Undetected, natural conception pregnancies in luteal phase stimulations-case series and review of literature.

STUDY QUESTION: What is the risk of an undetected natural conception pregnancy during luteal phase ovarian stimulation, and how does it impact the pregnancy's course? SUMMARY ANSWER: The risk for an undetected, natural conception pregnancy in luteal phase ovarian stimulation is low and it appears that ovarian stimulation is unlikely to harm the pregnancy. WHAT IS KNOWN ALREADY: Random start ovarian stimulation appears to be similarly effective as early follicular stimulation start; and it allows ovarian stimulation to be started independent of the cycle day and throughout the cycle, in accordance with the patients' and clinics' schedule as long as there is no intention of a fresh embryo transfer in the same cycle. Starting ovarian stimulation in the luteal phase bears the possibility of an-at the timepoint of stimulation start-undetected, natural conception pregnancy that has already occurred. There is scarce data on the incidence of this event as well as on the possible implications of ovarian stimulation on the course of an existing pregnancy. STUDY DESIGN, SIZE, DURATION: This retrospective observational study, performed between June 2017 and January 2024, analyzed luteal phase stimulations, in which a natural conception pregnancy was detected during the ovarian stimulation treatment for IVF/ICSI. Luteal phase stimulation was defined as ovarian stimulation started after ovulation and before the next expected menstrual bleeding, with a serum progesterone (P4) level of >1.5 ng/ml on the day of stimulation start or 1 day before. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women who underwent a luteal phase ovarian stimulation in a tertiary referral ART center. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 488 luteal phase stimulation cycles were included in the analysis. Luteal phase stimulation was only started after a negative serum hCG measurement on the day or 1 day before commencement of ovarian stimulation. Ten patients (2.1%) had an undetected natural conception pregnancy at the time of luteal phase stimulation start. Eight of these patients underwent an ovarian stimulation in a GnRH-antagonist protocol and two in a progestin-primed stimulation protocol (PPOS). Recombinant FSH was used as stimulation medication for all patients, the patients with a PPOS protocol received additional recombinant LH. One pregnancy (0.2%) was detected after the oocyte retrieval, the other nine pregnancies were detected either due to persistent high serum progesterone levels or due to an increasing progesterone level after an initial decrease before oocyte retrieval. In the cycles with an undetected natural conception pregnancy, the median number of stimulation days was 8 days (range: 6-11 days) and median serum hCG at detection of pregnancy was 59 IU hCG (range: 14.91-183.1). From 10 patients with a pregnancy, three patients delivered a healthy baby, two patients had ongoing pregnancies at the time of summarizing the data, three patients had biochemical pregnancies (patient age: 30, 39, and 42 years), one patient had an ectopic pregnancy which required a salpingectomy, and one patient (age: 34 years) had an early pregnancy loss. LIMITATIONS, REASONS FOR CAUTION: The retrospective study design and the small sample size can limit the accuracy of the estimates. WIDER IMPLICATIONS OF THE FINDINGS: Overall, there is a small risk of undetected natural conception pregnancies when luteal phase stimulation is undertaken. It appears that there are no adverse effects through either direct effect on the embryo or indirectly through a detrimental effect on the corpus luteum function on the pregnancy in our cohort. STUDY FUNDING/COMPETING INTEREST(S): This study did not receive funding. The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Do women with severely diminished ovarian reserve undergoing modified natural-cycle in-vitro fertilization benefit from earlier trigger at smaller follicle size?

OBJECTIVE: To evaluate whether trigger and oocyte collection at a smaller follicle size decreases the risk of premature ovulation while maintaining the reproductive potential of oocytes in women with a severely diminished ovarian reserve undergoing modified natural-cycle in-vitro fertilization. METHODS: This was a retrospective cohort study including women who had at least one unsuccessful cycle (due to no response) of conventional ovarian stimulation with a high dosage of gonadotropins and subsequently underwent a modified natural cycle with a solitary growing follicle (i.e. only one follicle > 10 mm at the time of trigger). The association between follicle size at trigger and various cycle outcomes was tested using regression analyses. RESULTS: A total of 160 ovarian stimulation cycles from 110 patients were included in the analysis. Oocyte pick-up (OPU) was performed in 153 cycles and 7 cycles were canceled due to premature ovulation. Patients who received their trigger at smaller follicle sizes (≤ 15 mm) had significantly lower rates of premature ovulation and thus higher rates of OPU (98.9% vs 90.8%; odds ratio, 9.56 (95% CI, 1.58-182.9); P = 0.039) compared with those who received their trigger at larger follicle sizes (> 15 mm). On multivariable analysis, smaller follicle sizes at trigger (> 10 to 13 mm, > 13 to 15 mm, > 15 mm to 17 mm) were not associated significantly with a lower rate of cumulus-oocyte complex (COC) retrieval, metaphase-II (MII) oocytes or blastulation when compared to the > 17-mm group. On sensitivity analysis including only the first cycle of each couple, the maturity rate among those with COC retrieval was highest in follicle sizes > 15 to 17 mm (92.3%) and > 13 to 15 mm (91.7%), followed by > 10 to 13 mm (85.7%) and lowest in the > 17-mm group (58.8%). During the study period, five euploid blastocysts developed from 48 fertilized MII oocytes with follicle sizes of 12 mm (n = 3), 14 mm (n = 1) and 16 mm (n = 1) at trigger. Of those, four were transferred and resulted in two live births, both of which developed from follicles with a size at trigger of 12 mm. CONCLUSIONS: The ideal follicle size for triggering oocyte maturation may be smaller in women with a severely diminished ovarian reserve managed on a modified natural cycle when compared to conventional cut-offs. The risk of OPU cancellation was significantly higher in women triggered at follicle size > 15 mm and the yield of mature oocytes was not adversely affected in women triggered at follicle size > 13 to 15 mm compared with > 15 to 17 mm. Waiting for follicles to reach sizes > 17mm may be detrimental to achieving optimal outcome. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

The combination of dydrogesterone and micronized vaginal progesterone can render serum progesterone level measurements on the day of embryo transfer and rescue attempts unnecessary in an HRT FET cycle.

PURPOSE: To evaluate the role of serum progesterone (P4) on the day of embryo transfer (ET) when dydrogesterone (DYD) and micronized vaginal progesterone (MVP) are combined as luteal phase support (LPS) in a hormone replacement therapy (HRT) frozen ET (FET) cycles. METHODS: Retrospective study, including single euploid HRT FET cycles with DYD and MVP as LPS and P4 measurement on ET day. Initially, patients with P4 levels < 10 ng/ml increased MVP to 400 mg/day; this "rescue" was abandoned later. RESULTS: 560 cycles of 507 couples were included. In 275 women, serum P4 level was < 10 ng/ml on the ET day. Among those with low P4 levels, MVP dose remained unchanged in 65 women (11.6%) and was increased in 210 women (37.5%). Women with P4 levels ≥ 10 ng/ml continued LPS without modification. Overall pregnancy rates in these groups were 61.5% (40/65), 54.8% (115/210), and 48.4% (138/285), respectively (p = n.s.). Association of serum P4 levels with ongoing pregnancy rates was analyzed in women without any additional MVP regardless of serum P4 levels (n = 350); multivariable analysis (adjusted for age, BMI, embryo quality (EQ)) did not show a significant association of serum P4 levels with OPR (OR 0.96, 95% CI 0.90-1.02; p = 0.185). Using inverse probability treatment weights, regression analysis in the weighted sample showed no significant association between P4 treatment groups and OP. Compared to fair EQ, the transfer of good EQ increased (OR 1.61, 95% CI 1.22-2.15; p = 0.001) and the transfer of a poor EQ decreased the odds of OP (OR 0.73, 95% CI 0.55-0.97; p = 0.029). CONCLUSION: In HRT FET cycle, using LPS with 300 mg/day MVP and 30 mg/day DYD, it appears that serum P4 measurement and increase of MVP in patients with P4 < 10 ng/ml are not necessary.

Are systemic progesterone levels in true natural cycle euploid frozen embryo transfers with luteal phase support predictive for ongoing pregnancy rates?

STUDY QUESTION: Are serum progesterone (P4) levels on the embryo transfer (ET) day predictive of ongoing pregnancy (OP) following a single euploid blastocyst transfer in a natural cycle (NC) when luteal phase support is routinely given? SUMMARY ANSWER: In single euploid frozen ETs in NC, P4 levels on ET day are not predictive for OP, when luteal phase support (LPS) is routinely added after the ET. WHAT IS KNOWN ALREADY: In an NC frozen embryo transfer (FET), P4 produced by the corpus luteum initiates secretory transformation of the endometrium and maintains pregnancy after implantation. There are ongoing controversies on the existence of a P4 cutoff level on the ET day, being predictive for the chance of OP as well as of the possible role of additional LPS after ET. Previous studies in NC FET cycles, evaluating and identifying P4 cutoff levels did not exclude embryo aneuploidy as a possible reason for failure. STUDY DESIGN, SIZE, DURATION: This retrospective study analyzed single, euploid FET in NC, conducted in a tertiary referral IVF centre between September 2019 and June 2022, for which measurement of P4 on the day of ET and the treatment outcomes were available. Patients were only included once into the analysis. Outcome was defined as OP (ongoing clinical pregnancy with heartbeat, >12 weeks) or no-OP (not pregnant, biochemical pregnancy, early miscarriage). PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients with an ovulatory cycle and a single euploid blastocyst in an NC FET cycle were included. Cycles were monitored by ultrasound and repeated measurement of serum LH, estradiol, and P4. LH surge was identified when a rise of 180% above the previous level occurred and P4 levels of ≥1.0 ng/ml were regarded as confirmation of ovulation. The ET was scheduled on the fifth day after P4 rise and vaginal micronized P4 was started on the day of ET after P4 measurement. MAIN RESULTS AND THE ROLE OF CHANCE: Of 266 patients included, 159 (59.8%) patients had an OP. There was no significant difference between the OP- and no-OP-groups for age, BMI, and day of embryo biopsy/cryopreservation (Day 5 versus Day 6). Furthermore, P4 levels were not different between the groups of patients with OP (P4: 14.8 ng/ml (IQR: 12.0-18.5 ng/ml)) versus no-OP (P4: 16.0 ng/ml (IQR: 11.6-18.9 ng/ml)) (P = 0.483), and no differences between both groups, when P4 levels were stratified into categories of P4 levels of >5 to ≤10, >10 to ≤15, >15 to ≤20, and >20 ng/ml (P = 0.341). However, both groups were significantly different for the embryo quality (EQ), defined by inner cell mass/trophectoderm, as well as when stratified into three EQ groups (good, fair, and poor) (P = 0.001 and 0.002, respectively). Stratified EQ groups remained the only significant parameter influencing OP in the uni- and multivariate analyses (P = 0.002 and P = 0.004, respectively), including age, BMI, and P4 levels (each in categories) and embryo cryopreservation day. Receiver operator characteristic curve for the prediction of an OP revealed an AUC of 0.648 when age, BMI and EQ groups were included into the model. The inclusion of P4 measurement on ET day into the model did not add any benefit for OP prediction (AUC = 0.665). LIMITATIONS, REASONS FOR CAUTION: The retrospective design is a limitation. WIDER IMPLICATIONS OF THE FINDINGS: Monitoring serum P4 levels can be abandoned in NC FET cycles with routine LPS as they do not seem to be predictive of live birth. STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for this study. The authors state that they do not have any conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

How to identify patients who would benefit from delayed-matured oocytes insemination: a sibling oocyte and ploidy outcome study.

STUDY QUESTION: Which patients might benefit from insemination of delayed-matured oocytes? SUMMARY ANSWER: Delayed-matured oocytes had a ≥50% contribution to the available cohort of biopsied blastocysts in patients with advanced maternal age, low maturation, and/or low fertilization rates. WHAT IS KNOWN ALREADY: Retrieved immature oocytes that progress to the MII stage in vitro could increase the number of embryos available during ICSI cycles. However, these delayed-matured oocytes are associated with lower fertilization rates and compromised embryo quality. Data on the ploidy of these embryos are controversial, but studies failed to compare euploidy rates of embryos derived from delayed-matured oocytes to patients' own immediate mature sibling oocytes. This strategy efficiently allows to identify the patient population that would benefit from this approach. STUDY DESIGN, SIZE, DURATION: This observational study was performed between January 2019 and June 2021 including a total of 5449 cumulus oocytes complexes from 469 ovarian stimulation cycles, from which 3455 inseminated matured oocytes from ICSI (n = 2911) and IVF (n = 544) were considered as the sibling controls (MII-D0) to the delayed-matured oocytes (MII-D1) (n = 910). Euploidy rates were assessed between delayed-matured (MII-D1) and mature sibling oocytes (MII-D0) in relation to patients' clinical characteristics such as BMI, AMH, age, sperm origin, and the laboratory outcomes, maturation, fertilization, and blastocyst utilization rates. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 390 patients undergoing IVF/ICSI, who had at least one metaphase I (MI) or germinal-vesicle (GV) oocyte on the day of oocyte collection (Day 0), which matured in 20-28 h after denudation were included. MI and GV oocytes that matured overnight were inseminated on the following day (Day 1, MII-D1) by ICSI. Only cycles planned for preimplantation genetic testing for aneuploidy using fresh own oocytes were included. MAIN RESULTS AND THE ROLE OF CHANCE: Fertilization (FR) and blastocyst utilization rates were significantly higher for MII-D0 compared to delayed-matured oocytes (MII-D1) (69.5% versus 55.9%, P < 0.001; and 59.5% versus 18.5%, P < 0.001, respectively). However, no significant difference was observed in the rate of euploid embryos between MII-D0 and MII-D1 (46.3% versus 39.0%, P = 0.163). For evaluation of the benefit of inseminating MI/GV oocytes on D1 per cycle in relation to the total number of biopsied embryos, cycles were split into three groups based on the proportion of MII-D1 embryos that were biopsied in that cycle (0%, 1-50%, and ≥50%). The results demonstrate that patients who had ≥50% contribution of delayed-matured oocytes to the available cohort of biopsied embryos were those of advanced maternal age (mean age 37.7 years), <10 oocytes retrieved presenting <34% maturation rate, and <60% fertilization rate. Every MII oocyte injected next day significantly increased the chances of obtaining a euploid embryo [odds ratio (OR) = 1.83, CI: 1.50-2.24, P < 0.001] among MII-D1. The odds of enhanced euploidy were slightly higher among the MII-D1-GV matured group (OR = 1.78, CI: 1.42-2.22, P < 0.001) than the MII-D1-MI matured group (OR = 1.54, CI: 1.25-1.89, P < 0.001). Inseminating at least eight MII-D1 would have >50% probability of getting a euploid embryo among the MII-D1 group. LIMITATIONS, REASONS FOR CAUTION: ICSI of MII-D1 was performed with the fresh or frozen ejaculates or testicular samples from the previous day. The exact timing of polar body extrusion of delayed-matured MI/GV was not identified. Furthermore, the time point of the final oocyte maturation to MII for the immature oocytes and for the oocytes inseminated by IVF could not be identified. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study might provide guidance to the IVF laboratories for targeting the patient's population who would benefit from MII-D1 ICSI without adhering to unnecessary costs and workload. STUDY FUNDING/COMPETING INTEREST(S): No external funding was received for this study. There are no conflicts of interest to be declared for any of the authors. There are no patents, products in development, or marketed products to declare. TRIAL REGISTRATION NUMBER: N/A.

Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20µm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, P<0.05). There were no significant differences in total sperm motility between different chamber depths, however, use of the 20µm-chambers resulted in greater sperm progressive motility rate, VSL and LIN, and less VCL and VAP than chambers with a lesser depth. There was less sperm motility and lesser values for kinetic variables as time that elapsed increased between sample loading and sperm evaluation. For sperm motility, use of droplet-loaded chambers resulted in similar values of MOT in all microscopic fields, but sperm motility assessed in capillarity-loaded chambers was less in the central fields than in the outermost microscopic fields. For goats, it is recommended that sperm motility be analysed using the CASA-mot system with a drop-loaded chamber within 2min after filling the chamber.