Impact of reproductive history on in vitro fertilization and intracytoplasmic sperm injection outcome: evidence from the German IVF Registry

Reproductive history does not compromise subsequent live birth and perinatal outcome following in-vitro fertilization: analysis of 25 329 first frozen-thawed embryo transfer cycles without preimplantation genetic testing for aneuploidy

OBJECTIVE

To investigate the effect of women's reproductive history on live-birth rate and perinatal outcome after first frozen-thawed embryo transfer (FET) without preimplantation genetic testing for aneuploidy.

METHODS

This was a retrospective cohort study of women who had undergone their first FET cycle between January 2014 and December 2020 at a university-affiliated fertility center. No transferred embryo underwent preimplantation genetic testing for aneuploidy. The women were categorized into five groups based on their reproductive history: no previous pregnancy; previous termination of pregnancy (TOP); previous pregnancy loss; previous ectopic pregnancy (EP); and previous live birth. The women with no previous pregnancy were considered as the reference group. The primary outcome was the live-birth rate and secondary endpoints included rates of positive pregnancy test, clinical pregnancy, pregnancy loss and EP as well as perinatal outcomes such as birth weight and preterm birth. Multivariable logistic regression analyses were used to control for a number of potential confounders, including age, body mass index, education level, duration and cause of infertility, insemination method, type of endometrial preparation, number of embryos transferred, embryo developmental stage, quality of the embryos transferred, year of treatment and endometrial thickness. Additionally, propensity score matching (PSM) was used to check the robustness of the main findings.

RESULTS

In total, 25 329 women were included in the final analysis. On univariate analysis, each reproductive-history type except for previous EP was significantly associated with worse pregnancy outcome following in-vitro fertilization (IVF), including rates of positive pregnancy test, clinical pregnancy, pregnancy loss and live birth, when compared with the group of women with no previous pregnancy. However, after correcting for several potential confounders, the differences in rates of live birth, pregnancy loss, positive pregnancy test and clinical pregnancy were no longer significant between the study and control groups on multivariable regression models, while the risk of EP after embryo transfer was elevated among women with a previous TOP or EP. There was no increased risk of adverse perinatal outcome associated with reproductive history compared with the control group. Notably, similar results were obtained from the PSM models, confirming the robustness of the main findings.

CONCLUSION

Relative to women without a previous pregnancy, those with a prior TOP, pregnancy loss, EP or live birth did not have compromised live-birth rate or perinatal outcomes following FET without preimplantation genetic testing for aneuploidy, with the exception of an increased risk of EP in those with prior TOP or EP. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Evaluation of fertilization, usable blastocyst development and sustained implantation rates according to intracytoplasmic sperm injection operator experience

RESEARCH QUESTION

Is intracytoplasmic sperm injection (ICSI) operator experience associated with fertilization, usable blastocyst development and sustained implantation rates (SIR) when at least two embryologists carry out ICSI for a single cohort of oocytes?

DESIGN

A retrospective cohort study of all IVF/ICSI cycles at a single large infertility centre between 2008 and 2018. Cycles were included if a cohort of oocytes was split between two embryologists for ICSI. The embryologist's experience of ICSI was used to evaluate laboratory and clinical outcomes overall and by pairs of inseminating embryologists. Logistic regression, analysis of variance and Kruskal-Wallis testing were used where appropriate.

RESULTS

Analysis of 14,362 ICSI procedures showed an association between least ICSI experience and lower mean fertilization rates (P < 0.0001), higher odds of failed fertilization (adjusted OR 4.3; P < 0.0001) and lower number of fertilization 'wins' per cohort (P < 0.0001). Usable blastocyst development rates (number of usable blastocysts/number of two pronuclear zygotes) were not associated with ICSI embryologist experience (P = 0.44), but the odds of obtaining no usable blastocysts were higher (adjusted OR 1.4; P < 0.0001) and the proportion of usable blastocyst 'wins' was lower (P = 0.0001) when embryologists with the least experience carried out ICSI. Increased ICSI experience was associated with higher mean SIR (P < 0.0001). Laboratory and clinical outcomes were similar among embryologists once 1000 ICSI cycles and above were carried out.

CONCLUSIONS

Increased ICSI operator experience is associated with higher fertilization rates, SIR and a lower likelihood of failed fertilization and usable blastocyst development. Splitting a single oocyte cohort between more than one embryologist for ICSI is a quality-control measure that can be implemented.

A meta-analysis of the impact of IVF and ICSI on major malformations after adjusting for the effect of subfertility

OBJECTIVE

To estimate the effect of assisted reproductive technology (ART) on major malformation (MM) rate in ART offspring independent of the effect of subfertility on MM.

DESIGN

Meta-analysis.

METHODS

This meta-analysis is based on our previously published meta-analysis of observational studies evaluating the relationship between ART treatment and MM rates, as well as recent research by Zhu et al. to estimate the impact of subfertility alone on MM in subfertile couples conceiving spontaneously.

RESULTS

The overall odds ratio for MM in our original meta-analysis, in which all studies used apparently inappropriate control groups of "normal" populations, was 1.29 (95% CI 1.01-1.67). Here we attempted to estimate the risk of subfertility and used this estimate to perform an adjusted meta-analysis. Zhu et al. found that about 40% of the odds of MM was due to subfertility. When we took Zhu's finding into account, the adjusted odds ratio in the meta-analysis was 1.01 (95% CI 0.82-1.23).

CONCLUSIONS

Our study suggests ART does not increase the risk of MM as much as previously reported. More research is needed to quantify the underlying risk of subfertility and separate it from the risk associated with ART. Physicians who counsel subfertile couples should recognize that previous studies of MM rates in ART patients probably overestimated the risk.

Impact of female and male obesity on IVF/ICSI: results of 700,000 ART-cycles in Germany

To our knowledge, this is the first analysis in which male and female weights have been combined. The registry dataset covering a 12-year period was analysed for all treatment cycles where an embryo transfer was reported. In all, 706,360 cycles were analysed. Treatments include IVF, ICSI, IVF/ICSI and CPE. The highest success rate in IVF cycles was found in couples, with an obese male partner. In the group of obese women, the pregnancy rate decreased to 27.2%. Similar to IVF treatment, the highest success rate in ICSI cycles was found in couples, where either the male or the female partner was obese. The highest success rate in cycles with a cryopreserved embryo transfer was observed in couples where both partner were obese. The lowest success rate was seen where the female partner was obese. Our data analysis suggests that the combination of an obese male and a normal-weight female is positively related to better implantation rates in IVF as well as ICSI-cycles. This combination is more likely to be found in couples with a higher social status. Therefore, the increased pregnancy rate in this group might as well be related to other lifestyle factors associated with higher social status.

Predictive factors in in vitro fertilization (IVF): a systematic review and meta-analysis

BACKGROUND

Various models have been developed for the prediction of pregnancy after in vitro fertilization (IVF). These models differ from one another in the predictors they include. We performed a systematic review and meta-analysis to identify the most relevant predictors for success in IVF.

METHODS

We systematically searched MEDLINE and EMBASE for studies evaluating IVF/ICSI outcome. Studies were included if they reported an unconditional odds ratio (OR) or whenever one could be calculated for one or more of the following factors: age, type of infertility, indication, duration of infertility, basal FSH, number of oocytes, fertilization method, number of embryos transferred and embryo quality.

RESULTS

Fourteen studies were identified. A summary OR could be calculated for five factors. We found negative associations between pregnancy and female age [OR: 0.95, 95% confidence interval (CI): 0.94-0.96], duration of subfertility (OR: 0.99, 95% CI: 0.98-1.00) and basal FSH (OR: 0.94, 95% CI: 0.88-1.00). We found a positive association with number of oocytes (OR 1.04, 95% CI: 1.02-1.07). Better embryo quality was associated with higher pregnancy chances. No significant association was found for the type of infertility and fertilization method. A summary OR for IVF indication and number of embryos transferred could not be calculated, because studies reporting on these used different reference categories.

CONCLUSIONS

Female age, duration of subfertility, bFSH and number of oocytes, all reflecting ovarian function, are predictors of pregnancy after IVF. Better quality studies are necessary, especially studies that focus on embryo factors that are predictive of success in IVF.

A strict infertility diagnosis has poor agreement with the clinical diagnosis entered into the Society for Assisted Reproductive Technology registry

Based on a recent review of the medical literature, a clinical diagnosis of infertility may not agree with strict criteria. Standardized definitions of diagnostic categories are essential for accurate patient prognosis and future research.

Epidemiological factors influencing IVF outcome: Evidence from the Yale IVF program

Age, BMI, lifestyle, menstrual status and obstetric history can modulate the endocrine system and, therefore, have been hypothesised to play a role in in-vitro fertilisation (IVF) outcome. We designed a retrospective study, set in a medical school hospital. We evaluated the medical files of 297 infertile women who underwent laparoscopy and consecutive IVF-ET treatment in the Yale IVF unit between 1996 and 2002. The study group consisted of 151 women who conceived after IVF-ET and the control group of 146 women who underwent 288 IVF-ET cycles without pregnancy. The main outcome measure was the impact of epidemiological factors on the IVF outcome. There was no association between IVF outcome and race, BMI, age at menarche, length of cycle, duration and amount of flow, menstrual symptoms, other medical problems, medical history of allergies, and family history of endometriosis and cancer. We found that the degree of smoking and alcohol use was not a factor when comparing women with and without pregnancy after IVF (34.5% vs 29.5%, and 33.7% vs 27%, respectively). The rate of duration of infertility tended to be lower in pregnant women (35.9+/-23.4 months) vs (42.3+/-30.2) non-pregnant women. As expected, we also confirmed the inverse association between the age of women and IVF outcome. Overall, body attributes, lifestyle, family history, menstrual and reproductive factors were not related to IVF-ET outcome.

Does gravidity influence the success of in vitro fertilization-embryo transfer cycles?

OBJECTIVE

To evaluate the influence of gravidity on the results of in vitro fertilization (IVF)-embryo transfer (ET) cycles.

PATIENTS AND METHODS

All consecutive women aged <35 years admitted to our IVF unit from January 2002 to December 2004 were enrolled in the study. Only patients undergoing one of their first three IVF cycle attempts were included. Gravidity, ovarian stimulation characteristics, number of oocytes retrieved, number of embryo transferred and clinical pregnancy rate were assessed.

RESULTS

Three hundred and forty-two consecutive IVF cycles were evaluated. One hundred and sixty-one cycles were from nulligravidas and 181 from women with a history of at least one previous clinical pregnancy. Forty-eight (29.8%) clinical pregnancies were observed in the nulligravida group and 56 (30.9%) in the gravida group. There were no differences between nulligravidas and gravidas in causes of infertility, length of ovarian stimulation, peak estradiol and progesterone levels, number of oocytes retrieved, fertilization rate and number of embryos transferred. Gravidas were significantly older (30.4 vs. 27.6 years, p < 0.001) and used more gonadotropin ampoules (36.1 vs. 31.8, p < 0.004) compared with the nulligravidas.

CONCLUSIONS

Patient gravidity has no influence on the likelihood of achieving pregnancy in IVF-ET cycles.

Complications of IVF and ovulation induction

BACKGROUND

The frequency and importance of complications of IVF and other ovulation induction (OI) are poorly known. We examined the occurrence of serious complications and miscarriages leading to hospitalization or operation after IVF (including microinjections and frozen embryo transfers) and OI treatment (with or without insemination).

METHODS

Women who received IVF (n = 9175) or OI treatment (n = 10 254) 1996-1998 in Finland were followed by a register linkage study until 2000.

RESULTS

After the first IVF treatment cycle, 14 per 1000 women had a serious case of OHSS (ovarian hyperstimulation syndrome), with 23 per 1000 throughout the study period (mean of 3.3 treatments). The corresponding values after OI were very low. The rates of registered ectopic pregnancies and miscarriages after IVF were nine and 42 respectively per 1000 women, with corresponding rates after OI of eight and 42. Infections and bleeding were not common after IVF and even rarer after OI. Overall, 15% of IVF and 8% of OI women had at least one hospital episode during the study period.

CONCLUSIONS

Though there was a low risk of complications after each IVF treatment cycle, repeated attempts resulted in serious complications for many women, and these occurred much more often than after ovulation induction alone.

Cumulative pregnancy rates and drop-out rates in a German IVF programme: 4102 cycles in 2130 patients

Cumulative pregnancy rates are useful in counselling couples on their chance of conceiving during infertility treatment. Patients also have to be counselled about the physical and psychological stress of infertility treatment. Beside the pregnancy rates, drop-out rates are a direct, and may be the most important, marker of physician quality in an IVF programme. Data from 4102 IVF cycles in 2130 patients in Germany were analysed retrospectively. Data were analysed using descriptive statistics as well as the Kaplan-Meier procedure. A real cumulative pregnancy rate of 31.2% was achieved after four cycles with an expected cumulative pregnancy rate (ECPR) of 53.3%. Age was a significant factor regarding pregnancy rates (ECPR after four cycles: 57.1% <35 years, 44.8% > or =35 years, 35.4% > or =40 years). The drop-out rate of non-pregnant patients increased from 39.9% after the first cycle to 62.2% after the fourth cycle, indicating the enormous stress and frustration that increased during the course of treatment. The drop-out rate should be used as an important marker of quality control. The presented data give, for the first time, a good basis for this counselling procedure in Germany.

Previous miscarriages influence IVF and intracytoplasmatic sperm injection pregnancy outcome

Previous conceptions are one predictor for the outcome of assisted reproductive technology procedures. Approximately 18-34% of clinical pregnancies following assisted reproduction procedures result in spontaneous abortion. The risk of such pregnancy loss is believed to increase with women's age, previous miscarriages and use of frozen-thawed embryos. This study analyses German IVF Registry data to examine the impact of previous miscarriages on the outcome of assisted reproduction procedures. The data set consists of a total of 174,909 assisted reproduction procedures performed between January 1998 and December 2000. Multiple logistic regression is used to assess the correlation between women's age, spousal/partner change, and infertility diagnosis. It is demonstrated that any previous miscarriage will increase the treatment-dependent miscarriage rate in assisted reproduction procedures. A significantly higher impact is shown for one previous miscarriage achieved by assisted reproduction procedures compared with spontaneous conception. Partner change is shown to have no specific impact on the treatment dependent miscarriage rate, whereas a statistically significant increase in miscarriages in all assisted reproduction procedures was found among women older than 34 years of age. Overall, the highest rate of treatment-dependent miscarriages was seen in assisted reproduction procedures with cryopreserved embryo transfer.