Module 3 Flashcards
first stage of labour
begins when contractions start. At first, these contractions are usually weak, far apart, and irregularly spaced. As labour progresses for usually 12 – 24 hours for a woman’s first baby but shorter for subsequent children, contractions become close together and regularly spaced, or even uninterrupted, and very strong.
During this time, the cervix is dilating to 10 cm to allow the baby to pass through.
2nd stage of labour
Once a woman’s cervix is sufficiently dilated, she’ll feel a strong urge to push during contractions and the second stage of labour begins. Crowning is when the top of the baby’s head appears. The head will come first, usually facing down, and changes to a cone-like shape that will resolve itself after a couple of days or weeks. The baby will then rotate a bit toward the side to allow the shoulders to come next, one at a time
3rd stage of labour
Finally, the rest of the baby comes out quite easily, and the umbilical cord can be clamped and cut. This stage can take up to 1 hour for first babies but is shorter if a woman has given birth before.
The last stage is often forgotten about, maybe because it’s shadowed by the baby’s birth. In stage 3, which lasts for only about 10-15 minutes, the placenta is expelled from the uterus.
Apgar score
The Apgar score is a quick way to get an approximate idea of whether the baby is healthy.
Health care professionals look for 5 different vital signs: appearance of skin tone, like whether the baby is blue, which would suggest that they aren’t getting oxygen, pulse or heartbeat, breathing, muscle tone, and the presence of reflexes, which are truly innate, unlearned responses to stimulation.
The baby is scored between 0 and 2 points on each vital sign, where higher scores indicate good physical condition and lower scores indicate the need for emergency care.
Brazelton Neonatal Behavioral Assessment Scale, or NBAS
For a more comprehensive assessment for babies up to 2 months, the Brazelton Neonatal Behavioral Assessment Scale, or NBAS, is often used. It includes many more items that test the baby’s body functions, movement, sleep/wake states, and social interaction. It’s also commonly used in research.
sucking reflex
is triggered when something is placed in a baby’s mouth.
help the baby feed, especially through breastfeeding.
the rooting reflex
When their cheek is stroked, babies will turn their head toward that side and open their mouth, a response called the rooting reflex.
help the baby feed, especially through breastfeeding.
withdrawal reflex
occurs when the baby is poked in the foot with a pin – they withdraw their foot just like you would if you touched a hot stove or poked yourself with something sharp.
This reflex should help prevent injuries like cuts or burns
blink reflex
Babies also engage in the blink reflex when they hear a sudden loud sound or see a bright light, which would likely protect the eyes if something was coming at the baby.
grasping or palmar reflex
grasping or palmar reflex happens when something is placed in the baby’s hand, like an object, your finger, or even your hair.
Babies will automatically grip the object, which probably helps them build muscles and brain pathways that will eventually allow them to grasp objects voluntarily rather than automatically.
Moro reflex
Happens when a baby is startled from a loud noise, or a jolt, especially when the baby may feel like they’re falling. In this case, the baby throws out the arms and then hugs them inward.
The Moro reflex is thought to help a baby cling to their mother and avoid falls; the only problem is that humans can’t really do this.
Many researchers believe that this is a reflex that is leftover from our evolutionary past, because it may have benefited our ancestors.
Even though it might not help humans, it’s still around because it hasn’t been selected against, mostly because it doesn’t have any negative effects on survival or reproduction.
Babinski reflex
which is when a baby’s foot fans out and then curls when it is stroked from heel to toe.
Because this reflex looks a lot like the grasping reflex except with feet, researchers suggest that once again, it may have benefitted our ancestors who did need to grab things with their feet, like other primates do.
stepping reflex
When babies make stepping motions when they’re placed upright on a surface held by an adult.
This one is thought to be a precursor to later voluntary walking, kind of like the grasping reflex is a precursor to voluntary grasping.
The historical mystery though is why it disappears at around 8 weeks if babies don’t tend to walk until about one year of age.
Funnily enough, it’s only because the baby’s legs get too chubby to lift!
They’ll still engage in the stepping reflex if their legs are underwater because they’re more buoyant, or if they’re placed on a little baby treadmill that helps them move their legs a bit.
reflexes
reflexes indicates a normally-functioning nervous system. Many will disappear within the first year as they give rise to voluntary movements instead.
Others stick around because they’re still important for survival, like the withdrawal or blink reflexes.
newborns states
spend most of their time sleeping, usually for 16 – 18 hours every day. They don’t tend to sleep in large chunks though – they usually operate on a 4-hour cycle where they’re awake for 1 hour and asleep for 3. When they’re awake, they’ll typically cycle through three states: crying, waking activity, and alert inactivity.
Infants spend about 2 – 3 hours per day crying. Crying is an infant’s first form of communication, because it tells the caregiver that the baby needs something.
Waking activity is when the baby is moving in uncoordinated bursts and their eyes are open but unfocused – they are probably transitioning from sleep and so they’re not fully alert.
Finally, alert inactivity is when the baby is calm and and seems to be inspecting their environment. This is when the baby may be gazing at your face or at the space around them, learning about what they’re experiencing.
Influences on prenatal development: nutrition
Micronutrients are also very important, including iron, calcium, zinc, and most vitamins, especially vitamin B9, which is also known as folic acid or folate.
As an example, a deficiency in folate can affect the very early development of the neural tube, which eventually becomes the brain and spinal cord. Between about 3 and 4 weeks of gestation, if the neural tube doesn’t close properly, a child may be born with spina bifida, which can cause an opening in the spine at birth that can make the baby prone to infection and need crutches or a wheelchair as they grow up.
One reason why doctors recommend that women start taking daily prenatal vitamins a few months before trying to get pregnant is that they will help ensure that there is enough intake of folic acid.
Influences on prenatal development: stress
veryone experiences mild to moderate stress from time-to-time, but this kind of everyday stress is unlikely to harm a developing baby.
Chronic, or more intense stress can be cause for concern on the other hand.
Babies whose mothers experienced chronic stress are more likely to be born early or underweight, and they are more prone to attentional, behavioural, and cognitive problems when they’re older.
Severe, chronic stress causes the release of hormones that reduce oxygen flow to the baby, which interferes with development.
Stress also impairs the immune system, making a woman more likely to become ill, which can in turn have its own negative effects on prenatal development.
Stress also makes it difficult to lead a healthy lifestyle like getting enough sleep, exercising, eating healthy, and avoiding substances that people sometimes use to cope like caffeine, nicotine, and alcohol.
Influences on prenatal development: Biological parents age
Teenagers
For teen mothers, it’s true that outcomes are poorer: children are at risk for premature birth, low birthweight, and academic and behavioural problems.
This is probably for two main reasons: the first is through social selection, meaning that certain kinds of teenagers are more likely to become pregnant, such as girls with conduct disorder, who are aggressive and prone to lying and rule-breaking.
They would then pass on their genes to the developing baby, and would probably also provide a poor environment in which to raise the child.
The second reason for poorer outcomes is because of social influence: pregnancy and birth can interfere with a woman’s ability to provide a positive environment for her child, like completing her education, obtaining a good job and providing resources, and having enough time to dedicate to parenting.
Programs aimed at helping teen mothers complete their education and learning positive parenting techniques can be helpful, and children tend to do a bit better if the mother lives with relatives who can offer financial and emotional support.
More research is needed on the influence of teen dads on children’s outcomes.
Influences on prenatal development: Biological parents age
Older
there is a huge trend for women to be increasingly older when having their first child. Do children fare well when their mother is in her 30s or older?
Actually, they tend to do just fine, and in many cases, they have advantages over other children since they’re more likely to come from parents who are more mature, knowledgeable, and financially stable.
Biologically speaking, fertility starts to decline in a woman’s 30s, but the dramatic drop offs in fertility that supposedly happen in the mid 30s are not actually true: most women are still quite fertile during this time.
On the other hand, it is true that fertility drops off with age, especially in the early 40s.
The risk of miscarriage also increases, although it’s still low. For men, fertility also decreases with age, but much less dramatically: men are able to parent a child even into their 70s or later.
Influences on prenatal development: Biological parents age
Older. Disorders and genetic mutations
Older age also increases the chances of certain disorders. For example, both female and male age increase the likelihood of Down syndrome in the developing baby, although major disruptions to chromosomes are more likely to come from the mother.
On the other hand, genetic mutations seem to be much more likely when fathers are older, but unaffected by the mother’s age. These genetic mutations make older fathers more likely to have children with autism spectrum disorder, schizophrenia, and dyslexia.
teratogen
The term teratogen is used to describe anything that has a negative effect on prenatal development.
thalidomide
In the 1950s and 60s, many pregnant women with morning sickness were prescribed a drug called thalidomide, which was thought to be safe.
Unfortunately, many babies started to be born with limb deformities: missing or deformed arms, legs, hands, and feet,
fetal alcohol spectrum disorder, or FASD, or the most extreme form, fetal alcohol syndrome (or FAS for short)
These children have a host of difficulties, including slow growth, heart problems and certain facial characteristics like a small head, a thin upper lip, a short nose and smooth or flat skin between their upper lip and nose, and widely spaced eyes.
Behaviourally, these children can have severe attentional, cognitive, and behavioural problems.
One of the many reasons why alcohol has these effects is that it reduces the flow of oxygen and nutrients to the developing baby.
Effects of smoking, marijuana use during prenatal development
Cigarette smoking is also very harmful for fetuses, since it constricts the mother’s blood vessels and also reduces the baby’s intake of oxygen and nutrients.
In fact, smoking can reduce the size of the placenta, so oxygen, nutrients, and wastes are not exchanged as easily.
This makes miscarriage more likely, as well as low birth weight, which puts the baby at risk for various other negative outcomes.
These other negative outcomes can include attentional, language, cognitive, and behavioural difficulties.
Even if a mother doesn’t smoke herself, frequent exposure to second-hand smoke also causes negative outcomes.
Less is known about the use of marijuana during pregnancy, but evidence suggests that it has similar negative outcomes as smoking cigarettes, including low birth weight attention problems, as well as difficulties with motor control.
One of the active ingredients in marijuana, tetrahydrocannabinol, or THC, is associated with cognitive and behavioural problems and premature birth, but researchers aren’t sure about cannabidiol, or CBD,
