This three-arm parallel randomized control trial was conducted at Tikur Anbessa Specialized hospital (TASH)—the largest referral and teaching hospital in Ethiopia. The study protocol (attached as appendix) was approved by the institutional review board at the College of Health Sciences, Addis Ababa University (AAU/SPH-IRB/0056) and respective departments of obstetrics/gynecology and neonatology with in the TASH. written informed consent was provided by the participants before they were randomized in the study.
Study population and recruitment
The study participants were pregnant women with fetuses that are scheduled for a spontaneous vaginal delivery and with an inclusion criterion of; a gestational age of ≥ 37 weeks as diagnosed with first day of last menstrual period (LMP) or ultrasound and those with no gross complications related with the pregnancy and delivery, including mal-presentation, fetal distress, and congenital malformations. Women at greater risk of adverse effects due to delayed clamping were excluded from the study. The main exclusion requirements were those with previa or placenta abruption, early diagnosed fetal anomalies, those with fetal anemia, those with pre-eclampsia or significant maternal anemia.13 Participants were recruited in the period between October 2019 and January 2020.
Randomization and interventions
The eligible participants were initially approached by the principal investigator (who is a research midwife) to obtain consent before or on the day of delivery. The consented participants were randomized into three groups in a 1:1:1 ratio using pre-determined six block randomization sequences.
The interventions the different groups received are as follows:
Group 1: clamping of the umbilical cord immediately (<30seconds) after birth.
Group 2: clamping of the umbilical cord intermediately (30 – 60 seconds) after birth.
Group 3: clamping of the umbilical cord time was ≥ 180 seconds (3-minutes) after birth.
The allocation of the participants was performed after obtaining their informed consent earlier in the late first stage labor (i.e.≥8cm cervical dilatation). The principal investigator (PI) prepared the allocation codes with sealed, opaque, and identically colored envelopes initially at the beginning of the study. One of the co-investigators, who was blinded to the participant screening and randomization process, was responsible for opening the envelope and revealing the nature of intervention to the birth attendant when the mother enters the second stage of labor or was ready for childbirth proper.
The primary outcome is the level of total serum bilirubin of the newborns at the 24 hours of age and the secondary outcome is the proportion of neonates that developed hyperbilirubinemia before discharge to home.
Data collection procedure
The data collection had two phases. First, around time of birth; and both maternal and fetal characteristics were recorded. Second, at the age of 24 hour after delivery. Blood samples for the primary outcome were collected from veins and were transported to the laboratory with anti-coagulated test tube by one of the research investigators within 30 minutes of the sample collection. The source of sociodemographic and obstetric data was the medical record chart of both the mother and the newborn. The rest of the data was obtained from direct interview of the mother and laboratory findings. The sample size which was calculated using two independent proportions with a power of 90% and α=0.05 resulted in a total of 141 participants that were subsequently categorized into three arms (47 in each group).
The data collectors discussed with eligible participants and/or their companions about the procedure. The discussion includes explaining the risks and benefits associated with the interventions later in the first stage of labor. Informed consent was then secured either from the participant or respective companions before the second stage labor ensued or upon preparing the mother for delivery. When the mother is ready for delivery, the randomly assigned sealed-envelope containing the group assignment. The investigator monitored the clock with a digital second counter to inform the birth attendant when the time for that particular intervention ended.
After expulsion of the newborn, the birth attendant had to collect one milliliter cord blood and handed it to the assistant after separating the cord irrespective of the group assignment. The collected blood samples were then stored in a test tube, transported to the assigned laboratory. The results were recorded on the newborn chart by the attendant according to the hospital protocol.
Statistical analysis and data management
After data collection, the completeness and consistency of the questionnaires were checked. Then both the questionnaires and the variables coded, entered into the Epidata manager version 184.108.40.206 (Epi-Data Association, Denmark) and the necessary data cleaning performed.
Descriptive analysis was performed to compare baseline characteristics of the participants and reported using mean and standard deviation (SD) for discrete continuous data types. Ina addition, frequencies and percentages used for categorical data presentation. Pearson’s chi-square test was used to compare categorical variables across the different cord clamping times, and Fisher’s exact test used when there were less than five observations within the groups. Kruskal Wallis rank test was also used for comparison of continuous variables based on the time of clamping. We used unadjusted linear regression model to evaluate the effect of times for cord clamping on serum bilirubin level and multiple linear regression to conduct an adjusted analysis controlling for other important factors. Associations were considered significant at p<0.05 and analysis was performed using STATA version 14 software (Stata Corp LLC, College Station, TX, USA).