Babies born at ≥ 37 weeks of gestation are considered to be born at term, therefore any baby born earlier than 37 completed weeks of gestation are termed oas premature or preterm babies. In 1990, the Abortion Act 1967 was amended by the UK Parliament on a free vote, to lower the time limit from 28 weeks to 24 weeks for abortion. With the advancement of medical facilities the survival of preterm babies has improved in the UK and elsewhere (Select Committee on Science and Technology Twelfth Report, 2007). A consistent rise in preterm birth rate has been noted around the world (Norman, 2009). Available statistics from the US show that preterm births constituted 12.8 % of live births in 2006; this is an increase of 20 % since 1990 (Muglia and Katz, 2010). The challenges that result from preterm delivery will vary depending largely on the gestational age and birth weight. The general rule is that adaptation of the newborn to extra-uterine environment becomes more problematic with smaller and less mature babies. It is therefore important to understand some definitions related to the gestational age and weight; these are highlighted in Table 1 (Beck, 2010).
Age of viability
The UK Ambulance Service Clinical Practice Guidelines (2006) recommend that paramedic teams should make every effort to transport a mother where the delivery is imminent between 20 to 37 weeks of gestation as the baby is likely to need specialist care once delivered (Fisher et al. 2006). There are no clear recommendations available from the UK parliament regarding the ‘age of viability’. After consideration of the available evidence a conclusion was reached that while survival rates at 24 weeks and over has improved, this has not been the case below that gestational point (Select Committee on Science and Technology Twelfth Report, 2007).
It is also important that paramedic teams remain aware of the guidelines on giving intensive care to extremely premature babies as laid out by the Nuffield Council on Bioethics and this is highlighted in Table 2. These guidelines are also important in situations where an expectant mother in labour may ask the paramedic not to resuscitate the preterm baby (or enquire what to expect once the baby is transferred to hospital) and a quick but focussed discussion may be necessary in such situations.
Why babies are born prematurely?
Before embarking on a discussion about how to manage preterm babies in the pre-hospital environment it is useful to understand why babies are delivered prematurely. It is thought that three broad categories of factors may contribute to onset of premature labour and spontaneous preterm birth (Muglia and Katz, 2010):
Why it is increasingly becoming relevant to paramedic practice?
In England and Wales, nearly 8 % of babies i.e. 1 in 13 of every live birth were born preterm and 6 % of these occurred between 22 and 27 weeks of gestation (ONS 2005). The figures of premature delivery were around 5.8% in Scotland (Norman 2009).
Although most preterm babies are born in the labour ward with a neonatal team present at the time of birth; it is not rare for paramedic teams to attend such deliveries and some of these babies may be born extremely premature at home or in the pre-hospital setting. These are extremely testing situations for paramedic teams aiming to transfer these babies to the nearest neonatal unit or emergency department where further specialist management can be instituted. In the UK, with no availability of a ‘flying squad’ consisting of trained obstetric and neonatal staff to stabilise the baby at the place of delivery, before retrieval to a neonatal unit, the duty of such transfers will mostly fall to the paramedic professionals. The UK Ambulance Service Clinical Practice Guidelines (2006) recommend that where the birth is so far advanced that transfer to specialist care is not possible, a trained midwife plus a second ambulance should be urgently requested. Once the baby is delivered, the baby must be immediately transferred to the nearest emergency department or obstetric/neonatal unit depending on the local arrangements and the transfer should be done even if the midwife has not arrived (Fisher et al. 2006). An illustrated case study in Box 1 highlights some of these challenges that a paramedic team may face when attending an emergency call.
Managing the preterm baby in the pre-hospital environment
Although it is preferable that all preterm deliveries should take place in hospital, in some cases this remains impossible and paramedic teams should make every effort to maintain physiological stability in the baby and transfer to specialist care without delay (Fisher et al. 2006).
Paramedic teams attending a premature delivery, especially of a baby born at extreme prematurity who needs stabilising and immediate transfer, may improve outcome by addressing a few simple but vital issues that have a proven positive impact for the baby:
1) Preventing hypothermia
Premature infants are vulnerable to cold stress especially in the first hour of life, and hypothermia has been found to be a major cause of morbidity and mortality in these infants. Within a few minutes of delivery the core temperature of the newborn infant starts falling. Therefore, and in order to avoid hypothermic injury it is important to maintain the normal body temperature of at least 36 º C in the pre-hospital setting (Bissinger and Annabale, 2010). The axillary temperature should be measured prior to transfer for the hospital team to gauge whether the baby had suffered hypothermia en route and if so for how long. Cold stress can also cause or exacerbate hypoglycaemia which is particularly poorly tolerated in preterm babies; this primarily occurs due to rapid exhaustion of the infant's limited glucose and energy reserves.
2) Managing airway
If expertise is available the pre-term infant who is struggling to breathe should be intubated in the pre-hospital setting; however, in absence of retrieval personnel being experienced in neonatal intubation, the airway should be managed with an appropriate sized bag and mask ventilation to maintain adequate ventilation and oxygenation.
Pulse oximetry is useful during transfer. When oxygen saturations in air are recorded as lower than 92 % in air supplemental oxygen should be given. Oxygen should be administered with caution and minimal levels necessary should be used to maintain saturations at ≥ 92 %, as high flow oxygen has been found to be potentially harmful for the eyes of a preterm baby (increased risk of retinopathy of prematurity) (Tin and Gupta, 2007).
3) Preventing loss of moisture
Preterm babies have thin and delicate skin which is a poor retainer of moisture and heat, and it is important to minimise water loss from the skin. Use of plastic bags or wrap is a standard practice in neonatal units to preserve loss of moisture (Bissinger and Annabale 2010; McCall, 2010). Paramedic teams may need to use innovative ways such as use of unused freezer bags, cling film or even a new black bag as an alternative in the pre-hospital setting.
However, it needs to be considered where mother has accidently delivered a preterm baby in a wet environment, for example, in a bath, toilet pan, swimming pool, etc. the baby will need drying first before putting inside a plastic bag to prevent hypothermia.
4) Other suggested interventions
In the absence of a dedicated neonatal retrieval team only minimal interventions should be undertaken, and attempting technically difficult procedures such as intravenous cannulation or intubation is best avoided in the pre-hospital setting.
However, some other strategies such as leaving a longer piece of umbilical cord (for inserting umbilical arterial and venous line in hospital), measuring blood glucose level and temperature, giving prior notice to the local hospital and a quick review of mother's hand held notes may aslo be useful.
It is important to identify few pertinent information while reviewing maternal notes such as gestational age, risk factors for sepsis, use of prescribed drugs during pregnancy (for example, insulin, anticonvulsants, antidepressants, oral hypoglycaemic agents), maternal illness during pregnancy (for example, gestational diabetes, high blood pressure) and antenatal screening results (for example, blood group, hepatitis screen).
The changing scenario
The EPICURE studies in the UK have clearly demonstrated that survival of extremely preterm babies born between 22 and 25 weeks' gestation has increased since 1995, although the pattern of major neonatal morbidity and the proportion of affected survivors affected has remained largely unchanged (Costeloe, 2012).
It is not a regular event for paramedic professionals to attend an extremely premature baby in the pre-hospital setting, however, sticking to basics as highlighted above and immediate transfer to the local neonatal unit is likely to be beneficial. A study in Paris, France comparing out-of-hospital premature deliveries (24–35 weeks gestation) to in-hospital delivery, clearly demonstrated a mortality two times higher for out-of-hospital deliveries ( Jones, 2011). The study recommended administration of appropriate amount of oxygen to maintain appropriate saturations for gestational age, use of polyethylene plastic wraps to maximise chances for a better outcome.
It should also be noted that gestational age is only one of the factors that determines the likely outcome of an extremely preterm birth and due consideration needs to be given to other factors including birth weight, multiple pregnancy, ethnicity and gender of the foetus (Draper et al, 1999).
Conclusion
The paramedic team should remain aware of the challenges that may face when attending a premature delivery out-of-hospital. In the absence of a dedicated neonatal retrieval team for such situations and with limited resources available to paramedic teams it is important that such babies are rapidly transferred to the nearest neonatal unit or emergency department. Preventing hypothermia, administering oxygen adequately and use of plastic bags are likely to maintain physiological stability for the baby during transfer and minimise any adverse outcomes.