PRENATAL DEVELOPMENT AND BIRTH

Prenatal Development Time of fastest development in life span Environment extremely important Conception Ova travels from ovary to uterus Penetration by 1 of sperm Outcome: single-celled ZYGOTE

Prenatal Stages Germinal period: days 1-14 Implantation: 1/2 are successful Miscarriage: 15% (recognized) to 50% Embryonic period: 3 rd to 8 th week Organogenesis, Sexual differentiation Fetal period: 9 th week – birth Proliferation, migration Differentiation of stem cells Ends in tremendous brain development

Prenatal Environment Reciprocal influence Person and environment Good and bad influences important Teratogen: Environmental agent Harms the developing fetus Critical Period: Organogenesis Dosage and duration Genetic make-up: Susceptibility

The critical periods of prenatal development. Teratogens are more likely to produce major structural abnormalities during the third through the eighth prenatal week. Note, however, that many organs and body parts remain sensitive to teratogenic agents throughout the nine-month prenatal period

Teratogens: Drugs Thalidomide (for morning sickness) All or parts of limbs missing Tobacco: Miscarriage, low birth weight, SIDS, slows fetal growth Alcohol: FAS Small, facial deformities, retardation Cocaine: Processing difficulties

(A) Characteristic features of a child with fetal alcohol syndrome (FAS).

(B) Child with FAS, illustrating many features in the drawing. Such children may also have cardiovascular and limb defects.

Teratogens - Diseases Rubella (German Measles) Blind, deaf, heart, brain Syphilis: Miscarriage, blind, deaf, heart, brain After 18 th week AIDS: Mothers transmit to babies (15%-35%) Prenatally, perinatally, postnatally

Teratogens: Environmental Hazards Radiation: MR, leukemia, cancer, mutations, spontaneous abortions, etc. Avoid X-rays when pregnant Pollutants In air and water Lead: MR (also postnatally)

The Mother’s State Age: Typically age or younger don’t seek prenatal care Birth complications, low birth weight Over 35:Miscarriage, Down Syndrome (father’s age also) Emotion: Stress can stunt fetal growth Positive outlook most helpful Nutrition: lb weight gain Malnutrition: Smaller neurons, brain, child

The Father’s State Research limited except for genetic contribution Father’s age can also be influential Over 35: Increased number miscarriages, heart defects, Down Syndrome Over 50: Higher risk for schizophrenia Exposure to environmental toxins Radiation, anesthetic gases, pesticides Damage to genetic material in sperm

Postnatal Depression Baby Blues: mild, common Clinical depression: 1/10 Previous depression common Children of Depressed Mothers Insecurely attached, less responsive Negative to other children

The Father’s Experience Accepted, expected in delivery rooms Attend prenatal classes with wife Experience described as a significant event Anxiety, stress common during delivery Relief, pride, joy when baby is born Sometimes depression following birth Disappointed if sex does not resume soon

The Neonatal Environment Culture, early socialization, health status E.g., low birth-weight babies (8% in US) Less than 5½ lbs Strongly linked to low SES Environment: Neonatal intensive care Risk: Blindness, deafness, CP, autism, cognitive, and later academic problems Parenting must be attentive, responsive

Modern technology permits survival of younger and smaller babies, but many experts believe we have reached the lowest limits of viability at weeks gestation.

Learning Objectives What are the advantages of breast feeding? Are there disadvantages of breast feeding? How can at-risk newborns be identified? What treatments are available to optimize development of at-risk babies? To what extent are the effects of the prenatal and perinatal environments long lasting? What factors influence whether effects are lasting?

Breast or Bottle? Breast feeding most natural nutrition Practices vary across cultures Health benefits great for breast-fed infants At least first 6 months recommended More likely to bottle feed: Factors Younger, low SES, less education, employed, African American US values toward breast feeding ambivalent

Low Birth-Weight Babies < 5½ pounds: “Small for date” or “preterm” Leading cause of infant mortality 8% of all births, 65% of all infant deaths Factors: Low SES, smoking, stress, multiples Worse for minority, poverty, single-parent children For most, significant catch-up growth Low Birth-Weight Infants Greater risk for blindness, deafness, CP, autism, health problems - especially respiratory problems

Factors Helpful for LBW Infants Breastfeeding, skin-to-skin contact, massage Responsive parenting, intellectual stimulation Early intervention programs work with parents Childcare education and support Growth-enhancing home environment Consistently attentive, responsive parenting

Risk and Resilience Not all high-risk infants have problems Werner: Kauai Longitudinal study (40 yrs) Findings: Effects decrease over time Outcomes depend on postnatal environment Protective factors Personal resources Supportive postnatal environment