Long term tolerability and clinical outcomes associated with tocilizumab in the treatment of refractory antibody mediated rejection (AMR) in pediatric renal transplant recipients

BACKGROUND

Treatment options for antibody-mediated rejection (AMR) are limited. Recent studies have shown that inhibition of interleukin-6 (IL-6)/interleukin-6 receptor (IL-6R) signaling can reduce inflammation and slow AMR progression.

METHODS

We report our experience using monthly tocilizumab (anti-IL6R) in 25 pediatric renal transplant recipients with AMR, refractory to IVIg/Rituximab. From January 2013 to June 2019, a median (IQR) of 12 (6.019.0) doses of tocilizumab were given per patient. Serial assessments of renal function, biopsy findings, and HLA DSA (by immunodominant HLA DSA [iDSA] and relative intensity score [RIS]) were performed.

RESULTS

Median (IQR) time from transplant to AMR was 41.4 (24.367.7) months, and time from AMR to first tocilizumab was 10.6 (8.317.6) months. At median (IQR) follow up of 15.8 (8.435.7) months post-tocilizumab initiation, renal function was stable except for 1 allograft loss. There was no significant decrease in iDSA or RIS. Follow up biopsies showed reduction in peritubular capillaritis (p = .015) and C4d scoring (p = .009). The most frequent adverse events were cytopenias.

CONCLUSIONS

Tocilizumab in pediatric patients with refractory AMR was well tolerated and appeared to stabilize renal function. The utility of tocilizumab in the treatment of AMR in this population should be further explored.

Preventive malaria treatment among school-aged children in sub-Saharan Africa: a systematic review and meta-analyses

BACKGROUND

The burden of malaria infection in sub-Saharan Africa among school-aged children aged 5-15 years is underappreciated and represents an important source of human-to-mosquito transmission of Plasmodium falciparum. Additional interventions are needed to control and eliminate malaria. We aimed to assess whether preventive treatment of malaria might be an effective means of reducing P falciparum infection and anaemia in school-aged children and lowering parasite transmission.

METHODS

In this systematic review and two meta-analyses, we searched the online databases PubMed, Embase, Cochrane CENTRAL, and Clinicaltrials.gov for intervention studies published between Jan 1, 1990, and Dec 14, 2018. We included randomised studies that assessed the effect of antimalarial treatment among asymptomatic school-aged children aged 5-15 years in sub-Saharan Africa on prevalence of P falciparum infection and anaemia, clinical malaria, and cognitive function. We first extracted data for a study-level meta-analysis, then contacted research groups to request data for an individual participant data meta-analysis. Outcomes of interest included prevalence of P falciparum infection detected by microscopy, anaemia (study defined values or haemoglobin less than age-adjusted and sex-adjusted values), clinical malaria (infection and symptoms on the basis of study-specific definitions) during follow-up, and code transmission test scores. We assessed effects by treatment type and duration of time protected, and explored effect modification by transmission setting. For study-level meta-analysis, we calculated risk ratios for binary outcomes and standardised mean differences for continuous outcomes and pooled outcomes using fixed-effect and random-effects models. We used a hierarchical generalised linear model for meta-analysis of individual participant data. This study is registered with PROSPERO, CRD42016030197.

FINDINGS

Of 628 studies identified, 13 were eligible for the study-level meta-analysis (n=16 309). Researchers from 11 studies contributed data on at least one outcome (n=15 658) for an individual participant data meta-analysis. Interventions and study designs were highly heterogeneous; overall risk of bias was low. In the study-level meta-analysis, treatment was associated with reductions in P falciparum prevalence (risk ratio [RR] 0·27, 95% CI 0·17-0·44), anaemia (0·77, 0·65-0·91), and clinical malaria (0·40, 0·28-0·56); results for cognitive outcomes are not presented because data were only available for three trials. In our individual participant data meta-analysis, we found treatment significantly decreased P falciparum prevalence (adjusted RR [ARR] 0·46, 95% CI 0·40-0·53; p<0·0001; 15 648 individuals; 11 studies), anaemia (ARR 0·85, 0·77-0·92; p<0·0001; 15 026 individuals; 11 studies), and subsequent clinical malaria (ARR 0·50, 0·39-0·60; p<0·0001; 1815 individuals; four studies) across transmission settings. We detected a marginal effect on cognitive function in children older than 10 years (adjusted mean difference in standardised test scores 0·36, 0·01-0·71; p=0·044; 3962 individuals; five studies) although we found no significant effect when combined across all ages.

INTERPRETATION

Preventive treatment of malaria among school-aged children significantly decreases P falciparum prevalence, anaemia, and risk of subsequent clinical malaria across transmission settings. Policy makers and programme managers should consider preventive treatment of malaria to protect this age group and advance the goal of malaria elimination, while weighing these benefits against potential risks of chemoprevention.

FUNDING

US National Institutes of Health and Burroughs Wellcome Fund/ASTMH Fellowship.

Clinicians’ perspectives on diagnosing polycystic ovary syndrome in Australia: a qualitative study

STUDY QUESTION

What are clinicians’ views about the diagnosis of polycystic ovary syndrome (PCOS), and how do they handle any complexities and uncertainties in practice?

SUMMARY ANSWER

Clinicians have to navigate many areas of complexity and uncertainty regarding the diagnosis of PCOS, related to the diagnostic criteria, limitations in current evidence and misconceptions surrounding diagnosis, and expressed concern about the risk and consequences of both under- and overdiagnosis.

WHAT IS KNOWN ALREADY

PCOS is a complex, heterogeneous condition with many areas of uncertainty, raising concerns about both underdiagnosis and overdiagnosis. Quantitative studies with clinicians have found considerable variation in diagnostic criteria used and care provided, as well as a lack of awareness around the breadth of PCOS features and poor uptake of recommended screening for metabolic complications. Clinicians’ views about the uncertainties and complexities of diagnosing PCOS have not been explored.

STUDY DESIGN, SIZE, DURATION

Semi-structured telephone interviews were conducted with clinicians from September 2017 to July 2018 to explore their perceptions about the diagnosis of PCOS, including how they handle any complexities and uncertainties in practice.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A group of 36 clinicians (15 general practitioners, 10 gynaecologists and 11 endocrinologists) currently practicing in Australia, were recruited through advertising via professional organisations, contacting a random sample of endocrine and gynaecology teams across Australia and snowballing. Transcribed audio-recordings were analysed thematically using Framework analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Clinicians expressed a range of uncertainties and complexities regarding the diagnosis of PCOS, which were organised into three areas: (i) establishing diagnosis (e.g. lack of standardisation regarding diagnostic cut-offs, risk of misdiagnosis), (ii) factors influencing the diagnostic process (e.g. awareness of limitations in evidence and consideration of the benefits and harms) and (iii) strategies for handling challenges and uncertainties (e.g. using caution and communication of uncertainties). Clinicians also varied in their concerns regarding under- and overdiagnosis. Overall, most felt the diagnosis was beneficial for women provided that it was the correct diagnosis and time was taken to assess patient expectations and dispel misconceptions, particularly concerning fertility.

LIMITATIONS, REASONS FOR CAUTION

There is possible selection bias, as clinicians who are more knowledgeable about PCOS may have been more likely to participate. Clinicians’ views may also differ in other countries.

WIDER IMPLICATIONS OF THE FINDINGS

These findings underscore the vital need to first consider PCOS a diagnosis of exclusion and use caution before giving a diagnosis in order to reduce misdiagnosis, as suggested by clinicians in our study. Until there is greater standardisation of diagnostic criteria, more transparent conversations with women may help them understand the uncertainties surrounding the criteria and limitations in the evidence. Additionally, clinicians emphasised the importance of education and reassurance to minimise the potential harmful impact of the diagnosis and improve patient-centred outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the University of Sydney Lifespan Research Network and an NHMRC Program Grant (APP1113532). T.C. is supported by an Australian Government Research Training Program (RTP) Scholarship and a Sydney Medical School Foundation Scholarship, from the The University of Sydney, Australia. B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA and Guerbet. No further competing interests exist.

TRIAL REGISTRATION NUMBER

N/A

The benefits and harms of receiving a polycystic ovary syndrome diagnosis: a qualitative study of women's experiences

STUDY QUESTION

What are the benefits and harms of receiving a polycystic ovary syndrome (PCOS) diagnosis in a community sample of women, including impact on psychosocial wellbeing, lifestyle choices and behaviour?

SUMMARY ANSWER

Although some women benefit considerably from the diagnosis, such as through increased awareness and reassurance, women with minimal symptoms may experience more harm than benefit, including long-lasting anxiety and altered life plans.

WHAT IS KNOWN ALREADY

Disease labels can validate symptoms and play a vital role in understanding and coping with illness; however, they can also cause harm by evoking illness schemas about severity and permanence. Regarding PCOS, the diagnostic criteria have expanded over time to include women with milder phenotypes (such as those without signs of androgen excess). This has occurred despite limited investigation of the benefits and harms of the diagnosis and has increased the number of women diagnosed.

STUDY DESIGN SIZE DURATION

Semi-structured interviews were conducted face-to-face or by telephone with 26 participants from April-July 2018 to explore women's experiences with the diagnosis, including the benefits and harms of receiving the diagnosis and the impact on their life.

PARTICIPANTS/MATERIALS SETTING METHODS

In total, 26 women in the community self-reporting a diagnosis of PCOS (reporting mild to severe symptoms) made by a medical doctor, aged 18-45 years and living in Australia were recruited through social media. Data were analysed thematically using Framework analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

The study identified a range of both positive and negative effects of a PCOS diagnosis in the immediate, short and long-term, which were influenced by symptom severity, expectations and experience. For women with previously unexplained and bothersome symptoms, it was a relief to receive a diagnosis, and this resulted in an increased understanding about the importance of a healthy lifestyle. By contrast, women with milder symptoms often reported feeling shocked and overwhelmed by the diagnosis, consequently experiencing anxiety about the associated long-term risks. The majority of women, regardless of symptom severity, experienced prolonged worry and anxiety about infertility, resulting for some in risk taking with contraception, unintended pregnancies, pressure to conceive early or altered life plans. With time, many women developed positive coping strategies and perceived the diagnosis to be valuable, including those who felt they had experienced minimal benefit or even harm.

LIMITATIONS REASONS FOR CAUTION

PCOS diagnosis was self-reported and the sample was highly educated.

WIDER IMPLICATIONS OF THE FINDINGS

Fear of infertility was salient for many women, underscoring the need for accurate information, counselling and reassurance of fertility potential. Given the risk of significant consequences, health professionals should use a tailored approach to PCOS diagnosis to increase the benefits of appropriate and timely diagnosis for women affected by significant symptoms, while reducing the harms of unnecessarily labelling healthy women for whom the benefits of a diagnosis are small.

STUDY FUNDING/COMPETING INTERESTS

The study was funded by the University of Sydney Lifespan Research Network and an NHMRC Program Grant (APP1113532). B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA and Guerbet. No further competing interests exist.

TRIAL REGISTRATION NUMBER

N/A.

A decrease in serum estradiol levels after human chorionic gonadotrophin administration predicts significantly lower clinical pregnancy and live birth rates in in vitro fertilization cycles

BACKGROUND

Although close observation of serum estradiol (E2) levels remains a mainstay of assessing clinical response to controlled ovarian stimulation, the prognostic value of any change in E2 levels after administration of hCG remains unclear. The objective of this study is to evaluate the relationship between serum E2 response after hCG administration and the clinical pregnancy and live birth rates in fresh IVF cycles.

METHODS

We conducted a retrospective cohort study of women aged 21-45 years undergoing their first IVF cycle from 1999 to 2008 at a single practice. We compared the post-hCG serum E2 level with values on the day of hCG trigger. IVF cycles were stratified by post-hCG E2 response and appropriate parametric and non-parametric statistics were performed. Clinical intrauterine pregnancy and live births were the primary outcomes of interest. Multivariable logistic regression models were created to identify predictive factors associated with outcomes while adjusting for potential confounders.

RESULTS

Among the 1712 IVF cycles, 1065 exhibited a >10% increase (Group A), 525 had a plateau (± 10%, Group B) and 122 showed a >10% decrease (Group C) in post-hCG E2 levels. While the E2 levels on the day of hCG were similar across groups, Group C had more patients with diminished ovarian reserve, required higher gonadotrophin doses and had the lowest implantation rates. After adjusting for age, total gonadotrophin dose, infertility diagnosis, number of oocytes and number of transferred embryos, the associations between post-hCG E2 decline (Group C) and clinical pregnancy [adjusted odds ratio (aOR): 0.53; 95% confidence interval (CI): 0.33-0.84, P= 0.007] and live birth (aOR: 0.40; 95% CI: 0.22-0.71, P= 0.002) were significant. We also found significant associations between E2 plateau (Group B) and clinical pregnancy (aOR: 0.73; 95% CI: 0.57-0.94, P= 0.013) and live birth (aOR: 0.74; 95% CI: 0.56-0.97, P= 0.032) when adjusting for the same factors.

CONCLUSIONS

In our study, >10% decrease in E2 levels after hCG administration was associated with 40-50% reduction in clinical pregnancy and live birth rates. Similarly, post-hCG E2 plateau (± 10%) lowered the clinical pregnancy and live birth rates by >25%. Our study suggests that the change in the post-hCG E2 level is another parameter that can be used by clinicians to counsel patients regarding their likelihood of success with assisted reproductive technologies prior to oocyte retrieval.

The tumour suppressor gene maspin is differentially regulated in cytotrophoblasts during human placental development

Identification of factors that play a role in regulating the highly invasive ability of human placental cells throughout gestation will contribute to a better understanding of this unique developmental process. The aims of this study were to determine whether the tumour suppressor gene maspin is present in the human placenta and plays a putative role in the regulation of cytotrophoblast invasion during placental development. The data showed that the expression of maspin mRNA was maximum in term placentae compared to the first and second trimester tissues, and absent in the HTR-SVneo (immortalized extravillous cytotrophoblast), JEG-3 and JAR (choriocarcinoma) cell lines. Maspin protein, detected by Western blot analysis, was twofold higher in the second trimester and 4.4-fold higher in the third trimester compared to the first trimester. Maspin immunohistochemical staining was localized in cytotrophoblasts with increased and more diffuse staining in the second and third trimesters. Corresponding to the period of maximum maspin expression, cytotrophoblasts isolated from term placentae had significantly lower invasive ability as compared to first and second trimester cytotrophoblasts (P< 0.03). Further, addition of recombinant maspin significantly decreased cytotrophoblast invasion in vitro by 40-50 per cent in all three trimesters of gestation. This study provides the first evidence of the temporal expression of maspin during human gestation and suggests a putative role for maspin in regulating the invasive activity of cytotrophoblasts at term. The down-regulation of maspin expression may be critical at the time of implantation and early placental development, whereas upregulation of maspin may serve as a signal for the end of cytotrophoblast invasion and gestation.

Regulation of human cytotrophoblast morphogenesis by hepatocyte growth factor/scatter factor

In vitro morphogenesis of epithelial cells to form tube-like structures is regulated by hepatocyte growth factor-scatter factor (HGF/SF). The placenta is a rich source of HGF/SF, and its absence in mice has been shown to lead to impaired placental growth and embryonic death. There is no information in the literature regarding in vitro morphogenesis of human cytotrophoblasts or the effect of HGF/SF on this process. In this study, cytotrophoblasts were isolated from human placentae obtained from all three trimesters of gestation and cultured on the recombinant basement membrane matrix (Matrigel). Under these conditions, cytotrophoblasts participated in morphogenetic events including formation of spheroid-like structures, radial linear processes with branching, and invaded Matrigel and formed large, tube-like structures. The presence of a developing lumen was documented in the linear projections arising from spheroids and in the tube-like structures by both confocal and transmission electron microscopy. Immunohistochemistry was used to characterize the phenotype of the cells, and staining with anti-cytokeratin and anti-E-cadherin antibodies confirmed the presence of cytotrophoblasts in both the spheroids and tube-like structures. Recombinant HGF (rHGF) significantly increased the invasive activity of cytotrophoblasts isolated from the first and second (P < 0.001) and third trimesters (P < 0.01). In addition, rHGF significantly increased the percentage of spheroids with branching processes in the first and second trimesters (P < 0.05). Anti-HGF antibody inhibited both these effects in a dose-dependent manner, indicating the specificity of the above findings. This study provides new evidence indicating that HGF/SF regulates invasion and branching morphogenesis of cytotrophoblasts throughout gestation, with maximum effects in the first and second trimester. These findings may help to elucidate the importance of the reduced expression of HGF/SF identified in placentae from women with preeclampsia or intrauterine growth restriction and suggest that HGF/SF may serve as an important candidate in therapeutic intervention strategies.

Bilateral undescended ovaries: association with infertility and treatment with IVF

OBJECTIVE

To describe the clinical findings in a patient with bilateral undescended ovaries and infertility who was successfully treated by IVF.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

A 35-year-old woman with bilateral undescended ovaries.

INTERVENTION(S)

Hysterosalpingography, laparoscopy, and an IVF cycle.

MAIN OUTCOME MEASURE(S)

Anatomic description and pregnancy test.

RESULT(S)

This patient conceived and delivered a twin gestation after laparoscopic retrieval of oocytes and transfer of two blastocysts.

CONCLUSION(S)

Bilateral undescended ovaries is a rare condition that can be associated with infertility but can be successfully treated by IVF.

Secretion of inhibin B during ovarian stimulation is decreased in infertile women with endometriosis

OBJECTIVE(S)

To determine the levels and pattern of inhibin B secretion during ovarian stimulation in patients with endometriosis and to evaluate the correlation between inhibin B levels and variables of follicular and oocyte development.

DESIGN

Retrospective cohort study.

SETTING

IVF center.

PATIENT(S)

Women with endometriosis (n = 20) and tubal factor (n = 10) as the only cause of infertility.

INTERVENTION(S)

Inhibin B levels were measured during gonadotropin stimulation on day 1, days 8-11, day of hCG administration, and oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Patterns and levels of inhibin B secretion were compared in the two groups. Other variables analyzed were age, days of gonadotropin stimulation and total ampules used, oocytes retrieved, and the fertilization and pregnancy rate.

RESULT(S)

Inhibin B levels and number of oocytes retrieved were significantly lower in patients with endometriosis than in the control group. Two patterns of inhibin B secretion were noted: It peaked in the midfollicular phase or on the day of hCG administration. In contrast, E2 levels peaked on the day of hCG administration. Inhibin B in the midfollicular phase in both groups correlated positively with number of oocytes retrieved. In addition, E2 and inhibin B levels in the midfollicular phase correlated positively.

CONCLUSION(S)

Decreased inhibin B secretion in patients with endometriosis suggests impaired granulosa cell function. Inhibin B may serve as an alternate marker to assess follicular development or to predict the number of oocytes retrieved.

Septate uterus associated with cervical duplication and vaginal septum

A woman had an unusual müllerian anomaly with a septate uterus, cervical duplication, and longitudinal vaginal septum. Gynecologists should be aware of the possibility of cervical duplication associated with uterine septum and not didelphic uterus, as this disorder in a patient with infertility or recurrent miscarriages can be treated surgically by resection of the uterine and vaginal septum. Embryologic explanations may account for the occurrence of the anomaly.

Cornual heterotopic pregnancy: contemporary management options

This review covers the clinical presentations, treatments, and outcomes of cornual heterotopic pregnancies reported in the literature. Infertile women with a history of ectopic pregnancy, tubal surgery, or disease are at increased risk for cornual heterotopic pregnancy when they undergo in vitro fertilization. Women who have undergone bilateral salpingectomy also seem to be predisposed to this condition when they undergo in vitro fertilization. We recommend that these patients be followed up closely after a successful in vitro fertilization cycle with monitoring of serum beta-human chorionic gonadotropin levels and serial transvaginal ultrasonography because of the high associated morbidity. Laparotomy remains the treatment of choice for rupture of a cornual heterotopic pregnancy. In the absence of cornual rupture, however, medical management is an option that eliminates the risk of surgery and anesthesia and results in outcomes similar to those associated with surgical treatment. Currently there is insufficient evidence to recommend any single treatment modality, and the decision should be based on such factors as clinical presentation, surgeon's expertise, side effects, overall cost, and the patient's preference.

Endometriosis and assisted reproductive technologies

The association between endometriosis and infertility is well established, and different mechanisms have been postulated to cause infertility depending on the stage of endometriosis. Controlled ovarian hyperstimulation improves pregnancy outcome for minimal to mild endometriosis; however, there are no randomized controlled studies of this technique in patients with severe disease. Further, ART appears to have an overall beneficial effect for all stages of endometriosis. Based on the current staging system, several studies have not been able to demonstrate a significant difference in true outcomes for different stages of the disease. The limitations of these studies have been discussed above. Similarly, the effect of endometriomas when considered independent of the stage is still unclear. In addition to ART, pretreatment with GnRH analogues or surgical intervention may be beneficial and needs to be addressed in randomized controlled studies. It is evident that we urgently need large randomized studies to answer several questions about the treatment of endometriosis-associated infertility with ART. Although our current practice is based primarily on retrospective observational studies and small randomized studies, the overall impact on pregnancy outcome is beneficial.

Embryotoxicity as a marker for recurrent pregnancy loss

Some cases of unexplained recurrent pregnancy loss may be due to embryotoxic factors present in the mother's serum. In vitro assays have been devised to study the effect of these factors on pre-implantation, peri-implantation, and somite stage rodent embryos. Embryotoxic activity has been found in a high percentage of recurrent aborters but is also present in women with endometriosis and unexplained infertility, suggesting that there may be a range of factors acting at different stages of development. Embryotoxic activity may be predictive of pregnancy outcome and has been shown to be decreased after hormone and immunotherapy. However, its true value can only be assessed when the nature of the toxic factors is understood. Preliminary characterisation studies suggest that toxic activity may due to both immunological (antibodies or cytokines) and nutritional factors.

Does isolated teratozoospermia affect performance in in-vitro fertilization and embryo transfer?

The effect of the strict classification of spermatozoal morphology on the outcome of in-vitro fertilization and embryo transfer treatment cycles has been assessed in a retrospective analysis of 2144 consecutive cycles. The patients all had a standardized long protocol gonadotrophin-releasing hormone analogue cycle, with luteal phase start, to achieve down-regulation. All treatment cycles where the sperm density was abnormal (< 20 x 10(6)/ml), or where progressive motility was abnormal (< 40%), were excluded. The study excluded treatment cycles where the oocytes inseminated did not include at least one grade 1 or grade 2 oocyte. The percentage of couples achieving the normalized results of the clinic, including median fertilization rate per patient, insemination rates, numbers of embryos transferred, rates of 'spare embryo' blastocyst formation, cumulative pregnancy rates and pregnancy outcome, were calculated. No statistically significant difference arose between the two groups of patients with regard to the percentage of patients achieving the normalized median fertilization rate or higher (group 1 with > 14% normal forms, and group 2 with > or = 4%, < or = 14% normal forms). There was a statistically significantly lower chance of achieving this rate in patients of group 3 (< 4% normal forms) (P < 0.005), but 68.6% did achieve that fertilization rate or higher. There was no statistically significant difference in any of the other end points. In conclusion, a morphological classification may be appropriate as an indicator for counselling patients with regard to treatment expectations, but its use would be seem inappropriate as an index of fertilizing potential in clinical management.(ABSTRACT TRUNCATED AT 250 WORDS)

Micromanipulation of human embryos to assist hatching

OBJECTIVE

To determine the effects of zona slitting and subsequent embryo transfer performed on different days of in vitro human embryonic development to allow appropriate application of assisted hatching techniques to clinical IVF-ET.

DESIGN

A microsurgical technique was used to make a standardized slit in the zona pellucida of bipronucleate human embryos on day 2, 3, or 5 after oocyte retrieval. A mock ET was performed after the procedure and the rate of blastocyst formation and the process of hatching in each embryo was monitored.

SETTING

All embryos used were donated for research by patients attending the IVF Unit at the John Radcliffe Hospital, Oxford, United Kingdom.

MAIN OUTCOME MEASURES

The effects of the mock ET on the integrity of zona-slit embryos was documented. The embryos were cultured further and parameters such as blastocyst formation, initiation, and completion of hatching were monitored in all three groups of embryos.

RESULTS

The mock ET did not have a detrimental effect on embryos as assessed by their morphology and subsequent blastocyst formation rate. The technique used in this study to make an opening in the zona increased the rate and number of blastocysts hatching in all three groups compared with nonmanipulated controls. However, the day on which the slit was made did not significantly alter the outcome.

CONCLUSION

A gap in the zona pellucida of human embryos significantly increases the rate of hatching. Micromanipulative techniques such as zona slitting can be suitably used for this purpose without loss of blastomeres through the gap in the zona or trapping of the embryo during the process of hatching.