Lactate plus analyzer

Maternal measurements were obtained as previously described (Moyer et al., 2015 (link)). Maternal age, parity, prepregnancy weight and height and body mass index (BMI, kg/m²), gestational diabetes mellitus status (yes or no), 1‐h glucose value during an oral glucose tolerance test (OGTT), gestational weight gain (GWG), length of gestation, mode of delivery, and breastfeeding status, were abstracted from various sources including prescreening eligibility and postpartum questionnaires as well as maternal and neonatal electronic health records. At 16 weeks of gestation, we obtained maternal BMI and determined maternal percent body fat using a previously validated skinfold technique and age‐adjusted equations (Durnin & Womersley, 1974 (link); Liguori, 2018 ). Additionally, maternal fingerstick blood was analyzed using Cholestech LDX Analyzer (Alere Inc., Waltham, MA, USA) and point of care Lactate Plus Analyzer (Nova Biomedical, Waltham, MA, USA) for the quantification of maternal lipids (total cholesterol (TC), triglycerides (TG), HDL, non‐HDL, and LDL), glucose, and lactate.

Blood lactate levels were measured by making a small puncture in the ear lobe using a Unistik 3, single-use safety lancet (Owen Mumford Ltd.; Oxfordshire, UK). A 0.2 µL blood sample was collected and blood lactate concentration was measured with a lactate Plus analyzer (Nova Biomedical; Waltham, MA, USA). The lactate Plus analyzer has been found to be a reliable and accurate alternative to laboratory-based bench top analyzers [22 (link)]. Lactate Plus, single use, disposable test strips (Nova Biomedical; Waltham, MA, USA) were used to collect the sample during the study protocol.

An iSTAT portable clinical analyzer (Abbot Point of Care Inc., Princeton, NJ, USA) was used to obtain biochemistry, blood gas, and electrolyte results utilizing Chem8 cartridges (Abbot Point of Care Inc., Princeton, NJ, USA). The following parameters were measured and recorded: sodium (Na), potassium (K), chloride (Cl), ionized calcium (iCa), Total CO₂, glucose (GLU), blood urea nitrogen (BUN), hematocrit (HCT), hemoglobin (Hb), anion gap and lactate. Blood lactate was determined using a portable Lactate Plus^TM analyzer (Nova Biomedical, Waltham, MA, USA).

An iSTAT Clinical Analyzer (Heska Corporation, Fort Collins, Colorado, USA) and CG8+ cartridges were used to obtain biochemistry, blood gas, and electrolyte values. The iSTAT is a handheld, battery-powered, device that measures selected blood gas, biochemical, and hematology parameters using just 0.095 mL of non-coagulated whole blood. The following parameters were measured: Base excess in the extracellular fluid compartment (BEecf), glucose, bicarbonate (HCO₃^-), hematocrit, hemoglobin, ionized calcium (iCa), potassium (K), sodium (Na), partial pressure of carbon dioxide (pCO₂), pH, partial pressure of oxygen (pO₂)_, and percent oxygen saturation (sO₂%). Temperature corrected values are automatically produced by the iSTAT for pCO_2, pH and pO₂ once the animal’s body temperature is entered. Blood lactate was determined using a portable Lactate Plus^TM analyzer (Nova Biomedical, Waltham, Massachusetts, 02454 USA).
Whole blood samples were placed on ice packs immediately after and later transferred to a refrigerator upon arrival in the laboratory until analyzed. Time-sensitive analyses were performed within 12 hours. Packed cell volume and total solids were determined using high-speed centrifugation of blood-filled microhematocrit tubes.