semen fertilise egg to get pregnant

How Much Semen Does It Take To Get Pregnant?

Worried that you might be producing too little semen? Semen volume isn’t the only, nor most important, factor when trying for pregnancy. Here’s the lowdown on how much semen is actually needed for pregnancy.

The popular conception of, well, conception is that it happens when one sperm survives the long and arduous journey required to finally meet the egg

But if that’s strictly true, why do men need to expel between 1.5ml to 7ml of semen that contains between 15 million to 200 million sperm cells per ejaculation [1]? Could it be that men’s stubborn refusal to follow directions is actually encoded at a genetic level? 

Well, it turns out that it's not simply nature applying an overabundance of caution. Semen volume can impact your chances of getting pregnant, but it is important to note that how much ejaculate you produce is not the only factor that determines your fertility. 

The difference between sperm and semen

Before we dive into things, it might be useful to discuss the difference between sperm and semen.

Sperm is the male germ cell that carries a genetic copy of the male, expressed as 23 chromosomes. This is exactly half the number of chromosomes required for a healthy baby to form, and when combined with the other 23 chromosomes contained in the egg goes on to do just that [5]. 

Sperm is suspended and nourished by semen, which is a fluid that is produced in the seminal vesicles in the testicles, prostate and bulbourethral glands [2].

Upon ejaculation, semen coagulates and takes on the appearance of a thick, white fluid, but turns more watery within 20 minutes [3]. This liquefaction is important as it helps sperm gain the motility required to start off on its journey towards the egg, and failure of semen to liquify (or semen that stays too viscous) can be a cause of male infertility [4].

The bulk of semen’s volume is made up of fructose, which is used as an energy source by sperm. Other nutrients including proteins, amino acids, potassium, magnesium and zinc are also present. The last, zinc, plays a crucial role in stabilising the DNA of sperm  [2].

So while it is sperm that makes the journey to meet and fertilise the egg, semen is also important in the nourishment, protection and delivery of sperm. 

How much semen does it take to get pregnant?

The World Health Organisation sets a reference range of between 1.5ml and 7.5ml for semen volume per ejaculation [6]. With such a wide range (up to 5 times difference), we can infer that the actual volume of semen isn’t as important in pregnancy as many presume it to be. 

Additionally, more than semen volume, what is more important in pregnancy is sperm motility, morphology and count.

In a normal sperm count, at least 15 million sperm per ml of semen is present. Anything lower indicates low sperm count, which makes pregnancy harder to achieve [8]. 

As for motility, sperm needs to move in a relatively forward direction in order to progress along the route to meet the egg. Morphology can affect motility as misshapen or improperly formed sperm cannot move in the right direction, or even at all. Such sperm may also not be able to penetrate the shell of the egg [9].

Therefore, for best chances of pregnancy (assuming there are no other infertility causes), semen discharged should contain at least 15 million sperm per ml, with an overall sperm motility rate of 40% or higher [10].

And even though there are millions of sperm at the start of the race to meet the egg, it is estimated that only around 2 hundred sperm actually complete the journey [11]. What happened to the rest?

Well, some of them may be ‘non-starters’ due to poor motility or morphology, while others may be lost along the way due to a number of biochemical and physical obstacles, including semen leakage, the body’s natural defences, or even entering the wrong fallopian tube [11].

The ‘finalists’, once they reach the egg, begin working on weakening the shell of the egg. This continues until a single sperm manages to penetrate the egg and fertilise it, kicking off the process of forming an entirely new human [11]. 

So even though there is only one eventual ‘winner’, fertilising the egg is a team effort for sperm, in which the more viable sperm there is, the better the chances of conception.

How do I find out if I am producing enough semen or sperm to get pregnant?

Well, you could try ejaculating into a container and measure how much semen there is with a syringe. You could also attempt to eyeball your volume — 5 ml is about how much liquid you can scoop up using a standard teaspoon. 

However, as discussed above, semen volume is not the only (or even the most important) factor in getting pregnant. Hence, a semen analysis performed by a fertility clinic or certified laboratory may be the better option, as you will be able to find out in detail if your sperm are within normal range [12].

Does low semen volume mean I can’t get pregnant?

No, having low semen volume doesn't completely rule out the possibility of pregnancy. It is still completely possible to get pregnant even with a low amount of sperm. Just consider the abysmal success rate of the ‘pull-out’ method of birth control that is estimated to be about 78% [13]. 

Also, semen volume decreases naturally with age, with one study finding a near 30% decrease from age 45 to age 56 [14]. Yet, many older men still manage to conceive naturally. 

Nevertheless, low semen volume — less than 1.5 ml per ejaculation — may be a sign of low testosterone or other fertility or health problems, especially if onset is acute [7]. This could create obstacles in getting pregnant. 

Tips for increasing pregnancy success rates with low semen volume

Make sure your sperm is in tip-top shape

Perhaps the most important tip for improving your success is to ensure that your sperm is in the best shape possible. You should start by finding out important parameters such as your sperm count, motility and morphology, and consulting a fertility specialist for personalised guidance on how to resolve issues or improve your sperm health.

Also, it is worth noting that an unhealthy lifestyle can impact sperm and semen quality, so taking steps to improve problematic areas may also have a beneficial effect. 

Check for semen non-liquefaction

As mentioned earlier, semen coagulates upon ejaculation, and slow turns watery again within 20 minutes.

However, in some cases, semen take an abnormally long period to liquify, reducing sperm motility. The causes of semen non-liquefaction are inflammation of the prostate and/or the seminal vesicles [15]. As dark as it might seem, this condition is reversible! Some healthcare practitioners have found that it responds well to treatment with alpha-amylase [16]. 

Reduce semen leakage

After sex, some semen may be lost through leakage, which in turn, reduces the number of viable sperm available for fertilisation. As such, reducing the amount of semen leakage may be helpful when dealing with low semen volume.

As a fertility product for men and women, the twoplus Fertility Sperm Guide (S$68 single, S$138 3-pack) is a designed to ensure maximum sperm retention after sex. Made from medical grade soft silicone, the Sperm Guide is easily worn inside the body before sex, and has a smooth flap for the penis to glide over. It is also biocompatible with sperm and has small grooves that help guide semen towards the cervix. 

Learn More About The Sperm Guide

 

Sources:
[1] Healthline, What Is A Normal Sperm Count?,  https://www.healthline.com/health/mens-health/normal-sperm-count
[2] stdcheck.com, What Is Semen Made Of And Where Does It Come From?, https://www.stdcheck.com/blog/what-is-semen-made-of/
[3] National Centre for Biotechnology Information, Semen Analysis And Sperm Function Tests: How Much To Test?, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3114587/
[4] PubMed.gov, Mechanism Of Semen Liquefaction And Its Potential For A Novel Non-Hormonal Contraception, https://pubmed.ncbi.nlm.nih.gov/32529252/
[5] Invitra, What Is A Sperm Cell Like? Its Structure, Parts And Functions,  https://www.invitra.com/en/sperm-cell/
[6] Oxford Academic, World Health Organisation Reference Values For Human Semen Characteristics, https://academic.oup.com/humupd/article/16/3/231/639175
[7] Men’s Health, Is Your Semen Volume Normal? Here's How To Tell., https://www.menshealth.com/health/a19538361/semen-during-sex/
[8] Healthline, Oligospermia And Fertility: What You Should Know,  https://www.healthline.com/health/mens-health/oligospermia
[9] Mayo Clinic, Abnormal Sperm Morphology: What Does It Mean?, https://www.mayoclinic.org/diseases-conditions/male-infertility/expert-answers/sperm-morphology/faq-20057760
[10] Mayo Clinic, Getting Pregnant, https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/fertility/art-20047584
[11] Invitra, How Sperm Meets Egg: A Journey From Production To Fertilisation, https://www.invitra.com/en/sperms-journey-to-the-egg/
[12] MedlinePlus, Semen Analysis, https://medlineplus.gov/ency/article/003627.htm
[13] WebMD, Pull Out Method (Withdrawal), https://www.webmd.com/sex/birth-control/pull-out-withdrawal
[14] Wiley Online Library, Semen And Sperm Reference Ranges For Men 45 Years Of Age And Older, https://onlinelibrary.wiley.com/doi/full/10.2164/jandrol.05156
[15] Fertilitypedia, Non-Liquefaction Of The Semen,  https://fertilitypedia.org/edu/symptoms/non-liquefaction-of-the-semen#/
[16] PubMed.gov, Infertility And Semen Non-liquefaction,  https://pubmed.ncbi.nlm.nih.gov/1117524/