Zinc Supplementation During Pregnancy: Analysis of Maternal Serum Zinc, Cord Blood Osteocalcin and Neonatal Birth Length
Condition: Zinc Deficiency; Birth Length
Study type: Interventional

Summary: 
      This experimental study was conducted with pre-test/post-test control groups and double-blind
      randomization from March to December 2019 at Universitas Sumatera Utara Hospital and others
      in Medan. Subjects were pregnant mothers in second or third trimester and with their newborns
      who met the inclusion criteria. Subjects were divided into two groups and administered either
      zinc supplementation 20 mg/day or placebo, respectively, for 12 weeks. The parameters
      assessed were maternal serum zinc levels cord blood osteocalcin and birth length
      measurements.
    

Detailed description: 
      Patients and Study Design This was an experimental study with pre-test/post-test control
      groups, double-blind with randomization block technique. This study was conducted from March
      to December 2019 in the obstetrics and neonatology unit of Universitas Sumatera Utara
      Hospital, Malahayati Islamic Hospital and Royal Maternity Hospital in Medan. Research
      subjects were pregnant mothers with their newborns who met the inclusion criteria. The study
      samples were divided into two groups and administered either zinc supplementation 20 mg/day
      or placebos, respectively, for 12 weeks. The zinc tablets or placebos were given in the
      morning after meals. All subjects were also given iron and folic acid tablets in accordance
      with the Indonesian government program. Subjects were healthy pregnant mothers in their
      second or third trimester, 20-35 years old, with a height of >150 cm and no indication of
      cons following this study, as determined by obstetrician and gynaecology specialists;
      subjects were enrolled with a consecutive sampling technique. Births involving twins,
      congenital abnormalities, prematurity (gestation age <37 weeks) or stillbirth were excluded.

      Informed consent was given by all subjects' legal guardians following the provision of
      sufficient information prior to the study.

      This study was approved by the Health Research Ethical Committee, School of Medicine,
      Universitas Sumatera Utara in accordance with the principles of the Helsinki Declaration
      (No.179/TGL/FK USU-RSUP HAM/2019).

      Methods The parameters assessed in this study were maternal serum zinc levels, cord blood
      osteocalcin and birth length measurements. Maternal serum zinc levels were measured twice
      with 6 ml of vein blood each time, both during initial antenatal care and after 12 weeks of
      supplementation. Samples were subsequently centrifuged for 15 minutes at 3000 rpm. Specimens
      were processed by the inductively coupled plasma-mass spectrometry (ICP-MS) method using
      Agilent 7700 analyser (Santa Clara, USA, 2014). Normal serum zinc levels were defined based
      on a cut-off value of ≥ 56 µg/dL in accordance with Second National Health and Nutrition
      Examination Survey data from 1976-1980 (NHANES II).

      Cord blood osteocalcin levels were measured with 6 ml cord blood samples prior to delivery,
      which were subsequently centrifuged for 15 minutes at 1000 rpm using Cobas e601 analyser
      (Roche Diagnostic, Mannheim, Germany) and N-Mid Osteocalcin (Abbexa) reagent. Osteocalcin was
      measured using the enzyme-linked immuno-sorbent assay (ELISA) method, and in accordance with
      Prodia clinical laboratory standards.

      Neonatal birth length was performed with a SECA 232 digital baby scale for length with an
      accuracy of 0.1 cm. Maternal zinc intake was calculated in accordance with the NutriSurvey
      2007 Indonesian version.

      Statistical Analysis Descriptive analyses, correlation tests, and linear regression tests
      were performed using SPSS version 23.0 (SPSS Inc., Chicago, Illinois, USA). Statistical
      significance was considered at a p-value < 0.05 with a 95% confidence interval.
    

Intervention name(s): Zinc Supplementation Group; Placebo Group
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Enrolled subjects received zinc capsule 20mg daily in the morning after meal for 12 weeks; Enrolled subjects received placebo tablet, which was inserted into capsule of the same shape and color as zinc capsule, daily in the morning after meal for 12 weeks
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: An experimental study with pre-test/post-test control groups, double-blind with randomization block technique
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: Zinc; Maternal zinc; Osteocalcin; Birth length