Following the CONSORT guidelines, a randomized clinical trial was conducted in Kasr El-Ainy Hospital (Obstetrics and Gynaecology Department, Faculty of Medicine, Cairo University) from January 2020 to May 2021 after approval of the Medical Ethical Committee. It was first registered at ClinicalTrials.gov on 10/12/2019 with registration number NCT04193345.
The study included 62 pregnant women diagnosed with preeclampsia at near-term (36-38+6 weeks, i.e., late-preterm and early-term). All study cases had been assigned for lower segment caesarean section (LSCS) under spinal anaesthesia. According to ACOG, preeclampsia was diagnosed with new-onset hypertension after 20 weeks of gestation accompanied by either new-onset proteinuria or new-onset of any of the following; thrombocytopenia, renal insufficiency, impaired liver function, pulmonary oedema, or headache unresponsive to medication [16].
Inclusion criteria were maternal age 20-40 years, gestational age ≥36 weeks, and singleton living healthy foetus. Women who had intrapartum surgical complications such as uterine artery injury or lower segment extension, IUFD, or cases with medical disorders such as severe anaemia or diabetes mellitus were excluded. Women with abnormal placentation, placenta abruption, liquor abnormalities, or anomalous foetuses were also excluded.
Informed consent was obtained from all patients after explaining the aim of the study. For all participants, full history was taken, followed by a complete physical examination and routine obstetric ultrasound to confirm the eligibility of the current pregnancy to participate in the study, as well as to confirm the gestational age. The routine preoperative laboratory tests were performed, including complete blood count, liver and kidney function tests, prothrombin time and prothrombin concentration.
On the day of the scheduled caesarean delivery, participants were randomly assigned using computer-generated random numbers into two equal groups; the ECC group (n= 31) in whom the umbilical cord was clamped within 15 seconds and the DCC group (n= 31) in whom the umbilical cord was clamped at 60 seconds. Caesarean sections were done under spinal anaesthesia by an experienced obstetrician, while recording the time between the delivery and cord clamping was the responsibility of a research staff member who attended all deliveries. For the DCC group, the research staff member recorded 60 seconds before asking the obstetrician to clamp the umbilical cord. During this period, their neonates were placed on the sterile drapes on the mother’s legs at the level of the placenta until cord clamping was performed.
The attending neonatologist assessed all neonates in both groups for APGAR scores, jaundice, and the need for neonatal ICU admission. Neonatal haemoglobin and haematocrit were done 4 hours after delivery and then repeated after 24 hours. Serum bilirubin was done 12 hours after delivery and repeated on day 3 for follow-up.
The number of the operative towels and the blood volume in the suction unit were recorded. The maternal complete blood count (CBC) test was repeated after 12 hours. All mothers were observed for primary postpartum haemorrhage (PPH) and the need for blood transfusion for the first 24 hours. The estimated blood loss (EBL) was calculated by the following formula:
$$\mathrm{EBL}=\mathrm{EBV}\times \frac{\mathrm{Preoperative}\kern0.34em \mathrm{hematocrit}\hbox{-} \mathrm{Postoperative}\kern0.34em \mathrm{hematocrit}}{\mathrm{Preoperative}\kern0.34em \mathrm{hematocrit}},$$
where EBV is the estimated blood volume of the patient in mL= weight in kg × 85 [17].
The primary outcome was comparing the effect of DCC versus the ECC on maternal intraoperative blood loss, while the secondary outcomes were comparing both groups regarding the neonatal outcomes and the incidence of postpartum haemorrhage.
Sample size calculation
The sample size for each group of 28 achieves 70% power to detect a difference of 0.04 between the null hypothesis that both group means are 0.61 and the alternative hypothesis that the mean of group 2 is 0.57 with estimated group standard deviations of 0.05 and 0.07 and with a significance level (alpha) of 0.05 using a two-sided two-sample t-test [18]. The sample size increased by 10% to be 31 for each group to allow for dropouts.
Statistical methods
Data were coded and entered using the statistical package for the Social Sciences (SPSS) version 26 (IBM Corp., Armonk, NY, USA). Data were summarized using mean and standard deviation for continuous quantitative variables; and frequencies (number of cases) and relative frequencies (percentages) for categorical variables. The independent samples t-test was used to compare groups regarding the numerical data. For comparing categorical data, a Chi-square test was performed, but Fisher’s exact test was used instead when the expected frequency was less than 5. P values less than 0.05 were considered statistically significant.
