Pregnancy Test
What was the pregnancy test that ancient greeks used? and how did it work?
pee on barely or wheat seeds if your pregnant then the seeds grows this was due to high levels of eostrogen in the pregnant women's blood
What doe the recent pregnancy tests detect
the hormone HCG
Qualitative blood preganacy test
yes or no answer available as early as 10 days
Monozygotic twins - identical twins
- morula splits - end up with two embryos
What releases the HCG hormone? and What does it contain?
- syncytiotrophoblast - glycoprotien hormone
Implantation of the blastocyst
- the endometrium swells - increasing the glycogen stores - trophoblast starts secreting enzymes to dissolve away the wall of the endometrium - paracrines are also secreted which increase the number of capillaries, allowing more oxygen and nutrients into the area
Invalid urine tests
- when no band is in the control area - only 1 band in the test region
How accurate is the home urine pregnancy testing
- you need to follow the instructions - take the test first thing in the morning(conc. urine) --> otherwise make sure the urine stayed in the bladder for 4 hours - do not drink excessive amount of fluid in an attempt to increase the volume of urine, this can make your urine dilute making HCG not detectable
What is the amount of HCG one week after postimplantation? And what happens to its leaves throughout preganacy
-50 mlu/ml - double every 72 hours till it reaches its peak during 3rd trimester - it then starts to decline and level off for the remainder or pregnancy
What morula
-formed after 3-4 days amid fertilisation - ball of cells - contains 30 cells
Zones of the pregnancy test from the shop (urine test)
1. Reaction zone - antibodies grab onto HCG - urine carries these antibodies to the next zone 2. Test Zone - where the test results show up - more antibodies are found - forms sandwich assay - allows enzymes to work and create a visible pattern - if not HCG present the wave of urine just passes by 3. Control zone - confirms that the test is working properly
Blastocyte
- Hollow-ball embryo that becomes implanted in the uterus. - 4-5 days
Quantitative blood pregnancy test
- meaures the exact amount of HCG present - can detect even at low levels - may help to track problems like ectopic pregnancy
What does HCG do to the body?
- development of the placentae - keeps the corpus luteum functioning - this continous to produce progestrogen and oestrogen until the plancenta is fully developed - the uterine lining will continue to thicken and strengthen and embryo can implant
Problems with these pregnancy tests
- false negatives--> when test is taken too early during pregancny, when certain beverages are taken - false positives - due to IVF injections, ecotopic preganacy, cervical or prostate cancer, certain fertitily treatments, miscarriages, previous pregnancy, certain rare conditions
Dizygotic twins
- fertilisation of two eggs - faternal twins
Factors that can give a negative result
1. you took the test too early during pregnancy - the conc of HCG is not high enough to be detected 2. not following the procedure properly 3. test not stored properly --> dont store at high temperatures 4. pregnancy tests vary in their sensitivity 5. if you let the test sit for too long the tests can be invalid
What is the amount of HCG at the time of the first missed menstrual cycle
100 mlu/ml
What is the amount of HCG at first trimester
100,000-200,000 mlu/ml
How long is the secondary ooctye viable for?
12-24 hours
How long does it take for the secondary ooctye to reach the urteeru s
4 days
How long is the sperm viable for?
5 days
when should the sperm be introduced into the female reproductive system?
5 days before ovulation -
When does implantation occur
6-10 days after conception
When can HCG be detected in blood?
6-15 after conception
HCG amount of non-pregnant females
<5.0mlu/ml
HCG amount in postmenopausal
<9.5 mlu/ml
What is the cut-off point for HCG positive pregnancy
>25 mlu/nl
What is HCG
Human Chorionic Gonadotropin A hormone found in the urine of women only when they're pregnant Produced during the early times of pregnancy
Where does fertilization takes place?
ampulla of the uterine tube
Where does implantation takes place
in anteroir posteroir uterine body