Methods for endometrial implantation of embryos

DETAILED DESCRIPTION A central focus of the invention is deposition of an embryo within the uterine lining or endometrium of a mammal.
Preferably, the recipient mammal is a human.
Visualization of the endometrium and visual guidance of deposition of the embryo are preferably practiced with the invention and can be provided by fiberoptic technology.
Conveniently, a method of the invention includes placing at least one embryo in a microcatheter having an elongate tubular body and a distal tip.
Preferably, four to eight embryos are transferred per fertilization attempt.
The distal tip of the catheter is introduced into the mammal's cervical os or opening and directed into the mammal's uterine tissue.
Preferably, the microcatheter has a non-stick surface to prevent the embryos from adhering to the catheter, thus assisting with embryo deposition.
A non-stick surface can be formed of polytetrafluoroethylene which is commercially available under the trade name "TEFLON.
TM.
".
The microcatheter preferably measures about 0.
1-1.
0 millimeter (mm) in diameter and can deliver one or two embryos per fertilization attempt.
Methods of the invention are preferably performed with fiberoptic guidance to assist with steps such as introducing the microcatheter tip through the cervical opening and into the endometrial cavity, directing the tip into the uterine tissue, and depositing the embryo within the endometrial lining.
The depth at which the embryo is deposited is typically from about 0.
5 mm to about 5 mm beneath the endometrial surface.
More preferably, the embryo is deposited at a depth of about 0.
5 mm to about 2 mm.
Most preferably, the embryo is deposited at a depth of about 1.
0 mm.
The deposition of the embryo into the uterine tissue can be accomplished by flushing the microcatheter with a physiologic irrigant.
Such irrigants are well known to the artisan and include amniotic or follicular fluid, saline solution, Ringer's solution and culture medium such as stock Ham's F-10 or Earle's medium (both available from GIBCO, New York)