Early neonatal death refers to the death of a baby within the first seven days of life. Babies who die shortly after birth, even if they were born at full term, are classified under this definition.

See also Neonatal Death

An ectopic pregnancy occurs when a fertilised egg implants outside the womb, most commonly in one of the fallopian tubes, but sometimes at the join between the fallopian tube and the womb, in the cervix or abdomen, or on scar tissue from a previous Caesarean section.

An ectopic pregnancy cannot result in a viable baby and can pose serious risks to the mother’s health if not treated promptly. Occasionally, a twin pregnancy may occur where one embryo implants in the womb and the other in a fallopian tube.

A miscarriage is the loss of a baby before 24 weeks of pregnancy*. In the UK, the legal cutoff for a miscarriage is 23 weeks and 6 days. Miscarriages are categorised into early and late, based on the gestational age** at which they occur:

• Early Miscarriage: this occurs within the first 12-13 weeks of pregnancy and is the most common form of miscarriage

• Late Miscarriage (also known as mid-trimester loss): occurs from 14 weeks up to 23 weeks and 6 days.

*Why is 24 weeks considered such an important stage?

In the UK, if a baby is born alive at or after 24 weeks of pregnancy, they have a good chance of survival with the right medical support. This is known as the age of viability.

**gestational age: the period of time the pregnancy develops in the womb, starting at conception.

A molar pregnancy, also called a hydatidiform mole, occurs when an abnormally fertilised egg attaches to the uterus but does not develop into a viable pregnancy. Instead of forming a baby and placenta, a cluster of abnormal cells develops, which can grow rapidly and invade the uterus.

Partial molar pregnancies involve some normal embryonic development, but do not result in a live birth.

Complete molar pregnancies involve no normal embryonic development.

Molar pregnancies require close monitoring and extensive follow-up, and in some cases can result in development of a rare type of cancer.

A neonatal death is the death of a baby within the first 28 days after birth.

In the UK, even if a baby is born before 24 weeks but shows signs of life, their death would be considered a neonatal death, regardless of their gestational age at birth.

Perinatal death describes death of a baby during the perinatal period: the time shortly before and just after birth. Stillbirths and neonatal deaths are both considered perinatal deaths.

Post-neonatal death occurs when a baby dies between the age of 28 days and one year, including deaths due to Sudden Infant Death Syndrome (SIDS).

Historically defined as three consecutive miscarriages, recurrent miscarriage is now defined as the loss of three or more pregnancies before 24 weeks, irrespective of live births between losses.

A stillbirth is when a baby dies after 24 weeks of pregnancy but before or during birth. In the UK, this is a legal definition used to distinguish from earlier pregnancy losses or neonatal deaths. The baby may be delivered naturally or through medical intervention.

SIDS, also known as "cot death," refers to the unexpected and unexplained death of a baby under one year of age.

Other names used to describe this condition include sudden unexplained death in infancy (SUDI), or sudden unexpected death in childhood (SUDC) if the child is over 12 months old.

A termination for medical reasons (TFMR) occurs when continuing the pregnancy is considered a significant risk to the health or life of the mother, or there are complications associated with the health of the baby such as chromosomal abnormalities or severe physical conditions.

You may also hear the term TOPFA (termination of pregnancy for fetal anomaly).

Termination of pregnancy (TOP) for non-medical reasons refers to the ending of a pregnancy within the first 24 weeks of pregnancy by medical intervention (surgery, or medicine). This may also be referred to as an abortion and is performed legally in the UK for various personal reasons.