The effect of long zona dissection using ICSI pipettes for mechanical assisted hatching in vitrified-thawed blastocyst transfers.
OBJECTIVE
To investigate the effect of long zona dissection (LZD) compared with partial zona dissection (PZD) using ICSI pipettes for mechanical assisted hatching (AH) in vitrified-thawed blastocyst transfers.


METHODS
Prospective study.


METHODS
University IVF clinic.


METHODS
A total of 120 women ≦ 38 years old undergone vitrified-thawed blastocyst transfers with LZD or PZD.


METHODS
The culture of all pronucleate embryos to the blastocyst stage and the selection of blastocysts ≧ grade 3BB (Gardner and Schoolcraft score), followed by vitrified-thawed blastocyst transfers with LZD (n = 60) or with PZD (n = 60)


METHODS
Complete hatching rates, implantation rates, pregnancy rates.


RESULTS
At 5 h after thawing, complete hatching rates of blastocysts were significantly higher in LZD group compared with PZD group, 52.4 % vs. 31.8 % (P = 0.001). Implantation and clinical pregnancy rates were significantly higher in LZD group compared with PZD group, 40.9 % vs. 25.7 % and 63.0 % vs. 40.0 %, respectively (P = 0.010, P = 0.011).


CONCLUSIONS
LZD using ICSI pipettes for mechanical AH improves significantly complete hatching, implantation and pregnancy rates in vitrified-thawed blastocyst transfers.
Department of Obstetrics and Gynecology, Pusan National University, School of Medicine, Gu-Duk-Ro 305, Su-Gu, Busan, Republic of Korea.
Sheng-Ta
ST
Sun
Jong-Ryeol
JR
Choi
Jung-Bin
JB
Son
Jong-Kil
JK
Joo
Gyoung-Rae
GR
Ko
Kyu-Sup
KS
Lee
D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic; D058989:Vitrification; D015044:Zona Pellucida / Q000502:physiology