The study is a double blind, randomized controlled trial of women at risk of late preterm delivery. The Maternal and Child Centre (MCC), an annex of the Obstetrics Department of the Lagos State University Teaching Hospital, located at Ifako Ijaye local government area of Lagos state was the location for this study.[17] The facility has 100 Obstetric beds and has five units each of which runs an antenatal clinic one day a week with an average clinic attendance of 150 per clinic.[17] It also has an emergency unit which provides a 24-hour service on a daily basis. The total monthly deliveries are about 250–300. The study was conducted from June 2017 to July 2018. This study was registered with the Pan African Clinical Trials Registry (PACTR) on April 19, 2023 (Reference Number: PACTR202304579281358).
Pregnant women were included if they were at 34–36+ 6 weeks’ gestation and were at risk of imminent premature delivery (either spontaneously or if early delivery was recommended because of fetal or maternal indications) at the time of admission to the hospital. Gestational age was defined according to the first day of the woman’s last menstrual period, if known and reliable, or by early ultrasonography carried out below 20 weeks of gestation if the last menstrual period was not known. All consenting pregnant women of gestational age 34 + 0 and 36 + 6 weeks, who were at high risk of delivering before 37 weeks were included in the study. A high probability of preterm delivery includes women with intact membranes and at least 3 cm dilation or 75% effacement of the cervix, spontaneous rupture of the membranes, expected preterm delivery for any other indication by induction of labor or caesarean section.[5]
INCLUSION CRITERIA
All consenting pregnant women at the General Hospital Ifako Ijaye with gestational age between 34 + 0 and 36 + 6 weeks, who were at high risk of delivering before 37 weeks.
A high probability of preterm delivery includes:
Women with intact membranes and at least 3 cm dilation or 75% effacement of the cervix
Spontaneous rupture of the membranes
Expected preterm delivery for any other indication by induction of labour or caesarean section.
EXCLUSION CRITERIA
All pregnant women with multiple pregnancy.
Suspected or diagnosed major congenital malformations.
Uncertain gestational age
Clinical evidence of chorioamnionitis
Previous corticosteroid use during the antenatal period
A woman who is expected to deliver in less than 12 hours.
Randomization and follow-up
There was a random allocation sequence of all the serial numbers assigned to all the eligible and consenting women in a 1:1 ratio by an independent statistician. The table of random numbers was prepared in a single block using random allocation software (version 2.0) in which 143 women were randomized to receive dexamethasone and 143 were given placebo. Two hundred and eighty-six drug envelopes containing either 2 doses of dexamethasone or placebo which were identical in appearance, volume and colour were prepared by a member of the pharmacy department and were numbered using the random allocation sequence generated. Thus, the drugs (i.e dexamethasone and placebo) were packaged and numbered based on the random allocation sequence generated by the independent statistician. Since the patient presented to the hospital in batches, they were numbered serially as they presented at the hospital.
The hospital pharmacist who was responsible for packing the drugs and placebo withdrew 12mg of dexamethasone (3mls) into 5ml syringes and withdrew 3mls of 0.9% saline solution into 5ml syringes. Each drug envelope contained 2 of such 5ml syringes containing either dexamethasone or 0.9% saline solution, and each participant was given the content of one 5ml syringe initially and the other 5ml syringe in the drug envelope 12hours later.
Only the hospital pharmacist responsible for packing the drugs into the drug envelopes was aware of their contents. The investigator, the obstetrician who cared for the women, and the women were not aware of the content of the drug envelopes.
Women who met the inclusion criteria were identified and were given an informed consent form to sign. They received the sealed envelope corresponding to their randomization number and the drug contained in the envelope was administered by a trained research assistant at the level of a house officer cadre. Three ampoules were applied intramuscularly, with three more administered 12 hours later. After administering the medications, all the pregnant women were subsequently managed based on the standard treatment protocol of the labour ward of the hospital. In the case of patients scheduled for induction of labour or elective caesarean section, this was planned such that the procedure commenced not before 24 hours after the administration of the drug.
The investigators followed up the women prospectively and collected data on the pregnant women and their newborns on a standardized form. An independent neonatologist who was also blinded from the treatment arms assessed the neonates for acute respiratory distress syndrome and/or Transient Tachypnea of the Newborn based on the clinical signs, symptoms, and chest x-ray results (where indicated) and the trained research assistant entered his/her findings in the proforma.
Women who were discharged from the hospital while still pregnant and who went on to deliver elsewhere were excluded from the study after randomization. When the study was completed, the research team were then unblinded to the serial numbers in each block (cases and controls) in the random allocation sequence.
Ethical considerations
Permission to conduct the study was sought from the Head, Obstetrics and Gynaecology department, Lagos State University Teaching Hospital, Ikeja. Ethical approval to conduct the study was sought from the ethical committee of the Lagos State University Teaching Hospital (LASUTH) Health Research and Ethical Review Committee. Informed consent was obtained from the pregnant women who agreed to participate in the study. Those who chose not to participate did not have their treatment affected in any way. Confidentiality and anonymity were maintained throughout the study using serial numbers only.
Data management
The data were entered into the computer and analyzed using Epi Info 3.5.3 statistical software for the centre for disease control and prevention Atlanta USA. The results were presented using appropriate frequency tables and charts while measures of central tendencies (mean or median) and measures of dispersion (standard deviation and range) were calculated for quantitative variables.
Statistical associations between categorical variables were tested using Pearson's chi-square test or Fisher test as appropriate. Continuous variables were compared using the student T test or Anova as appropriate and logistic regression analysis was used to identify the predictors of the outcome of the neonatal health status. Level of statistical significance was set at p-value less than 5%.
MEASUREMENT OF KEY VARIABLES
Primary outcome variables
Presence of neonatal respiratory morbidity. These include respiratory distress syndrome; Transient tachypnea of the newborn and the need for ventilatory support within 72 hours of delivery with supplemental oxygen for at least 2 hours. Any neonate who had any of the 3 conditions is said to have had respiratory morbidity.
Secondary Outcome Variables
These include type of delivery; gestational age at birth; Apgar Scores at first and fifth minutes; admission to the Special Care Baby Unit (SCBU); neonatal hypoglycemia; neonatal jaundice; neonatal sepsis; other neonatal morbidities; length of stay at the hospital; neonatal death within 72 hours of delivery; the need for resuscitation at birth and feeding difficulties.
DEFINITIONS
Respiratory Distress Syndrome
Presence of clinical signs of respiratory distress (tachypnea, chest wall retraction, flaring of the alae nasi, grunting or cyanosis), with a requirement for supplemental oxygen and a chest x ray showing reduced air entry and reticulogranular infiltrates.
Transient Tachypnea of the Newborn
Tachypnea in the absence of chest x ray or with a chest x ray showing normal or increased perihilar interstitital markings resolving within 72 hours.\