Fertility & Conception


There are things that a couple should be doing to prepare themselves as parents.  First, women should be taking vitamins, especially 800mcg to 1000mcg (1mg) of folic acid each day as a vitamin supplement.  These vitamins are necessary for a developing baby and not having them in the first two weeks of pregnancy (before she even knows she’s pregnant) can cause birth defects.  So starting a prenatal vitamin or a multivitamin plus folic acid (equaling 800mcg) is suggested. 

Men on the other hand may need to stop some medications that may cause birth defects.  


If couples are trying to get pregnant, sexual activity may need to occur more frequently around the time she ovulates (2-3 weeks before your wife starts her period).  This can include being sexually active every one to two days.  For couples that aren’t in a rush to conceive within couple of months, then simply being sexually active when desired and letting pregnancy occur when it occurs is often less stressful on the couple.  For information on increasing the chances of getting pregnant or on infertility, see the section on infertility.


Fertility, as defined for men, is the ability to father a child.  For men, this requires multiple reproductive functions to be working in order – the ability to get an erection rigid enough to insert into the vagina, ability to ejaculate, and presence of sperm in his semen.  For women, the ability to ovulate an egg and the ability to maintain a pregnancy are primarily important.  Infertility is caused either by disruptions in erections, ejaculation, and sperm count in men or ovulation issues in women.

Conception is defined as a sperm from the father fusing with an egg from the mother.  Conception occurs in the fallopian tubes.  Ovulation (releasing of an egg from the woman’s ovary) occurs once per menstrual cycle.  So if a woman has a menstrual cycle every four weeks, she will ovulate only once every four weeks.  After ovulation, the fimbriae draw the egg into the fallopian tubes through their wafting motions.  After an egg is ovulated, it must be fertilized within 10 hours by a sperm.  After 10 hours, the egg is not viable for fertilization. 

On average it take nearly four days for a fertilized egg to pass through the fallopian tubes and down into the uterus.  When it attaches to the wall of the uterus we call this “impregnation” or becoming pregnant.  The rich endometrium that lines the inside of the uterus then serves as a rich blood supply to which the baby’s placenta can attach to receive nutrients and eliminate waste products.


Sperm is introduced into the female reproductive tract through the release of semen during sexual intercourse.  This obviously requires that the penis become erect and rigid in order to enter the vagina.  Ejaculation should occur within the vagina – preferably as high up in the vagina as possible next to the cervix.    The pumping action of the penis and the high pressure release of semen from the penis help propel the sperm into the cervix.  Sperm then must swim through mucus in the os of the cervix that acts as “plug” or barrier between the vagina and the uterus. 

Millions of sperm are released with each ejaculation.  In fact, there are 15 million to 200 million sperm per milliliter of semen.  When we think about 2.5-5 ml being the average amount of semen ejaculated, anywhere from 40 million up to 1 billion sperm can be ejaculated at a time, although around 200-300 million is typical.   Anything less than 15 million sperm per milliliter or less than 39 million sperm per ejaculation is considered “low” and may be a cause for difficulties becoming pregnant.  The reason so many sperm are released is to increase the chances of fertilizing an egg.  Less than 1 in a million sperm will make it to the fallopian tube (where conception occurs).  Of the 100-300 million sperm released in the vagina, only 60-80 million will make it through the cervix.  During the time near ovulation, the mucus in the cervix thins out a little to give sperm a fighting chance at entering the uterus.  At other times of the month, even less sperm may get through the cervix.  The number of sperm then takes another drop as only 100,000 (less than 1 in 10 sperm) will make it through the os to the uterus.  After swimming approximately 4 inches in the uterus, only 200 or so sperm may reach the fallopian tubes.  Sperm are viable to fertilize and egg for up to three days; however, they may take one to two days to swim up to the fallopian tubes where pregnancy occurs.  If a couple is trying to become pregnant, it is best to have intercourse two days prior to ovulation to maximize the number of sperm present when the egg is ovulated. 

If the sperm makes it to the fallopian tubes, it can be directed to the egg through chemical signals that help it find its way.  Once a sperm has fused with an egg, a change occurs in the outer layer of the egg that will prevent additional sperm from fertilizing the egg – we now call this fertilized cell a zygote.  The zygote will then divide (called first cleavage).  Over the next three days continue dividing leads to a mass of cells called or morula).  Over the next day, the morula will then begin to hollow out into portions that will become the baby and another portion that will become the placenta – this is called a blastocyte.  The blastocyt then arrives in the uterus where implantation in the uterine wall can occur – we can then officially say a woman is pregnant.  This is nicely outlined in the illustration below.

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Planning and actively working towards pregnancy can be an exciting time for a couple.  However, if expectations are unrealistic (all we have to do is have unprotected sex once and we will get pregnant) can lead to frustration.  In fact, most couples can take anywhere from 6-12 months of frequent, unprotected sex in order to conceive a child.

For information on infertility or how to increase your chances of becoming pregnant, click HERE.



Often the first sign of pregnancy is when a woman misses her period.  If she does not have regular periods she may not know for a few weeks.  Pregnancy tests that are found over the counter sometimes don’t show pregnancy until a few weeks into pregnancy, so if a woman gets a negative test but still wonders, then she can wait a few days and try the test again.

Pregnancy can be a magical time for couples as they anticipate bringing a child into the world.  Having a medical provider to follow a woman during pregnancy is important to her health and the health of the developing baby.  Some men may wonder if sexual activity may continue during pregnancy, and in nearly all pregnancy, sexual activity poses no risk to the pregnancy; however, asking a her healthcare provider can let a couple know how to proceed sexually during the pregnancy.



Many of the medications that can disrupt fetal development are medications that are prescribed to men, not women.  Therefore, a man who is sexually active and could father a child and more importantly a man who is sexually active with a pregnant woman should take precautions to prevent malformations in the developing baby.  However, it is worthy to note the two main drugs that should be avoided. 

  • Testosterone blockers are often used in men to prevent male pattern baldness or treat prostate disorders.  The most potent are called 5-alpha reductase inhibitors and include medications such as dutasteride (Avodart®) and finasteride (Proscar® and Propecia®).  These medications prevent testosterone from converting into DHT (dihydroxytestosterone) which dictates the formation of the male reproductive system and glands.  These medications are so toxic to a developing male fetus that exposure by a pregnant woman (even simply touching an unsealed tablet or capsule can result in major birth defects or death of the fetus).  In men who take these medications, the drug has to be excreted or discharged in some way from the body.  Some of this occurs through the urine and in some small amounts in the semen.  Therefore, when a man has intercourse with a pregnant woman, he can expose the woman (and thereby his unborn child) to these hormone disruptors through his semen.  Men are often advised not to take 5-alpha reductase inhibitors when trying to father children or when their wives are pregnant.  Of special note, finasteride only takes 5 days to clear the body.  However, dutasteride can take 6 months for the body to clear.  So in the case of men taking dutasteride, they may need to wait six months or more after stopping dutasteride before trying to father a child.  If drug therapy is necessary after pregnancy has begun, then the use of condoms are recommended during sex to prevent exposure of the mother to drug in the semen. 

  • Testosterone replacement is used medically in men with low testosterone levels and is often used cosmetically for athletic performance.  If a man is going to be fathering a child, many healthcare providers recommend injections rather than topical agents to prevent the woman from absorbing testosterone from skin to skin contact with the skin area where her husband applies testosterone gel to (arms, shoulders, torso, thighs, etc.).  If testosterone can absorb through a man’s skin into his body, then it can absorb into a girl or woman’s body as well.  Exposure to topical testosterone is not only a concern during pregnancy, but fathers with young children in the home may also inadvertently expose his children to testosterone by skin to skin contact (children’s hands on their father’s shoulders or torso).  If a young boy is exposed to testosterone it may trigger puberty long before it is due.  If a young girl is exposed to testosterone, it may trigger male type genital growth (clitoris elongating into a penis-like structure).  Women and children should not handle or touch skin surfaces that have been exposed to testosterone products.

Some hormone disruptors can also be given to women as well.  One medication that is no longer available in the United States was routinely given to pregnant women to prevent miscarriage.  This drug was called diethylstibesterol or DES.  Reproductive disorders were triggered by exposure to DES; however, most of the information is in regards to girls born to DES mothers.  Since this is a sit about men, it is important to note that reproductive disorders were caused by exposure to DES sons.  These included malformations of the male genitals[i] and sexual glands as well as lower testosterone levels throughout life.  These birth defects include penile malformations like epispadias and congenital penile curvature as well as some prostatic disorders that may predispose a man to prostatitis and prostatic congestion.  The rate of birth defects was anywhere from two to five times greater in DES sons than in boys whose mothers were not exposed to DES.  Furthermore, although studies have not looked at mothers that took DES, studies with granddaughters have been performed.  This typically would occur in boys whose grandmothers took DES when pregnant with their mother.  Since girls are born with all of the eggs they will ever have, then a girl was exposed to DES during fetal development can be born with eggs affected by DES and pass malformations onto her children.  It is thought that boys born to mothers who took DES are less likely to pass on these birth defects since men are continually producing new sperm and don’t make sperm at birth. 



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  1. diluck/Shutterstock.com