Male factor
Infertility caused by a problem in the male partner such as the inability to ejaculate or suboptimal semen quality or sperm preventing pregnancy from occurring; it might include the presence of a varicocele, cryptorchidism, chromosomal abnormality, vas deferens obstruction and exposure to environmental toxins or drugs.

Male partner
A husband or male who may undergo the Donor/Recipient IVF cycle with the female recipient, and whose sperm is used.

Menarche
The time when a woman has her first menstrual period.

Menopause
The time when a women stops having menstrual periods.

Micromanipulation
The mechanical manipulation of eggs, sperm or embryos under a microscope. Intracytoplasmic sperm injection (ICSI), assisted hatching and embryo biopsy are all forms of micromanipulation.

Microsurgery
Reconstructive surgery performed under magnification using delicate instruments and precise techniques.

Miscarriage
Spontaneous abortion.

Morphology
The study of form, such as assessing the shape of sperm during semen analysis.

Motility
Motion, such as the forward swimming motion of health sperm.

Mucus
Secretion from a gland that can be watery, gel-like, stretchy, sticky or dry; fertile mucus is watery and stretchy.

Mycoplasm
An infectious agent that falls structurally between a virus and a bacterium.

Myomectomy
Surgical removal of a uterine fibroid tumor.