Marc Dhont

Ghent University | UGhent · Department of Uro-gynaecology

Pelvic endometriosis is one of the most frequent diseases in women of reproductive age. In a minority of the cases, endometriosis also affects extrapelvic organs. Three cases of different extrapelvic location of endometriosis -diaphragmatic, ureteral and inguinal - are presented to illustrate the challenge for diagnosis and treatment. Cyclical symp...

The safety of systemically administered sex steroids continues to be a major focus of researchers. The negative results of the Women's Health Initiative study (WHI), and follow-up reports published in JAMA, evaluating the safety of estro-progestogen in postmenopausal women, elicited an unprecedented reaction in the press by women and doctors alike....

Abnormal uterine bleeding is a frequent symptom in gynecology, caused by functional as well as by anatomic genital tract abnormalities. An endocervical diverticulum was diagnosed in a patient with secondary infertility, intermenstrual bleeding, and a prior cesarean delivery. Dehiscence of the cesarean scar was visualized by ultrasound, hysterosalpi...

Recurrent miscarriage is defined as the occurrence of three consecutive pregnancy losses during the first trimester. Although it affects only 1% of all couples, it is a most frustrating experience for the patient as well as for the clinician. Frustrating for the couple because they rarely obtain clear-cut reasons for the repeated failure to sustain...

Objectives To study the spread of endometrial cells through the fallopian tubes during endometrial ablation. Study Design In the Department of Gynecology at the State University Clinic of Ghent, 22 patients undergoing an abdominal hysterectomy were included in this prospective study. Immediately before the hysterectomy, endometrial resection of the...

To create a neovagina and an endocervival canal in two patients with vaginal aplasia and a functioning uterus. Technique and instrumentations. University hospital. A 31-year-old woman with vaginal aplasia and a double noncommunicating uterus (classified as Mayer-Rokitansky-Kuster-Hauser syndrome) and a 19-year-old woman with partial vaginal aplasia...

To describe the results of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) of Dutch patients who came to Ghent University Hospital (GHU), Belgium, for treatment, during the period 1993-2002. Retrospective data collection, description and analysis. Dutch and Belgian patients were compared with respect to: age, indication for...

The risk of spontaneous first trimester abortion is estimated to be between 10 and 20%. Although it is common knowledge that the incidence of abortion decreases as pregnancy progresses, exact data in relation to the duration of pregnancy are scarce. We reviewed 1597 clinical IVF/ICSI pregnancies with known outcome and tabulated the number of miscar...

One of the most problematic issues of assisted reproduction is the high incidence of multiple pregnancies, resulting from the transfer of more than one embryo. Particularly at risk are young women who have good quality embryos. The only strategy to reduce the incidence of multiple pregnancies, including twin pregnancies, after assisted reproduction...

To investigate whether the diminished efficacy of ART in young poor responders compared to young normal responders is due to a quantitative or a qualitative oocyte factor. Retrospective comparative analysis. University-based infertility center. Nine thousand six hundred forty-four patients who underwent ART procedures at our hospital from 1993 unti...

A "frameless" intrauterine drug delivery system that releases 14 microg/d of levonorgestrel was used to treat nonatypical and atypical endometrial hyperplasia in 12 women. This noncomparative study had up to 3 to 4 years of follow-up. The cure rate was 100%, as confirmed by repeat endometrial biopsy. This method could be considered an alternative t...

A previously reported enzyme assay on a membrane filter using 4-methylumbelliferyl (4-MU)-N-acetyl-beta-D-galactosaminide, -phosphate and -pyrophosphate as substrates for the differentiation of four Candida spp. has been extended to Candida parapsilosis. The substrate 4-MU-beta-D-glucoside was hydrolyzed by 28 test strains of this species but to a...

Cervico-isthmic pregnancy is a rare and life-threatening form of ectopic pregnancy. While in the past a hysterectomy was frequently required, early diagnosis by ultrasound and the advent of medical treatment have changed the picture. The use of methotrexate, a folic acid antagonist, constitutes a breakthrough in the management of this unusual compl...

The purpose of this study was to assess the FA composition of both cholesteryl esters (CE) and phospholipids (PL) in maternal plasma during pregnancy and at delivery and in umbilical plasma at birth. A longitudinal study of 32 normal pregnant women was carried out with three cutoff points during pregnancy (first, second, and third trimester) and at...

Mouse follicles grown in vitro from preantral to mature stages yield oocytes that can be fertilized in vitro, but embryonic development is poor. To investigate whether this poor development is due to a nuclear or a cytoplasmatic factor, we designed an experiment in which the MII chromosome spindle was exchanged between in vitro-matured oocytes and...

A transsexual patient has the constant and persistent conviction that he or she belongs to the opposite sex, thus creating a deeply seated gender identity conflict. With psychotherapy being unsuccessful, it has been proven that in carefully selected patients, gender reassignment or adjusting the body to the mind (both with hormones and surgery) is...

The aim of this study was to describe the dietary fat intake during pregnancy and to study the relationship between the intake of polyunsaturated fatty acids (PUFAs) and the fatty acid composition of maternal and umbilical plasma phospholipids (PLs) and cholesterol esters (CEs) at delivery. In addition, the contribution of food groups to the intake...

In vitro-matured germinal vesicle oocytes are an interesting source of cytoplast recipients in both animal and human nuclear transfer (NT) experiments. We investigated two technical aspects that might improve the developmental potential of nuclear transfer mouse embryos constructed from in vitro-matured germinal vesicle oocytes. In a first step, th...

Cryopreserved human primordial follicles grafted into immunodeficient hosts are susceptible to gonadotrophic stimulation but the optimal interval between grafting and stimulation has not been determined. The effect of stimulation with FSH at different time intervals after grafting was therefore investigated. Cryopreserved human ovarian cortical gra...

Single embryo transfer (SET) is the sole strategy with which to reduce the incidence of twins following assisted reproductive technology (ART), but SET may increase the number of ART cycles needed per live-born child. Its cost-effectiveness compared with double embryo transfer (DET) is therefore unknown. A decision-analytic model comparing SET with...

Type I inositol 1,4,5-trisphosphate-sensitive receptors (InsP(3)R) are expressed in human oocytes and may be involved in operating the Ca(2+) release triggered by the fertilizing sperm. This study examines the contribution of type I InsP(3)R in operating Ca(2+) release in human oocytes secondary to InsP(3) itself, using a specific function-blocking...

The purpose of this study was to determine the prevalence of vaginal colonization by Candida with the use of a rapid detection method, to examine the determinants of vaginal candidiasis, and to evaluate susceptibility for fluconazole. Vaginal swabs were collected from unselected women at the outpatient clinic of the Department of Obstetrics and Gyn...

Failed fertilization after IVF occurs in 10-20% of cycles. Conflicting results of rescue fertilization by ICSI have been reported. We therefore compared the success rate in terms of fertilization and pregnancy of cycles in which rescue ICSI was performed with those from a matched control group of primarily ICSI cycles. Unfertilized oocytes from IVF...

The fact that most of the advances in mouse cloning by nuclear transfer originate from research in a limited number of laboratories demonstrates the complexity of the reported technologies. The development of alternative and more simple techniques of nuclear transfer may therefore be of interest. Furthermore, the preimplantation biology of cloned m...

Early preantral mouse follicles with a diameter of 110-160 microm were cultured in vitro for 10 or 12 days. Mature oocytes were retrieved following hCG, and fertilization was attempted either by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Two-cell and blastocyst formation rates and blastocyst cell numbers were compared...

Phenylketonuria (PKU) is an autosomal recessive disease with a prevalence between 1/10,000 and 1/15,000. The disease is due to a partial or complete block of the conversion of phenylalanin to tyrosine. If left untreated, PKU leads to mental retardation and other, mainly neurological, disorders. As a result of high serum concentrations of phenylalan...

To evaluate the return to fertility following removal of the GyneFix intrauterine implant system in women wishing to conceive. A retrospective study was performed on a sample of healthy, sexually active nulligravid/nulliparous and parous women. The participants were 18-41 years of age, with no apparent infertility problem, living in a stable relati...

Ovarian tissue cryopreservation and transplantation can be used to restore fertility to sterile females. A question that warrants further investigation is whether the follicular content is affected by the freeze-thawing and grafting procedure, and if so, to what extent and by what mechanism. Intact newborn mouse ovaries were allografted under the k...

A case-control study was designed to determine the possible association between chronic exposure to dioxins and polychlorinated biphenyls (PCBs), and the occurrence of endometriosis. The study group consisted of 42 infertile endometriosis cases and 27 mechanical infertile controls, both groups attending one of the collaborating Centres for Reproduc...

Aim: To evaluate the validity and usefulness of a food frequency questionnaire (FFQ) which was designed to evaluate individual fat consumption for a Dutch population relative to 7-day estimated records (7d ER). The FFQ has been validated previously and was adapted to the Belgian situation. Methods: Longitudinal study in 26 healthy pregnant women; F...

The high incidence of multiple pregnancy is a major side effect of assisted reproductive technology that has recently given rise to justified criticism from different sides. The reasons for the high incidence of multiple pregnancies are discussed and a brief review is given of the steps that have been proposed to solve or at least reduce the proble...

The overall aim of this prospective, randomized study was to compare the reproductive potential of fresh and frozen-thawed ejaculated spermatozoa from oligoasthenoteratozoospermic patients in an intracytoplasmic sperm injection (ICSI) procedure. All patients consenting to participate in this study had a sperm sample frozen prior to the start of a c...

A transsexual patient has the constant and persistent conviction that he or she belongs to the opposite sex, thus creating a deeply seated gender identity conflict. With psychotherapy being unsuccessful, it has been proven that in carefully selected patients, gender reassignment or adjusting the body to the mind (both with hormones and surgery) is...

To investigate follicle growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice. Fresh or frozen-thawed human ovarian cortex was grafted subcutaneously or under the kidney capsule of 43 mice (35 nude mice and eight SCID mice), 14 of which were non-stimulated controls, 21 injected intra-peritoneally with...

In 24 healthy pregnant women, parameters related to the oxidative stability of low density lipoproteins (LDL) were determined at three times during pregnancy and shortly after delivery. The fatty acid composition of plasma phospholipids (PL) and the plasma concentrations of vitamin E, vitamin A, and beta-carotene were assessed in the same samples....

It is believed that delayed transfer of embryos after IVF allows for a better selection of good quality embryos. Hence, the number of embryos and all other prognostic factors being equal, transfer of day 3 embryos should be associated with higher implantation and pregnancy rates than transfer of day 2 embryos. To investigate this hypothesis, a pros...

Along with improved survival, methods to preserve or restore the fertility potential of young women and children treated with cytotoxic chemotherapy or pelvic radiotherapy have been developed or are in the offing. Surgery, radiotherapy and chemotherapy can all impact on the future ovarian function, but patient and disease tailored application and u...

The effect of simple and sequential embryo culture media on the preimplantation development of mouse nuclear transfer (NT) embryos reconstructed with cumulus cell nuclei using a mechanical NT technique was studied. Blastocyst formation rate was evaluated using CZB medium and the sequential media G1/G2 and KSOM/G2. Arrested two- and three-cell NT em...

The aminopryine breath test (ABT) measures hepatic reserve in patients with acute and chronic liver disease and gives an assesment of the hepatic function in patients undergoing major liver surgery. Aminopyrine is metabolized by the mixed cytochrome P-450 system, which can be influenced by many foreign compounds and drugs. Whether these foreign com...

It has been demonstrated that in pathological conditions with an increase in the calculated mean melting point (MMP) of phospholipid (PL) fatty acids (FA) there are changes in the composition of the saturated FA (SFA), which partially counteract this effect: shorter-chain SFA with lower melting points are increased, while longer-chain less fluid SF...

We demonstrated that ovaries removed from female-to-male transsexuals can be used as research material for ovarian cryopreservation, grafting and culture studies. A 21 year old female-to-male transsexual individual, who had been treated with androgens for 12 months, donated her ovaries removed in the sex reversal operation. She had normal numbers o...

The objectives of the present study were to achieve 1) oocyte maturation, 2) oocyte competence of fertilization, and 3) oocyte competence of embryogenesis with oocytes from primordial follicles obtained from cryopreserved newborn mouse ovaries by using a two-step method. In the first step, frozen-thawed newborn mouse ovaries were transplanted under...

To evaluate the validity and usefulness of a food frequency questionnaire (FFQ) which was designed to evaluate individual fat consumption for a Dutch population relative to 7-day estimated records (7d ER). The FFQ has been validated previously and was adapted to the Belgian situation. Longitudinal study in 26 healthy pregnant women; FFQ and 7d ER w...

The purpose of diagnostic fertility tests is to divide infertile couples into two groups: those that probably cannot become pregnant without treatment and those that, with some patience, will presumably become pregnant without treatment. Discussed are the position of the ultrasound study of the small pelvis and the ultrasound contrast study of the...

the purpose of this study was to assess the endometrial safety and patient acceptability of a pulsed estrogen therapy provided by S21400 (intranasal 17 beta-estradiol) in the treatment of postmenopausal symptoms. postmenopausal women (n=408) entered an open-label, community based, multicentre trial. Patients received S21400 plus sequential (>90% of...

To study the influence of low-sodium cryopreservation media (CPM) on the survival and development of frozen-thawed germinal vesicle (GV) stage and in vitro matured human oocytes. Prospective experimental study. Academic hospital-based fertility center. Experimental groups: Oocytes cryopreserved at the GV (group A, n = 63 and group B, n = 64) or M I...

Since the inception of in-vitro fertilization (IVF), questions about contamination and the transmission of infection have been raised. In this review, screening for Chlamydia trachomatis, as well as medical and ethical considerations on IVF in couples infected with hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (H...

This study was performed to determine and compare persistent organic pollutant (POP) levels in different matrices in a female population. A total of 96 serum and 46 adipose tissue samples were collected from infertile women (n = 101) attending Centers for Reproductive Medicine in Belgium from 1996 to 1998. Gas chromatography with electron-capture d...

The aetiology of azoospermia can be grossly divided into obstructive and non-obstructive causes. Although in both cases testicular spermatozoa can be used to treat male fertility, it is not well established whether success rates following intracytoplasmic sperm injection (ICSI) are comparable. Therefore, a retrospective analysis of fertilization, p...