Prenatal Development And Birth PDF

Chapter 4: Prenatal Development and Birth September 18, 2024 Exam #1 Check-in How did you feel about the exam (1-6 scale)? Ideas for how to prepare differently for Exam #2 if you weren’t feeling like pup #2 or #4?  Before Prenatal Development: Deciding whether to have...

Chapter 4: Prenatal Development and Birth September 18, 2024 Exam #1 Check-in How did you feel about the exam (1-6 scale)? Ideas for how to prepare differently for Exam #2 if you weren’t feeling like pup #2 or #4?  Before Prenatal Development: Deciding whether to have children Rijken (2009): potential parents report little deliberation about timing of childbearing, career-oriented people tend not to actively choose to postpone childbearing Deliberation begins when parents are ready to start More than 50% of pregnancies in the US are planned  The decision to remain childless Can be an active choice or can happen more passively Couples without children report higher marital satisfaction, more freedom and have higher standards of living  Cost of child- rearing is an important consideration in the decision to have children Conception Conception occurs when the genetic material of the sperm and egg unite to form a single-celled zygote One in four couples experience difficulties conceiving Infertility is defined as not being able to get pregnant after a year of trying Fertility treatments Infertility is equally likely to be traced to the man or woman and has a variety of root causes. Fertility treatments include: prescription drugs to stimulate follicular ripening in females, artificial insemination, and in vitro fertilization. IVF in the US is costly: each attempt estimated to cost between $12,000- $15,000 (based on numbers from your textbook published in 2018) Success rate of IVF using fresh (i.e., not frozen) eggs is about 25% overall: 40% in women under 35 but only 5% success rate in women between 43-44 Although couples report that fertility treatments were a source of stress as they were going through them, later on those who seek fertility treatment seem to be happy with their choice to do so even if pregnancy and children do not result from the treatment How IVF works Questions about the decision to have children and/or conception and fertility? Prenatal Development: Germinal Period First two weeks of pregnancy During this time, the zygote becomes a blastocyst (a hollow ball of about 150 cells), and implants on the uterine wall around day 6. Estimated that between 8%- 50% of pregnancies result in miscarriage, with many of these occurring during the germinal period before pregnancy is even detected. Prenatal Development: Embryonic Period 3rd to 8th week of pregnancy Organogenesis and cell differentiation begin to take place Outer layer of blastocyst becomes the amnion (the watertight membrane that protects the the embryo) and the chorion (which eventually becomes the lining of the placenta) Interior cells become the ectoderm, mesoderm and endoderm Early Brain Development During Embryonic Period Takes place between 18-26 days after conception. Sex differentiation Although biological sex is determined at conception by the sperm cell that fertilizes the egg, sex differentiation begins during the 7th and 8 th weeks of gestation XY results in the development of testes, whereas XX results in the development of ovaries The testes secrete testosterone, stimulating the development of the male reproductive system (along with another hormone that suppresses the development of the female reproductive system). The embryo will develop a female reproductive system in the absence of these hormones. Prenatal Development: Fetal Period Lasts from 9th week of pregnancy-birth Three major processes related to brain development occur during this period: Prenatal Development: Fetal period Other important events from fetal period: Prenatal Influences on Infant Temperament & Behavior Fetuses who display matched heart rate and movement at 36 weeks gestation show better behavioral regulation at 2 weeks old Fetuses with slower and more variable heart rates show higher levels of mental and language development in early childhood May reflect optimal regulation of the nervous system Active fetuses tend to be active, difficult, unpredictable newborns whereas fetuses who show better organized behavior in the womb also exhibit less disrupted less patterns at 3 months old Questions about development in the womb? Prenatal Environment Fetal programming: environmental events and maternal conditions during pregnancy may alter genetic expression or reset physiologic functioning of embryo/fetus Prenatal experiences can change neural connections, physiology, and response to postnatal events and environment. Prenatal alcohol exposure in fraternal twins as an example of differential susceptibility The importance of sensitive periods