With the holiday season ahead of us, you might be interested in some “weighty matters”. Let me start with a topic that can be of interest to parents, especially to those who anxiously monitor the weight gain of their newborn. As the icing on the cake, I will grab the opportunity to bring the new perinatal growth standards to the attention of health professionals.
Regaining Birth Weight
Quite quickly after our birth, we end up on the scales for our first exam. Our worth in pounds often becomes the reference point for our growth. Wrongly. Instead of the birth weight, the weight after some days should be the baseline for calculating weight loss or gain.
According to the American Pregnancy Association, a weight loss of 5% (formula fed) and 7-10% (breast fed) in the 5 to 7 days after birth is considered normal in full term babies. An often mentioned cause is the physiologic diuresis of extracellular fluid that takes place as a result of the transition to extrauterine life. Recent studies show that maternal IV infusion during labor can play a role as well, as it passes fluids to the placenta which can result in overhydration in the baby, leading to an excessive diuresis and weight loss in the first days.
In 2003, a study was done to define the range of neonatal weight loss related to the feeding method. About 95% of the formula fed babies did regain their birth weight at an average of 14.5 days while 95% of the breastfed babies did hit their birth weight at an average of 18.7 days. The clinical protocol of the Academy of Breastfeeding Medicine mentions an average of 8.3 days for well breastfed newborns to regain their birth weight, with 97,5% having regained their birth weight by 21 days.
Until recently, the golden rule of the American Academy of Pediatrics was that newborns should surpass their birth weight around day 10 to day 14. All the while, this rule seems to have been lacking a foundation in studies on natural weight change patterns in the first month of life. A recent study, executed among 144,000 newborns in California between 2009 and 2013 tries to fill this knowledge gap. The study shows that it is not uncommon for newborns to be below birth weight at day 10 to 14. Overall, nearly 14% of the vaginally born babies and nearly 25% of the babies born by c-section didn’t live up to the 10 to 14 day rule. One out of 20 newborns hadn’t reached their birth weight at the age of 3 weeks, while for newborns delivered by c-section any point in time throughout the first month of life could be the moment of reaching birth weight.
This study might be good news for worrying breastfeeding mothers as it indicates that it can be a matter of natural variation that some baby’s take longer to regain their birth weight than others. With the current 10 to 14 days rule they can easily feel under pressure when their baby is not gaining weight quickly enough in the first week after birth. They will not seldom start doubting their milk supply, milk composition or adequacy in nursing. These worries alone can already have detrimental effects on the breastfeeding. Staring oneself blind on just weight gain and initiating interventions for the sole reason of not meeting the 10 to 14 days rule is not the way to go. It is better to focus on supporting a good kick off of the breastfeeding, while of course at the same time keeping a close eye on the baby’s overall clinical presentation (signs of dehydration, jaundice, lethargy, etc.) to assure there is indeed no other underlying condition that demands early intervention.
At the same time, we have to bear in mind that we should not consider every situation of delayed weight gain a natural variation. It is in the utter interest of a newborn to timely discover an underlying condition or medical problem. A low birth weight infant that has a compromised system can slip away into a life-threatening situation quite easily and quickly.
Formula fed babies and breastfed babies have different growth patterns. One has to assure that one is using the chart for breastfed babies as the biological reference norm. The WHO growth standards for infants and children ages 0 to 2 years of age (breastfed infant as the norm for growth) can be found here. Interesting information for parents on a baby’s weight loss and gain can be found here.
New Growth Standards
Our intrauterine growth is an important determinant of health. Preterm birth and poor intrauterine growth are important variables in mortality risk in the first year of life, childhood developmental problems, and the risk of various diseases in adulthood.
During prenatal ultrasounds, growth is based on measurements of head circumference (HC), bi-parietal diameter (BPD), occipito-frontal diameter (OFD), femur length (FL), and abdominal circumference (AC). After birth, growth is based on measurements of birth weight, length and head circumference. Thanks to the INTERGROWTH research project we now have new, globally-validated standards to plot growth.
INTERGROWTH-21st is an international fetal and newborn growth research consortium. As the name already gives away, it is all about “growth” and especially intrauterine growth, preterm birth and perinatal health and about how to reduce preventable neonatal mortality worldwide.
The research group is coordinated by the University of Oxford and unites 300 professionals from 25 institutions in 18 countries and from multiple disciplines. The study is unique in its kind. It is a population-based, multi-ethnical and multicentric study that looks at the neonatal health risk in 8 geographically diverse populations in relation to normal fetal growth, preterm growth and newborn nutritional status.
One of the first major achievements of INTERGROWTH-21st is the design of a Global Perinatal Package of standards, among which the first Preterm Postnatal Growth Standards (PPGS), valid for all populations around the world and an important tool in detecting sub-optimal growth and overfeeding. The set of standards addresses growth, nutritional status and the neurodevelopment of preterm neonates.
Recently, the consortium received a $ 2,8 million research grant from the Larsson-Rosenquist Foundation which dedicates itself to promoting and supporting breastfeeding and human milk. With the help of this fund, the Preterm Postnatal Growth Standards and a feeding protocol will be implemented in neonatal units around the world. The ambition is to improve the health and development of preterm babies around the world and to promote breast milk as an important means to reach that end.
INTERGROWTH-21st is extended with the INTERBIO-21st Study that tries to understand the effects of an adverse intrauterine environment by studying the phenotypic characteristics of intrauterine growth restriction (IUGR) and small for gestational age (SGA) infants and looks into preterm birth syndromes at the molecular, biochemical and clinical level.
The websites of both projects offer a wealth of information. Clinicians can access the Global Perinatal Package and training toolkits and become part of the online community of health professionals facilitating collaboration and resource sharing around the world.
Via the website an online application can be accessed where the gestational age, the weight, length and head circumference at birth can be entered and compared to international standards and references set by INTERGROWTH-21st.