PubMed Health⌕ Search

Biomedical subjects

N Lédée

Publications and source records attributed to N Lédée.

6 recordsLinked to original sources
PubMed2006

[Late paternity: spermatogenetic aspects].

The effect of maternal age on the risk of meiotic abnormality is well documented. In contrast little is known about the effect of the paternal age. The question of the risk related to paternal age is raised because of the increased demand of Assisted Reproduction Techniques for older men. This review focuses on the alterations of male semen parameters, testis histology and genetic risks related to age. The motility, vitality and morphology of spermatozoa and semen volume are found decreasing with age. Histomorphometric studies reveal various alterations including a thickening of the basal membrane when spermatogenesis is arrested. The number of germinal and Sertoli cells decreases with increased age. Up to 95 years old, we could find subjects with complete spermatogenesis. Chromosomal analyses in different studies have provided controversial results. Our investigation on subjects aged from 29 to 102 showed that the rate of aneuploidy in the group of aged subjects with preserved spermatogenesis was not statistically different from the young control group. However the incidence of postmeiotic aneuploidy was increased when spermiogenesis had stopped. On the other hand from epidemiological studies, autosomal dominant diseases are known to be associated with paternal age. However, in the case of achondroplasia and Apert syndrome, direct DNA sperm analysis did not reveal significant increase in the mutation frequency with paternal age.

Adult↗
PubMed2001

Management in intractable obstetric haemorrhage: an audit study on 61 cases.

OBJECTIVE: To refine the indications of bilateral hypogastric artery ligation (BHAL) and angiographic selective embolisation (ASE) in intractable obstetric haemorrhage. DESIGN: an audit study. SETTING: Tertiary care university hospital. POPULATION AND METHODS: Retrospective analysis of 61 cases of obstetric intractable post partum haemorrhage (PPH) initially managed either by hysterectomy or a conservative approach in a tertiary referral centre between 1983 and 1998. Procedures were reviewed as a primary (P) or secondary (S) attempt to arrest the haemorrhagic process. RESULTS: Ten hysterectomies (5 P, 5 S), 49 BHAL (48 P, 1 S) and 9 ASE (8 P, 1S) were successfully performed in arresting the haemorrhagic process. There were 7 maternal deaths, 5 following hysterectomy and 2 following a conservative approach. Atony of the uterus was the main cause of haemorrhage (n=21) and genital tract laceration was associated with the worst prognosis. Time-elapse between delivery and surgery appears to be the main prognostic factor. Nine patients became pregnant 1 to 4 years later following a conservative approach. CONCLUSIONS: ASE seems to be indicated in haemodynamically stable patients with birth canal trauma or uterine atony and clotting anomalies. BHAL is indicated when haemorrhage occurs after a cesarean section or when the patient is haemodynamically unstable. BHAL should be taught to Junior doctors in an attempt to decrease the number of patients transferred in tertiary referral centers for intractable PPH. This might also decrease the number of hysterectomies in intractable PPH.

Adult↗
PubMed2001

[GnRH antagonists in IVF].

New GnRH antagonists are available in clinical practice. The different studies have confirmed the efficacy of these antagonists in preventing the LH surge. Two protocols have been described: in the multiple dose regimens, small doses of antagonist (0.25 mg) are injected starting on stimulation day 5 or 6 until hCG. In the single dose protocol, one injection of a larger dose (3 mg) is proposed in the late follicular phase. Local and general tolerance of the two compounds is very good. The results obtained with both regimens as compared with GnRH agonists in long protocols are showing a reduction in the stimulation length, in the consumption of gonadotrophins and in the incidence of the OHSS. The pregnancy rates are comparable in the good prognosis patients selected in the published studies. When the final tuning of these new protocols will be done, the advantages of GnRH antagonists in reducing the complications and side effects of ovarian stimulation will give to GnRH antagonists an important place in IVF.

Chorionic Gonadotropin↗
PubMedDate not supplied

Perinatal outcome and developmental studies on children born after IVF.

Since the first birth after IVF, many scientific papers have been published on the technical aspects of the IVF procedure, but few studies have addressed the issue of the perinatal outcome of IVF pregnancies and of the children's development and well-being. A high rate of adverse outcome has been demonstrated in a large group of IVF pregnancies. Prematurity, low birth weight and perinatal mortality are higher than in the general population. The majority of these complications are related to multiple births, but they are also found in singleton pregnancies. An analysis of the multiple risk factors involved in these complications is needed. The infertile status of IVF patients clearly plays a role in the risk of adverse outcome. Age and parity may be important factors. The role of IVF itself has not been demonstrated convincingly. The effect of ovarian stimulation deserves further study. Most of the studies published on the follow-up of IVF children are reassuring, but it is clear that these studies are not sufficient to eliminate without doubt any adverse effects on the well-being of IVF children. All IVF pregnancies should be followed with great care, not because they are more precious than spontaneous pregnancies, but because they are exposed to an increased risk of complications. The main problem of IVF remains the high rate of multiple pregnancies, including twins.

Age Factors↗