Placental transfusion provides sufficient iron reserves for the first 3 to 6 months of life; thus, preventing or delaying the development of iron deficiency until the use of iron-fortified foods is implemented [4]. Delayed cord clamping (defined variably as clamping till cessation of pulsations or up to 60-180 seconds) leads to improvement in levels of hemo-globin and hematocrit at two months of age [5]. However, universal application is limited in particular due to obstetrician concerns for the risk of hypothermia, and delay in initiation of resuscitation, when indicated [6,7].

Umbilical cord milking, on the other hand, involves milking the entire contents of the umbilical cord towards the baby. Cut umbilical cord milking (umbilical cord detached from placenta) limits the refilling of cord from placenta, so less blood is likely to be transfused when compared to intact umbilical cord milking (pushing the blood toward the infant at least four times before clamping the umbilical cord) [8-12].

Till date, two studies [13,14] have evaluated the effect of delayed cord clamping and umbilical cord milking in term neonates. In both studies, cut umbilical cord milking was performed. Hence, we planned the present study to evaluate the effect of intact umbilical cord milking on venous hematocrit at 48 hours of age in late preterm and term neonates when compared with delayed cord clamping.

This open labelled randomized trial was conducted in the department of obstetrics and gynecology, All India Institute of Medical Sciences, New Delhi from May to September, 2016. All late preterm and term neonates (350/7 - 426/7 week) were included in the study. Neonates with fetal hydrops, major congenital malformation, Rh isoimmunization (Rh positive neonate born to Rh negative mother with indirect Coombs test (ICT) positive) [15], newborns born through meconium stained liquor who were non-vigorous at birth (defined by poor/no respiratory efforts, weak/no muscle tone and heart rate less than 100 beats per minute, limp or apneic or poor tone at birth) [16], forceps or vacuum assisted delivery, and newborns born to HIV positive mother (on enzyme-linked immunosorbent assay (ELISA) followed by Western blot test for HIV) and maternal eclampsia (defined as generalized seizure in pregnant females with preeclampsia) [17] were excluded from the study. The study was approved by the institutional ethics committee.

All eligible mothers admitted in the labor room were screened for eligibility and enrolled, after informed written consent. We allocated mothers using computer generated random sequence to intact umbilical cord milking group and delayed cord clamping group. Opaque envelopes containing allocation group were serially numbered, and sealed to conceal the identity. The sealed envelope was opened by the nursing staff when the expectant mother was wheeled inside the labor room. The intervention written on slip was carried out by the obstetrics and gynecology resident and pediatric resident team posted in the labor room. Blinding of the clinicians was not possible due to the obvious nature of intervention.

Intact umbilical cord milking (MUC) group: The intact umbilical cord for its remaining accessible length (nearly half of the total length) was milked four times towards the baby by the residents on duty in the obstetrics department, and then clamped. All the health care providers (postgraduate residents of pediatrics and obstetrics) were trained in a structured manner for intact umbilical cord milking.

Delayed cord clamping (DCC) group: Umbilical cord was clamped at least 60 seconds from the time of delivery.

Time of all interventions was recorded by a stopwatch and noted in the study form. In both the groups, the baby was held at introitus after vaginal delivery, and over mother’s thigh in caesarean delivery. After delivery, the babies were kept with mothers unless they required admission in the neonatal intensive care unit (NICU) for standard indications. Gestational age was assigned based on the last menstrual period. The appropriateness of birthweight for gestational age was assigned by stan-dard intrauterine growth chart [18]; weight less than 10th centile and weight more than 90th centile being adjudged as small for gestational age (SGA) and large for gestatio-nal age (LGA), respectively [18]. Early breastfeeding was encouraged in all babies as per standard guidelines. The infants were evaluated at birth, and at the age of 24 hours and then at 48 hours.

The primary outcome was venous hematocrit evaluated at 48 (±6) hours. Additional outcomes were venous hematocrit at 48 (±6) hours in newborns delivered by lower segment caesarean section (LSCS), incidence of polycythemia (defined as venous hematocrit greater than 65% at 48 (±6) hours of life) [19] requiring partial exchange (PET), incidence of hyperbilirubinemia requiring photo-therapy (as per American Academy of Pediatrics (AAP) charts) [20], venous hematocrit at 6 (±1) weeks, and levels of serum ferritin at 6 (±1) weeks.

Venous sample was collected in micro- capillaries for measurement of hematocrit, and an additional 1 mL sample was separately collected for serum ferritin levels. Micro-capillaries were micro-centrifuged at a speed of 9000 rpm for 5 minutes and analyzed with card reader for hematocrit measurement. Serum bilirubin was assessed in babies with clinical icterus by spectrophotometer (Apel BR 5100, APEL). Calibration of the spectrophotometer was done at defined intervals, as recommended by the manufacturer and phototherapy was instituted, if required. Serum ferritin levels were evaluated with ELISA orgentech kit (analytical sensitivity, 5 ng/mL; range of evaluated concentrations 5-1000 ng/mL).

Attendants were counseled by the principal investi-gator to follow up at 6 (±1) weeks, which coincided with their immunization visit. Hematocrit evaluation and serum ferritin levels were evaluated at this time point. On follow up, parents were asked about any intercurrent illnesses since birth, and type and mode of feeding (top fed, exclusively breastfed or predominantly breastfed.

Venous hematocrit at 48 (±6) hours in a previous study was 50% [10]. Anticipating that intact umbilical cord milking will lead to at least a 5% absolute increase in the hematocrit and assuming a standard deviation (SD) of 7 in each group with power of 90% and alpha of 0.05, we needed to enroll at least 42 neonates in each arm. Considering an attrition rate of 40% on follow up, total sample size was increased to 72 in each group.

Statistical analyses: Statistical analyses were performed with Stata 11 (Stata Corp LP). Baseline categorical variables were compared using Chi-square or Fisher exact test, as appropriate, and whereas continuous variables were compared using Student t-test. A P-value of less than 0.05 was considered as significant. The analysis was by the intention to treat.

A total of 375 babies were delivered during the enrolment period, of which 144 babies fulfilled the inclusion criteria and were enrolled (Fig. 1). Baseline characteristics including maternal pregnancy induced hypertension, gestational diabetes, gestational age and birthweight were comparable between the two groups (Table I). 72 neonates were enrolled to DCC and 72 neonates to MUC group. Out of the 144 neonates, 118 (82%) completed the trial at 6 (±1) weeks. There were no adverse events in either group during the study period.

Fig. 1 Study flow chart.

 

The mean (SD) hematocrit at 48 (±6) hours in the MUC group [57.7 (4.3)] was significantly higher than the DCC group [55.9 (4.4)] [mean difference (MD) 1.7 (95% CI 0.21 to 3.1); P=0.002] (Table II). Venous hematocrit in newborn delivered by caesarean section at 48 (±6) hours was similar in the two groups. Incidence of polycythemia was also similar in the two groups. One neonate in each group required phototherapy. Mean (SD) Venous hematocrit at 6 (±1) weeks was higher in MUC than in DCC group [MD (95% CI) 1.75 (0.53 to 2.9); P= 0.005] (Table II). The levels of serum ferritin were similar in the two groups (Table II and Fig. 2).