Anatomy & Physiology of Pregnancy

pregnancy

• aka gestation

• 40 wks or 280 days

• measured form last menstrual period

• Naegele’s Rule": (LMP - 3 months) + 7 days

• 3 trimesters

  • 1st day of LMP - 13 wks & 6 days

  • 14 wks - 27 wks & 6 days

  • 28 wks - 40 wks & 6 dyas

pregnancy Hx

• gravidity: # of pregnancies

• Parity: # of pregnancies to reach 20 wks

• Nulli: none

• Primi: one

• Multi: 2 +

• GTPAL

  • gravidity

  • term births (37 wks +)

  • preterm births (viability to 36 wks & 6)

  • abortions (induced/miscarriage prior to viability)

  • living children

adaptations to pregnancy

• affect all body systems

• attribute to hormones & mechanical pressures

• adaptations:

  • protect normal physiologic function

  • meet metabolic demands

  • provide nurturing environment for fetal development & growth

signs of pregnancy

• presumptive

  • symptoms felt by mom

  • amenorrhea

  • breast enlargement/soreness

  • N/V

  • quickening

• probable

  • symptoms felt/seen by doctor

  • Goodell’s sign

  • Chadwick’s sign

  • Hegar’s sign

  • Ballottement

• positive

  • definite diagnosis for pregnancy

  • the baby is heard, felt, seen

verifying pregnancy

• blood/urine tests

• hCG

reproductive system - Uterus

• early enlargement results from:

  • increased vascularity/dialtion of blood vessels

  • hyperplasia

  • hypertrophy

  • development of decdiua

• later enlargement results from mechanical pressure

• from 4-70g to 1200g

• from 10 mL to 5 L

• height/shape changes

• lightening (dropping)

• Hegar sign - softening of lower uterus

• braxton hicks - intermittent contractions, don’t increase intensity or duration, don’t cause cervical dilation

• ballottement - feels like pushing on balloon (pushing on cervix)

• quickening - felt by mom

reproductive system - cervix

• responsive to hormonal changes

• firm, nondistensible, closed changes to soft, highly elastic

• Goodell sign - 6 wks, softening of cervix

• mucous plug

reproductive system - ovaries

• corpus luteum produces progesterone & estrogen

• placenta becomes primary source of progesterone at 10 wks

• estrogen & progesterone suppress FSH & LH = no ovulation

• amenorrhea

reproductive system - vagina

• prepares for stretching

• chadwick sign - violet blue coloring of vaginal mucosa & cervix (6-8 wks)

• increased vaginal discharge - leukorrhea

• microbiome change, lowering pH

reproductive system - breast

• fullness, heightened sensitivity, tingling, & heaviness

• increased pigment of nipple & areolae

• areolae enlarge & nipple become more erectile

• being prepared for lactation

• colostrum production & lactogenesis stage I

CV system

• blood volume increase; greatest increase in plasma

• CO increase

• BP remains same due to reduced systemic vascular resistance

• vena cava (VC) syndrome

• structural adaptation - slight hypertrophy

• blood components - increased WBC & hypercoagulable state

respiratory system

• oxygen consumption increases

• pregnancy-related dyspnea

• capillary engorgement in the mucosa (nose might get bigger)

GI system

• swollen gums

• pyrosis

• constipation

• N/V - hyperemesis gravidarum

• abdominal discomfort

urinary system

• enlarged kidneys

• dilated renal pelvis & ureter

• frequency

• proteinuria

integumentary system

• melasma (chloasma)

• linea nigra

• striae gravidarum

musculoskeletal system

• center of gravity shifts forward

• lordosis

• increased mobility of joints

• waddling gait

• diastasis recti abdominis

neurologic system

• alternation in sleep

• enhanced sense of smell

• carpal tunnel syndrome

endocrine system

• placenta - producing majority of hormones

• profound endocrine changes