Prenatal therapy with magnesium sulphate and intestinal obstruction due to meconium in preterm newborns

Magnesium sulphate (MgSO₄) therapy has shown to be useful as a neurological protector in the preterm newborn below 32 weeks of gestation. The most documented adverse effect is cardiorespiratory failure, whereas its relationship with meconium obstruction is controversial. The main objective of this study was to analyse the possible association between prenatal MgSO₄ therapy and meconium obstruction.

An analytical retrospective study was conducted on <32 weeks preterm babies admitted to a tertiary-level hospital (January 2016-December 2017). Epidemiological, prenatal and postnatal data on the outcomes were obtained, analysed and compared in both groups (exposed to MgSO₄ and not exposed).

The study included 201 patients (146 exposed and 55 non-exposed). There were no significant differences in the mean gestational age (28.4 ± 2.2 vs. 28.7 ± 2.8 weeks, respectively), or in the rest of epidemiological and perinatal variables. Prenatal corticosteroid therapy was more frequent in the MgSO₄ group (75.9 vs. 53.7%; p = .002), and in the non-exposed group there were more multiple pregnancies (52.7 vs. 36.6%; p = .027), and female gender (56.4 vs. 37%; p = .013). There were no statistically significant differences in the presence of meconium obstruction (75.9% in exposed vs. 67.3% in non-exposed; p = .23), although repeated rectal stimulation was more frequent in the exposed group (43.2 vs. 27.9%; p = .08). Furthermore, there were no significant differences in the main cardiorespiratory variables: 1-min Apgar score (6.2 in MgSO_4- exposed vs. 5.6 in non-exposed; p = .75), 5-min Apgar score (7.9 vs. 7.6; p = .31), advanced newborn resuscitation (26 vs. 31.5%; p = .44), maximum FiO₂ (45.5 vs. 48; p = .58), and initial inotropic requirements (10.3 vs. 20.8%; p = .55).

This study found no correlations between MgSO₄ therapy and meconium obstruction or cardiorespiratory failure.