Introduction
As a continuing conundrum, adenomyosis has besieged clinicians over than
one hundred years, which is manifested with displacement of endometrial
glands and stroma in the myometrium, surrounded by smooth muscle
hyperplasia(1). Adenomyosis can induce a series of
clinical problems, such as heavy menstrual bleeding, chronic pelvic pain
and infertility. As time passes, the lesions gradually exacerbated, and
eventually result in infertility and severe impact on life quality. A
cross-sectional study showed that the incidence of adenomyosis was
respectively 20% and 29.7% in ≤40 years and >40 years infertile
patients (2). In infertile women receiving artificial
reproduction technology(ART), the proportion can rise to
30%-40%(3).
The negative effect of adenomyosis on outcomes of ART were accumulated,
and persistent endeavors were made to improve the pregnancy
outcomes(3-5). So far, ultr-along protocol had
received more approvement because of possible improvement on clinical
pregnancy rate(CPR) or live birth rate(LBR) (6-9). A
widely accepted mechanism was downregulation induced by long acting
GnRHa could counter hyperestrogenism and progesterone resistance of
adeomyosis. However, ultra-long protocol had an obvious defect, that
was, deep inhibition of ovarian function, which usually resulted in the
increase of gonadotropin duration and dosage. More seriously, for
adenomyosis patients with poorer ovarian reserve, the inhibition of long
acting GnRHa could induce poor ovarian response, manifesting with
decreased oocyte retrieval and negative pregnancy outcomes. Besides
ultra-long protocol, conventional protocols, such as long, antagonist
and short protocols all could be adopted, however, systematic evaluation
about these protocols was absent. In frozen embryo transfer (FET)
cycles, if embryos originating from different protocols, did any
differences of pregnancy outcomes exist? There were no answers.
So, we designed this study and tried to systematically evaluate the
pregnancy outcomes of different protocols in fresh embryo thansfer (ET)
cycles. Additionally, we also aimed to elucidate whether embryo deriving
from different protocols could affect the outcomes of FET cycles.