Related Experiment Video
Updated: Apr 27, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Sequential protocol with urinary-FSH/recombinant-FSH versus standard protocol with recombinant-FSH in women of
Nicola Colacurci1, Francesca Caprio, Eugenio La Verde
1Outpatient Fertility Clinic, Second University of Naples , Naples , Italy.
Abstract:
A stimulation protocol mimicking the physiological pattern of FSH release may improve IVF outcome in women of advanced age. Urinary-FSH delivers a wider range of isoforms including the most acidic produced during the early follicular phase when oestradiol level is low, a common condition in women of advanced reproductive age. We hypothesized that a stimulation protocol using urinary-FSH during the early follicular phase and then shifting toward recombinant-FSH may improve oocyte quality and pregnancy rate in 35-40 years old patients in IVF program. A retrospective study was performed: after a standard down-regulation with GnRH-analogue, 115 women underwent stimulation with urinary-FSH for 6 days according to a step-down approach and then shifting to recombinant-FSH (group A), 115 women underwent a stimulation protocol with only recombinant-FSH (group B). Days of stimulation were lower in group A than in group B, a higher proportion of MII oocytes and of grade 1 embryos, higher implantation rate and pregnancy rate were observed in group A versus group B. We conclude that a sequential protocol using urinary-FSH in the early days of stimulation and subsequently recombinant-FSH may improve the IVF outcome in patients of advanced reproductive age.
Related Concept Videos
In Vitro Fertilization
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...
Infertility in Females
Endometriosis, a condition characterized by abnormal growth of...
Meiosis II

