Dichorionic triamniotic triplet pregnancy with monozygotic twins discordant for trisomy 13 after preimplantation genetic screening: case report.
OBJECTIVE
To report the first dichorionic triamniotic triplet pregnancy discordant for trisomy 13 after in vitro fertilization (IVF) treatment with preimplantation genetic screening (PGS).


METHODS
Case report.


METHODS
Private IVF center.


METHODS
A 40-year-old para 1+6 woman.


METHODS
IVF combined with PGS for chromosomes 13, 16, 18, 21, and 22, resulting in the transfer of two embryos.


METHODS
Prenatal fetal ultrasonography revealed a dichorionic triamniotic triplet pregnancy. An amniocentesis, performed at 15-weeks' gestation, confirmed that the singleton and one monozygotic twin were normal but the other monozygotic twin was trisomy 13.


RESULTS
After diagnosis and counseling, selective termination of the trisomy 13 monozygotic twin was performed at 16 weeks and 4 days. At 18 weeks and 4 days the co-twin died. A healthy boy was delivered by elective caesarean section at 36-weeks' gestation.


CONCLUSIONS
Assisted reproductive techniques that breach the embryo's zona pellucida such as assisted hatching and PGS embryo biopsy increase the incidence of monozygotic twins. Due to high levels of mosaicism in human preimplantation embryos, PGS cannot ensure that embryos diagnosed as normal and selected for transfer do not contain abnormal cells. Hence, further reports of discordant monozygotic twins following PGS are expected, emphasizing the need for appropriate counseling of patients wishing to embark on an IVF/PGS treatment cycle.
Taylor
Deborah M
DM
The Lister Fertility Clinic, Lister Hospital, London, United Kingdom. debbietaylor@LFClinic.com
Thum
Meen-Yau
MY
Abdalla
Hossam
H
D000328:Adult; D000649:Amniocentesis; D002585:Cesarean Section; D002882:Chromosomes, Human, Pair 13; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005313:Fetal Death; D005817:Genetic Counseling; D005820:Genetic Testing; D005865:Gestational Age; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D050498:Live Birth; D008297:Male; D009030:Mosaicism; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal; D011272:Pregnancy, Multiple; D019836:Preimplantation Diagnosis; D014310:Triplets / Q000235:genetics*; D014314:Trisomy / Q000175:diagnosis* / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics*; D016216:Ultrasonography, Prenatal