Chapter 4: Prenatal Development and Birth—Review

What occurs in the final 3 months of pregnancy?

In addition to the maturation of the neurological, respiratory, and cardiovascular systems, the fetus usually gains about 4.5 pounds in the third trimester. Also, the testicles of the male fetus descend.

What distinguishes a fetus from a baby?

A fetus's neurological, respiratory, and cardiovascular systems are not mature until it has reached full term, at about 36 weeks. and, depending on how many weeks past conception it is, the fetus can be up to 4.5 pounds smaller than a full-term fetus.

What is the prognosis of a baby born after 22 weeks of gestation?

Many babies born within 22 and 24 weeks die, and those before 27 weeks often develop slowly. Advanced neonatal care can improve the prognosis of such babies, but survival is far from automatic.

How are fathers affected by birth?

Many fathers experience biological symptoms of pregnancy and birth along with their partners. They may experience weight gain and indigestion during pregnancy and pain during labor, indicative of a phenomenon known as couvade.

What are the 3 stages of prenatal development?

1. The germinal period is the first stage, which culminates in implantation. 2. The embryonic period, in which all basic organs and features develop, is the second stage. 3. The third stage—the fetal period—extends from the ninth week until birth.

What are the causes and consequences of low birthweight?

Being born preterm, maternal or fetal illness, maternal psychoactive drug use, and maternal malnutrition can all cause a baby to be LBW. Many LBW infants are late in milestones such as smiling, holding a bottle, walking, and talking. Cognitive difficulties as well as visual and hearing impairments may emerge as time passes. Even in adulthood, some risks persist—those born LBW have higher rates of obesity, heart disease, and diabetes.

Why do the rates of cesareans vary internationally?

Countries with low rates of cesareans often have high rates of infant and maternal mortality. rates are higher in industrialized nations such as the U.S., perhaps because they are easier to schedule, are quicker, and benefit hospitals financially.

Why would a woman want a doula?

Doulas time contractions, use massage, provide encouragement, and do whatever else is helpful to women in labor. In the U.S., doulas typically help couples decide when to leave home, avoiding long waits between hospital admittance and birth. Laboring mothers and their doulas are often together from early labor to the first breastfeeding of the newborn.

What evidence suggests that teratogens are affected by genes and chromosomes?

Genes can influence the effects of teratogens. For example, the Y chromosome makes male fetuses more vulnerable. They are more likely to be spontaneously aborted or stillborn and more likely to be harmed by teratogens than are female fetuses. maternal genes may be important during pregnancy. One allele results in low levels of folic acid in a woman's bloodstream. Her deficiency, via the placenta, affects the embryo, which may develop neural-tube defects.

Why is it difficult to determine whether behavioral teratogens affected a child?

Genes, postnatal experiences, and/or lack of preventive information and services may have affected the child instead.

What might make a home birth a safe one?

Having a trained midwife or doctor present, ensuring that speedy transportation to a hospital is available, and ensuring that the birth is not high-risk.

What causes postpartum depression?

Hormonal changes play a part, but financial stress, marital problems, or a difficult (or lonely) birth also correlate with postpartum depression.

Why is kangaroo care beneficial?

Many studies have concluded that newborns who received kangaroo care sleep more deeply, gain weight more quickly, spend more time alert, and are healthier overall than newborns who do not. It is especially beneficial because it helps infants adjust to being outside the womb and also encourages parental sensitivity and effectiveness.

What are the immediate and long-term results of a cesarean birth?

More medical complications and reduced breast-feeding are the immediate results; childhood obesity may be a long-term result.

How can a newborn be socially interactive?

Newborns stare, cry, stop crying, and cuddle in their first hours of life, which aids in bonding.

When do sex organs appear?

Sex organs appear during the third month; they may be visible via ultrasound at the end of the third month.

Who was Virginia Apgar and what did she do?

She was an anesthesiologist in the 1950s who noticed that doctors focused mothers in the delivery room, often neglecting small and struggling babies. She developed a simple scale, measuring heart rate, respiratory effort, muscle tone, color, and reflexes, to alert doctors to newborn health.

What parts of the embryo form first?

The brain and spinal column, eyes, ears, nose, and mouth start to form, as do the heart, arms, and legs.

Why are no teratogens certain to cause harm?

The impact of teratogens depends on the interplay of many factors, timing being the most crucial. For example, some teratogens cause damage only during a critical period of development.

What are the advantages and disadvantages of drugs during birth?

The obvious advantage is pain relief. Disadvantages include possible side effects like headaches, but the most common problem is that labor slows down and the drugs in the mother's bloodstream slows down the baby's reflexes.

How do we know that the placenta does not screw out all harmful substances?

Two tragic episodes proved that placenta cannot screen out all harmful substances: a rubella outbreak at an Australian military base that resulted in a sudden increase of babies being born blind, and the sudden increase of British babies born with deformed limbs because of maternal use of thalidomide.

When does the parent-infant bond form?

This bond forms in the first hours of birth, when parents hold, examine, and feed their newborn.