Preconception Flashcards
(49 cards)
Development of female and male reproductive systems
-begins during first months after conception
-continue to grow and develop through puberty
Two faces of menstrual cycle…
-follicular phase is the first half of menstrual cycle and follicle growth and maturation
-luteal phase is the last half of menstrual cycle, begins after ovulation and formation of corpus luteum
Ovarian cycle hormones…
-during follicular phase, rise in FSH signals ovarian follicle to secrete more estrogen
-rise in estrogen feeds back to inhibit FSH secretion
-LH rises and peaks in mid-cyle
-LH rise triggers ovulation
-estrogen output deceases as mature follicle is converted to a corpus luteum
-corpus luteum secretes progesterone and estrogen during luteral phase
-progesterone output inhibits release of FSH and LH
-low LH results in corpus luteum degeneration
-progesterone levels decline
-FSH inhibition removed
-FSH rises initiating new cycle
Follicular phase
-one follicle usually grows more rapidly
-matures in about 14 days after beginning of follicular development
-follicle ruptures to release oocyte from ovary (ovulation0
-released oocyte enters oviduct
Luteal phase
-final 14 days of ovarian cycle
-follicular cells converted into corpus luteum
-corpus luteum produces progesterone and estrogen
-hormones prepare uterus for implantation if fertilized egg is present
-if fertilization or implantation does not occur corpus luteum degenerates
Uterine cycle
-reflects hormonal changes during ovarian cycle
-averages 28 days
-consists of three phases: menstrual phase, proliferative phase, secretory or pro gestational phase
Menstrual phase
-characterized by discharge of blood and endometrial debris from vagina
-first day of menstruation starts new cycle
-corpus luteum degenerates
-progesterone and estrogen levels fall
-triggers release of uterine prostaglandin
-uterine prostaglandins causes vasoconstriction of endometrial vessels
-blood supply disrupted and endometrium degenerates
-prostaglandins stimulates rhythmic contractions of uterus
-contractions expel blood and endometrial debris from uterine cavity (menstrual flow)
Proliferative phase
-begins with last portion of ovarian follicular phase
-estrogen from growing follicles promotes endometrial repair and proliferation
-phase lasts from end of menstruation to ovulation
-peak estrogen levels at mid- phase trigger LH surge responsible for ovulation
Secretory phase
-phase begins after ovulation when new corpus luteum is formed
-corpus luteum secretes large amounts of progesterone and estrogen
-progesterone converts endometrium to vascularized, glycogen- filled tisseu
-if fertilization and implantation do not occur corpus luteum degenerated and cycle repeats
Regulation of Testes
-testes are regulated by the anterior pituitary hormones, luteinizing hormone (LH) and follicle- stimulating hormone (FSH)
-LH and FSH are controlled by GnRH hypothalamus
-testosterone secretion is regulated by LH stimulation of the Leydig cells
-testosterone feedback inhibits LH secretion
Undernutrition and Fertility
-undernutrition among previously well- nourished women
-associated with dramatic decline in fertility; recovers when food intake improves
-food shortages have been accompanied by dramatic declines in birth rates
-body fat and fertility: excessive and inadequate levels of body fat are related to declines in fertility in women and men
-excessive body fat and fertility: more likely to be subfertile
-inadequate body fat and fertility: critical level of body fat is needed for reproductive functions
Nutrient status and fertility…
-antioxidant status and fertility: no reliable conclusions
-zinc status and fertility in men: deficiency can impair normal functions
-soy isoflavones and fertility: related to reduced sperm count in men and decreased fertility in woman
Nutrition during the periconceptional period…
-the time around conception
-one month before conception through three months after conception
-critical period when nutritional and other exposures can impact conception, pregnancy maintenance, and the growth, developement and health of the offspring
Preconceptional women…
-the recommended dietary intake and healthy dietary patterns
-400 mcg of folic acid
-more than 10,000 IU of Vitamin A
-limit or omit alcohol- containing beverages
-additional sources: Dietary Reference Intakes (DRI’s) and ChooseMyPlate.gov
Contraceptives contain forms of estrogen
-together estradoil and progestin suppress the action of LH and FSH and thereby ovulation
-progestin blocks LH and ovulation and induces a barrier to sperm by causing cervical mucus to become thick and sticky
Nutritional side effects of hormonal contraception…
-progestin only: weight gain and decreased bone mineral accretion
-combination contraceptives: altered blood lipid levels, increased blood and insulin levels, and increased stroke
Nutrition care standards developed by the National Academy of Nutrition and Dietetics
-part of new technology- based systems
-facilitate health- services delivery
-cost evaluation
-electronic charting
-coding and outcome measurement
-four steps: nutrition assessment, diagnosis, intervention, monitoring and evaluation
-the nutrition care process related to the preconception period: tailored to nutritional needs of women before pregnancy and reproductive needs of men
Healthy People 2020 Goals
-increase the proportion of women who are at a healthy weight prior to pregnancy by 10%
-reduce the proportion of women and men aged 18 to 44 years who have impaired fecundity by 10%
-increase the proportion of women who did not drink alcohol prior to pregnancy by 10%
-reduce iron deficiency among females of childbearing age by 10%
-increase the proportion of women of childbearing potential with intake of at least 400 mcg of folic acid from fortified foods or dietary supplements by 10%
-reduce the proportion of women of childbearing potential who have low red cell folate concentrations by 10%
-increase the proportion of women delivering a live birth who received preconception care services and practiced key recommended preconception health behaviors by 10%
estrogen
-stimulates release of GnRH in follicular phase and inhibits in luteal phase; stimulates thickening of uterine wall during menstrual cycle
Progesterone (progestin, progestogen and gestagon are similar)
-“progestational” it prepares uterus for fertilized ovum and to maintain a pregnancy; stimulates uterine lining buildup during menstrual cycle; helps stimulate cell division of fertilized ova; inhibits action of testosterone
hormonal effects during the menstrual cycle…
-at the beginning of the follicular phase, estrogen stimulates the hypothalamus to secrete GnRH, which causes the pituitary glands to release the follicle- stimulating hormone (FSH) and luteinizing hormone (LH)
-FSH promotes the growth and maturation of 6 to 20 follicles, or capsules in the surface of the ovary in which ova mature
-the presence of FSH stimulates the production of estrogen by cells within the follicles.
-Estrogen and FSH further stimulate the growth and maturation of follicles while rising LH levels cause cells within the follicles to secrete progesterone
-estrogen and progesterone also prompt uterine wall ( or endometrium) to store glycogen and other nutrients and to expand the growth of blood vessels and connective tissue
-these changes prepare the uterus for nourishing a conceptus after impantation
-just prior to ovulation, which usually occurs on day 14 of a 28-day menstrual cycle, blood levels of FSH ad LH peak
-the surge in LH level results in the release of an ovum from a follicle and ovulation occurs
-the luteal phase of the menstrual cycle begins after ovulation
-the hormonal activity that regulates biological processes during the half of the cycle is initiated by the cells in the follicle left behind when the egg was released.
-these cells form the corpus luteum from the original follie
-the corpus luteum secretes large amounts of progesterone and some estrogen
-these hormones now inhibit the production of GnRH and the secretion of FSH and LH
-without sufficient FSH and LH, ova within follicles do not mature and are not released
-estrogen and progesterone secreted by the corpus luteum further stimulate the development of the endometrium
-if the ovum is not fertilized, the production of hormones by the corpus luteum declines, and blood levels of progesterone and estrogen fall
-the decline removes the inhibitory effect of these hormones on GnRH release, and GnRH is again able to stimulate release of FSH for the next cycle of follicle development, and of LH for the stimulation of progesterone and estrogen production
-decreased levels of progesterone and estrogen also causes blood vessels in the uterine wall to constrict, allowing the uterine wall to release its outer layer in the menstrual flow
-these substances cause the uterus to contract and release the blood and nutrients stored in the uterine wall
-if the ovum is fertilized, it will generally implant in the lining of the uterus within 8 to 10 days
Sources of Disruptions in Fertility
Adverse nutritional exposure
Contraceptive use
Severe stress
Infection
Tubal damage or other structural damage
Chromosomal damage
-endocrine abnormalities that modify hormonal regulation of fertility are the leading diagnosis related to infertility
leptin
protein hormone secreted by fat cells; when abundant, causes brain to increase metabolism and decrease hunger
obese women…
-tend to have higher levels of estrogen, androgens and leptin than nonobese women
