Source One:
http://uofmhealthblogs.org/womens/pregnancy-childbirth/oh-body-will-change-pregnancy/8463/
Posted by Helen Kang Morgan, MD on September 24, 2013
In addition to the obvious physical changes as your belly grows during pregnancy, what other surprises may your body have in store for you? Pregnancy is an exciting time, but often one filled with many questions — is my baby healthy, can I do this/eat that, and what the heck is happening to my body?
During your first trimester, you’ll probably feel tired, perhaps more tired than you’ve ever felt before. Get as much rest as you can. About 70 percent of women will also experience nausea or vomiting during their first trimester. Eating a balanced diet of bland foods can help. A great over-the-counter combination that has proven effective and safe in controlling nausea and vomiting is taking Unisom (or a generic version) and vitamin B6 before you go to sleep at night.
You may also experience in an increase in urinary frequency during the first trimester. This is caused by the increased progesterone in your body.. Throughout your pregnancy, you may experience heartburn, constipation and/or hemorrhoids, also caused by the increase in progesterone early in your pregnancy and the pressure from the baby later in your pregnancy. Drink lots of water and eat a high fiber, bland diet. Stay away from garlic and acidic foods like tomatoes. Over-the-counter antacids can help with the symptom relief.
You’ll see changes to your hair and skin. While you are pregnant, you lose less hair, giving you a wonderful, full head of hair. After pregnancy, you’ll start to lose that hair, but don’t be alarmed when it seems like you are losing a lot of hair. It’s just your body catching up. You’ll get back to where you started eventually. During pregnancy, your skin is more sensitive to sun, so be sure to protect yourself with sunscreen and a hat. Some women also experience acne. Unfortunately, other than good hygiene, there’s not much you can do for acne during pregnancy.
Some women, particularly those with darker complexions, also get what’s referred to as the “mask of pregnancy.” The dark splotches that can appear on your upper lip, nose, cheekbones, forehead and jawline are caused by an increased production of melanin during pregnancy. Increased melanin can also cause what is called linea negra — a dark line that appears from the belly button to the pubic bone.
The second trimester is probably the favorite time of pregnancy for most women — you feel good, your energy levels are higher, and you can feel the baby start moving. Some women also experience an increased sex drive.
As your pregnancy progresses, your joints will start to loosen as your body prepares for childbirth. This can cause joint pain, especially in your back. Treat the pain with acetaminophen, a heating pad and gentle stretching or yoga. Pregnancy belts, which are sold in many maternity stores, can also help.
Two other body changes you may experience are closely tied to genetics — varicose veins and stretch marks. Whether or not you get stretch marks depends on how much collagen you have in your skin. No expensive lotion or cream will change the amount of collagen or your likelihood of avoiding stretch marks. Because your blood volume increases by 20 percent during pregnancy, varicose veins are not uncommon. Compression stockings and avoiding standing for long periods of time can help.
You will certainly experience a wide range of physical changes during your pregnancy. Some are more pleasant than others, but always remember that your body is doing the amazing job of growing another life.
SOURCE TWO:
http://www.tulane.edu/~embryo/Lectures/exam%201/04%20pregancy%20physiology%20complete.pdf
Physiology of Pregnancy
• Maternal Physiology
• Fetal Physiology
• First Trimester
• Second Trimester
• Third Trimester
• Birth – Labor and Parturition
• LactationMaternal Physiology
• Basal metabolic rate increases 15%
• Cardiac output transiently increases 30-40%
• Blood volume increases 30%
• utilization increases 20%
• Ventilation increases 50%
• Renal tubule reabsorption increased 50%
• Glomerulus filtration rate increased 50%Weight Gain and Pregnancy
• Average – 24 lbs, can be as much as 75lbs
• Fetus – 7 lbs
• Extraembryonic fluid/tissues – 4 lbs
• Uterus – 2 lbs
• Breasts – 2 lbs
• Body fluid – 6 lbs
• Fat accumulation – 3 lbsFetal Physiology - Circulation
Fetal heart rate (FHR) – beating at 5 weeks –
100 beats/min
8 weeks – 160 beats/min
15 weeks – 150 beats/min
Birth – 130 beats/min
Bradycardia – slow pulse rate – very
dangerous to fetus
Blood flow – 40% to head/upperbody
30% to placenta
30% to lower body4-Chamber view
Aortic Root view
Pulmonary Artery & Duct view
Crest of Aortic Arch viewTricuspid Atresia
Atrioventricular septal defect
Right Ventricular tumorFetal Physiology - Lungs
Lung development – limiting for su
rvival of premature births – record 23 weeks
Pulmonary hypoplasia – reduced lung volumeFetal Physiology - Respiration
Gross breathing movements at 11 weeks
Rapid and irregular – associated with REM
(rapid eye movements
Function of fetal breathing:
Stimulates growth of the lungs
Conditioning of musclesFetal Physiology - Respiration
Pulmonary surfactants – produced 24 weeks –
phospholipids, proteins functions to reduce
surface tension – prevents lung collapse;
induced by glucocorticoids and thyroid hormone
Respiratory Distress Syndrome (RDS)
Common newborn health concern
Associated with low birth weight / Prematurity
Symptoms: rapid and labored breathing at birth
Cause: insufficient pulmonary surfactantFetal Behavior
Passive behavior
Early pregnancy – 7-15 weeks
All movement types present at 15 weeks
Diurnal pattern begins 20-23 weeks
peaks evening – maternal corticosteroid levels
Stimulated behavior
Vibro-acoustic stimulus (VAS) – broad band frequencies
Assay – FHR, fetal movements, breathing rate
Females – 28 weeks; Males – 30 weeks
Habituation (learning)
Cessation of response after repeated novel stimulation
Requires 10-50 stimuli
Discrimination of vowel sounds or parental voicesDigestive Tract
Development anticipates physiological function
Enzyme secreting cell differentiation begins at 11-
12 weeks, but secretion is inhibited until after birth
Meconium – fetal poop – fills the lower digestive tract
Swallowing begins early, 11-12 weeks, and
continues throughout development
• Peaks during the first Trimester
• Positive correlation with birth weight
• Negative correlation with spontaneous abortions
• Nausea – 50-70% of pregnant women
• Vomiting – 40-50% of pregnant women
• Less than 2% is solely in the morningNausea to continuous vomiting 1st trimester to entire pregnancy
Possible causes:
Elevated hCG
Elevated estrogen / progesterone
Bacterial (Heliocobacter pylori)
Serotonin levels
Hyperemesis Gravidarum -- Severe
NVP (0.5-1.0%) - life threatening – fetus and mother
– Dehydration, electrolyte
imbalance, nutritional deficiencies
Transcutaneous Acupoint electrical
stimulation (ventral wrist where
median nerve is close to the skin)Second Trimester
Frequent urination
Insomnia, Indigestion,
Muscle cramping
Pains associated with stretching uterus
Leukorrhea – vaginal discharge - increased
secretion, vagina and cervix
Pregnancy Blahs – 10% experience mild to
moderate depression
Breathlessness – pressure on diaphragm
Edema – ankles, toes – pressure on vena cava
and pelvic vein – restricts blood flow
Preclampsia – edema elsewhere – high blood
pressure, protein in urine, incidence 4%,
restricted blood flow to placenta
Two prevalent theories:
Hormones
Immune response to fetus
Symptoms disappear soon after birthEclampsia
Extreme degree of preclampsia
Vascular spasms throughout the body
Possible convulsions / coma
Decreased kidney output
Liver malfunction
Extreme hypertension
Lethal without treatment
Treatment: Vasodilators and cesarean sectionUltrasound Assisted –
Intrauterine Therapy
Hepatic Vein
Needle
Fetal Blood SamplingMonth Nine
Lightening – Fetus descends to pelvic cavity
Cervix – Dilation, Effacement (softening,
thinning)
False Labor – Contractions initiate then diminish
Labor:
Cervical effacement – dilation to 10 cm
Bloody Show – mucus plug of the cervix – blood-colored
Breaking Water Bag – rupturing of the amnion
Contractions – shorter intervals, longer, strongerBirthUterine Contraction
Uterine musculature becomes progressively more excitable
Estrogen/progesterone ratio changes increases excitability
Progesterone inhibits contraction
Estrogen increases gap junctional communication between
smooth muscle cells
Oxytocin (maternal posterior pituitary gland) increases excitability
Mechanically stretching uter
ine smooth muscle increases
contractility
Fetal oxytocin is also producedLabor and Parturition
Parturition: Process by which the
baby is born
Labor: Strong uterine contractions,
Cervix stretching, Forcing the
fetus through the birth canal
Rhythmic strong uterine contractions expel the fetus
Continuous contractions (tetanus) can stop blood flow and
lead to death of the baby
First stage of labor: cervical dilation (8-24 hours)
Second stage of labor: passage through birth canal (few
minutes to half hour)
Third stage of labor: expulsion of the placentaLabor and Parturition
Episiotomy – midline surgical
incision just prior to delivery
Forceps aided delivery
Expulsion is by uterine contraction Breast
Development
Puberty
Estrogen-dependent growth Fat deposition
Functional Breast Anatomy: Nipple, areola glands (secretory, prevents chafing)
Lactiferous ducts – connects ni
pple to mammary gland lobes, distal lactiferous sinus accumulates milk Mammary gland - 15-20 lobes, each divided
Mammary ligaments to breast skin supports breastBreast
Development
Pregnancy
Hormone-Dependent Growth
Estrogen
Growth Hormone
Prolactin
Adrenal glucocorticoid
Insulin
Growth and branching of the ductal system
Fat Deposition
Progesterone: Final stages – synergistic with other hormones – growth
of lobules, budding of alveoli, secretory characteristics, but not
secretionLactation
Estrogen and Progesterone
inhibit lactation
Prolactin:
Promotes milk secretion
Anterior pituitary
Hypothalamus (inhibition)
Steady rise week 5 - birth
Stimulates colostrum – low volume, no fat
Birth – sudden drop in Estrogen and Progesterone
1-7 days prolactin induces high milk productionLactation (cont.)
Other hormones are required:
growth hormone, cortisol,
parathyroid hormone
