PSYC207 Week two

Germinal Period

The first period of prenatal development, lasting from conception to 2 weeks. Begins with conception and ends when the zygote implants in the uterine wall.

Embryonic Period

Prenatal period from the 3rd to 8th week after conception. Major developments occur in organs and bodily systems following implantation.

Fetal Period

Prenatal period from the 9th week to birth. Characterised by rapid growth, continued development of physical structures, and increasing levels of behaviour, sensory experience, and learning.

Gestation

The period between conception and birth.

Antenatal (Prenatal)

The period before birth.

Postpartum (Postnatal)

The period after birth.

Perinatal

Around the time of birth.

Neonatal (Newborn)

The first 4 weeks after birth.

Fetal Sight and Touch

Minimal visual experience in the womb; the fetus has more tactile (touch) experience than visual.

Fetal Taste

Flavours pass into the amniotic fluid, and fetal taste preferences are present prenatally.

Fetal Smell

Odorants in the amniotic fluid provide olfactory (smell) experiences to the fetus.

Fetal Hearing

External sounds are audible to the fetus. By the sixth month, the fetus responds to sounds.

Kisilevsky et al. (2003)

Study of 60 fetuses (avg. 38.4 weeks). Used a three-phase design (no voice → mother's or stranger's voice → no voice). Conclusion: Fetuses learn, prefer, and remember their mother's voice.

Fetal Long-Term Learning — Movahed et al. (2023)

A review of studies on sound stimulation (e.g., music and speech) during pregnancy. 8 out of 8 studies supported the idea that fetal learning persists into the neonatal period.

Sensitive Period

A window of time during which a person is most susceptible to change (either positive development or harm).

Sensitive Period: Dark Green (Prenatal Chart)

Highly sensitive period — when exposure to hazards is most likely to cause major defects.

Sensitive Period: Light Green (Prenatal Chart)

Less sensitive period — when exposure to hazards is more likely to cause minor defects.

Teratogen

An environmental agent that causes damage during the prenatal period.

Dose-Response Relation (Teratogens)

The amount and length of exposure to a teratogen is related to a higher probability of fetal defects and more severe problems. Example: thalidomide.

Alcohol as a Teratogen

Alcohol is the most common human teratogen. Approximately 20% of pregnant women in NZ drink alcohol (10% in USA). It is the leading cause of fetal brain injury.

Fetal Alcohol Syndrome (FAS)

Caused by maternal alcoholism or binge drinking during pregnancy. Associated with facial deformity and intellectual disability. Binge drinking and cognitive development: r = −0.065.

Safe Level of Alcohol in Pregnancy

There is no known safe level of alcohol consumption during pregnancy. Even low consumption (< 32g pure alcohol/week, ~3 beers or 2 glasses of wine) showed a small significant effect on small-for-gestational-age (SGA) outcomes.

Smoking During Pregnancy

Linked to severe cognitive impairments, low birth weight, and Sudden Infant Death Syndrome (SIDS).

Smoking/Vaping and Child Development — O'Connell et al. (2025)

Meta-analysis finding: Links with self-regulation: r = −0.17 to −0.24. Link with motor development: r = −0.10.

Maternal Age Risk Factors

Babies born to very young mothers (< 15 years, sometimes < 20 years) or mothers of advanced age (> 35 years) face increased prenatal risks.

Maternal Nutrition

An inadequate supply of specific nutrients or vitamins is a hazard to prenatal development.

Maternal Disease

A variety of diseases — including sexually transmitted infections — can harm prenatal development.

Maternal Depression: Prevalence

Depression affects approximately 5–16% of pregnant women.

Maternal Anxiety: Prevalence

Anxiety affects approximately 10–20% of pregnant women.

Maternal Stress: Prevalence

Low-to-moderate stress affects ~78% of pregnant women; high stress affects ~6%.

Negative Outcomes of Maternal Emotional Distress

Associated with preterm birth, low birth weight, greater stress responsivity and fearfulness in infancy, more impulsivity and poorer attentional control in infancy, more respiratory problems (e.g., asthma) in childhood, and more impulsivity and behavioural problems in adolescence.

Madigan et al. (2018) — Maternal Depression & Socioemotional Development

Meta-analysis finding: Maternal depression and children's socioemotional development: r = −0.11.

Madigan et al. (2018) — Maternal Anxiety & Socioemotional Development

Meta-analysis finding: Maternal anxiety and children's socioemotional development: r = −0.16.

Delagneau et al. (2023) — Maternal Depression & Intellectual Development

Meta-analysis finding: Maternal depression and children's intellectual development: r = −0.12.

Tung et al. (2023) — Maternal Stress & Externalising Behaviours

Meta-analysis finding: Maternal perceived stress and children's/adolescents' externalising behaviours: r = 0.25 (not statistically significant).

Fetal Programming Hypothesis

The idea that prenatal experiences (e.g., maternal stress, nutrition, teratogen exposure) can programme or shape long-term biological and psychological development of the child.