This document summarizes key aspects of human reproduction and gestation. It discusses the stages of gestation including early, full, and late term periods. It describes health risks associated with prematurity and going past the due date. The document outlines the three trimesters of pregnancy and details the structure and functions of the uterus. It provides information on uterine size changes during and after pregnancy. It defines menopause and notes the average age of occurrence. Finally, it lists common hormonal changes and symptoms that can happen during menopause.

1. CHAPTER 10
THE REPRODUCTIVE
SYSTEM

2. Gestation
• The time required for the development of a fetus is called gestation.
• The time period averages about 40 weeks although duration does vary
• Early Term: A gestation period between 37 weeks, 0 days and 38 weeks, 6 days
• Full Term: A gestation period between 39 weeks, 0 days and 40 weeks, 6 days
• Late Term: A gestation period between 41 weeks, 0 days and 41 weeks, 6 days
• Post Term: A gestation period after 42 weeks, 0 days
• The chance of health risks to the mother and fetus increases the further away
from a full term gestation period
Health risks of premature/early
term
• Delayed mental/physical
development
• Breathing/ respiratory problems
• Hearing loss
• Feeding and digestive problems
• Death
Health risks of late term/post term
• Increased cesarean or forceps
assisted birth
• Longer labor and increased
stress on mother
• Improper nourishment from
extra calcium and protein in
placenta

3. Stages During Gestation
Gestation is also divided into 3
trimesters
• 1st trimester- Last period through the
13th week
• 2nd trimester- Week 14 through
week 27
• 3rd trimester- Week 28 through week
40

4. The Uterus
The organ in which the developing fetus resides is called the uterus.
Located in the pelvic cavity between the bladder and the colon
Divided into three sections:
Fundus: The upper portion of
the uterus, opposite the
opening to the vagina
Corpus: The central portion of
the uterus and the largest
region
Cervix: The lowest portion of
the uterus that opens to the
vagina
Made up of 3 layers
Perimetrium: Outermost
layer, attached to ligaments that hold
the uterus in place
Myometrium: Middle layer, made of
very thick smooth muscle, contracts
during labor to expel the fetus
Endometrium: Inner layer, contains a
rich blood supply in order to support a
growing fetus; gets expelled during
menstruation if there is no fetus

5. Uterine Sizes
• The average uterus is about the size of an orange without
a fetus.
• At full term pregnancy, the uterus has stretched to about
the size of a watermelon
• Within 1-2 days postpartum, the uterus shrinks down to
the size it was at 18 weeks prenatal
• At 1 week postpartum, it has shrunk to it’s 12 week
prenatal size
• At 6 weeks postpartum, the uterus has returned to it’s
normal size.

6. Menopause
The cessation of menstruation is called menopause.
• This is commonly defined as the time when a woman ceases having her
period and the condition of her uterus.
• The exact date of menopause is considered to be when a woman finishes
the flow of her last menstrual cycle
• Menopause is a gradual occurrence, it does not happen over night
• Menopause usually occurs in a woman’s late 40’s or early 50’s, although
the average age in the US is 51
• Post menopause, a woman’s ovaries are no longer active and she is
infertile, however she can still be sexually active.

7. Menopausal Hormone Changes
• During menopause, hormone levels fluctuate. Some of
the hormones and their functions are:
• Follicle-stimulating hormone (FSH) and Luteinising Hormone- Act in tandem to control
the production of estradiol, testosterone, and progesterone. High levels of FSH identify
if a woman is postmenopausal
• Estradiol- Strongest of the estrogens in a woman’s body and acts as a growth hormone
for tissue development, especially the lining of the uterus during menstruation. Created
primarily in the ovaries.
• Progesterone- Plays a large role in pregnancy and fertilization of ovum. Allows the
sperm to find the egg to begin fertilization process. Created primarily in the ovaries.
• Testosterone- Influence sexual arousal in women and testosterone patches are often
used in postmenopausal women to help with low libido. Created primarily in the ovaries
during menstruation.

8. Menopausal signs and symptoms
• Due to the changes in hormones, women will potentially
experience the following perimenopausal symptoms:
• Mood swings
• Depression
• Anxiety
• Irritability
• Hot flashes
• Palpitations
• Decreased skin elasticity
• Increased risk of
osteoporosis
• Vaginal itching and
dryness
• Difficulty reaching
orgasm
• Increasingly erratic
menstrual cycles