The presence of pinopodes in the human endometrium does not delineate the implantation window.
OBJECTIVE
To assess pinopode formation in human endometrium during the luteal phase of the menstrual cycle and in the first trimester of pregnancy.


METHODS
Prospective clinical study.


METHODS
Outpatient infertility clinics and outpatient family planning clinic.


METHODS
Thirty-two regularly cycling infertile women, 15 regularly cycling fertile women, 9 women receiving elective termination of pregnancy, and 1 woman receiving GnRH agonist and hormone therapy addback.


METHODS
Endometrial tissue was collected by suction pipelle and examined by scanning electron microscopy for pinopode formation.


METHODS
Endometrial tissue was scored (0, 1, 2, 3, or 4) depending on the percentage of the surface covered in pinopodes (from 0% to >20% of 100 fields).


RESULTS
Pinopodes were present throughout the luteal phase of the menstrual cycle, up to the 11th week of pregnancy, and in the endometrium of the woman on GnRH agonist and hormone therapy.


CONCLUSIONS
Pinopodes can be detected in the progesterone-exposed endometrium for an extended period of time, in contradistinction to the perception that they are markers for the implantation window in the human endometrium.
Quinn
Claire
C
Division of Reproductive Sciences, Samuel Lunenfeld Research Institute, and the Fran and Lawrence Bloomberg Department of Obstetrics and Gynecology, Mount Sinai Hospital, Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
Ryan
Edward
E
Claessens
E Anne
EA
Greenblatt
Ellen
E
Hawrylyshyn
Peter
P
Cruickshank
Barbara
B
Hannam
Thomas
T
Dunk
Caroline
C
Casper
Robert F
RF
D000328:Adult; D021961:Cell Membrane Structures / Q000648:ultrastructure*; D010064:Embryo Implantation / Q000502:physiology; D004624:Embryo Transfer; D004717:Endometrium / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008183:Luteal Phase / Q000502:physiology; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors