Prenatal Development

1 st time births

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Conception and Implantation Figure 3.3

Prenatal Development Stages Blastocyst – fluid filled sphere which floats in uterus for day or 2; then buries self in uterine wall

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Periods of Prenatal Development PeriodLength Key Events Zygote 2 weeks Fertilization Fertilization Implantation Implantation Start of placenta Start of placenta Embryo 6 weeks Arms, legs, face, organs, muscles all develop Arms, legs, face, organs, muscles all develop Heart begins beating Heart begins beating Fetus 30 weeks “Growth and finishing ” “Growth and finishing ”

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Table 3.3 Source: Moore & Persaud, Milestonesof Prenatal Development

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. The Placenta and Umbilical Cord Figure 3.4

9 week fetus

Fetus in uterus

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Sensitive Periods in Prenatal Development Figure 3.5

Prenatal brain development

Fetal Alcohol Syndrome (FAS)

FAS developmentally…

Prenatal Environmental Influences: Teratogens Teratogen – Any environmental agent that causes damage during the prenatal period Factors include: – Dose – Heredity – Other negative influences – Age

Prenatal Development and Later Health Low Birth Weight Greater chance of  Heart Disease  Stroke  Diabetes High Birth Weight Greater chance of  Breast cancer  Prostate and other cancers Steve LovegroveSteve Lovegrove | Dreamstime.comDreamstime.com

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Relationship of Birth Weight to Breast Cancer Risk in Adulthood Figure 3.6

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Teratogens Drugs –Prescription –Nonprescription –Illegal Tobacco Alcohol Radiation Pollution/Chemicals eg. Prenatal PCBs: lower IQ and attention at age 11 Infectious disease © Absolute Family

Can a Thalidomide-like Tragedy Occur Again? Accutane – toxic to developing organisms Efforts to control its damaging prenatal risks include: – restriction of this and other drugs for the treatment of severe conditions. – improved public and patient education. – interventions that promote widespread, effective contraceptive use.

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Fetal Alcohol Spectrum Disorder: Criteria for Diagnosis Table 3.4 Source: Loock et al., 2005.

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. The Effects of Environmental Pollution  More than 75,000 chemicals are in common use in the United States; many new pollutants are introduced each year.  Many babies are “born polluted” by chemicals that can impair development and increase chances of life-threatening diseases and later health problems.

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Effects of Some Infectious Diseases During Pregnancy Table = established finding; 0 = no present evidence; ? = possible effect that is not clearly established. Sources: Jones, Lopez, & Wilson, 2003; Kliegman et al., 2008; Mardh, 2002; O’Rahilly & Müller, 2001

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Maternal Factors in Healthy Prenatal Development  Exercise  Nutrition  Prevention and treatment  Emotional stress  Rh blood factor  Maternal age  Previous births © Ron Chapple Studios | Dreamstime.comRon Chapple StudiosDreamstime.com

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. The Effects of Emotional Stress on the Developing Fetus Stress hormones cross the placenta, causing a dramatic rise in fetal heart rate and activity. – Fetal neurological functioning can be permanently altered. Maternal emotional stress predicts anxiety, short attention span, anger, aggression, and overactivity among young children, above and beyond the impact of other risk factors. Stress-related prenatal complications can be greatly reduced when mothers receive support from family members and friends.

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Prenatal/Birth Complications Increase with Maternal Age Figure 3.7

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Expectant Mothers with Late or No Prenatal Care Figure 3.8

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Reasons Women Delay Prenatal Care  Financial hardship  Situational barriers  Personal barriers  Many are engaging in high-risk behaviors that they do not want to reveal to health care professionals. © Martin Novak | Dreamstime.comMartin NovakDreamstime.com

Copyright © 2012 Pearson Education, Inc. All Rights Reserved. Culturally Sensitive Prenatal Care Promotes Healthy Pregnancies  Low-SES ethnic minority expectant and new mothers were not receiving warm prenatal care and expressed difficulty getting questions answered.  Group prenatal care offers a sensitive alternative. © Lev Olkha | Dreamstime.comLev OlkhaDreamstime.com