intauterine

• Prenatal/Intrauterine Development


  Lasts approximately 9 calendar months (10 lunar months) or 38 to 40 weeks depending on method of calculation
• If the time is calculated from the day of conception


  This stage of life is about 38 weeks or 9 ½ lunar months
• If the time is calculated from the first day of last menstrual period

  It is 10 lunar months or 40 weeks
• Age of Gestation (AOG)

  38 - 40 weeks
• Pregnancy


  Divided into three periods called trimesters
• Trimester


  Three periods of pregnancy, divided into three months each
• Mother should avoid being ill during the first two semesters due to organogenesis. The organs of the baby may become underdeveloped
• Organogenesis


  The process of formation of organs from three germ layers (Week 3-8)
• Embryonic Phase


  Occurring in the first trimester, is the period during which the fertilized ovum develops into an organism with most of the features of the human
• Fetal heart is already present at first two weeks
• The first three weeks


  Embryonic tissues differentiate into three different layers: Ectoderm, Mesoderm, Endoderm/Entoderm
• Ectoderm


  Outer layer formed by the second week, includes epidermis, PNS, CNS
• Mesoderm


  Middle layer formed by the third week, includes kidneys, reproductive organs, bones, muscles, vascular system
• Endoderm/Entoderm


  Inner layer formed by the second week, includes intestines, lungs, liver
• Three other events occur concurrently during the first three weeks


  1. The embryo is implanted in the endometrium of the uterus

  2. The fetal membranes differentiate into the chorion, precursor to the placenta, and the amnion, precursor to the amniotic sac

  3. Placental function starts
• Fetal Phase


  Occurring in the second and third trimester of pregnancy, is characterized by a period of rapid growth in the size of the fetus
• Vernix Caseosa


  A protective covering that begins to develop over the skin, not removed since it may cause hypothermia
• Lanugo


  A fine downy hair, also covers the body. At about 5 months, the mother can feel the movement of the fetus, and the first fetal heartbeat may be heard
• Placenta


  A flat, disk-shaped organ that is highly vascular. It normally forms in the upper segment of the endometrium of the uterus. Its function is to facilitate the exchange of nutrients and gas between the embryo or fetus and the mother
• Chorion


  Precursor to the placenta
• Amnion


  Precursor to the amniotic sac
• At the end of the third trimester (9 ½ lunar months), the fetus has developed to approximately 50cm (20 in.) and 3.2kg to 3.4kg (7.0 lb to 7.5 lb.)
• Neonate


  Babies from birth to the end of first month
• Infants


  Babies 1 month to 1 year of age
• Anthropometric Measurement


  Consists of weight, head/chest/abdominal circumference, and length measurement as well as vital signs
• Vital signs (Baby must be calm before measuring)


  • HR: 120-160 bpm
  • RR: 40-60 bpm
  • Temp: 35.6-37 degrees Celsius (every 15 mins in the first hour)
• Weight


  • At birth, most babies weigh from 2.7 kg to 3.8 kg (6.0 to 8.5 lb) / 2.7 kg to 3.2 kg
  • Just after birth, most infants lose 5% to 10% of their birth weight because of fluid loss (Physiologic Loss)
  • After several days, babies usually gain weight at the rate of 150 to 210 g (5 to 7 oz) weekly for 6 months
  • By 5 months of age, infants usually reach twice their birth weight, and by age 12 months, three times their birth weight
• Length


  50 cm (20 in.)
• Head and Chest Circumference


  • At birth, the average infant's head circumference is 35 cm (14 in)
  • 3 months - 40 cm
  • 6 months - 43 cm
  • 1 yr - 45 cm
  • 2 yrs - 48 cm
  • 7 yrs - 50 cm
  • 12 yrs - 52 cm (almost the same as adults)
• Head Molding


  • Fontanels - unossified (i.e., without bone formation) membranous gaps in the bone structure of the skull
  • Sutures - junction lines of the skull bones that override to provide flexibility for molding of the head
  • Craniosynostosis - premature closure of skull sutures
• Vision


  The newborn can follow large moving objects and blinks in response to bright light and sound
• Hearing


  Newborns with intact hearing will react with a startle to a loud noise, a reaction called the Moro reflex
• Touch


  The sense of touch is well developed at birth. Skin-to-skin touching is important for an infant's development
• Smell and Taste


  The senses of smell and taste are functional shortly after birth
• Reflexes


  • Reflexes of the newborn are unconscious, involuntary responses of the nervous system to external and internal stimuli
  • Reflexes are very important to determine during the first year. Any discrepancies means problems with the nervous system
  • Rooting, Gripping, Toe Curling, Moro, Galant, Tonic neck, Grasp, Step, Crawl
• Motor Development


  The development of the baby's abilities to move and control the body
• Sucking Reflex


  A feeding reflex that occurs when the infant's lips are touched. The reflex persists throughout infancy
• Plantar Reflex


  Similar to the palmar grasp reflex; an object placed just beneath the toes causes them to curl around it. This reflex disappears after 8-10 months
• Rooting Reflex


  A feeding reflex elicited by touching the baby's cheek, causing the baby's head to turn to the side that was touched. The reflex usually disappears after 4 months
• Tonic Neck Reflex (TNR) / Fencing reflex


  A postural reflex. When a baby who is lying on its back turns its head to, for example, the right side, the left side of the body shows a flexing of the left arm and the left leg. This reflex disappears after 4-6 months