Effects of Mother Position in Skin-to-skin Contact Newborn on Oxygen Saturation Levels.

Inclusion criteria: 1. Single fetus pregnancy 2. Pregnancy controlled or partially controlled(1) 3. Normal pregnancy or with gestational diabetes treated with diet, high blood pressure controlled with only a drug as maximum (without preeclampsia) 4. Gestation to term (between 37 weeks to 41 weeks and 6 days of gestational age). 5. Maternal temperature at onset of labor ≤38 degrees Celsius 6. Presence of a companion during the 2 hours after delivery 7. Desire of the mother to perform early skin-to-skin Exclusion criteria pre-randomization: 1. Consumption of tobacco, alcohol, drugs or any medication with sedative or relaxing(2) effect or any pathology during pregnancy. 2. Prenatal diagnosis of chromosomal abnormalities or major malformations. 3. Prenatal diagnosis of intrauterine growth restriction with any degree of alteration in the flow as well as the abnormal small-for-gestational-age fetuses (due to malformations, intrauterine infection ...). 4. No companion during the first two hours postpartum Notes: 1. Partially controlled pregnancy: she has the 20 weeks ultrasound but lack the first and/or third trimester of pregnancy and/or analytical (serology, O'Sullivan test ...). 2. Medicinal products with sedative or relaxing effect: opioids, anticonvulsants, antipsychotics, benzodiazepines, anxiolytics, hypnotics, antidepressants and sedative plants. Post randomization exclusion criteria (at the end of delivery) 1. Related to childbirth: * Caesarean section or instrumental delivery (forceps, vacuum) * Maternal fever \>38 degrees Celsius * Mother hemodynamic instability (hypotension, tachycardia, altered level of consciousness, poor perfusion, striking pallor) * Cord prolapse * Signs of fetal distress with lower pH fetal scalp \<7.25 or umbilical artery pH \<7.20 * Any other obstetrical complication 2. Related mother: * Any type of illness * Sedatives or relaxants during or after birth(3) 3. Related Newborn (RN) * Need for resuscitation measures * Major malformation diagnosed intrapartum * Apgar ≤7 at one minute, 5 or 10 minutes * Presence of clinic(4) before the 10 minutes of life * Birth weight \<2300 g or\>4500 g 4. Interruption of skin contact because the mother present a problem Notes: (3) Sedatives or relaxants during or after birth: Pethidine (Dolantina®), scopolamine (Buscapina®), haloperidol, benzodiazepines and opiates. (4) Clinic: general discomfort, fever, hypothermia, pallor, mottled skin (cutis marmorata), cyanosis, petechiae, purpura, lethargy, weakness, poor responsiveness, seizures, tremors, poor perfusion, maintained tachycardia, bradycardia, hypotension, apnea, tachypnea, respiratory distress (grunting, nasal flaring, intercostal or subcostal or substernal retractions, thoracoabdominal dissociation), vomiting, abdominal distesion, etc. Clarifications: It can include: 1. Newborns with intrauterine diagnosis of ectasia pyelocaliceal grades I and/or II, choroid plexus cysts, aberrant right subclavian artery or single umbilical artery (minor malformations). 2. Newborns whose time broken bag is ≥ to 18 hours provided that they do not present clinic(4). 3. Newborn with risk of infection without symptoms at birth. 4. Newborn with stained amniotic fluid, born crying, who does not require tracheal aspiration, or resuscitation and shows no clinical(4) signs during the first 10 minutes after birth. 5. Small for normal fetal gestational age (genetic-family origin)