Christophe Blockeel

STUDY QUESTION: How do unoperated ovarian endometriomas affect ovarian response during ovarian stimulation cycles? SUMMARY ANSWER: Ovaries affected by unoperated ovarian endometriomas show similar outcomes to unaffected ovaries following c…

Diminished ovarian reserve (DOR) is common in women with infertility and is associated with poorer in vitro fertilization (IVF) outcomes. Testosterone is widely used off-label in this patient group, although evidence for its efficacy and sa…

RESEARCH QUESTION: Are pregnancies in female same-sex couples at higher risk when using reception of oocytes from partner (ROPA) compared with intrauterine insemination (IUI)? DESIGN: A retrospective, single-centre, matched cohort study wa…

The aim of this study was to investigate whether gonadotrophin-releasing hormone agonist (GnRHa) pretreatment has a positive effect on pregnancy outcomes in women with adenomyosis who were undergoing a frozen embryo transfer (FET) cycle. A …

Research questionIn patients in whom endometrial polyps are diagnosed during ovarian stimulation for IVF, are there differences in reproductive outcomes in women continuing to undergo fresh embryo transfer, and those in whom embryos are cry…

Children conceived through assisted reproductive technologies (ART) have an elevated risk of lower birthweight, yet the underlying cause remains unclear. Our study explores mitochondrial DNA (mtDNA) variants as contributors to birthweight d…

INTRODUCTION: A Delphi consensus was performed to evaluate expert opinions on the management of key aspects of ovarian stimulation. METHODS: A Scientific Committee developed eleven statements for patient profiles corresponding to predicted…

The study investigates whether a 3-day pretreatment course with a GnRH antagonist in the early follicular phase has an impact on the number of retrieved COCs in a GnRH antagonist stimulation protocol. This is a retrospective single center c…

RESEARCH QUESTION: Does a frozen-embryo transfer in an artificially-prepared endometrium (FET-HRT) cycle yield similar clinical pregnancy rate with 7 days of oestrogen priming compared to 14 days? DESIGN: This is a single-centre, randomize…

It is generally accepted that microorganisms can colonize a non-pathological endometrium. However, in a clinical setting, endometrial samples are always collected by passing through the vaginal-cervical route. As such, the vaginal and cervi…

Although a wealth of data has been published regarding fertility preservation (FP) in women with malignant diseases who receive gonadotoxic treatment, the role of FP in non-malignant conditions has been studied to a much lesser extent. Thes…

PURPOSE: To evaluate the association between serum progesterone (P) at the day of ovulation trigger and neonatal birthweight in singletons born after frozen-thawed embryo transfer in segmented ART cycles. METHODS: A retrospective multicent…

STUDY QUESTION: Does addition of choriogonadotropin beta (recombinant CG beta) to follitropin delta increase the number of good-quality blastocysts following ovarian stimulation in a long GnRH agonist protocol? SUMMARY ANSWER: At the doses…

STUDY QUESTION: Does oocyte vitrification adversely affect the health of 2-year-old children compared with peers born after use of fresh oocytes in a donation programme? SUMMARY ANSWER: The growth and health of 2-year-old children born aft…

Background: The need for endocrine monitoring in artificial cycles for frozen embryo transfer (FET) remains unclear and, more specifically, the value of the late-proliferative phase serum estradiol (E2) levels is with conflicting evidence i…

BACKGROUND: The major difference between a natural cycle and an artificially prepared cycle is the lack of luteinizing hormone (LH) peak in the latter. The LH/hCG receptors were identified to express in human endometrium and evidences of ex…

Despite the considerate progress to which assisted reproduction technology (ART) has been subject since 1978, some issues remain unresolved. Notably, the clinical management of patients with a poor ovarian response is still a challenge in e…

PURPOSE: To evaluate whether ICSI offers any benefit compared with IVF in different ovarian response categories in case of non-male factor infertility. METHODS: This is a retrospective multicenter analysis using individual patient data, co…

Research Question: What is the effect of gonadotropin-releasing hormone (GnRH)-agonist treatment on serum anti-Müllerian hormone (AMH)? Design: This prospective cohort study conducted in a tertiary university hospital comprised patients (n …

Since the introduction of gonadotropin-releasing hormone (GnRH) antagonists, an extensive amount of literature investigating the role of the downregulation protocols on pregnancy outcomes has been published. However, these studies were main…

Several infertile patients, who may even represent around 40% of the infertile cohort, may respond "suboptimally" (4-9 oocytes retrieved) following IVF, despite being predicted as normal responders. The aim of our longitudinal study was to …

STUDY QUESTION: What is the effect of vitamin D deficiency on the pregnancy rates following frozen embryo transfer (FET)?. SUMMARY ANSWER: Vitamin D deficiency does not affect pregnancy rates in FET cycles. WHAT IS KNOWN ALREADY: Although…

The past decade has seen growing interest in ovarian stimulation protocols with GnRH antagonists in an effort to reduce the incidence of potential complications, such as cyst formation and ovarian hyperstimulation syndrome, and thus improve…

Introduction: Endometriosis, defined as the growth of endometrial tissue outside \nthe uterine cavity is a common gynaecological disorder affecting 10-15% \nof women in their reproductive years. It is a major clinical problem causing in- \n…