Week 3: Prenatal Development

Advanced maternal age pregnancy (35+)

increased risk of:
- fertility problems
- miscarriages
- C section
- still birth
- down syndrome

- increase in use of assisted human reproductive techniques
eg.
Fertility drugs
Cryopreservation
artificial insemination

Antenatal

conception to postpartum

Pregnancy

physical condition in which a woman's body is nurturing a developing embryo or fetus - 40 weeks

Prenatal

Process that transforms a zygote into a newborn

first trimester

zygote implantation to 12 weeks

second trimester

12 and 24 weeks you begin to feel the fetus moving

third trimester

25+ weeks increased emotional attachment to fetus

Key issues in first trimester:

- ectopic pregnancy
- abnormal urine or blood tests
- increased blood pressure
- malnutrition
- bleeding
- miscarriage

Key issues in second trimester

- gestational diabetes (too much glucose)
- excessive weight gain
- increased blood pressure
- Rh compatibility of mother and fetus
- miscarriage 13-20 weeks
- premature labour 21+ weeks

key issues in third trimester:

- increased blood pressure
- bleeding
- premature labour
- bladder infection
- toxemia

Preeclampsia (or toxemia)

What is it?
- occurs in 3rd trimester
- sharp rise in blood pressure
- constricted blood vessels (including placenta, meaning poor
development of placenta)
- too much protein into urine
- end-organ dysfunction
- can result in hypertension

Symptoms?
- headache
- blurred vision
- swelling hands, feet, face

Treatment?
- deliver the baby
- lower BP

Eclampsia

When preeclampsia causes seizures or even comas
- 2nd leading cause of maternal death in US

Anoxia

- temporary lack of oxygen to the brain, babies who suffer low birth weight and anoxia are more likely to have learning disability's

Age of viability

in Ontario: 23 weeks
- when medical professionals will intervene to save a baby
- the chance of survival is low
- In London, medical intervention starts at 24 weeks (depending
on the weight of the baby)
- Precision medicine is increasing, therefore the age of viability is
decreasing
- BUT this means an increase in children born with complex care
conditions
- these children use 32% of health care spending

Prenatal Behaviour 9-12 weeks

fingerprints,
grasping reflex,
facial expressions,
swallowing and rhythmic 'breathing' of amniotic fluid,
urination,
genitalia appear,
alternating periods of physical activity and rest

Prenatal Behaviour 13-16 weeks

hair follicles,
responds to mother's voice and loud noises,
8-12 cm long - crown to rump,
weights 25-100g

Prenatal Behaviour 17-20 weeks

fetal movements felt by mother,
heartbeat detectable with stethoscope,
lanugo (hair) covers body,
eyes respond to light introduced into the womb,
eyebrows,
finger nails

Prenatal Behaviour 21-24 weeks

vernix (oily substance) protects skin,
lungs produce surfactant (vital to respiratory function),
viability becomes possible

Prenatal Behaviour 25-28 weeks

recognition of mother's voice,
regular periods of rest and activity,
good chance of survival if born now

Prenatal Behaviour 28-32 weeks

very rapid growth,
antibodies acquired from mother,
fat deposited under skin

Prenatal Behaviour 33-36 weeks

movement to head-down position for birth,
lungs mature

Prenatal Behaviour 37+ weeks

full-term status

Issues in prenatal development - Genetic disorders

- autosomal dominant disorders:
eg. Huntington's disease, extra fingers

- autosomal recessive disorders:
eg. sickle-cell, cystic fibrosis

- Sex-linked recessive disorders:
eg. red-green colour blindness, missing front teeth

Issues in prenatal development - chromosomal errors

Trisomy
- three copies - eg. Down Syndrome

Anomalies with sex
chromosomes
- Turner's syndrome

Issues in prenatal development - Teratogens

maternal disease- deviations in prenatal development stemming
from teratogens (agents causing damage to the fetus) - greatest risk is in the first 8 weeks

Teratogens - Obesity, Alcohol, Smoking

Obesity
- gestational diabetes
- hypertension
- childhood obesity
Alcohol:
- Fetal Alchohol syndrome
Smoking:
- higher likelihood of miscarriage
- higher risk of SIDS
- low birth weight

Teratogens - Marijuana, depression, anxiety

Marijuana
- developmental problems?
- higher rates of depression and anxiety
Depression
- miscarriage
- low birth weight
- high risk of postpartum depression
Anxiety
- Lower APGAR scores
- low birth weight

4 Categories of teratogens

1. Physical teratogens:
- saunas, hot tubs, woman's body temp raised to 102 degrees or higher
2. Metabolic conditions affecting pregnant females:
- abnormalities in the chemical process of producing energy from food, thereby affecting the development and function of the body
3. infections:
- maternal infections eg. rubella virus, herpes, syphillis
4. Drugs and chemicals:
- cause a variety of different effects based on specific agents, exposure and timing.

Fetal Alchohol Syndrome

Physical:
- facial malformations that usually includes small eye sockets, smooth skin between the nose and upper lip instead of a crease, and flattened cheekbones

Developmental:
- struggle with interpersonal boundaries, has trouble remembering things, shortened attention span, and struggle with motor skills, hyperactivity, impulsivity, inability to complete tasks/disruptiveness, poor social skills, need for constant supervision, and disregard for rules and authority

Cannabis as a teratogen

may affect:
- brain development
- behaviour
- mental health

0 – 3 years:
- Difficulty calming down, exaggerated startles, sleep problems
3 – 6 years:
- Poorer memory, more impulsive, less attentive, less able to understand
and follow instructions
6 – 10 years:
More hyperactive and impulsive, more difficulty learning, symptoms of depression and anxiety, more difficulty making decisions, less attentive
14 – 18 years:
Poorer school performance, delinquency problems, may try and/or use cannabis earlier, continue to be hyperactive, impulsive and less attentive

Depression as a teratogen

Untreated depression after the birth can lead to:
more negative face-to-face interactions with the baby, less eye contact during feeding, less playfulness with the baby, more withdrawal from the baby
Infants of untreated depressed mothers tend to:
look away from their mother, react with more crying, sadness and fussiness, have more trouble sleeping

Female fetuses

- more sensitive to external simulation
- advance more rapidly in skeletal development

Male fetuses

- more physically active in utero
- more vulnerable to all kinds of prenatal problems
- more likely to be spontaneously aborted and have birth defects

A mothers voice - Queens Study

Newborns appear to remember stimuli from the womb -they respond to their mothers voice
why?
- emotional connection
- bonding and attachment

Preterm/ low birth weight

- cerebral palsy,
- cognitive impairment
- visual and hearing impairment

extremely low birth weight, very low birth weight, low birth weight

ELBW
< 2.3lbs
VLBW
< 3.9lbs
LBW
< 5.5lbs
Normal
< 5.8 - 8.13lbs

- negative effects on mental and motor development
- negative impact on growth at 9-24 months

Types of Care

Prenatal:
health of mother
- blood pressure, urine, weight gain
health of baby
- uterus growth, heart beat, fetal movement

Intrapartum care:
- labour and delivery

Postpartum care:
- generally from birth to 6-8 weeks

Care: OB and Midwife

OB:
- twins
- high risk pregnancies
- high risk deliveries

Midwife:
- 'normal' baby
- single baby deliveries

Birth location

In London:

Hospital vs home

Home
- better health outcomes
- only offered to moms with with low risk births
- natural birth
- fear of hospitals
- 9% of 1st time moms, 21% of second time moms

Julia Moment

- steady increase in hospital births
- 2020 was highest year for home births
- In 2018, 71% of women received an epidural

Global shortage of 1.1 million reproductive, maternal, newborn and adolescent healthcare providers

Canada has 0.51 midwives per 10,000 population. Australia has 17.41

The 4 stages of Labour

1.
Muscles of uterus start to tighten and then relax these contractions help to thin (efface) and open (dilate) the cervix so the baby can pass through the birth canal
- typically longest stage
2.
The cervix is dilated completely (10cm) and the baby is born
-
3.
This stage occurs after the baby is born you have contractions until the placenta is delivered
4.
This is the first few hours after birth (breastfeeding etc)

The 3 types of Environment correlations

1. passive genotype-environment correlation
- children passively inherit the genes and the environments their family provides
eg. being athletic

2. Evocative genotype-environment correlation
- individuals seek out environments that support their genetic tendencies - niche picking

3. genotype-environment interactions
- genetic susceptibility to the environment
- adoption studies

The Germinal period

14 days
- conception to implantation of the fertilized egg in the lining of the uterus
- organism begins cell division through cell mitosis
- after 5 days of mitosis a blastocyst forms

Embryonic Period

3rd week
- blastocyst implants into uterine wall
- multi-cellular organism is called an embryo
- blood vessels grow to form the placenta

The fetal period

9th week until birth - organism is a fetus

Gestational Diabetes

- too much glucose in blood stream
- usually goes away after giving birth
- if untreated can cause:
- premature birth
- jaundice
- stillbirth

Hypertension

- pressure against artery walls becomes too high

gestational BP
- only occurs in pregnancy and goes away after birth
Chronic BP
- developed before or during pregnancy and goes away after birth

Rh Disease

Rh = a protein found in the blood
most people have this protein, but people who don't are Rh negative
- mothers who are rH negative are at risk for having a baby with a form of anemia called rH disease

hyperemesis gravidarum

characterized by severe nausea, vomiting, weight loss, and sometimes dehydration.
- if severe it can result in damage to the brain and liver and kidney
- treatment: drinking fluids and bland diet

Ectopic pregnancy

Zygote becomes attached to the fallopian tube before reaching the uterus.
- number of these pregnancies have been increasing because of the higher rates of pelvic inflammatory disease and chlamydia

Spontaneous abortion

experienced in 20-40% undiagnosed pregnancies and 10% in diagnosed pregnancies
- usually the body aborts due to chromosomal abnormalities before the 12th week of pregnancy

APGAR assesment

conducted 1 minute and then 5 minutes after birth
A: Appearance
P: Pulse
G: Grimace
A: Activity
R: Respiration

a score from 0-2 is given to each measure

Vernix

a newborn baby is covered in white substance - vernix that acts as an antibacterial barrier