The Effect of Antenatal Paracetamol on Breathing Effort of Premature Infants at Birth: A Feasibility Trial

Background: Prostaglandin E2 (PGE2) suppresses perinatal breathing. Reducing antenatal PGE2 concentrations with paracetamol could stimulate spontaneous breathing in premature infants at birth. We aimed to assess feasibility and potential effects of antenatal paracetamol. Methods: In this randomised, placebo-controlled, triple-blind feasibility trial, pregnant women <31 weeks’ gestation were randomised to receive either intravenous paracetamol (intervention) or placebo (control). Multiple pregnancies were also eligible, and the number of infants could exceed the number of enrolled women. The primary outcome was feasibility of administering study medication within 30–120 min prior to birth. Secondary exploratory outcomes included measures of breathing and other physiological parameters of infants during the first 1–10 min after birth and were compared between infants from mothers who received paracetamol and infants from mothers who received a placebo irrespective of timing of administration. Planned enrolment was 40 women. Results: The trial enrolled 23 women before termination due to low recruitment. Five women did not receive study medication, while 18 did (9 per group). Overall, 11 of the 23 enrolled women (48%) received study medication within the specified timeframe. The nine women in the intervention group gave birth to 13 infants, while the nine women in the control group gave birth to 12 infants. Among infants, average minute volume did not differ significantly between groups (intervention (n = 13) vs. control (n = 12); mean ± SEM; 147 ± 12 vs. 114 ± 14 mL/kg/min, p = 0.093). However, the intervention group had a significantly higher area under the curve for minute volume, greater inspiratory drive, and a higher heart rate (1120 ± 410 vs. 707 ± 346 mL/kg, p = 0.020; 11.8 ± 1.0 vs. 8.4 ± 1.3 mL/kg/breath/s, p = 0.046; 137 ± 5 vs. 121 ± 5 beats/min, p = 0.037). Conclusions: Antenatal paracetamol administration 30–120 min prior to birth was feasible in only half of the women, below the pre-specified threshold of 80%, but the exploratory findings suggest that it may improve the breathing effort of premature infants.