Reproductive and treatment outcomes in chronic intervillositis of unknown etiology: A systematic review and meta-analysis.

Chronic Intervillositis of Unknown Etiology (CIUE) is a rare idiopathic inflammatory disorder of the placenta. The evidence suggests an increased risk for poor obstetrical outcomes and a risk of recurrence as high as 100 %. This meta-analysis examined CIUE prevalence, recurrence, association with autoimmune disorders, reproductive outcomes, pregnancy complications, and the benefits of medical treatments. A systematic review, following PRISMA guidelines, involved a thorough search across multiple databases including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Evidence Based Medical Reviews, and Scopus. Out of 590 initially identified studies, 19 studies were included for both qualitative synthesis and meta-analysis after full-text review. Risk of bias was assessed using appropriate tools: The Risk Of Bias In Non-randomized Studies of Interventions tool was applied to twelve studies, while the Joanna Briggs Institute case series critical appraisal tool was used for seven studies. Our findings confirm that CIUE is a rare condition (0.7 %). CIUE is associated with decreased live birth rates (53 %), increased recurrent pregnancy loss (23 %), fetal loss beyond 22 weeks gestation (25 %), a higher prevalence of autoimmune diseases (14 %), and a recurrence rate of 30 % in subsequent pregnancies. Moreover, individuals with CIUE had higher rates of pregnancy complications, including gestational hypertension (19 %), intrauterine growth restriction (45 %), and preterm births (43 %). No significant improvement in live birth rate was observed among treated CIUE patients; however, caution is warranted when interpreting these findings due to the limited sample size. Future research in CIUE is crucial given its rarity and complexity.

A history of recurrent pregnancy loss is associated with increased perinatal complications, but not necessarily a longer birth interval: a population study spanning 18 years.

STUDY QUESTION: Is there a difference in the time interval between the first and second live births among individuals with and without recurrent pregnancy loss (RPL)? SUMMARY ANSWER: Primary RPL (two or more pregnancy losses before the first live birth) is associated with a shorter time interval between the first and second live births compared with individuals without RPL, but this association is reversed in patients with secondary RPL (RPL patients with no or one pregnancy loss before the first live birth). WHAT IS KNOWN ALREADY: There is limited information regarding the ability to have more than one child for patients with RPL. Previous studies have investigated the time to live birth and the live birth rate from the initial presentation to clinical providers. Most of the previous studies have included only patients treated at specialized RPL clinics and thus may be limited by selection bias, including patients with a more severe condition. STUDY DESIGN, SIZE, DURATION: We conducted a population-based retrospective cohort study of 184 241 participants who delivered in British Columbia, Canada, and had at least two recorded live births between 2000 and 2018. The aim was to study the differences in the time interval between the first and second live births and the prevalence of pregnancy complications in patients with and without RPL. Additionally, 198 319 individuals with their first live birth between 2000 and 2010 were studied to evaluate cumulative second live birth rates. PARTICIPANTS/MATERIALS, SETTING, METHODS: Among individuals with at least two recorded live births between 2000 and 2018, 12 321 patients with RPL and 171 920 participants without RPL were included. RPL was defined as at least two pregnancy losses before 20 weeks gestation. Patients with primary RPL had at least two pregnancy losses occurring before the first live birth, while patients with secondary RPL had no or one pregnancy loss before the first live birth. We compared the time interval from the first to second live birth in patients with primary RPL, those with secondary RPL, and participants without RPL using generalized additive models to allow for a non-linear relationship between maternal age and time interval between first and second live births. We also compared prevalence of pregnancy complications at the first and second live births between the groups using non-parametric Kruskal-Wallis H test and Fisher's exact test for continuous and categorical variables, respectively. We assessed the cumulative second live birth rates in patients with primary RPL and those without RPL, among participants who had their first live birth between 2000 and 2010. Cox proportional hazards model was used to estimate and compare hazard ratios between the two groups using a stratified modelling approach. MAIN RESULTS AND THE ROLE OF CHANCE: The adjusted time interval between the first and second live births was the longest in patients with secondary RPL, followed by individuals without RPL, and the shortest time interval was observed in patients with primary RPL: 4.34 years (95% CI: 4.09-4.58), 3.20 years (95% CI: 3.00-3.40), and 3.05 years (95% CI: 2.79-3.32). A higher frequency of pregnancy losses was associated with an increased time interval between the first and second live births. The prevalence of pregnancy complications at the first and second live births, including gestational diabetes, hypertensive disorder of pregnancy, preterm birth, and multiple gestations was significantly higher in patients with primary RPL compared with those without RPL. The cumulative second live birth rate was significantly lower in patients with primary RPL compared with individuals without RPL. LIMITATIONS, REASONS FOR CAUTION: This study may be limited by its retrospective nature. Although we adjusted for multiple potential confounders, there may be residual confounding due to a lack of information about pregnancy intentions and other factors, including unreported pregnancy losses. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study provide information that will help clinicians in the counselling of RPL patients who desire a second child. STUDY FUNDING/COMPETING INTEREST(S): This study was supported in part by a grant from the Canadian Institutes of Health Research (CIHR): Reference Number W11-179912. M.A.B. reports research grants from CIHR and Ferring Pharmaceutical. He is also on the advisory board for AbbVie, Pfizer, and Baxter. The other authors report no conflict of interest. TRIAL REGISTRATION NUMBER: NCT04360564.

Growth differentiation factor myostatin regulates epithelial-mesenchymal transition genes and enhances invasion by increasing serine protease inhibitors E1 and E2 in human trophoblast cells.

Placental insufficiency disorders, including preeclampsia and intrauterine growth restriction, are major obstetric complications that can have devastating effects on both the mother and the fetus. These syndromes have underlying poor placental trophoblast cell invasion into uterine tissues. Placental invasion is controlled by many hormones and growth factors. Myostatin (MSTN) is a transforming growth factor-ß superfamily member recognized for its important role in muscle growth control. MSTN has also been shown to be secreted and functioning in the placenta, and its serum and/or placental levels were found to be upregulated in preeclampsia and intrauterine growth restriction. Considering that the mechanistic role of MSTN in placentation remains poorly understood, we hypothesized that MSTN uses ALK4/5-SMAD2/3/4 signaling to increase human trophoblast invasion through a group of epithelial-mesenchymal transition genes including SERPINE2, PAI-1, and SOX4. mRNA sequencing of control and MSTN-treated primary human trophoblast cells (n = 5) yielded a total of 610 differentially expressed genes (false discovery rate <0.05) of which 380 genes were upregulated and 230 were downregulated. These differentially expressed genes were highly enriched in epithelial-mesenchymal transition genes, and a subset including SERPINE2, PAI-1, and SOX4 was investigated for its role in MSTN-induced trophoblast cell invasion. We found that MSTN induced upregulation of SERPINE2 via ALK4/5-SMAD2/3/4 signaling; however, SMAD2 was not involved in MSTN-induced PAI-1 upregulation. SOX4 was involved in MSTN-induced upregulation of SERPINE2, but not PAI-1. Collectively, this study discovers novel molecular mechanisms of MSTN-induced human trophoblast cell invasion and provides insight into the functional consequences of its dysregulation in placental insufficiency disorders.

Uterine Septum and Other Müllerian Anomalies in a Recurrent Pregnancy Loss Population: Impact on Reproductive Outcomes.

STUDY OBJECTIVE: To study the impact of Müllerian anomalies on reproductive outcomes in a recurrent pregnancy loss (RPL) population and to evaluate the effect of surgical correction of uterine septum on the odds of achieving live birth in RPL patients with a septate uterus. DESIGN: A retrospective cohort study. SETTING: A specialized RPL clinic at a tertiary center. PATIENTS: RPL patients with ≥ 2 pregnancy losses before 20 weeks' gestation who attended a specialized RPL clinic. INTERVENTION: We aimed to assess the association between a possible risk factor (Müllerian anomalies) and reproductive outcomes and that between having surgery for septate uterus and achieving a live birth. MEASUREMENTS AND MAIN RESULTS: The primary outcome is live birth rate in RPL patients with Müllerian anomalies compared with those without; secondary outcome measures include rates of full-term live birth, preterm live birth, first and second trimester pregnancy loss, and stillbirth. After adjusting for patient age at the initial RPL visit, the number of pregnancy losses, and the presence of any other abnormal RPL investigation, the odds of achieving live birth were on average 49.4% lower for patients with a septate uterus than those without Müllerian anomalies (odds ratio, 0.51; 95% confidence interval, 0.30-0.86) in the studied cohort (n = 377). A subanalysis of 72 patients with septate uterus demonstrated a higher likelihood of live birth in those who underwent septum resection (46/72; 63.9%) than those who elected to go for expectant management (26/72; 36.1%), yet this study was underpowered to establish a significant difference (52.2% vs 34.6%; p = .22). CONCLUSION: In RPL patients, having a septate uterus significantly decreased the chances of achieving live birth. Patients with septate uterus who received hysteroscopic septum division had a higher tendency to achieve more live births than those who elected expectant management. However, our study was underpowered to detect a statistically significant difference.

Immunohistochemistry of Leukemia Inhibitory Factor and Integrin αVß3 in Mouse Endometrium Following Kisspeptin-54 Ovulation Trigger.

Kisspeptin (KP) is a group of hypothalamic neuropeptides encoded by KISS-1 gene. KP-54, a 54-amino-acid peptide, helps regulate the hypothalamic-pituitary-ovarian axis and plays a potential role in implantation. C57BL/6 J female mice were superovulated via intraperitoneal injection of 5 International Units (IU) pregnant mare serum gonadotrophin (day 1). Forty-eight hours later, mice (5/group) were injected with phosphate-buffered saline (PBS) (group A), 5 IU human chorionic gonadotrophin (hCG) (group B), or 3 nmol KP-54 (group C). On day 7, mice were euthanized and uteri excised to create paraformaldehyde-fixed paraffin-embedded sections that were immunostained for the implantation markers: leukemia inhibitory factor (LIF) and integrin αVß3 (ITG αVß3). Slides were scored for intensity of staining in endometrial glandular epithelium (GE) and stromal cells (SCs) via histoscore (H-score). Data were analyzed using the Kruskal-Wallis test followed by the Mann-Whitney U test for pairwise comparisons. LIF expression was significantly higher in GE and SCs of mice triggered with KP-54 compared to placebo (P = .009 for both), but only higher than hCG trigger group in SCs (P = .009). Meanwhile, ITG αVß3 expression was significantly higher in SCs of mice triggered with KP-54 compared to placebo (P = .028). In conclusion, using KP-54 as an ovulation trigger resulted in higher expression of the implantation markers LIF and ITG αVß3 in mice endometrium compared to hCG or placebo. This suggests a potential role for KP-54 trigger in improving embryo implantation in clinical IVF. However, further studies are needed to correlate these results with clinical implantation rates and pregnancy outcomes.

The Clinical Significance of Embryonic Chromosomal Errors in Recurrent Pregnancy Loss: an Analysis of 1107 Miscarriages.

The objective of this study was to characterize the relationship between embryonic chromosomal errors in the products of conception (POC) and maternal age, gestational age (GA) of pregnancy loss, and findings on routine recurrent pregnancy loss (RPL) workup. This is a retrospective cohort study of women with a history of ≥ 2 pregnancy losses and who underwent cytogenetic testing on the POC of a subsequent pregnancy loss at an academic tertiary RPL referral center. The association between the odds of embryonic chromosomal errors in POC and maternal age, GA of pregnancy loss, as well as RPL work up findings was investigated. A total of 1107 miscarriages were analyzed from 741 women. There was an overall linear relationship between embryonic chromosomal errors and maternal age, with a nearly twofold increase in the odds of chromosomal error with every 5-year increase in maternal age (P < 0.0001). The association between chromosomal errors and GA was also linear (P = 0.0001), with most losses having no chromosomal errors after 13 weeks' gestation. Women with ≥ 1 positive findings on routine RPL diagnostic workup had lower odds of embryonic chromosomal errors compared to those with a normal workup [OR 0.57 (95% CI = 0.41-0.80)]. Notably, the estimated prevalence of chromosomal error remained high (> 60%) in women ≥ 35 years old irrespective of findings on routine evaluation. While embryonic chromosomal errors were associated with advanced maternal age, early GA of loss, and a negative routine RPL evaluation, the prevalence of chromosomal errors remained high in all subpopulations. These findings suggest that primary cytogenetic testing on POCs should be offered at the time of second and subsequent pregnancy losses in all RPL patients.

Kisspeptin and kisspeptin receptor immunoreactivity in euploid and aneuploid choriodecidual tissues of recurrent pregnancy losses.

OBJECTIVE: To study choriodecidual immunoreactivity of kisspeptin (KISS1) and its receptor (KISS1R) in recurrent pregnancy loss (RPL) due to aneuploidy (AnE) and unexplained (UE) RPL in comparison to control elective abortions (EAbs). DESIGN: This is a case-control study. SETTING: Tertiary care facility and affiliated research institute. PATIENT(S): Patients with either UE RPL (n = 10) or RPL due to AnE (n = 10) vs. a control group of patients who underwent EAb (n = 10). INTERVENTION(S): Immunohistochemistry of archived choriodecidual tissue samples. MAIN OUTCOME MEASURE(S): Histoscores of KISS1 and KISS1R immunoreactivity in the syncytiotrophoblast (SyT), cytotrophoblast (CyT), decidual glands (DeGs), and decidual stroma (DeS) across the 3 study groups. RESULT(S): There was no difference in both maternal and gestational ages among the 3 groups. Kisspeptin immunoreactivity was similar in the SyT, CyT, DeGs, and DeS of all groups. Similarly, KISS1R expression was not different in the DeGs or DeS among all study groups. In addition, there was no difference in KISS1R immunoreactivity in the SyTs and CyTs between patients with RPL due to AnE and those with UE RPL. However, KISS1R was significantly lower in the SyT and CyT of patients with RPL due to AnE and UE RPL than in those who underwent EAb. CONCLUSION(S): The expression of KISS1R is lower in the chorionic tissues of euploid (unexplained) and aneuploid RPLs than in the control group. The current results broaden our understanding of the role played by KISS1 and KISS1R in early placentation. Further investigation is necessary to determine whether KISS1 activity is the cause or a sequel of defective placentation.

Temporal trends in thyroid-stimulating hormone and live birth rate in subclinical hypothyroid patients in a recurrent pregnancy loss population.

OBJECTIVES: The purpose of this study was to explore if thyroperoxidase antibody positivity impacts thyroid stimulating hormone levels during pregnancies following the index visit and how live birth rate is impacted when treated subclinical hypothyroidism is treated with levothyroxine or not. STUDY DESIGN: A retrospective chart review of 1443 recurrent pregnancy loss patients from BC Women's Hospital recurrent pregnancy loss clinic was conducted. Thyroid stimulating hormone in pregnancies after the index visit across thyroperoxidase antibody status was analyzed using mixed-effects linear regression. Live birth rate in patients with subclinical hypothyroidism (thyroid stimulating hormone 2.5-10 mIU/L) with levothyroxine treatment was compared to those without relative to euthyroid patients using logistic regression. RESULTS AND CONCLUSIONS: There was no significant difference in patient demographics including age, body mass index, or number of previous live births or pregnancy losses between groups. The distribution of recurrent pregnancy loss causes between groups revealed no difference in proportion of patients with anti-phospholipid antibody syndrome, hereditary thrombophilia, hyperprolactinemia, or anatomic causes. There was no significant change in thyroid stimulating hormone across thyroperoxidase antibody or treatment status (p = 0.24) for up to four subsequent pregnancies. An increased live birth rate in subclinical hypothyroidism when treated with levothyroxine relative to untreated (OR = 2.25, p < 0.001) was seen. Thyroid stimulating hormone values do not change over time following the index visit for up to 4 subsequent pregnancies irrespective of the thyroxperoxidase antibody status. An increase in live birth rate was found in patients with borderline subclinical hypothyroidism when treated with levothyroxine.

Clinical, Hormonal, and Metabolic Parameters in Women with Subclinical Hypothyroidism and Polycystic Ovary Syndrome: A Cross-Sectional Study.

BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in reproductive age women, yet its clinical presentation shares similarities with several other endocrine disorders such as thyroid disease. Hence, the objective of this study was to further evaluate this association by investigating the clinical, hormonal, and metabolic parameters between subclinical hypothyroidism (SCH) and PCOS. METHODS: This is a cross-sectional study conducted in a tertiary care clinic at Cleveland, Ohio, USA. A total of 137 women diagnosed with PCOS by Rotterdam criteria were examined. SCH was defined as thyroid-stimulating hormone >2.5 mIU/L in the absence of symptoms of overt hypothyroidism. The mean age, body mass index (BMI), fasting plasma glucose (FPG), glucose tolerance test, hemoglobin A1c, fasting insulin, a 2 hours insulin level after 75 g glucose load, cholesterol, LDL, HDL, and homeostatic model assessment (HOMA) were compared between women with and without SCH. Logistic regression was used to adjust for age and BMI. RESULTS: Among 137 women with PCOS, 21.9% had SCH. Comparison groups were similar in both age and BMI and there was no difference in the mean values of all endocrine and metabolic parameters tested. However, abnormal FPG levels (OR 3.01; CI: 1.12-8.07. p = 0.03) and abnormal HOMA (OR 3.7; CI: 1.14-12.00. p = 0.03) were more likely in women who had SCH than in women without SCH independent of age and BMI. CONCLUSIONS: Women with PCOS and SCH are more likely to have impaired FPG values and impaired insulin sensitivity even after adjusting for age and BMI. Hence, close monitoring of PCOS patients for SCH may be beneficial.

The Effect of Age and Body Mass Index on the Surgical Anatomy of Supraumbilical Port Insertion: Implications for Laparoscopic and Robotic Surgery.

BACKGROUND: Minimally invasive surgery is the preferred approach for performing many gynecologic procedures. Occasionally, supraumbilical port placement may be preferable to optimize visibility and maneuverability although the risks of complications are less well characterized compared to umbilical entry. METHODS: We conducted a retrospective review of computed tomograms from 92 patients to evaluate the anatomic considerations for umbilical and supraumbilical port entry based on patient age, body mass index (BMI), parity, abdominal wall thickness, and distance to the great vessels. RESULTS: Supraumbilical entry was not associated with differences in distance to the great vessels compared to the umbilicus. However, supraumbilical location and BMI were associated with greater abdominal wall thickness. Age and BMI were associated with greater distance to the great vessels, while age was associated with thinner abdominal wall. Multiple linear regression confirmed independent effects of age and BMI. No association between parity and distance to retroperitoneal vessels was observed. CONCLUSION: Younger patients may be at increased risk for great vessel injury and pre-peritoneal insufflation. Obese patients may be at risk for pre-peritoneal insufflation, while patients with BMI < 30, particularly with a skin-to-aorta distance < 7 cm, may be at an increased risk for great vessel injury. Surgeons should consider these factors when considering supraumbilical port entry.

Does preimplantation genetic diagnosis improve reproductive outcome in couples with recurrent pregnancy loss owing to structural chromosomal rearrangement? A systematic review.

Recurrent pregnancy loss (RPL) is a common, yet elusive, complication of pregnancy. Among couples at high risk of RPL, such as those carrying a structural chromosomal rearrangement, preimplantation genetic diagnosis (PGD) has been proposed as a tool to improve live birth rates and reduce the incidence of miscarriage; however, no clear consensus has been reached on its benefits in this population. This systematic review summarizes existing published research on the effect of PGD on pregnancy outcomes among carriers of chromosomal abnormalities with RPL. A comprehensive search of common databases was conducted, which yielded 20 studies. Meta-analysis was precluded owing to significant heterogeneity between studies. The primary outcome of interest was live birth rate (LBR), and a pooled total of 847 couples who conceived naturally had a LBR ranging from 25-71% compared with 26.7-87% among 562 couples who underwent IVF and PGD. Limitations of the study include lack of large comparative or randomized control studies. Patients experiencing RPL with structural chromosomal rearrangement should be counselled that good reproductive outcomes can be achieved through natural conception, and that IVF-PGD should not be offered first-line, given the unproven benefits, additional cost and potential complications associated with assisted reproductive technology.

Tactile Electrosurgical Ablation: A Technique for the Treatment of Intractable Heavy and Prolonged Menstrual Bleeding.

Objective. To study the efficacy and safety of tactile electrosurgical ablation (TEA) in stopping a persistent attack of abnormal uterine bleeding not responding to medical and hormonal therapy. Methods. This is a case series of 19 cases with intractable abnormal uterine bleeding, who underwent TEA at the Women's Health Center of Assiut University. The outcomes measured were; patient's acceptability, operative time, complications, menstrual outcomes, and reintervention. Results. None of the 19 counseled cases refused the TEA procedure which took 6-10 minutes without intraoperative complications. The procedure was successful in the immediate cessation of bleeding in 18 out of 19 cases. During the 24-month follow-up period, 9 cases developed amenorrhea, 5 had scanty menstrual bleeding, 3 were regularly menstruating, 1 case underwent repeat TEA ablation, and one underwent a hysterectomy. Conclusions. TEA represents a safe, inexpensive, and successful method for management of uterine bleeding emergencies with additional long-term beneficial effects. However, more studies with more cases and longer follow-up periods are warranted.

Clinical Effectiveness of Modified Laparoscopic Fimbrioplasty for the Treatment of Minimal Endometriosis and Unexplained Infertility.

Objective. To study the reproductive outcomes of modified laparoscopic fimbrioplasty (MLF), a surgical technique designed to increase the working surface area of the fimbriated end of the fallopian tube. We postulated that an improvement in fimbrial function through MLF will improve reproductive outcomes. Design. Retrospective cohort study. Setting. Academic tertiary-care medical center. Patients. Women with minimal endometriosis or unexplained infertility, who underwent MLF during diagnostic laparoscopy (n = 50) or diagnostic laparoscopy alone (n = 87). Intervention. MLF involved gentle, circumferential dilatation of the fimbria and lysis of fimbrial adhesions bridging the fimbrial folds. Main Outcome Measures. The primary outcome was pregnancy rate and the secondary outcome was time to pregnancy. Results. The pregnancy rate for the MLF group was 40.0%, compared to 28.7% for the control group. The average time to pregnancy for the MLF group was 13 weeks, compared to 18 weeks for the control group. The pregnancy rate in the MLF group was significantly higher for patients ≤35 ys (51.5% versus 28.8%), but not for those >35 ys (17.6% versus 28.6%). Conclusion. MLF was associated with a significant increase in pregnancy rate for patients ≤35 ys.

Laparoendoscopic single-site surgery for benign ovarian cystectomies.

BACKGROUND: Single-port laparoscopy (LESS) utilizes a single, multichannel port in an attempt to decrease postoperative pain, while enhancing cosmesis and minimizing the potential risks and morbidities associated with the multiple ports used in conventional laparoscopy. METHODS: We performed a retrospective study examining three tertiary care referral centers. From September 2009 until March 2013, 31 patients with ovarian cystic lesions were treated using the LESS technique. A control group of 57 patients who underwent conventional laparoscopic ovarian cystectomy was included for comparison. RESULTS: All patients underwent a technically successful cystectomy. There were no statistically significant differences in the mean operative time or estimated blood loss between the two groups. Narcotic use during the recovery period was reported in less patients in the LESS group than in the laparoscopic group (p = 0.05). CONCLUSIONS: The LESS technique can be used to safely perform cystectomies on women with benign ovarian cysts. Additional investigation is needed to evaluate the safety, cost-effectiveness and long-term outcomes of this new approach.

Slow freezing, vitrification and ultra-rapid freezing of human embryos: a systematic review and meta-analysis.

Embryo cryopreservation is an important aspect of assisted reproduction. Many methods have been described, but they have been poorly investigated in randomized trials, highlighting the need for a systematic review of the literature. Meticulous electronic/hand searches were performed to locate randomized trials (RCT) comparing embryo cryopreservation methods. Primary outcomes were clinical pregnancy rate (CPR) and incidence of congenital abnormalities. Secondary outcomes included live-birth (LBR), ongoing pregnancy (OPR), implantation (IR), and miscarriage (MR) rates. Data were extracted to allow for an intention-to-treat analysis and analysed using a random-effects model. Literature search revealed 11 RCT, of which five were excluded. The quality of the included studies was variable, but generally poor. There was a significantly higher CPR, OPR and IR with vitrification compared with slow freezing (odds ratio (OR)=1.55, 95% confidence interval (CI)=1.03-2.32, OR=1.82, 95% CI=1.04-3.20 and OR=1.49, 95% CI=1.03-2.15, respectively). In addition, there was a significantly lower CPR and OPR with embryo ultra-rapid freezing compared with slow freezing (OR=0.35, 95% CI=0.16-0.76 and OR=0.37, 95% CI=0.17-0.81, respectively). Vitrification is superior to slow freezing, which in turn is superior to ultra-rapid freezing. However, more well-designed and powered studies are needed to further corroborate these findings.

Granulocyte-macrophage colony stimulating factor (GM-CSF) and co-culture can affect post-thaw development and apoptosis in cryopreserved embryos.

PURPOSE: The objective of this study was to evaluate the effects of growth factor supplementation and Vero cell co-culture on apoptosis and development of frozen thawed one-cell mouse embryos. METHODS: The following treatment regimens were assessed: (a) control medium (b) Vero cell co-culture and (c) growth factor supplemented medium. The individual growth factors tested were: GM-CSF, IGF-I, IGF-II, TNF-alpha, FGF-4, LIF, TGF-alpha, TGF-beta, IL-6, PDGF and EGF. Blastocyst development and differentiation were monitored. At termination of the experiments, overall blastomere number and apoptosis were assessed using the TUNEL assay. RESULTS: No differences were observed in blastulation and hatching rates. ICM differentiation in thawed embryos was notably improved with either co-culture or growth factor supplementation. The only growth factor significantly modulating apoptosis in thawed embryos was granulocyte-macrophage colony stimulating factor (GM-CSF). GM-CSF enhanced continued cell survival and prevented apoptosis but did not influence overall cell number in developing blastocysts. Vero cell co-culture significantly increased cell number in blastocysts (124+/-42 vs 100+/-44 in control; P<0.05). Embryonic apoptosis was higher in the co-cultured embryos. The increased presence of apoptotic cells in blastocysts of high cell number may reflect the regulatory role of apoptosis in balancing ICM: TE ratios. CONCLUSION: These data indicate that culture conditions can modulate post-thaw embryonic development and apoptosis.