Poop Patrol

Cite this article as:
Andrew Tagg. Poop Patrol, Don't Forget the Bubbles, 2017. Available at:
https://doi.org/10.31440/DFTB.10986

It’s the one question that all parents seem to ask about their newborn – “Is this normal? How can such a small thing create such a lot of mess? One of the things that stood out to me from Ross Fisher’s presentation on “What every Paediatric Surgeon wished you knew” was the line “There is no such thing as a normal bowel habit“. In an effort to avoid changing yet another nappy (diaper to some of you) I thought I would take a closer look.

The very first poo – meconium

What is meconium?

As the fetus matures in utero, surrounded by amniotic fluid, it ingests anything that is floating alongside it, like a child in a poorly kept public swimming pool. Along with amniotic fluid and bile, mucus, lanugo and epithelial cells are swallowed down and retained until after birth (usually).  This doesn’t usually start to happen until about the 26th week of gestation. Initial bacterial colonization of the neonatal gut was thought to occur as a result of contamination from the mother at this time but some studies have revealed the presence of bacteria in seemingly sterile meconium.

Meconium poop
Day 1 meconium

Most babies (around 90%) will pass their first meconium stool within 12 hours of birth. Some, between 8% and 10% of term deliveries, may pass it before birth leading to meconium stained amniotic fluid (MASF). Whilst this is, in itself, harmless if swallowed it may lead to respiratory distress if inhaled. Meconium is often described as thick and tarry and it is easy to see how it might plug small bronchioles leading to meconium aspiration syndrome (MAS).

Passing meconium too early

The passage of meconium in utero is linked with fetal distress. As the number of pregnancies that go on beyond 41 weeks has dropped the incidence of MAS has also dropped.

Risk factors for meconium passage in utero

  • Late gestational age
  • Intrauterine growth restriction
  • Fetal distress

One theory, based on animal models, is that periods of cord compression and subsequent fetal hypoxia lead to increased parasympathetic activity. This causes stronger waves of peristalsis coupled with relaxation of the anal sphincter and thus the passage of meconium. Whilst meconium-stained amniotic fluid is relatively common, only 2% to 3% of infants born through this liquor exhibit MAS. In the olden days (the 1970s) paediatricians aggressively suctioned the neonate’s airway in order to remove any meconium and this was thought to be the cause of reduced MAS mortality and morbidity. A large randomized controlled trial of over 2500 children with MSAF found no difference in rates of MAS or mortality if they had undergone intrapartum suction of the oropharynx.

Risk factors for meconium aspiration syndrome

  • Gestational age > 40 weeks
  • Moderate or thick stained amniotic fluid
  • Fetal tachycardia or bradycardia
  • Maternal smoking
  • Small or large for gestational age
  • Emergency caesarean

A number of trials have also shown that routine intubation and suction of vigourous infants born through MSAF did not decrease the risk of MAS.

There appears to be no correlation between the type of feed (breast milk vs formula) and time to passage of meconium. Delay in passage of meconium after day 2 occurs in 32% of preterm infants. The usual rate of passage (in unfed infants) is around one per day. As feeding is introduced stool frequency increases by one for every 50ml/kg of milk.

Normal

The average amount of meconium passed is between 200 and 600g (Grulee and Bonar, 1926) which amounts to between 5% and 17% of the average infants body weight!

Passing meconium too late

Failure to pass meconium in a timely fashion may herald intestinal obstruction. This may be due to a myriad of causes that are beyond the remit of this post.

Differential of failure to pass meconium

  • Hirschsprung’s disease
  • Meconium plug syndrome
  • Meconium ileus (of which Cystic Fibrosis is the most common cause)
  • Cystic fibrosis
  • Anorectal malformation
  • and some super rare surgical conditions

Meconium can be used to screen neonates for drug exposure in utero.

The transition phase

As a diet of amniotic fluid makes way for colostrum and breast milk, stool changes colour from a green-black tar to something else entirely. Whilst it should be a mustard yellow (wholegrain) in appearance, a pale stool may herald the presence of biliary atresia. Taiwan has a national stool colour card screening program to help detect the disease early whilst those of us who rely on technology might like to know that “there is an app for that“.

Normal baby poop
Breast fed stool

So is there a normal?

A small 1979 study collected a smorgasbord of samples on children ranging between birth and 24 months. Repeated studies have given provided similar data.

Number of times a baby poops per day
Number of times a breast-fed baby poops each day

Breast fed infants

Stool frequency peaks around day 5 as lactation becomes established and then slowly drops to 4 actions per day by day 7.  Anyone that has changed a breast fed infant’s nappy will have marvelled at the ‘seedy’ nature of the poo.

Formula fed infants

Children that receive breast milk pass softer stools and do so more often than those that receive formula. It’s a different consistency from that of the breast fed child – it’s thicker and more like (smooth) peanut butter. By the time they reach 16 weeks of age there is very little difference between the two.

Normal baby poops

As children get older they tend to pass stool once (or more per day) dependent on diet. A fascinating study, performed on kids in the 1980s who seemed to subsist on a diet of snack foods, tinned spaghetti and fish fingers and chips found that most kids passed small sausage sized stools, that became harder with age. The mean transit time was around 33 hours – useful information for parents of kids that have swallowed coins (or Lego)!

Selected references

Arias A, Bennison J, Justus K, Thurman D. Educating parents about normal stool pattern changes in infants. Journal of Pediatric Health Care. 2001 Oct 31;15(5):269-74.

Franciscovich A, Vaidya D, Doyle J, Bolinger J, Capdevila M, Rice M, Hancock L, Mahr T, Mogul DB. PoopMD, a Mobile Health Application, Accurately Identifies Infant Acholic Stools. PloS one. 2015 Jul 29;10(7):e0132270.

Grulee G C, Bonar B E 1926 The newborn: physiology and care and care, Appleton-Century Crofts, New York

Gulcan H, Gungor S, Tiker F, Kilicdag H. Effect of perinatal factors on time of first stool passage in preterm newborns: An open, prospective study. Current therapeutic research. 2006 Jun 30;67(3):214-25.

Jiménez E, Marín ML, Martín R, Odriozola JM, Olivares M, Xaus J, Fernández L, Rodríguez JM. Is meconium from healthy newborns actually sterile?. Research in microbiology. 2008 Apr 30;159(3):187-93

Lemoh JN, Brooke OG. Frequency and weight of normal stools in infancy. Archives of disease in childhood. 1979 Sep;54(9):719.

Meerkov M, Weiner G. Management of the meconium-stained newborn. NeoReviews. 2016 Aug 1;17(8):e471-7.

Nyhan WL. Stool frequency of normal infants in the first week of life. Pediatrics. 1952 Oct 1;10(4):414-25.

Ostrea EM, Brady M, Gause S, Raymundo AL, Stevens M. Drug screening of newborns by meconium analysis: a large-scale, prospective, epidemiologic study. Pediatrics. 1992 Jan 1;89(1):107-13.

Steer CD, Emond AM, Golding J, Sandhu B. The variation in stool patterns from 1 to 42 months: a population-based observational study. Archives of disease in childhood. 2008 Aug 1.

Vain NE, Szyld EG, Prudent LM, Wiswell TE, Aguilar AM, Vivas NI. Oropharyngeal and nasopharyngeal suctioning of meconium-stained neonates before delivery of their shoulders: multicentre, randomised controlled trial. The Lancet. 2004 Aug 20;364(9434):597-602.

Weaver LT, Lucas A. Development of bowel habit in preterm infants. Archives of disease in childhood. 1993 Mar 1;68(3 Spec No):317-20.

Weaver LT, Steiner H. The bowel habit of young children. Archives of disease in childhood. 1984 Jul 1;59(7):649-52.

Weaver LT, Ewing G, Taylor LC. The bowel habit of milk-fed infants. Journal of pediatric gastroenterology and nutrition. 1988 Jul 1;7(4):568-71.

Or Not…

Cite this article as:
Andrew Tagg. Or Not…, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.10499

With an impending new arrival I was excited about the educational opportunities that would arise.  I’d read up my fetal physiology and was eagerly awaiting the chance to write a series of posts on what normal babies do.  I had planned to take pictures of meconium filled nappies and film normal neonatal reflexes. I’d made a little list of the things I really wanted to capture. But things don’t always turn out the way you expect them to.

Coffee culture

Cite this article as:
Andrew Tagg. Coffee culture, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.10045

Melbourne is the coffee capital of the world (according to me at least). It’s the city that is home of the deconstructed latte and coffee bars can be found on most street corners. Every morning I am woken at 5-ish by one of my children calling out to me.  After the yell of “Daaaaaddy“, the second word she utters is “Coffee“.  Perhaps she is a little too young for her first espresso shot?

Neonatal dermatology – the rashes you shouldn’t ignore

Cite this article as:
Trisha Parmar. Neonatal dermatology – the rashes you shouldn’t ignore, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.8193

Neonates have rashes of all shapes and sizes. It’s important for us to be able to reassure parents where appropriate and act when we need to. This two part series deals with neonatal dermatology. In Part 1, we looked at the benign conditions, but in Part 2 we will look at the conditions that you shouldn’t ignore.