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 as premature babies. 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).
| According to completed gestational weeks | According to birth weight |
| Moderately preterm: 33 to < 37 weeks of gestation | Low birth weight baby: < 2.5 kg |
| Very preterm: 28 to < 32 weeks of gestation | Very low birth weight baby: 1.0 kg – < 1.5 kg |
| Extremely preterm: < 28 weeks of gestation | Extremely low birth weight baby: < 1.0 kg |
Before embarking on a discussion about how to manage preterm babies it is useful to understand why babies are delivered prematurely. It is thought that three broad categories of factors may contribute to onset of spontaneous preterm birth (Muglia and Katz, 2010):
In England and Wales, nearly 8 % babies, that is 1 in 13 of every live birth were born preterm and 6 % (out of the total 8 %) 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 hospital where further management can be instituted. In most countries there is no longer 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, and now the duty of such transfers mostly fall to the paramedic professionals. An illustrated case study in Box 1 highlights some of these challenges that a paramedic team may face when attending an emergency call.
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 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 noted prior to transfer for the hospital team to gauge whether the baby had suffered hypothermia and if so for how long. Cold stress can also cause or exacerbate hypoglycaemia which is particularly poorly tolerated in preterm infants; and occurs primarily from the rapid exhaustion of the infant's limited glucose and energy reserves.
2) Managing airway
If expertise is available the preterm 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 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 % supplemental oxygen should be given. Oxygen should be administered with caution with minimal levels necessary should be used to maintain saturations at ≥ 92 %, as high flow oxygen has been found to be potentially harmful for the baby's eyes (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.
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 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 be useful.
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.
Conclusion
The paramedic team should be aware of the challenges that may be faced 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. Preventing hypothermia, administering oxygen adequately and use of plastic bags are likely to maintain physiological stability for the baby during transfer and minimise adverse outcomes.