Monozygotic twins in infertile patients with advanced maternal age: case reports and review of the literature.
OBJECTIVE
To report two cases of successful monozygotic twin pregnancies in women undergoing infertility treatment and to review possible etiologic factors.


METHODS
Case report and review of the literature.


METHODS
University of Toronto-affiliated infertility clinic.


METHODS
A 43-year-old woman and a 44-year-old woman with history of secondary infertility.


METHODS
In vitro fertilization and ET.


METHODS
Monozygotic twin pregnancy.


RESULTS
Delivery of two sets of monozygotic twins.


CONCLUSIONS
The only identified potential risk factors for monozygotic twins are maternal age and assisted reproductive technologies. Both patients reported here were aged >40 years and underwent assisted reproduction procedures, including high-dose gonadotropin stimulation, embryo culture, and, in case 2, intracytoplasmic sperm injection plus assisted hatching.
Esfandiari
Navid
N
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. Electronic address: navid.esfandiari@utoronto.ca.
Kapoor
Monica
M
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada.
Burjaq
Hasan
H
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada.
Chang
Paul
P
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.
Gotlieb
Lynda
L
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada.
Casper
Robert F
RF
Toronto Centre for Advanced Reproductive Technology, University of Toronto, Toronto, Ontario, Canada; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.
D000328:Adult; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D008423:Maternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome; D027724:Reproductive Techniques, Assisted; D012307:Risk Factors; D014430:Twins, Monozygotic