icmart logo


The International Glossary on Infertility and Fertility Care

The following glossary was developed in 2017 by a global panel of more than 100 multidisciplinary experts, professional organisations, and patient representatives to provide consensus agreement on 283 items and definitions. Published in Fertility and Sterility (FNS) and Human Reproduction (HR).
A printable version of the 2017 Glossary and more information on the methodology, and a list of previous compiled glossaries can be found here.

Natural cycle ART

An ART procedure in which one or more oocytes are collected from the ovaries during a menstrual cycle without the use of any pharmacological compound.


The description of an ejaculate in which no live spermatozoa can be found.

Neonatal death/mortality

Death of a live born baby within 28 days of birth. This can be sub-divided into a) early, if death occurs in the first 7 days after birth; and b) late, if death occurs between 8 and 28 days after birth.

Neonatal mortality rate

Number of neonatal deaths (up to 28 days) per 1000 live births.

Neonatal period

The period which commences at birth and ends at 28 completed days after birth.

Non-obstructive azoospermia

Absence of spermatozoa in the ejaculate due to lack of production of mature spermatozoa.

Nuclear maturation

The process during which the oocyte resumes meiosis and progresses from prophase I to metaphase II.
Scroll to Top