Obstetric outcome of women with in vitro fertilization pregnancies hospitalized for ovarian hyperstimulation syndrome: a case-control study

Efficacy of acupuncture for pregnancy with early-onset ovarian hyperstimulation syndrome: study protocol for a randomised controlled clinical trial

INTRODUCTION

Although ovarian hyperstimulation syndrome (OHSS) is a common complication primarily seen in patients undergoing in vitro fertilisation-embryo transfer, there is no recognised effective treatment to manage it, especially for pregnant patients. As an alternative non-pharmacological treatment, acupuncture presents itself as a promising, safe and effective intervention for those suffering from OHSS. Despite its potential, there is a noticeable absence of randomised controlled trials providing solid evidence on the efficacy of acupuncture in the management of pregnancy with OHSS. Therefore, the primary objective of this study is to conduct an initial investigation into the efficacy of acupuncture in pregnant patients with OHSS, hoping to contribute valuable insights from a medical-scientific perspective.

METHODS AND ANALYSIS

This is a three-arm, single-blind, parallel-design, randomised controlled clinical trial. A total of 384 patients will be enrolled and randomised in a ratio of 1:1:1 into acupuncture group (MA group), sham acupuncture group (SA group) and control group (C group) for a 20-day treatment period. The primary outcomes include 24-hour urine output, amount of ascites shown on ultrasound, abdominal circumference, degree of abdominal distension and chest tightness. The secondary outcomes are weight, ovarian size, rate of ascites drainage by tube placement and serum hCG. Besides, the study will consider changes in blood counts and hormonal levels as additional outcomes.

ETHICS AND DISSEMINATION

This study received authorisation from the Institutional Review Board of the Sixth Affiliated Hospital of Sun Yat-sen University on 4 February 2024 (Approval No. 2024ZSLYFEC-084). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry ChiCTR2400081751.

Ovarian Hyperstimulation Syndrome (OHSS): A Narrative Review and Legal Implications

BACKGROUND

Infertility is a highly meaningful issue with potentially life-changing consequences, and its incidence has been growing worldwide. Assisted reproductive technology (ART) has made giant strides in terms of treating many infertility conditions, despite the risk of developing ovarian hyperstimulation syndrome (OHSS), a potentially life-threatening complication.

METHODS

This narrative review draws upon scientific articles found in the PubMed database. The search spanned the 1990-2024 period. Search strings used included "OHSS" or "ovarian hyperstimulation" and "IVF" and "GnRH" and "hCG"; 1098 results were retrieved and were ultimately narrowed down to 111 suitable sources, i.e., relevant articles dealing with the condition's underlying dynamics, management pathways, and evidence-based criteria and guidelines, crucial both from a clinical perspective and from the standpoint of medicolegal tenability.

RESULTS

The following features constitute OHSS risk factors: young age, low body weight, and polycystic ovarian syndrome (PCOS), among others. GnRH antagonist can substantially lower the risk of severe OHSS, compared to the long protocol with a gonadotropin-releasing hormone (GnRH) agonist. However, a mild or moderate form of OHSS is also possible if the antagonist protocol is used, especially when hCG is used for the final maturation of oocytes. For women at risk of OHSS, GnRH agonist trigger and the freeze-all strategy is advisable. OHSS is one of the most frequent complications, with a 30% rate in IVF cycles.

CONCLUSION

Providing effective care for OHSS patients begins with early diagnosis, while also evaluating for comorbidities and complications. In addition to that, we should pay more attention to the psychological component of this complication and of infertility as a whole. Compliance with guidelines and evidence-based best practices is essential for medicolegal tenability.

Clinical Features of Severe Ovarian Hyperstimulation Syndrome with Hydrothorax

PROBLEM

Does the presence of hydrothorax suggest that severe ovarian hyperstimulation syndrome (OHSS) is associated with more severe conditions and worse pregnancy outcomes?

METHOD OF STUDY

The clinical data for 868 hospital patients with severe OHSS following IVF-ET at Peking University Third Hospital between 1 January 2016 and 21 July 2021 were retrospectively analysed. The patients were divided into two groups, the ascites alone group (n = 417) and the ascites combined with hydrothorax group (n = 451), to investigate the clinical features and pregnancy outcomes of patients with severe ovarian hyperstimulation syndrome (OHSS) combined with hydrothorax plus ascites.

RESULTS

The clinical data for 868 hospital patients with severe OHSS following IVF-ET were included. A total of 51.96% of patients with severe OHSS had hydrothorax plus ascites, mainly bilateral and moderate hydrothorax. Most cases with hydrothorax could be monitored and observed, and only 2.66% of the cases required thoracentesis and pleural drainage. Clinically, the time to visit due to worsening symptoms was longer; the hospital stay was shorter; and the OHSS-related laboratory tests, such as white blood cells (WBC), haematocrit (HCT), and ovarian diameter, were less severe in the ascites combined with hydrothorax group than in the ascites alone group. For live-birth outcomes of IVF-ET, the presence and the volume of hydrothorax were not independent risk factors, while the late onset of OHSS (odds ratio [OR]: 0.857 95% confidence interval [CI]: 0.795, 0.925) and a history of foetal reduction (OR: 13.796 95% CI: 1.808, 105.288) were independent protective factors for live birth.

CONCLUSIONS

Patients with severe OHSS combined with hydrothorax plus ascites have less severe clinical manifestations and laboratory tests than those with ascites alone. The presence and the volume of hydrothorax are unrelated to live-birth outcomes following in vitro fertilization and embryo transfer (IVF-ET).

Abnormal alanine aminotransferase levels in patients with moderate or severe ovarian hyperstimulation result in an increased risk of obstetric complications

OBJECTIVES

To explore the effect of abnormally elevated serum alanine aminotransferase (ALT) on pregnancy outcomes in patients with moderate and severe ovarian hyperstimulation syndrome (OHSS) at disease onset.

METHODS

This was a single-center retrospective cohort study conducted between January 1, 2014 and October 31, 2021. A total of 3550 fresh in vitro fertilization/intracytoplasmic sperm injection embryo transfer cycles were included, using Golan's three-degree, five-level classification to diagnose patients with OHSS. According to the patient's ALT level after diagnosis of OHSS, 123 (3.46%) patients with moderate-to-severe OHSS were divided into two groups. A control group included 3427 (96.54%) non-OHSS patients, and 91 (2.56%) abnormal ALT patients were matched with the control group for propensity scores.

RESULTS

There was no difference in baseline data between the abnormal ALT and matched control groups. The incidence of obstetric complications was significantly higher in the abnormal ALT group than in the matched control group (P < 0.05). After adjusting for confounding factors, the incidence of obstetric complications in the abnormal ALT group was still higher than that in the normal ALT group (P < 0.05).

CONCLUSION

In patients with moderate and severe OHSS, higher ALT levels resulted in an increased risk of obstetric and neonatal complications.

Pregnancy Outcomes Associated with Ovarian Hyperstimulation Syndrome: A Retrospective Cohort Study of Infertile Women

Objective

To assess the relationship between ovarian hyperstimulation syndrome (OHSS) and adverse outcomes using population-based data in the United States. The hypothesis is that patients with OHSS were more likely to deliver preterm and more likely to have hypertensive disorders.

Methods

This retrospective cohort study identified 94 patients with OHSS and 183 matched referents in eight counties in Minnesota. Data were collected regarding pregnancy history, infertility treatment, and pregnancy outcomes. Using the Rochester Epidemiology Project, study subjects were identified from female patients, aged 18 to 49 years, who were diagnosed with infertility from January 2, 1995 to December 1, 2017, and had a pregnancy greater than 20 weeks' gestation. The primary outcome was preterm delivery or hypertensive disorder of pregnancy incidence in the OHSS group when compared with control patients. Chi-squared test, t test, and multivariate logistic models were used where appropriate.

Results

Patients with OHSS were more likely to deliver preterm (odds ratio, 2.14; 95% confidence interval, 1.26-3.65; P < 0.01), and their neonates were more likely to be small for gestational age (odds ratio, 4.78; 95% confidence interval, 1.61-14.19; P < 0.01). No significant differences between the groups were observed in any other outcome. Patients with OHSS are more likely to deliver preterm if they undergo fresh transfer compared with a freeze all and subsequent frozen transfer (odds ratio, 3.03, 95% confidence interval, 1.20-7.66, P = 0.02).

Conclusion

OHSS may lead to preterm birth and small-for-gestational-age neonates, which changes patient counseling and leads to arranging specialized obstetrical care for these patients with OHSS.

Spontaneous and iatrogenic ovarian hyperstimulation syndrome in the absence of FSHR mutations: a case report of two unexpected cases

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a complication of controlled ovarian hyperstimulation (COH). It is a potentially life-threatening condition that usually occurs either after human chorionic gonadotropins (hCG) administration in susceptible patients or as a result of an implanting pregnancy, regardless of whether it was achieved by natural conception or infertility treatments. Despite many years of clinical experience regarding the adoption of preventive measures and the identification of patients at high risk, the pathophysiology of OHSS is poorly understood and no reliable predictive risk factors have been identified.

CASES PRESENTATION

We report about two unexpected cases of OHSS following infertility treatments, occurring after freeze-all strategy with embryo cryopreservation approaches. The first case developed spontaneous OHSS (sOHSS), despite efforts to prevent its manifestation by a segmentation approach, including frozen embryo replacement cycle. The second case developed a late form of iatrogenic OHSS (iOHSS), even though the absence of any risk factors. No mutations in the follicle-stimulating hormone (FSH) receptor (FSHR)-encoding gene were detected, suggesting that the high levels of hCG due to the twin implanting pregnancies could be the only triggering factor of OHSS outbreak.

CONCLUSION

Freeze-all strategy with embryo cryopreservation cannot entirely prevent the development of OHSS, which may occur in its spontaneous form independently from the FSHR genotype. Although OHSS remains a rare event, all infertile patients requiring ovulation induction or controlled ovarian stimulation (COS) may be at potential risk of OHSS, either in the presence or in the absence of risk factors. We suggest closely monitoring cases of pregnancy following infertility treatments in order to provide early diagnosis and adopt the conservative management.

Obstetric outcomes following ovarian hyperstimulation syndrome in IVF - a comparison with uncomplicated fresh and frozen transfer cycles

Background

We aimed to assess the correlation between ovarian hyperstimulation syndrome (OHSS) in the early course of in vitro fertilization (IVF) pregnancies and obstetric outcomes.

Methods

We identified records of patients admitted due to OHSS following IVF treatment at our institution between 2008 and 2020. Cases were included if pregnancy resulted in a live singleton delivery (OHSS group). OHSS cases were matched at a 1:5:5 ratio with live singleton deliveries following IVF with fresh embryo transfer (fresh transfer group) and frozen embryo transfer (FET group), according to maternal age and parity. Computerized files were reviewed, and maternal, obstetric and neonatal outcomes compared.

Results

Overall, 44 OHSS cases were matched with 220 fresh transfer and 220 FET pregnancies. Patient demographics were similar between the groups, including body mass index, smoking and comorbidities. Gestational age at delivery, the rate of preterm births, preeclampsia and cesarean delivery were similar between the groups. Placental abruption occurred in 6.8% of OHSS pregnancies, 1.4% of fresh transfer pregnancies and 0.9% of FET pregnancies (p=0.02). On post-hoc analysis, the rate of placental abruption was significantly higher in OHSS pregnancies, compared with the two other groups, and this maintained significance after adjustment for confounders. Birthweights were 3017 ± 483, 3057 ± 545 and 3213 ± 542 grams in the OHSS, fresh transfer and FET groups, respectively (p=0.004), although the rate of small for gestational age neonates was similar between the groups.

Conclusions

OHSS in the early course of IVF pregnancies is associated with an increased risk of placental abruption.

Ovarian hyperstimulation syndrome and adverse pregnancy outcome

INTRODUCTION

The aim of this study was to investigate the association between ovarian hyperstimulation syndrome (OHSS) and adverse pregnancy outcome.

EVIDENCE ACQUISITION

Medline, Embase and Cochrane databases were searched. The primary outcome was a composite score of adverse maternal outcome including either preterm birth (PTB), gestational diabetes mellitus (GDM), pre-eclampsia (PE) or pregnancy induced hypertension, intrahepatic cholestasis of pregnancy, thromboembolic events or need for caesarean section (CS). Secondary outcomes were a composite score of adverse fetal outcome including either miscarriage, low birthweight, fetal anomalies or intrauterine fetal death (IUD) and the individual components of both primary and secondary outcomes.

EVIDENCE SYNTHESIS

Thirteen studies (3303 ART pregnancies with and 89,720 without OHSS) were included. The risk of composite adverse maternal outcome (RR: 8.8, 95% CI: 8.1-9.5) was higher in women with compared to those without OHSS. The association between OHSS and adverse pregnancy outcome was mainly due to the higher risk of PTB (RR: 11.4, 95% CI: 10.5-12.4), while there was no difference in the risk of others primary outcome. Likewise, the risk of composite fetal outcome was higher in pregnancies with a prior OHSS (RR: 1.5, 95% CI: 1.1-2.0). The strength of association between OHSS and composite adverse maternal outcome persisted when considering singleton pregnancies or those with severe disease.

CONCLUSIONS

Pregnancies complicated by OHSS are at high risk of adverse pregnancy outcome, especially PTB.

Predictive Factors for Recovery Time in Conceived Women Suffering From Moderate to Severe Ovarian Hyperstimulation Syndrome

OBJECTIVE

This study aimed to evaluate potential predictors for recovery time in pregnant patients with moderate to severe ovarian hyperstimulation syndrome (OHSS).

METHODS

A total of 424 pregnant patients with moderate to severe OHSS who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) were retrospectively identified. The clinical features and laboratory findings within 24 h after admission were collected. Treatment for OHSS was carried out according to standard procedures, including fluid replacement therapy, human albumin, aspirin, low-molecular-weight heparin, and paracentesis, when necessary. Patients were discharged from the hospital when the tmorning hematocrit was <40% and no obvious clinically relevant symptoms existed, such as abdominal distension, abdominal pain, and shortness of breath. Meanwhile, ultrasound indicating little pleural or abdominal effusion and biochemical abnormalities returning to normal were required. Spearman's correlation analysis was used to assess the association between the blood-related parameters and recovery time. Multiple linear regression models were used to assess the relationship between the clinical or laboratory parameters and recovery time.

RESULTS

The median recovery time of these patients was 11 days. In Spearman's correlation test, leukocytes, hemoglobin, platelets, hematocrit, creatinine, prothrombin time (PT), fibrinogen (Fib), D-dimer, and fibrinogen degradation products (FDPs) were positively correlated with recovery time. On the other hand, albumin and thrombin time (TT) were negatively correlated with recovery time. Multiple linear regression analysis showed that polycystic ovary syndrome (PCOS), hemoglobin, platelets, albumin, and Fib were significantly associated with the recovery time of patients with OHSS (p = 0.023, p < 0.001, p = 0.007, p < 0.001, and p = 0.019, respectively).

CONCLUSIONS

In pregnant patients with OHSS, PCOS and hypoalbuminemia were associated with a significantly longer recovery time. Meanwhile, the recovery time was longer when patients have high levels of hemoglobin, platelets, and Fib.

Perinatal outcomes of singleton live births after late moderate-to-severe ovarian hyperstimulation syndrome: A propensity score-matched study

OBJECTIVE

To evaluate whether singleton live births achieved following in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) in women with late moderate-to-severe ovarian hyperstimulation syndrome (OHSS) is associated with adverse perinatal outcomes.

METHODS

This was a single-center retrospective cohort study conducted from January 2016 to June 2021. A total of 4,012 IVF/ICSI-fresh embryo transfer cycles that achieved singleton live births were included. According to the diagnosis of OHSS, the cycles were divided into two groups: late moderate-to-severe OHSS (MS-OHSS) group (n = 114) and non-OHSS group (n = 3,898). Multiple baseline covariates were controlled by propensity score matching, yielding 114 late MS-OHSS singleton live births matched to 337 non-OHSS singleton live births. The primary outcome of the study was normal term infant. The secondary outcomes were perinatal complications, gestational age at birth, birth weight, and birth height.

RESULTS

Before propensity score matching, no significant difference in perinatal outcomes was identified between late MS-OHSS group and non-OHSS group. After matching maternal age, BMI, basal serum FSH level, basal serum AMH level, basal antral follicle count, type of stimulation protocol, day of embryo development for embryo transfer, number of embryo transfer, and number of oocytes retrieved, there was still no significant difference in obstetric outcomes and neonatal outcomes between the two groups.

CONCLUSIONS

The findings demonstrate that the perinatal outcomes were similar between the two groups. However, because the sample size of patients with late MS-OHSS was limited in this study, further investigations are warranted using a larger sample size.

Ovarian Hyperstimulation: Diagnosis, Prevention, and Management

Ovarian hyperstimulation syndrome (OHSS) is a severe complication of controlled ovarian stimulation (COS). Pathogenesis of the disease is based on massive transudation of protein-rich fluid from the vascular compartment into the peritoneal, pleural and pericardial spaces, with a variable picture of clinical manifestations depending on its severity. Nowadays OHSS can easily be avoided by several prevention methods, ranging from identification of high-risk patients, choice of a correct protocol stimulation, trigger with gonadotropin-releasing hormone (GnRH) agonists or, finally, the freeze-all strategy. When OHSS occurs, it can usually be managed as outpatient care. Only if severe/critical cases are diagnosed hospitalization is necessary for appropriate rehydration, monitoring of fluid balance and eventual drainage of ascitic fluid. One of the most dangerous complications of OHSS is venous thromboembolism (VTE). Thromboprophylaxis has shown to be cost effective and widely used, while there are controversies regarding the usage of low dose aspirin (LDA) as a preventive measure.

The Association between Ovarian Hyperstimulation Syndrome and Pregnancy Complications following Fertility Treatments

OBJECTIVE

 This study was aimed to assess the association between ovarian hyperstimulation syndrome (OHSS) and pregnancy complications among women who conceived following fertility treatment.

STUDY DESIGN

 A retrospective population-based cohort study, including all singleton deliveries of patients conceived following ovulation induction (OI) or in vitro fertilization (IVF) between 1988 and 2016, was conducted. All births occurred in a single tertiary medical center. A comparison was performed between deliveries of women who had experienced OHSS at early gestation and subsequently had a pregnancy and women without OHSS. Women lacking prenatal care, multiple gestations, and stillbirths were excluded from the analyses. A multivariable logistic regression model was used to control for confounders.

RESULTS

 During the study period, 351,373 deliveries met the inclusion criteria, of which 6,748 were deliveries of infants who were conceived by either IVF or OI. Of this study population, 105 cases (1.6%) composed the exposed group, that is, women who had experienced OHSS with a subsequent live birth. In the multivariate analyses, after controlling for confounders, OHSS was not found as an independent risk factor for preeclampsia, gestational diabetes mellitus (GDM), intrauterine growth restriction (IUGR), preterm delivery (both <37 and <34 weeks), low birth weight (LBW), very LBW (VLBW), small for gestational age (SGA), and caesarean delivery. In a subanalysis conducted solely on the IVF population, similar results were found, aside from the association between OHSS and preterm delivery before 34 weeks of gestation which was statistically significant (adjusted odds ratio [AOR] = 2.3 95% confidence interval [CI]: 1.0-5.3, p = 0.049).

CONCLUSION

 In our population, OHSS was not found as a risk factor for adverse pregnancy and perinatal outcome. In IVF patients, OHSS is a risk factor for preterm delivery before 34 weeks of gestation.

KEY POINTS

· OHSS is not a risk factor for pregnancy complications.. · Complications investigated were preeclampsia, GDM, prematurity, and others.. · In IVF patients, OHSS is a risk factor for preterm delivery..

The influence of obesity on incidence of complications in patients hospitalized with ovarian hyperstimulation syndrome

OBJECTIVE

To study the impact of body habitus on risk of complications resulting from ovarian hyperstimulation syndrome (OHSS) in hospitalized patients.

METHODS

This is a retrospective observational study examining the National Inpatient Sample between January 2012 and September 2015. Patients were women < 50 years of age diagnosed with OHSS, classified as non-obese, class I-II obesity, or class III obesity. Intervention included multinomial logistic regression to identify factors associated with obesity and binary logistic regression for independent risk factors for complications. Main outcome measures were incidence of (i) any or (ii) multiple complication(s).

RESULTS

Of 2745 women hospitalized with OHSS, 2440 (88.9%) were non-obese, 155 (5.6%) had class I-II obesity, and 150 (5.5%) had class III obesity. Obese women (either class I-II or III) had a higher degree of comorbidity, had lower incomes, and were less likely to have private insurance than non-obese women (all P < 0.001). Obese women had lower rates of OHSS-related complications than non-obese women (any complication: non-obese 65.2%, class I-II 54.8%, and class III 46.7%, P < 0.001; and multiple complications: non-obese 38.5%, class I-II 32.3%, and class III 20.0%, P < 0.001). In the multivariable model, obesity remained independently associated with a decreased risk of complications (class I-II odds ratio 0.57, 95% confidence interval 0.39-0.83, P = 0.003; class III odds ratio 0.30, 95% confidence interval 0.20-0.44, P < 0.001). Obese women were also less likely to require paracentesis (non-obese 32.8%, class I-II 9.7%, and class III 13.3%, P < 0.001).

CONCLUSION

Our study suggests that obesity is associated with decreased OHSS-related complication rates in hospitalized patients.

Patients with IVF complicated by moderate-to-critical OHSS experience increased thrombosis, GDM and neonatal NICU admission but slightly shorter gestation compared with matched IVF counterparts: A retrospective Chinese cohort study

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a common disease during controlled ovarian hyperstimulation treatment. However, the obstetric and neonatal outcomes of this group of patients are unknown. The aim of this study was to explore the effects of late moderate-to-critical OHSS on obstetric and neonatal outcomes.

METHODS

This prospective observational study included 17,537 patients who underwent IVF/ICSI-fresh embryo transfer (ET) between June 2012 and July 2016 and met the inclusion criteria, including 7,064 eligible patients diagnosed with clinical pregnancy. Ultimately, 6,356 patients were allocated to the control group, and 385 patients who were hospitalized and treated at the center for late moderate-to-critical OHSS were allocated to the OHSS group. Then, propensity score matching analysis was performed, matching nine maternal baseline covariates and the number of multiple gestations; 385 patients with late moderate-to-critical OHSS were compared with a matched control group of 1,540 patients. The primary outcomes were the live birth rate, preterm delivery rate, miscarriage rate, gestational age at birth (weeks), obstetric complications and neonatal complications.

RESULTS

The duration of gestation in the matched control group was significantly higher than that in the OHSS group. The live birth delivery rate did not significantly differ between the OHSS and matched control groups. The incidence rates of the obstetric complications venous thrombosis (VT) and gestational diabetes mellitus (GDM), neonatal complications and the number of neonates admitted to the NICU were significantly higher in the OHSS group than in the matched control group.

CONCLUSIONS

Pregnant women undergoing IVF with fresh ET whose course is complicated by late moderate-to-critical OHSS appear to experience shortened gestation and increased obstetrical and neonatal complications compared with matched controls whose course is not complicated by OHSS. However, the live birth rate, average neonatal weight, and incidence rates of premature delivery, miscarriage, early abortion, hypertensive disorder of pregnancy (HDP), placenta previa (PP), intrahepatic cholestasis of pregnancy (ICP), and low neonatal birth weight (LBW) did not differ significantly between the two groups.

Risk of spontaneous preterm labor in pregnancies achieved by in vitro fertilization and complicated with severe form of ovarian hyperstimulation syndrome: A case control study

Objectives:

The purpose of this study was to examine the potential impact of severe Ovarian hyper stimulation syndrome (OHSS) on the risk of preterm birth. Severe ovarian hyperstimulation syndrome is a serious complication in the methods of in vitro fertilization. The pathophysiology of this process is not clear enough and the treatment is symptomatic. Human chorionic gonadotropin (h-CG) is the most important known cause of this condition. Findings of other authors often do not match when it comes to complications that may occur in pregnancy.

Methods:

In the Gynecology and Obstetrics Clinic “Narodni Front” a case control study was conducted on 50 female patients with severe forms of OHSS in the period from January 2008 to March 2015. A control group was created based on age and it involved 59 patients with pregnancy achieved with IVF/ICSI during the same period, but in which OHSS did not occur.

Results:

Patients with the pregnancy complicated by OHSS, had a considerably higher rate of preterm labor, whether this was labor before gestation week 37 (56.0% vs. 30.5%) or before gestation week 34 (34.0% vs. 6.8%); significantly lower weight of newborns, as in the newborns with low body weight <2500g (45.6% vs. 25.0%) and specially in the newborn with very low body weight <1500 grams (19.1% vs. 3.8%), as well as preterm premature rupture of membranes (PPROM), (11.76% vs. 1.59%).

Conclusions:

Pregnancy achieved by the IVF/ICSI method in which severe form of OHSS has been developed could have an increased risk of preterm birth.

Clinical parameters of ovarian hyperstimulation syndrome following different hormonal triggers of oocyte maturation in IVF treatment

OBJECTIVE

Ovarian hyperstimulation syndrome (OHSS) is a serious iatrogenic condition, predominantly related to the hormone used to induce oocyte maturation during IVF treatment. Kisspeptin is a hypothalamic neuropeptide that has recently been demonstrated to safely trigger final oocyte maturation during IVF treatment even in women at high risk of OHSS. However, to date, the safety of kisspeptin has not been compared to current hormonal triggers of oocyte maturation.

DESIGN

We conducted a retrospective single-centre cohort study investigating symptoms and clinical parameters of early OHSS in women at high risk of OHSS (antral follicle count or total number of follicles on day of trigger ≥23) triggered with human chorionic gonadotrophin (hCG) (n = 40), GnRH agonist (GnRHa; n = 99) or kisspeptin (n = 122) at Hammersmith Hospital IVF unit, London, UK (2013-2016).

RESULTS

Clinical Parameters of OHSS: Median ovarian volume was larger following hCG (138 ml) than GnRHa (73 ml; P < .0001), and in turn kisspeptin (44 ml; P < .0001). Median ovarian volume remained enlarged 20-fold following hCG, 8-fold following GnRHa and 5-fold following kisspeptin compared to prestimulation ovarian volumes. Mean (±SD) ascitic volumes were lesser following GnRHa (9 ± 44 ml) and kisspeptin (5 ± 8 ml) than hCG (62 ± 84 ml; P < .0001). Symptoms of OHSS were most frequent following hCG and least frequent following kisspeptin. Diagnosis of OHSS: The odds ratio for OHSS diagnosis was 33.6 (CI 12.6-89.5) following hCG and 3.6 (CI 1.8-7.1) following GnRHa, when compared to kisspeptin.

CONCLUSION

Triggering oocyte maturation by inducing endogenous gonadotrophin release is preferable to the use of exogenous hCG in women at high risk of OHSS.

Elective frozen-thawed embryo transfer (FET) in women at risk for ovarian hyperstimulation syndrome

Elective cryopreservation of cultured embryos has become a treatment option for women at risk for ovarian hyperstimulation syndrome (OHSS). The aim of our study was to investigate the outcome of elective cryopreservation and consecutive frozen-thawed embryo transfer (FET) in a large IVF clinic in Austria. A total of 6104 controlled ovarian hyperstimulation cycles (COH) were performed on 2998 patients including 200 patients (6.7%) who were undergoing elective cryopreservation and FET due to high risk of OHSS. We estimated the cumulative live birth rate using the Kaplan-Meier method and evaluated independent predictors for successful live births with a Cox model. A total of 270 frozen-thawed embryo transfers were performed on 200 patients with up to 4 transfers per patient. The first embryo transfer showed a live birth rate of 42.0%, the second transfer showed a cumulative rate of 58.5%. After a total of 4 FETs from the same COH cycle, a cumulative live birth rate of 61.0% per COH cycle could be achieved. Four cases of OHSS occurred amongst these patients (2.0%), all of them of moderate severity. Multivariate analysis identified maternal age, the use of assisted hatching and the number of embryos transferred at the blastocyst stage as independent predictors for cumulative live birth. Our study clearly suggests that elective FET is safe and shows excellent cumulative live birth rates. This concept can, therefore, be used to avoid the severe adverse events caused by COH and the inefficient use of cultured embryos.

A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial

STUDY QUESTION

Can increasing the duration of LH-exposure with a second dose of kisspeptin-54 improve oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS)?

SUMMARY ANSWER

A second dose of kisspeptin-54 at 10 h following the first improves oocyte yield in women at high risk of OHSS.

WHAT IS KNOWN ALREADY

Kisspeptin acts at the hypothalamus to stimulate the release of an endogenous pool of GnRH from the hypothalamus. We have previously reported that a single dose of kisspeptin-54 results in an LH-surge of ~12-14 h duration, which safely triggers oocyte maturation in women at high risk of OHSS.

STUDY DESIGN, SIZE, DURATION

Phase-2 randomized placebo-controlled trial of 62 women at high risk of OHSS recruited between August 2015 and May 2016. Following controlled ovarian stimulation, all patients (n = 62) received a subcutaneous injection of kisspeptin-54 (9.6 nmol/kg) 36 h prior to oocyte retrieval. Patients were randomized 1:1 to receive either a second dose of kisspeptin-54 (D; Double, n = 31), or saline (S; Single, n = 31) 10 h thereafter. Patients, embryologists, and IVF clinicians remained blinded to the dosing allocation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Study participants: Sixty-two women aged 18-34 years at high risk of OHSS (antral follicle count ≥23 or anti-Mullerian hormone level ≥40 pmol/L). Setting: Single centre study carried out at Hammersmith Hospital IVF unit, London, UK. Primary outcome: Proportion of patients achieving an oocyte yield (percentage of mature oocytes retrieved from follicles ≥14 mm on morning of first kisspeptin-54 trigger administration) of at least 60%. Secondary outcomes: Reproductive hormone levels, implantation rate and OHSS occurrence.

MAIN RESULTS AND THE ROLE OF CHANCE

A second dose of kisspeptin-54 at 10 h following the first induced further LH-secretion at 4 h after administration. A higher proportion of patients achieved an oocyte yield ≥60% following a second dose of kisspeptin-54 (Single: 14/31, 45%, Double: 21/31, 71%; absolute difference +26%, CI 2-50%, P = 0.042). Patients receiving two doses of kisspeptin-54 had a variable LH-response following the second kisspeptin dose, which appeared to be dependent on the LH-response following the first kisspeptin injection. Patients who had a lower LH-rise following the first dose of kisspeptin had a more substantial 'rescue' LH-response following the second dose of kisspeptin. The variable LH-response following the second dose of kisspeptin resulted in a greater proportion of patients achieving an oocyte yield ≥60%, but without also increasing the frequency of ovarian over-response and moderate OHSS (Single: 1/31, 3.2%, Double: 0/31, 0%).

LIMITATIONS, REASONS FOR CAUTION

Further studies are warranted to directly compare kisspeptin-54 to more established triggers of oocyte maturation.

WIDER IMPLICATIONS OF THE FINDINGS

Triggering final oocyte maturation with kisspeptin is a novel therapeutic option to enable the use of fresh embryo transfer even in the woman at high risk of OHSS.

STUDY FUNDING/COMPETING INTEREST(S)

The study was designed, conducted, analysed and reported entirely by the authors. The Medical Research Council (MRC), Wellcome Trust & National Institute of Health Research (NIHR) provided research funding to carry out the studies. There are no competing interests to declare.

TRIAL REGISTRATION NUMBER

Clinicaltrial.gov identifier NCT01667406.

TRIAL REGISTRATION DATE

8 August 2012.

DATE OF FIRST PATIENT'S ENROLMENT

10 August 2015.

Pregnancy Outcomes of In Vitro Fertilization with or without Ovarian Hyperstimulation Syndrome: A Retrospective Cohort Study in Chinese Patients

Background:

The effect of ovarian hyperstimulation syndrome (OHSS) on pregnancy outcomes of in vitro fertilization (IVF) patients is still ambiguous. This study aimed to analyze pregnancy outcomes of IVF with or without OHSS in Chinese patients.

Methods:

A retrospective cohort study was undertaken to compare pregnancy outcomes between 190 women with OHSS and 197 women without OHSS. We examined the rates of clinical pregnancy, multiple pregnancies, miscarriage, live birth, preterm delivery, preterm birth before 34 weeks’ gestation, cesarean delivery, low birth weight (LBW), and small-for-gestational age (SGA) between the two groups. Odds ratios (ORs) and 95% confidence intervals (CIs) of measure of clinical pregnancy were also analyzed.

Results:

The clinical pregnancy rate of OHSS patients was significantly higher than that of non-OHSS patients (91.8% vs. 43.5%, P < 0.001). After controlling for drug protocol and causes of infertility, the adjusted ORs of moderate OHSS and severe/critical OHSS for clinical pregnancy were 4.65 (95% CI, 1.86–11.61) and 5.83 (95% CI, 3.45–9.86), respectively. There were no significant differences in rates of multiple pregnancy (4.0% vs. 3.7%) and miscarriage (16.1% vs. 17.5%) between the two groups. With regard to ongoing clinical pregnancy, we also found no significant differences in the rates of live birth (82.1% vs. 78.8%), preterm delivery (20.9% vs. 17.5%), preterm birth before 34 weeks’ gestation (8.6% vs. 7.9%), cesarean delivery (84.9% vs. 66.3%), LBW (30.2% vs. 23.5%), and SGA (21.9% vs. 17.6%) between the two groups.

Conclusion:

OHSS, which occurs in the luteal phase or early pregnancy in IVF patients and represents abnormal transient hemodynamics, does not exert any obviously adverse effect on the subsequent pregnancy.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.

Hematocrit as a simple method to predict and manage ovarian hyperstimulation syndrome in assisted reproduction

AIM:

The aim was to analyze the hematocrit levels in cases of ovarian hyperstimulation syndrome (OHSS), syndrome occurring during in-vitro fertilization (IVF), and study its role as a prognostic indicator.

SUBJECTS AND METHODS:

Two years data of 66 women at high risk for developing OHSS was analyzed. Twenty-seven women who developed OHSS were further analyzed based on their hematocrit levels on the day of oocyte pick-up (OPU) and the day of embryo transfer (ET) to see if there was a prognostic trend.

RESULTS:

Of the total 225 IVF cases, 66 were deemed high risk for developing OHSS. Twenty-seven of these developed OHSS (40.9%). Of these 27, 21 (77.8%) had a hematocrit >35% on the day of OPU. The mean hematocrit in women developing OHSS on the day of OPU was 37.39% (standard deviation [SD] 2.66) as against 35.97% (2.80) in those not developing OHSS. This difference was statistically significant (P = 0.043). On the day of ET, 23/27 (85.8%) who developed OHSS had a hematocrit of >35%. The mean hematocrit was 39.29% (SD 3.85) in those who developed OHSS as against 34.7% (2.88) in those who did not. This difference (4.85) was statistically significant (P < 0.001).

CONCLUSIONS:

Women undergoing IVF were at a higher risk of developing OHSS when their hematocrit on the day of OPU and ET was >35%. Those who required cancellation of ET had a hematocrit of >35% on the day of ET or showed a significant increase of 3% from OPU to ET.

Ovarian hyperstimulation syndrome: a clinical report on 4894 consecutive ART treatment cycles

BACKGROUND

Although a large number of studies have been dedicated to ovarian hyperstimulation syndrome (OHSS) none gave full embryological and clinical outcomes comparing oocyte trigger with human chorionic gonadotrophin (HCG) versus with a gonadotrophin-releasing hormone (GnRH) agonist (Buserelin) in cases with suspicious OHSS. The aim of the present study was thus to analyze 4894 consecutive assisted reproductive treatment cycles to undercover associated risk factors for development of OHSS, and the effects of the use of Buserelin as ovulation trigger on embryological and clinical outcomes.

METHODS

In the 51 cases that developed OHSS, ovulation trigger was performed with HCG as indicators were not suspicious for OHSS. These were compared against two types of groups: 71 cases where Buserelin was used for ovulation induction due to suspicious development of OHSS; and those remaining 4772 cases where ovulation trigger was currently performed with HCG (control).

RESULTS

Of the cases treated with Buserelin the oocyte maturation rate and the ongoing pregnancy rate were significantly lower, with higher rates of ectopic pregnancy and newborn malformations, but none developed OHSS. Of the OHSS cases, 23 needed hospitalization, with no major complications.

CONCLUSIONS

Young age, lower time of infertility, lower basal follicle stimulating hormone levels, higher number of cases with female factor and polycystic ovarian syndrome, high number of follicles and higher estradiol concentrations were the risk factors found associated with OHSS. Cases with OHSS also presented higher follicle count but the estradiol levels were within the normal range. It thus remains to develop more strict criteria to avoid all cases with OHSS.

Ovarian hyperstimulation syndrome: pathophysiology, staging, prediction and prevention

OBJECTIVE

To identify, appraise and summarize the current evidence regarding the pathophysiology, staging, prediction and prevention of ovarian hyperstimulation syndrome (OHSS).

METHODS

Two comprehensive systematic reviews were carried out: one examined methods of predicting either high ovarian response or OHSS and the other examined interventions aimed at reducing the occurrence of OHSS. Additionally, we describe the related pathophysiology and staging criteria.

RESULTS

Seven studies examining methods of predicting OHSS and eight more examining methods of predicting high ovarian response to controlled ovarian stimulation were included. Current evidence shows that the best methods of predicting high response are antral follicle count and anti-Müllerian hormone levels, and that a high ovarian response (examined by the number of large follicles, estradiol concentration or the number of retrieved oocytes) is the best method of predicting the occurrence of OHSS. Ninety-seven randomized controlled trials examining the effect of several interventions for reducing the occurrence of OHSS were included. There was high-quality evidence that replacing human chorionic gonadotropin by gonadotropin-releasing hormone agonists or recombinant luteinizing hormone, and moderate-quality evidence that antagonist protocols, dopamine agonists and mild stimulation, reduce the occurrence of OHSS. The evidence for the effect of the other interventions was of low/very low quality. Additionally, we identified and described 12 different staging criteria.

CONCLUSIONS

There are useful predictive tools and several preventive interventions aimed at reducing the occurrence of OHSS. Acknowledging and understanding them are of crucial importance for planning the treatment of, and, ultimately, eliminating, OHSS while maintaining high pregnancy rates.

Pregnancy outcome in severe OHSS patients following ascitic/plerural fluid drainage

BACKGROUND

Various inflammatory cytokines have been implicated in the pathophysiology of severe ovarian hyperstimulation syndrome, as well as, various pregnancy complications, including preterm labor, pregnancy induced hypertension/preeclampsia and intra-uterine growth restriction. We aim to determine whether severe OHSS, complicated by third space fluid accumulation necessitating drainage, is associated with increased risk of late obstetrics complications.

METHODS

We assessed the obstetrics and neonatal outcome measures of 16 patients admitted to our gynecology ward during a 6-year period, with severe OHSS complicated by third space fluid accumulation necessitating drainage.

RESULTS

Patients delivered at 37.3 ± 5.9weeks, with a mean birth weight of 3062 ± 757 gr. There was no single case of gestational diabetes, hypertensive diseases of pregnancy, nor placental abruption. Two (12.5%) patients had preterm delivery: one at 23 weeks' gestation and one at 28 weeks' gestation following preterm premature rupture of membrane. Another patient experienced an unexplained antepartum fetal death at 27 weeks' gestation.

CONCLUSIONS

Severe OHSS, complicated by third space fluid sequestration necessitating drainage, is not associated with adverse late pregnancy outcome, except probably for preterm labor. Following resolution of the OHSS, pregnancies should be regarded as any pregnancy resulting from IVF treatment, with special attention to prevent preterm labor.

Is severe OHSS associated with adverse pregnancy outcomes? Evidence from a case-control study

Ovarian hyperstimulation syndrome (OHSS) is a serious and potentially life-threatening complication of fertility treatment. This study evaluated pregnancy outcomes of women hospitalized for severe OHSS. A case-control study was performed of 125 women who were hospitalized due to severe OHSS compared with a control group, consisting of 156 women matched by age and aetiology of infertility, who conceived via IVF and did not develop OHSS. Among women with singleton pregnancies, patients with severe OHSS delivered significantly earlier (37.96 versus 39.11 weeks) and had smaller babies (2854 g versus 3142 g) compared with the matched controls. Similarly, rates of preterm delivery (<34 weeks of gestation: 8.9% versus 0%, P < 0.01; <37 weeks of gestation: 20.5% versus 5.1%, P < 0.01) were significantly increased among patients in the study group. There were no between-group differences in the rates of gestational diabetes, gestational hypertension and intrauterine growth restriction. In contrast, twin pregnancies following OHSS were not significantly different from matched control twins, with regard to the rates of delivery <34 weeks and <37 weeks of gestation, gestational diabetes, gestational hypertension and intrauterine growth restriction. In conclusion, severe OHSS at early gestation is associated with adverse pregnancy outcome only in singleton gestations.

Fine-mapping an association of FSHR with preterm birth in a Finnish population

Preterm birth is a complex disorder defined by gestations of less than 37 weeks. While preterm birth is estimated to have a significant genetic component, relative few genes have been associated with preterm birth. Polymorphism in one such gene, follicle-stimulating hormone receptor (FSHR), has been associated with preterm birth in Finnish and African American mothers but not other populations. To refine the genetic association of FSHR with preterm birth we conducted a fine-mapping study at the FSHR locus in a Finnish cohort. We sequenced a total of 44 kb, including protein-coding and conserved non-coding regions, in 127 preterm and 135 term mothers. Overall, we identified 288 single nucleotide variants and 65 insertion/deletions of 1-2 bp across all subjects. While no common SNPs in protein-coding regions were associated with preterm birth, including one previously associated with timing of fertilization, multiple SNPs spanning the first and second intron showed the strongest associations. Analysis of the associated SNPs revealed that they form both a protective (OR = 0.50, 95% CI = 0.25-0.93) as well as a risk (OR = 1.89, 95% CI = 1.08-3.39) haplotype with independent effects. In these haplotypes, two SNPs, rs12052281 and rs72822025, were predicted to disrupt ZEB1 and ELF3 transcription factor binding sites, respectively. Our results show that multiple haplotypes at FSHR are associated with preterm birth and we discuss the frequency and structure of these haplotypes outside of the Finnish population as a potential explanation for the absence of FSHR associations in some populations.

A rare case of small bowel obstruction secondary to ovarian torsion in an IVF pregnancy

A 39- year-old woman, who conceived following in vitro fertilisation (IVF) treatment, presented at 12 weeks gestation with symptoms of ovarian hyperstimulation syndrome (OHSS), abdominal pain, vomiting and diarrhoea. Subsequent investigations found small bowel obstruction  secondary to ovarian torsion. Surgical management to remove a necrotic ovary and fallopian tube led to a good recovery from the acute illness. A postoperative ultrasound scan confirmed a viable pregnancy and the patient was discharged. Her case demonstrates a rare complication of OHSS and ovarian torsion leading to small bowel obstruction.

[Ovarian hyperstimulation syndrome: pathophysiology, risk factors, prevention, diagnosis and treatment]

The ovarian hyperstimulation syndrome is a major complication of ovulation induction for in vitro fertilization, with severe morbidity and possible mortality. Whereas its pathophysiology remains ill-established, the VEGF may play a key role as well as coagulation disturbances. Risk factors for severe OHSS may be related to patients characteristics or to the management of the ovarian stimulation. Two types of OHSS are usually distinguished: the early OHSS, immediately following the ovulation triggering and a later and more severe one, occurring in case of pregnancy. As no etiologic treatment is available, the therapeutic management of OHSS should focus on its related-complications. Thrombotic complications that can occur in venous or arterial vessels represent the major risk of OHSS, possibly conducting to myocardial infarction and cerebrovascular accidents. Once the OHSS is diagnosed, prevention of thrombotic accidents remains the major issue.