Fertility 101

Posted by on November 16, 2012 in Fertility Facts | 0 comments

1% of couples experience infertility. Infertility is defined as one year of trying to conceive without success.

As women age, the chance of conceiving in any month declines from a high of 25% per month at age 20 to 5% per month to age 40.  We recommend an evaluation after that first year of trying . If you are > 35 years old after only 6months of trying, experts suggest an evaluation. This is not a contradiction; although it may take an older woman longer to conceive we recommend the evaluation sooner because if something is wrong there is more time to correct the problem.

So what is checked in a fertility evaluation. There can be problems with oocytes or eggs,  sperm , tubes and/or the uterus.

EGG FACTOR

First and foremost, it is necessary to confirm ovulation or the release of the egg from the ovary. Regular cycles are highly suggestive of ovulation but not confirmation. A positive midcycle LH surge with a   period 2 weeks later, progesterone levels>3 ng/ml drawn one week before the period is hormonal evidence of ovulation. Watching the disappearance of the dominant ovarian follicle on the ultrasound is confirmatory. Post ovulation basal body temperature also rises by a degree.  35% of female factor infertility is from not ovulating. If anovulation is discovered, first a reason for this must be elucidated and then a treatment plan designed.

As mentioned above, age is a significant factor in fecundity rates  the chance of getting pregnant in any one month). Chronological age is what most people know but the ovary and ovarian age may not be the same as the chronological age. In other words, some women have less  eggs at any specific age and this may affect their fertility chances. An assessment of “ovarian age” is usually done with a fertility evaluation. An ultrasound can be done and the “antral follicle count” (AFC) measured: this means the number of small ovarian follicles seen in each ovary counted when  a women is on her menses (period). A low AFC suggests fewer eggs and a lower response to fertility meds. Antimullerian hormone or AMH is a hormone made by the small ovarian follicles (the eggs that have not yet started to grow and ovulate). This level gives insight to how many follicles are left in the ovary and a low number may predict the onset of menopause at an earlier age. A low AMH may also predict a low response to fertility medications. FSH and LH are two hormones made by the pituitary gland (the master gland that controls the ovaries). When the ovary starts running low on eggs, FSH levels may start to rise. Levels > 10 or 14 (there is lab to lab variation) suggests the pituitary is working harder to make the ovary ovulate. This is another sign of ovarian aging and again predicts a lower response to fertility medications and a higher chance of treatment cancellations. Taken together these blood tests and ultrasound measurements combine for an ovarian age assessment. This combined with your age may help you and your doctor  determine success rates with fertility treatment s and likelihood of cancellation of treatment prior to finishing treatment. Quality of the egg is probably still most closely associated with your real chronological age.

TUBAL FACTOR

The fallopian tube is where fertilization occurs. The oocyte (egg) leaves the ovary and finds its way into the tube. The sperm negotiate the way from the vagina after sex and travel up the cervical canal through the uterus and out to the end of the tube to find the egg. If the tube is blocked at the junction of the uterus, the sperm are stuck in the uterus and can’t fertilize the egg. If the end of the tube is blocked, the egg can’t get into the tube and fertilization cannot occur. If the end of the tube is narrow or damaged, fertilization may occur, but the embryo may get stuck in the ovary. 1-2 % of pregnancies are in the fallopian tubes; these are compatible with delivery and can be life threatening to the mother. These pregnancies are removed surgically or medically. Extremely dilated tubes can also lower implantation or pregnancy rates from an IVF (IN VITRO FERTILIZATION) cycle and probably from natural fertilization as well. It is recommended to remove these very  dilated abnormal tubes rather than open them up. Mild tubal disease with adhesions/scar tissues can be corrected w surgery or bypassed with the use of IVF. Severe adhesions/scar tissue and blocked tubes are best dealt with w IVF.  An HSG is done to check the tubes: dye is pushed backwards from the cervix through the uterus and then through the tubes. If the dye is blocked along its way , an obstruction is noted. This test is traditionally done with XRAY dye and  fluoroscopy/Xray equipment. It can also be done now with normal saline ( salt water) and air mixed together and then viewed on the ultrasound machine.

UTERUS

The uterus is the womb where the baby grows. If the lining doesn’t grow right, it may not accept a pregnancy. Lack of hormones may be the reason for poor uterine growth. Uterine adhesions( scar tissue) or polyps or myomas( fibroids) may also be uterine reasons for a lack of pregnancy. An ultrasound should be done to ensure the cavity is normal shaped and has no growths such as myomas or polyps. A telescope can be inserted to look inside the uterus to ensure there is no scar tissue.  The uterus may also have not been formed correctly. A small subset of women were born with variants to the regular uterine shape and this may affect pregnancy success. Again, an ultrasound, 2d or 3d, may be done to check the uterus. THE HSG ( see above) can also check inside the uterus for possible masses. Myomas are masses: noncancerous growths that can grow in the uterine cavity or in the uterine muscle. These may or may not affect pregnancies: Size and location are major determinants of the need for removal of the myomas. At times, biopsies of the endometrium ( uterine inside) is done to check for infection or other causes of lack of implantation of an embryo.

SPERM/MALE Factor

Sperm is essential to a pregnancy and indeed in about 50% of cases, there is some element  of a male reason for subfertility. A semen analysis should be done at the outset of the fertility evaluation. Normals are considered >20million sperm per mL, 40% motile and 14 % normal. Semen volume should be between 2 and 6 ml and there should be normal PH, no clumping of sperm, and no or very few white cells. If semen parameters are abnormal, hormone tests and general health lab tests should be ordered. In addition a consult with a  urologist or endocrinologist should be done. If the count is much below 2mil/Ml then analysis of the male partners genes and chromosomes should be evaluated. Although 20 mil/ml is considered the normal count because fertility rates seem to decline below this count, most men have a semen analysis above 40 mil/ml. There are other tests of sperm: presently some doctors order tests to check the integrity of the DNA in the sperm cells: SCSA, Tunel, acridine orange test.

A FULL INFERTILITY DIAGNOSTIC WORKUP CAN USUALLY BE PERFORMED WITHIN ONE MENSTRUAL CYCLE> THIS SHOULD BE DONE PRIOR TO TREATMENT.

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