Birth and the Newborn Infant Notes

The Process of Birth: Labor

• Triggering the Process of Labor: The onset of birth is triggered by a specific protein called corticotropin-releasing hormone (CRH). The release of this protein signals the mother's pituitary gland to release oxytocin. Once oxytocin levels are high enough, uterine contractions begin.

• Prior Activity: Even before active labor, Braxton-Hicks contractions (sometimes called "false labor") have typically been occurring since the fourth month of pregnancy.

• The Mechanism of Labor: During labor, contractions force the head of the fetus against the cervix. This force becomes strong enough to eventually propel the fetus down the birth canal, at which point the child enters the world as a neonate.

• The Three Stages of Labor:

  • Stage 1: This is the longest stage of labor.

    • Uterine contractions initially occur every $8$ to $10$ minutes and last about $30$ seconds.

    • Toward the end of labor, contractions may occur every $2$ minutes and last as long as $2$ minutes.

    • The period of greatest intensity for contractions is known as transition.

    • This stage concludes when the mother’s cervix is fully open (dilated) to allow the baby’s head to pass through.

    • Duration: Typically takes $16$ to $24$ hours for firstborn children, though this varies widely and is usually shorter for subsequent births.

  • Stage 2: This stage typically lasts around $90$ minutes.

    • The baby's head moves through the cervix and birth canal.

    • Episiotomy: In some cases, an incision is made to increase the vaginal opening to allow the baby to pass.

    • This stage ends when the baby has completely left the mother's body.

  • Stage 3: This is the shortest and easiest stage, taking only a few minutes.

    • The child’s umbilical cord (still attached to the neonate) and the placenta are expelled from the mother.

• Dealing with Labor: Health care providers suggest that parents be flexible, communicate clearly with providers, recognize that labor is a laborious process, accept partner support, remain honest about pain levels, and focus on the overall outcome.

From Fetus to Neonate: The First Hours

• The Moment of Birth: Birth is defined by the moment the fetus passes through the vagina and emerges from the mother's body. Most neonates cry immediately upon birth to clear their lungs and begin independent breathing.

• Health Personnel Attendance:

  • In North America, $99\%$ of births are attended by skilled health personnel.

  • In the least developed countries, only $66\%$ of births have skilled health personnel in attendance.

• The Apgar Scale: Developed by Apgar (1953), this is a standard measurement system used to evaluate the health of newborns. Each of the five qualities is scored from $0$ to $2$, for a total possible score of $10$.

  • A - Appearance (skin color): $0$ (Blue-gray, pale all over); $1$ (Normal except for extremities); $2$ (Normal over entire body).

  • P - Pulse (heart rate): $0$ (Absent); $1$ (Below $100\,\text{bpm}$); $2$ (Above $100\,\text{bpm}$).

  • G - Grimace (reflex irritability): $0$ (No response); $1$ (Grimaces); $2$ (Sneezes, coughs, pulls away).

  • A - Activity (muscle tone): $0$ (Absent); $1$ (Arms and legs flex); $2$ (Active movement).

  • R - Respiration (respiratory effort): $0$ (Absent); $1$ (Slow, irregular); $2$ (Good, crying).

  • Scoring Interpretations: Scores are taken at $1$ and $5$ minutes after birth (and $10$ minutes if problems persist). A score of $7$ to $10$ is normal. A score of $4$ to $7$ requires resuscitative measures. A score less than $4$ requires immediate life-saving resuscitation.

• Oxygen Deprivation (Anoxia): The birth process can lead to a restriction of oxygen, known as anoxia. If this lasts for more than a few minutes, it can produce brain damage. Causes include the umbilical cord becoming wrapped around the neck or pinched during contractions.

• Newborn Medical Screening: The American College of Medical Genetics and Genomics recommends screening for $34$ disorders; the Health Resources and Services Administration (HRSA) recommends screening for $35$ core and $26$ secondary conditions. These include:

  • Hearing difficulties

  • Sickle cell disease

  • Isovaleric acidemia: A rare metabolism disorder.

Physical Appearance and Initial Interactions

• Neonate Physical Features:

  • Vernix: A "greasy cottage cheese" substance that smooths the passage through the birth canal.

  • Lanugo: Fine dark fuzz covering the neonate's body.

  • Puffy Eyelids: Caused by fluid accumulation during labor.

  • Newborns may also have blood and other fluids on their bodies at birth.

• Bonding: This refers to the close physical and emotional contact between parent and child immediately after birth. Some argue this period is critical for the long-term strength of the parent-child relationship.

• Caregiving Styles:

  • Proximal Caregiving: Parents stay in close contact (carrying babies close, bed-sharing). Babywearing is a hallmark of this style and is thought to increase maternal responsiveness by helping mothers perceive subtle cues and strengthening the bond.

  • Distal Caregiving: Use of tools like strollers, cribs, and playpens to limit constant physical contact.

Approaches to Childbirth and Pain Management

• Birthing Strategies: No single approach has been proven significantly more effective than others. Cultural attitudes often dictate the choice of procedure.

  • Lamaze: Focuses on breathing and relaxation.

  • Bradley Method: A "partner-coached," natural approach.

  • Mindfulness-based Birthing: Incorporates meditation.

  • Hypnobirthing: Uses self-hypnosis.

  • Water Birthing: Labor and delivery occur in a warm pool.

• Birth Attendants:

  • Obstetricians: Medical doctors specializing in baby delivery (the most common choice in the US).

  • Midwives: Usually nurses specializing in delivery. They assist with $80\%$ of births worldwide but only $10\%$ in the United States.

  • Doulas: Provide emotional, psychological, and educational support; they do not replace medical personnel.

• The Subjectivity of Pain: Perceptions of childbirth pain vary culturally.

  • India: Labor is often reported as less painful than in the US.

  • Belgium: Pain is viewed as something to be avoided with medication.

  • Netherlands: Pain is seen as helpful and normal.

• Anesthesia and Drugs: Epidural anesthesia numbs from the waist down.

  • Potential Side Effects: It may slow labor, depress oxygen flow, and lead to newborns being less responsive or having difficulty breastfeeding.

  • Long-term effects are generally not significant when used properly.

• Postdelivery Hospital Stay: The average stay dropped from $4$ days in $1970$ to $2$ days today. Early discharge carries risks, leading the U.S. Congress to mandate insurance coverage for at least $48$ hours.

Birth Complications: Preterm and Postmature Infants

• Preterm (Premature) Infants: Born prior to $38\,\text{weeks}$ after conception (affects approximately $1\,\text{out of } 10$ infants).

  • Low-birthweight: Weight less than $2,500\,\text{grams}$ (approx. $5\frac{1}{2}\,\text{pounds}$).

  • Small-for-gestational-age (SGA): Weight is $90\%$ or less than the average for that gestational age due to delayed fetal growth.

  • Respiratory Distress Syndrome (RDS): Common in low-birthweight infants who may require an incubator.

• Very-Low-Birthweight Infants: Weight less than $1,500\,\text{grams}$ (approx. $3\,\text{pounds, 4 ounces}$) or in the womb less than $30\,\text{weeks}$.

  • Age of Viability: Medical advances have moved this down to about $22\,\text{weeks}$.

  • Survival Odds: A baby born before $25\,\text{weeks}$ has less than a $50-50$ chance of survival.

• Causes of Preterm Births: About half are unexplained. Known causes include multiple births, maternal age (younger than $15$ or older than $40$), closely spaced births, older fathers, maternal health issues, and racial/socioeconomic inequalities.

• Postmature Infants: Those unborn $2\,\text{weeks}$ after the due date.

  • Risks: Insufficient placental blood supply, decreased blood to the brain (potential brain damage), and riskier labor due to the large size of the fetus.

Cesarean Delivery and Infant Mortality

• Cesarean Delivery (C-section): Surgical removal of the baby from the uterus.

  • Indications: Fetal stress, breech position (feet first), transverse position (crosswise), or older maternal age.

  • Trends: Rates have increased by $500\%$ since the early $1970\text{s}$, partly due to the routine use of fetal monitors.

  • Criticisms: Major surgery with long recovery; higher infection risk; potential breathing problems for the infant; and evidence of unnecessary procedures due to racial and socioeconomic factors.

• Stillbirth and Infant Mortality:

  • Stillbirth: Delivery of a non-living child ($1\,\text{in } 160$ births in the US).

  • Infant Mortality: Death within the first year of life. The US rate is $5.7\,\text{deaths per } 1,000\,\text{live births}$.

  • Racial Disparity: In the US, Black non-Hispanic infants are more than $2\,\text{times}$ as likely to die before age $1$ compared to White non-Hispanic infants.

• International Comparisons of Parental Leave (Table 3-3):

  • United States: $12\,\text{weeks}$, Unpaid.

  • Canada: $54\,\text{weeks}$, approx. $55\%$ pay.

  • Sweden: $60\,\text{weeks}$, $12\,\text{months}$ at $80\%$ pay, $3\,\text{months}$ flat, $3\,\text{months}$ unpaid.

  • Norway: $36-46\,\text{weeks}$, $100\%$ pay.

  • France: $156\,\text{weeks}$, Flat rate.

  • Japan: $1\,\text{year}$, $60\%$ pay.

Postpartum Depression

• Definition: A period of deep depression following childbirth affecting about $10\%$ of new mothers.

• Symptoms: Enduring, deep feelings of sadness that can last for months or years.

• Causes: Likely triggered by the massive shift in hormone production after birth. It is more common in women with a history of depression.

The Competent Newborn: Physical and Sensory Capabilities

• Physical Reflexes: Unlearned, involuntary, and automatic responses to stimuli.

  • Sucking reflex: For ingestion of food.

  • Swallowing reflex: For ingestion of food.

  • Rooting reflex: Turning the head toward a touch on the cheek.

  • Other reflexes: Coughing, sneezing, blinking.

• Internal Progress:

  • Meconium: The first greenish-black feces, remnant of fetal days.

  • Neonatal Jaundice: Occurs in nearly half of all newborns; characterized by a yellowing of the skin.

• Sensory Capabilities:

  • Vision: Not fully developed but shows preference for color, contrast, and brightness. Possesses size constancy.

  • Hearing: Auditory acuity is not complete, but neonates show familiarity with specific sounds.

  • Other Senses: Touch, smell, and taste are reasonably sophisticated at birth.

Learning and Social Competencies

• Newborn Learning (Table 3-5):

  • Classical Conditioning: Learning to respond to a neutral stimulus (e.g., a baby stops crying when picked up because they associate it with feeding).

  • Operant Conditioning: Voluntary responses are strengthened or weakened by consequences (e.g., smiling more because it brings positive attention).

  • Habituation: Decrease in response to a repeated stimulus. This involves the orienting response (becoming quiet/attentive to new stimuli). It is a measure of physical and cognitive maturation.

• Social Competencies:

  • Imitation: Infants can imitate some behaviors early on.

  • Facial Expressions: They can differentiate between happiness, sadness, and surprise.

  • States of Arousal: Degrees of wakefulness ranging from deep sleep to great agitation.

  • Interaction Factors: Neonates show stimulus preferences and predictable arousal cycles, helping parents adapt their own behaviors to establish a social bond.