What happens in a baby's first 72 hours

Dr Nick Walker takes us through the earliest milestones in the lives of a new baby and mother.

At the precise moment of the birth of your baby, at the very second that his or her body breaks contact with yours (which is most commonly a tiny newborn foot exiting the vagina), your attending health professional will notice two things: the rush of their own joy, wonder and relief which accompanies any delivery, and the exact day, date and time according to a 24-hour clock. Like any important moment in life, this recorded timestamp is vital and unique, serving both personal and pragmatic functions from then on. Congratulations, your baby is finally born!

THE FORMALITIES
On a personal level, curious family and friends like to know the time of birth. At the administrative level, the timestamp is matched by clerical staff to a newly minted National Health Index (NHI) number allocated for your baby, consisting of three letters and four numbers in the pattern ABC1234. The NHI provides a lifelong method of identifying your new individual across all areas of the New Zealand health sector, from vaccinations to blood tests to health check-ups.

At the pragmatic level, the timestamp provides the initial reference point for the first 72 hours following birth for both mother and baby; for more details on this new adventure, please keep reading!

 POST-BIRTH CONTRACTIONS
While your new baby is being placed on your chest, the uterus, now relieved of most of its contents, will respond with a sustained contraction, often helped by an oxytocin injection offered by your Lead Maternity Carer (LMC). This helps separate the placenta from the inner uterine surface and constrict the large blood vessels which had been supplying it. In a beautiful dual action, the placenta is then expelled from your body and your blood, which was earlier flowing to the placenta, is now directed back to full body circulation, leading to a flash of good feelings. Over the next few hours, the suckling of your baby encourages bursts of natural oxytocin, further contracting and shrinking the uterus and causing ‘afterpains’ – a reassuring discomfort returning your body to a non-pregnant state. It’s common and normal for these to be accompanied by some bleeding or clots which have been left behind, as the uterus effectively purges itself to stay healthy. 

BLADDER AND BOWEL
Soon after birth you’ll be encouraged to eat and drink, and an important early task is to ensure you regularly empty your bladder. During vaginal birth it’s common for the bladder to become temporarily confused with regards to ‘normal’ function, and regular emptying is a good way to pre-empt any accidents. Depending on the circumstances of the birth, maternal bowel function should also be monitored and your LMC will question you about this. Avoiding constipation is a key goal!

 
During pregnancy, certain placental hormones were inhibiting your breasts from producing full milk supply. At the separation and birth of the placenta, these hormone levels fall, an important part of understanding why full breast milk production takes two to three days to establish. Fortunately, full-term healthy babies can easily wait out this time as they have enough hydration and energy reserves to last. The normal demanding newborn behaviour (read on for more) exhibited during days two and three also ensures your body is encouraged into lactation mode.

THE FIRST BREATHS
Within seconds of arrival, healthy babies born in good condition will startle and gasp and begin the simple yet vital task of breathing on their own. Their lungs are like little sponges, and similar to releasing a tightly squeezed sponge, they inflate with air when the baby’s body is released from the pressure of being in utero. This inflation is produced mostly by a very strong action of the breathing muscles, mainly the diaphragm and rib muscles.

Your baby has spent many months practising and rehearsing movements, such as breathing, hiccupping, yawning and even sneezing, which all strengthen their action when this moment finally happens. Crying within moments of birth helps keep the lungs inflated too, though many babies will not cry excessively if the initial gasp has sufficed. Within one minute, your baby will be breathing steadily and easily, with the occasional burst of crying, if required, for more inflation.

THE FIRST TEN MINUTES
At the one-minute mark, your healthcare professional now notes the baby’s first milestone called an ‘Apgar score’ – a composite measure of wellbeing designed to identify babies which require extra assistance with the transition to independence. Another few minutes elapse, and at the five-minute mark another Apgar score is noted for the same purpose. If these scores are satisfactory, the conventional practice is to keep the baby warm by placing them skin-to-skin on Mum’s chest. Around this time, usually within ten minutes, the umbilical cord is clamped and cut (attending persons are usually welcomed to participate in this part!) which truly separates the newborn; this time is also carefully documented. All of a sudden your baby is ten minutes old!

ESTABLISHING SUCKLING
As the next hour goes by, your baby is usually showing feeding cues: opening their mouth, sticking out their tongue, and turning their head from side to side in a searching gesture because, having established breathing, it’s time to establish suckling. Again, your baby has been practising suckling and swallowing in utero to be ready for this moment, so the tongue, cheek, jaw and oesophageal muscles are already strong and coordinated for the task. During initial suckling efforts, your baby will stare up towards your face and begin to make out your features. Newborn researchers have found that the point of natural focus for a newborn’s eyes is roughly the distance from a breast nipple to a face, which is clearly an adaption to help them recognise their mother.

‘SECOND NIGHT’ SYNDROME
The first 24 hours after birth are a chance for your baby to become accustomed to the outside world. If full-term and a healthy birth weight, your baby will be content with suckling and colostrum for several days. However, due to the fact that an important part of establishing a maternal milk supply is regular and frequent nipple stimulation, a baby becomes more demanding between 24 and 72 hours of age. Commonly known as baby’s ‘second night’ behaviour, it’s normal and healthy, though it can leave new parents feeling very tired. You’ll need lots of support and your caregivers will help you through as best they can. In certain circumstances it may be appropriate to assist the process by using a breast pump and/or providing supplemental milk to the baby – this should be under the guidance of an experienced midwife or lactation consultant. (See page 50 for more helpful insights into baby’s second night behaviour.)

THE FIRST HOUR
In this first hour, a healthy target to aim for is a successful latch and suckle, which is known to then promote and optimise full milk supply (more about this later in the article). Breasts contain a variable amount of a liquid called colostrum, which is, in most cases, plenty to satisfy the baby for several days. Your new baby is also attuned to sounds and has likely been aware of parental voices while in utero. It’s therefore good for new parents to speak and make non-verbal sounds to them, which, in my experience, always seems to come totally naturally, even to first-time parents! During the next few hours, a standardised newborn check is completed. This is a ‘top to toe’ assessment of 22 checkpoints, including actual counting of fingers and toes. Measurements of weight, head circumference and body length are recorded as a baseline. Vitamin K, essential for healthy blood function, is also administered at this time. Vitamin K is made by bacteria in the human digestive system and babies (being devoid of bacteria at birth) are occasionally deficient in it. The vitamin K supplement given is a one-off to last until babies are able to get their own supply from their own bacteria in due course.

BABY'S FIRST MOTIONS
In the first 72 hours we must mention not only baby input, but also output! Being well-hydrated at birth, babies will pee frequently on the first day, but a bit less on days two and three prior to the full milk supply. Their first bowel motions are a sticky black goo called meconium. As the bowel empties this, and over the initial three days when milk is being ingested, the motions become more liquid and a pale yellow.

TWO FINAL TESTS
The two final important health milestones are the newborn screening ‘heel prick’ test taken sometime after 48 hours (this screens for a dozen rare, but silent, health conditions, AKA the Guthrie Test) and a newborn hearing screening test. Your LMC will guide you through these.

Finally we are through to 72 hours old. All going well, you’ll all be back home and settling into your new lives. Enjoy it all!

Dr Nick Walker is a specialist obstetrician working in both public practice at National Women’s Hospital and private practice in Mt Eden, Auckland. He divides his time between these roles and helping his wife in caring for their four young children.