Menstrual Cycle
• Fertilization occurs when with the sperm and ovum unite
• The fertilized ovum is now called a zygote
• This zygote will implant
... [Show More] approximately 6-8 days after ovulation
• The zygote matures into a blastocyst
• The blastocyst will cause the body to produce human chorionic gonadotropin (hCG). This tells the corpus luteum to
continue secreting progesterone to maintain the pregnancy until the placenta takes over production when it develops
fully, 2-3 months later.
• Ovarian Changes
o Preovulation phase: Starts FSH + LH secretion -> ends with follicular rupture and release of ovum
o Luteal phase: ovulation -> starts with declining estrogen and ends with progesterone
• Uterine Changes
o Menstrual phase (4-6 days): Starts with menstruation -> ends with increasing FSH, starting a new cycle
o Proliferation phase (about 9 days): Starts with increase estrogen production, which causes the decreasing FSH
and increase of LH -> ends with ovulation, high levels of estrogen, low levels of progesterone
o Secretory phase (about 12 days): starts in response to increased LH -> corpus luteum secreting progesterone
OB Assessment
Gestation
• From time of conception to estimated date of delivery
• Nägele’s Rule: the patient must have a normal 28-day menstrual cycle, – 3 months, + 7 days to the first day of the
last period, + 7 days to the last period, then count ahead 9 days
Gravity and Parity
• Gravida = pregnant woman
• Gravidity = number of pregnancies
• Parity = the number of births carried to a viable gestation age (past 20 weeks), whether or not the fetus was born alive
• The number of pregnancies/births is what is counted, so if the mother has had twins, triplets, etc. that would be counted
as 1
• Nullipara = never given birth
• Use of GTPAL acronym- please note, this system explains parity in more depth than just saying number of births carried to
a viable gestational age. It’s not different, it’s just further explaining parity
G Gravidity = Number of pregnancies, including any current pregnancies (regardless of current gestational age)
T Term births = number of children born at 37+ weeks gestation
P Preterm births = number of births between 20-37 weeks
(so twins, triplets, etc. count as 1 birth)
A Abortions = number of miscarriages, abortion (include in gravidity if before 20 weeks, include in parity if past 20 weeks)
L Living children
Important Signs of Pregnancy
• Signs of pregnancy are divided into 3 categories
o Presumptive signs = “You might be pregnan [Show Less]