What is transient neonatal pustular melanosis (TNPM)

• Transient - Short time
• Neonatal - Newborn
• Pustular - Small swollen skin bump that contains pus
• Melanosis - Darkening of skin colour

Transient Neonatal Pustular Melanosis (TNPM) is a harmless skin condition that occurs in the early days after childbirth, roughly up to 28 days.

Newborns that are born with small blisters on their skin, when these blisters rupture, they cause skin discolouration, which does fade on its own over time, so TNPM does not need any treatment.¹

It is also important to note that the cause of TNPM has not been confirmed. Even though TNPM affects only 2.2% of infants, it appears to be more common in black newborns, with an incidence of 4.4%, while white infants have an incidence of only 0.6%. There is also no statistical preference between male or female infants.²

It could be suggested that TNPM occurs as a result of Birth trauma, but we will look further into this.

What is birth trauma?

There are two associated definitions of Birth Trauma as a result of a difficult childbirth, also known as a traumatic birth:

Psychological Birth trauma - Giving birth is a notoriously very frightening event. Birth trauma can describe the symptoms of distress that were experienced during a traumatic birth or witnessing a traumatic birth that could result in a Post-Traumatic Stress Disorder (PTSD) diagnosis.

Physical Birth Trauma  - Refers to the damage of tissues and organs experienced during childbirth that affects the birthing person and/or newly delivered child as a result of a traumatic birth. When an infant experiences birth trauma, which is more commonly known as Neonatal (newborn) birth trauma, complications can occur, which can include damage to important areas for development such as the head, spinal cord, skin, soft tissues and organs.³

In this article, we will address whether TNPM and neonatal Birth Trauma have any correlation with certain methods during childbirth.

Neonatal birth trauma risk factors

There are several risk factors that are associated with birth trauma that separate groupings: fetal and pregnancy factors, birthing person factors and factors as a result of delivery methods.

Fetus and pregnancy risk factors:

• Macrosomnia, where the fetal weight is greater than 4000g, which is larger than the average⁴
• Macrocephaly, where the fetus’s head circumference is much larger than is considered normal for its age and sex, is more common in males⁵
• Extreme prematurity, fetus is born before 28 weeks⁶
• Low birth weight, the opposite of macrosomnia, where the fetus has a very low birth weight⁶
• Abnormal presentation, where the baby is not positioned head first during childbirth, instead comes out face, brow, breech or shoulder first⁷
• Fetal congenital anomalies, also known as birth defects⁶
• Epidural anaesthesia, an injection in the back to prevent the birthing parent from feeling pain during birth⁸

Birthing person risk factors:

• Obesity, where the pregnant person has a lot of body fat⁷
• Diabetes, where the pregnant person has diabetes⁹
• Short stature, where the pregnant person is less than 145 cm or 4’9” tall¹⁰
• Presence of pelvic anomalies or pelvic floor disorders, which are conditions that affect the pelvis and can affect the bladder, uterus, cervix and vagina¹⁰
• Race of birthing person⁴
• Nulliparity, where the birthing person has never given birth before¹¹
• Primiparity, where the birthing person has given birth once before⁶

Delivery method risk factors

• Prolonged labour and rapid labour can cause birth trauma³
• Instrumental delivery, using vacuums or forceps as forceful extraction methods during labour³

The most important risk factors that have been listed are: Macrosomnia, abnormal presentation and instrumental delivery.

Common traumatic clinical conditions

There are many conditions that are associated with Birth Trauma. 

• Scalp swelling: Formally known as Caput Succedaneum, which is a common scalp swelling in newborns as a result of increased pressure from the birth canal during delivery¹² 
• Skull fractures: A break in the skull bone, most fractures are small and do not move, most commonly associated with instrumented vaginal delivery¹³
• Cephalohematoma: A generally harmless type of hemorrhage, where the blood pools under the scalp after a difficult delivery, it has been found to be more common with instrumented vaginal delivery¹³
• Paralysis: Traumatic birth can cause the baby to be partly or completely unable to move parts of the body, which could be temporary or permanent. The most common areas are: Face, shoulders, arm, wrist and fingers, as they are the most affected during traumatic births^3,14
• Skin & soft tissue injuries: Soft tissue is all tissue in the body that is not bone. During childbirth, it is possible for any soft tissue to develop swelling and bruising, particularly during a traumatic birth. This has been found to be more common with instrumental delivery as they do put significant pressure on the baby’s skin¹⁵

So, it’s entirely possible that as birth trauma affects soft tissue and skin, it could be a cause for TNPM. Also, as a lot of skin conditions are found to be more associated with instrumental delivery, it could be further suggested that instrumental delivery that results in birth trauma could result in these skin conditions.

Birth trauma and skin conditions

There are many types of skin conditions in newborn babies that cause different kinds of blisters and sores of varying sizes and colours (lovely).

The most common skin condition/disorder is Erythema toxicum neonatorum (ETN), which means Toxic erythema of newborn. 

ETN is so common that half of all newborns develop it. It appears at birth or in the early days after birth with small red and pink papules (small bumps) and blisters all over the face and body. It generally does not bother the baby and goes away on its own.¹ 

You may have noticed that it shares similar symptoms to TNPM; this is because TNPM is a more severe form of ETN.²

A baby is also more likely to have ETN occur if it is the first pregnancy, if the baby is male, and has a higher birth weight, such as macrosomia.

During birth,  this risk factor has been shown to increase if the baby was birthed vaginally, as well if the labour is prolonged.¹⁶

Whilst no one is certain of what causes ETN, a popular hypothesis is that it is the skin of the newborn is simply adapting to its new environment.¹⁷ Top researchers still do not know the direct cause of ETN, and as a result, TNPM.

We can assume from the literature that ETN/TNPM and birth trauma share very similar risk factors; it could be possible that newborn babies with ETN/TNPM were also born traumatically, however, there is no apparent research that has studied this link. An important risk factor of birth trauma is an instrumental delivery, and whilst current research suggests that vaginal births increase the risk of ETN, there is not any available data that explicitly states that these vaginal deliveries had any assistance with instrumentation like forceps or vacuums.

Whilst we do not have any concrete evidence from the current literature, it could be suggested that TNPM and Birth Trauma could be correlated to instrumental delivery methods; it would be very interesting for any future research to study this link.  

Whilst Birth Trauma can cause a variety of issues to the parent and newborn, TNPM and ETN is a very low-priority concern.

Summary

Transient Neonatal Pustular Melanosis (TNPM) is an uncommon skin condition present at birth, characterised by ruptured blisters that discolour the skin. However, these blisters typically resolve over time, making treatment unnecessary. There are different types and definitions of birth trauma, although Neonatal birth trauma is when the newborn baby has injuries as a result of a difficult birth. Many risk factors could potentially result in birth trauma, the most notable of which are: baby that is heavier than normal (macrosomnia), baby that is not positioned normally during vaginal birth (abnormal presentation), and a delivery that uses instruments such as forceps or vacuums that use a lot of force to help deliver the baby.

Birth trauma can result in a variety of clinical conditions, the most common of which involve the head and shoulders, but it also affects the skin and soft tissue. Many forms of skin conditions happen after birth, particularly with instrumental delivery, but not many are seen to be related to birth trauma. The most common type of skin condition that affects 50% of newborn babies is Erythema toxicum neonatorum (ETN). The risk factors for ETN are similar to birth trauma; also, TNPM is a more severe version of ETN, so it could be suggested that ETN/TNPM could be a result of birth trauma from instrumental delivery. Further research is needed to confirm this linkage.