly higher when comparedwith the P group on the 6th, 9th and 12th day after oocyte retrieval(Wilcoxon P<0.001). In accordance with the high oestradiolconcentrations, more cases of ovarian hyperstimulation syndrome(OHSS) were found in the P/HCG group. Oestradiol values on the9th day after oocyte retrieval, presumably the day of implantation,appeared to be higher in women who did not become clinicallypregnant. We conclude that vaginal progesterone alone providessufficient luteal support in GnRHa/HMG induced IVF cycles. Thecombination of vaginal progesterone and HCG as luteal supportleads to significant high luteal oestradiol and progesteroneconcentrations. But a high concentration of oestradiol seemsto have a deleterious effect on the implantation process, resultingin a low pregnancy rate.     

Infertility: Predicting and optimizing success in an intra-uterine insemination programme

We analysed 381 consecutive cycles of homologous intra-uterineinsemination (IUI) in 215 infertile couples, resulting in 48pregnancies (12.6%/cycle, 22.3/patient). Cycle fecundity rangedfrom 0.11 to 0.14 in women aged 25–39 years, falling to0.04 beyond age 40 years. Of the 48 pregnancies, 43 occurredin the first three treatment cycles, in which fecundity was0.14, 0.16 and 0.10 respectively. Beyond three cycles, fecunditywas 0.07 (P = 0.05 versus first two cycles). The occurrenceof pregnancy varied with diagnosis (P = 0.04). Fecundity wassignificantly greater for women with ovulatory dysfunction (0.30)than for endometriosis, male factor, tubal factor, idiopathicinfertility or multifactorial (0.08–0.14). Ovulation inductionusing menopausal gonadotrophins offered significant advantageover natural cycles or cycles using clomiphene citrate withoutgonadotrophins (0.15 versus 0.03, P = 0.01). Cycles in whichpre-ovulatory surges were either induced or supported with humanchorionic gonadotrophin (HCG) were superior to spontaneous luteinizinghormone surges (0.13 versus 0.03, P = 0.05). Recruitment ofat least two mature (>1.6 cm) follicles was critical. Onlyone pregnancy occurred in 64 cycles characterized by one maturefollicle, compared with a pregnancy rate of 0.15 in cycles characterizedby two or more mature follicles (P = 0.006). IUI is not beneficialto women >40 years old, and has the best chance of successwithin three cycles. Multiple follicle recruitment using gonadotrophin-basedstimulation protocols and mid-cycle HCG are necessary to achievean acceptable pregnancy rate.     

Serum inhibin A, VEGF and TNFalpha levels after triggering oocyte maturation with GnRH agonist compared with HCG in women with polycystic ovaries undergoing IVF treatment: a prospective randomized trial

BACKGROUND: We aimed to examine the serum levels of inhibin A, vascular endothelial growth factor (VEGF), tumour necrosis factor alpha (TNFalpha), estradiol (E2) and progesterone levels after triggering of final oocyte maturation with GnRH agonist compared with HCG in patients with polycystic ovaries (PCO) and to investigate the relationship between these markers and ovarian hyperstimulation syndrome (OHSS). METHODS: Twenty-eight patients with PCO, undergoing controlled ovarian hyperstimulation with FSH and GnRH antagonist for IVF-embryo transfer treatment, were randomized for triggering of final oocyte maturation with GnRH agonist (GnRH agonist group, n = 15) or HCG (HCG group, n = 13). Blood samples were obtained on the day of randomization and thereafter every 2-7 days. Serum levels of inhibin A, VEGF, TNFalpha, E2 and progesterone, the incidence of OHSS, ovarian size and pelvic fluid accumulation were evaluated. RESULTS: Serum inhibin A, E2 and progesterone levels were significantly lower in the GnRH agonist group compared with the HCG group, particularly on the day of embryo transfer (P < 0.0001). Serum VEGF and TNFalpha levels were similar between the two groups. Four patients in the HCG group developed severe OHSS, whereas no patient had any symptoms or signs of OHSS in the GnRH-agonist group (P < 0.05). CONCLUSIONS: In patients with PCO treated with FSH/GnRH antagonist, final oocyte maturation with GnRH agonist instead of HCG reduces significantly inhibin A, E2 and progesterone levels during the luteal phase. This phenomenon reflects the inhibition of the corpus luteum function and may explain, at least in part, the mechanism of OHSS prevention in high-risk patients. Our results do not support a crucial role for VEGF or TNFalpha in OHSS.     

Activation of plasma kinin system correlates with severe coagulation disorders in patients with ovarian hyperstimulation syndrome

The aim of this study was to evaluate status of plasma kinin system in patients with ovarian hyperstimulation syndrome (OHSS), in order to investigate whether activation of the plasma kinin system correlates with increased blood coagulability. In the first part of the study, concentrations of plasma prekallikrein (PK) in OHSS cycles (n = 13) were monitored from the day of human chorionic gonadotrophin (HCG) administration to the mid-luteal phase, and were compared with those of control cycles (n = 17). The average value of PK in OHSS cycles began to decrease on day 8, and by day 10 was significantly lower than that of control cycles (86 +/- 6 versus 106 +/- 4%, P <0.01). The time course of changes in PK concentration correlated well with the clinical condition of OHSS patients. In the second part of the study, we obtained data from 26 patients who were hospitalized because of severe OHSS, to investigate the correlation between PK and other haemostatic markers. OHSS patients with severe PK reduction (<80% normal, n = 9) demonstrated significantly higher values of plasma thrombin- antithrombin III and plasmin-alpha2 antiplasmin, and more severe haemoconcentration, compared to those OHSS patients who had no reduction in PK (n = 17). In conclusion, our data suggest that activation of the plasma kinin system occurs specifically and occasionally in OHSS patients, and is associated with increased blood coagulability. Thus, when an OHSS patient demonstrates a low value of plasma PK, more careful management is required to prevent thromboembolic complications.      

Soluble vascular endothelial-cadherin levels correlate with clinical and biological aspects of severe ovarian hyperstimulation syndrome

BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of ovarian stimulation, and the pathophysiological mechanisms that trigger the syndrome remain unknown. HCG increases serum vascular endothelial growth factor (VEGF) concentrations, and VEGF modulates transendothelial permeability via endothelial adherens junctions, a downstream target for VEGF signalling. We examined whether women with severe OHSS have altered serum levels of soluble vascular endothelial (sVE)-cadherin. METHODS: We conducted a prospective, case-control study of 28 women with severe OHSS and 34 women undergoing controlled ovarian hyperstimulation (COH) for IVF without developing OHSS. We collected serum samples from both groups on the day of ovum retrieval (Day 0), and on Days 3, 6, 9 and 15. Samples were assayed for sVE-cadherin by enzyme-linked immunosorbent assay. RESULTS: Women with severe OHSS had significantly higher levels of sVE-cadherin than patients without OHSS (P = 0.001). sVE-cadherin serum levels decreased with clinical improvement; however, they did not reach normal levels in the resolution phase. A positive correlation was demonstrated between sVE-cadherin and serum estradiol levels at the time of HCG administration (r = 0.621; P < 0.001). Serum sVE-cadherin levels were more closely chronologically correlated with corpus luteum function than with biological and clinical aspects of severe OHSS. CONCLUSIONS: sVE-cadherin may be involved in the pathogenesis of severe OHSS and may possibly serve as an indicator of corpus luteum function after COH.     

Total ovarian volume before human chorionic gonadotrophin administration for ovulation induction may predict the hyperstimulation syndrome

Total ovarian volumes were measured before the administrationof HCG in 42 women undergoing treatment for infertility by in-vitrofertilization (IVF) and embryo transfer and considered to havean exaggerated response to stimulation (>20 follicles). Sevenwomen who subsequently developed moderate or severe ovarianhyperstimulation syndrome (OHSS) (n = 7; group 1) were comparedwith 35 matched controls (five matched controls per case; n= 35; group 2) of similar age, number of follicles and durationof infertility who underwent follicular stimulation, oocyterecovery, in-vitro fertilization and embryo transfer duringthe same period but did not develop moderate or severe OHSS.The mean age, duration of infertility and total number of follicleswere similar but the mean total ovarian volume was significantlyhigher in the group of women who developed moderate or severeOHSS compared with controls (271.00 ± 87.00 versus 157.30± 54.20 ml; P < 0.01). We conclude that total ovarianvolume measured before HCG administration is higher in womenwho develop moderate or severe OHSS compared with controls andmay therefore be used as an additional parameter in the preventativestrategy for the ovarian hyperstimulation syndrome.     

Incidence of severe ovarian hyperstimulation syndrome after GnRH agonist/HMG superovulation for in-vitro fertilization

In 1673 treatment cycles stimulated with buserelin and HMG, for IVF, GIFT or ZIFT, the severe ovarian hyperstimulation syndrome (OHSS) occurred in 10 cycles (0.6%). Eight patients were hyperandrogenic and showed an increased ovarian response to HMG. After replacement of a maximum of three embryos or zygotes, seven women became pregnant. Three women had a multiple gestation. All patients recovered uneventfully with conservative treatment. Support with progesterone or continuation of the agonist during the luteal phase did not prevent OHSS, confirming that the ovulatory HCG dose is the most important factor in inducing this severe complication. Luteal supplementation with HCG and/or HCG production during implantation could exacerbate OHSS.     

Comparison of GnRH agonists and antagonists in assisted reproduction cycles of patients at high risk of ovarian hyperstimulation syndrome

BACKGROUND: During IVF or ICSI cycles, ovarian hyperstimulation syndrome (OHSS) is a major problem. The aim of this prospective, multicentre, comparative study (using historical controls) was to assess the efficacy of a GnRH antagonist protocol in preventing OHSS in selected patients who had experienced OHSS or had been at risk of OHSS in their previous IVF/ICSI attempt. METHODS AND RESULTS: Patients underwent a new cycle where the same gonadotrophin protocol was used [same dose of recombinant FSH (rFSH)] but a different protocol was used for pituitary desensitization: cetrorelix 0.25 mg multiple-dose antagonist instead of GnRH agonist long protocol. Cetrorelix 0.25 mg was administered daily, starting when the leading follicle reached a diameter of 14 mm. In other words, rFSH was administered in the new cycle according to the dosage and the step-up or step-down modalities used during the previous cycle, independently of ultrasound findings and serum estradiol (E(2)) levels. Eighty-seven patients entered the study. Out of the 87 cycles involving GnRH agonists, 49 (56.3%) were cancelled and out of the 87 involving GnRH antagonists 28 (32.2%) were cancelled [McNemar's test; 95% confidence interval (CI) -35.8% to -11.2%; P < 0.001]. After GnRH agonist cycles, we recorded 24 cases of OHSS (18 moderate and six severe; 27.6%), whereas after the GnRH antagonist cycles there were 10 cases of OHSS (nine moderate and one severe; 11.5%) (95% CI-26.4% to -5.7%; P = 0.006). There was a statistically significant reduction in the total number of follicles with a diameter >10 mm (Wilcoxon's test; Z = 6.1; P < 0.001) and of E(2) levels on the day of HCG administration (2538 versus 4322.4 pg/ml; P < 0.001) in the GnRH antagonist cycles versus GnRH agonist cycles. Twenty-nine patients had an embryo transfer in the first cycle (76.3% of oocyte retrievals) and 57 in the cycle using GnRH antagonist (96.6%). This 20.3% difference was also significant (Z-test; 95% CI 6.8-36.0%; P = 0.003). After the antagonist cycles, 18 pregnancies (20.7 per initiated cycle; 31.6% per embryo transfer) were obtained. CONCLUSIONS: Although this study presents some limitations owing to the use of historical controls, our data show a favourable effect of GnRH antagonists in reducing the incidence of OHSS and the number of assisted fertilization cycles cancelled because of the risk of OHSS in high responder patients. As a consequence, GnRH antagonist plus gonadotrophin administration could also increase the percentage of oocyte retrievals and embryo transfers in this high risk group of patients.     

Pregnancy: Reduced circulating placental protein concentrations during the first trimester are associated with preterm labour and low birth weight

Serum concentrations of human chorionic gonadotrophin (HCG),Schwangerschaftsprotein 1 (SP-1), pregnancy-associated plasmaprotein A (PAPP-A), progesterone and oestradiol were measuredat weekly intervals between the fifth (embryo transfer plus3 weeks) and 13th week of gestation during the first trimesterof pregnancies achieved following in-vitro fertilization (IVF)and embryo transfer in a group of women who delivered before(n = 8) or at term (n = 52). Those women who had a preterm deliveryhad significantly lower concentrations of PAPP-A (weeks 7–13;P = 0.0001–0.028) and SP-1 (weeks 6–8 and 10–12;P = 0.004–0.04). After correction of birth weight forsex and gestational age at delivery, preterm delivery was foundnot to be associated with growth retardation. However, comparisonof the circulating concentrations of the substances analysedin mothers who delivered babies of < 85% of the 50th centileof the normal range of birth weight for a given gestationalage and sex, with those who delivered babies of >85% revealedthat the concentrations of HCG (P = 0.012–0.04 on weeks6–9) and SP-1 (P = 0.003–0.03 on weeks 7, 9–13)were significantly lower in the former group. Weak, inconsistentassociations were found between the circulating concentrationsof HCG, SP-1 and PAPP-A and both corrected birth weight andgestational age at delivery. Thus, both the gestational ageat delivery and low birth weight may be related to impairedplacental development/function during the first trimester.