Sperm Selection by Microfluidic Separation Improves Embryo Quality in Patients With a History of Poor Embryo Quality

More than 70 million couples worldwide are infertile and up to 40 million are actively
seeking infertility care. In the year 2013, a total of 160,521 assisted reproductive
technology (ART) procedures were performed in the United States. Isolation of motile and
morphologically normal sperm is an integral part of assisted reproduction. Traditional sperm
processing for assisted reproduction involves centrifugation and "swim up" techniques that
employ a density gradient to isolate motile sperm. This technique involves several steps of
centrifugation (200-1800g) with colloidal silica particles. In this process, sperm and other
material form distinct bands. It is thought that this procedure allows for elimination of
abnormal/immotile sperm as well as debris, thereby isolating motile human sperm.
Nevertheless, the centrifugation process has been shown to induce DNA damage and produce
reactive oxygen species, thereby potentially compromising sperm quality and subsequent
laboratory outcomes such as fertilization rate and embryo quality. Increased sperm DNA damage
has been associated with poor outcomes in assisted reproduction, including lower
fertilization rates, impaired embryo progression, and decreased pregnancy rates. The details
of the density gradient centrifugation process are not regulated by the FDA.

In contrast, microfluidic-based sperm sorting has the capability of selectively isolating
highly motile, morphologically normal sperm with high DNA integrity from an unprocessed semen
sample. Microfluidic technology isolates healthy sperm by laminar flow, creating gradients
through channels. The microfluidic chip we plan to study in our randomized clinical trial
utilizes space-constrained microfluidic sorting to select highly motile and morphologically
normal sperm in a flow and chemical-free design. Unlike the standard of density gradient
centrifugation, no manipulation of sperm is required in this process. Raw semen is introduced
into the inflow and only motile and morphologically normal sperm are able to swim through the
chip to the outflow where it is collected for use.

In semen samples from healthy male volunteers split into standard processing via
centrifugation and swim-up procedure compared with microfluidic sperm sorting, a
significantly higher percent motility and lower rate of sperm DNA fragmentation was detected
with microfluidic sperm sampling. The microfluidic sperm sorting technique has thus proven to
be an efficient and reliable means of sperm preparation compared with the centrifugation and
swim-up procedure. While this microfluidic chip has been used clinically in Mexico, Turkey,
South Africa, Italy, Greece, and Switzerland resulting in over 5,000 live births, its use in
clinical practice has not been rigorously studied. We aim to compare traditional preparation
and microfluidic sperm sorting on assisted reproductive technology outcomes including oocyte
fertilization and embryo quality in subjects with a history of poor embryo quality electing
to undergo a repeat in vitro fertilization cycle for infertility.

Inclusion Criteria:The target population includes couples planning in vitro fertilization
(IVF) with or without intracytoplasmic sperm injection for unexplained infertility at the
UCSF Center for Reproductive Health with a history of poor embryo quality as defined by <
=40% high quality D3 embryos in a prior IVF cycle. All eligible couples where both partners
are >=18 years of age will be asked to join the study.

Exclusion Criteria:

Male partner with severe oligoasthenospermia (concentration < 5 x 10^6 spermatozoa/mL;
motility< 10%) Female partner with anovulation (PCOS, FHA) Female partner age >41 Female
partner AFC< 7 Female partner with obstructed fallopian tubes (assessed in all patients
prior to IVF) Use of oocyte donor

Either Partner:

Cancer diagnosis in either partner Any significant disease or psychiatric disorder that
would interfere with consenting process

Treatment History:

History of >1 prior cycle cancellation due to poor response

Treatment Plan:

Embryo co-culture Use of adjunctive non-gonadotropin medications to improve embryo quality:
growth hormone, sildenafil