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So what REALLY happens during conception and infertility?

science behind conception and infertilityWe all have a vague idea of what happens during conception but for many people, it isn’t something they’ve thought too much about since Year 9 science class.

The basic idea is pretty simple but the science behind it is fascinatingly complex.

So what EXACTLY does go on down there during conception? And why does it not always go as planned?

What happens during conception?

It’s all happening! A healthy, well-nourished egg is released from the ovary, and is caught by the waving arms of the tiny filaments around the end of the fallopian tube. This tube is about as wide as a hairbrush bristle, and about 10cm long. The egg itself is even smaller than the dot at the end of this exclamation mark! Isn’t that amazing, but to the sperm, the egg is a giant. Twenty five million sperm could fit on this full stop.

As far as sperm is concerned, we talk in millions. Normal sperm counts range from 30 to 60 million per milliliter of seminal fluid, which will result in a healthy male depositing 280 to 400 million sperm in the vagina during one ejaculation. This might seem like an enormous number when just one is needed to fertilize the egg, but sperm face many hazards on their journey.

They move along by lashing their tails, and are encouraged to do this by a substance found in the female reproductive tract. It takes them about an hour of vigorous tail-lashing to complete the 18cm marathon trip from the neck of the uterus, known as the cervix, to the place in the Fallopian tubes where, hopefully, the egg is waiting.

While the egg is waiting, part of the fluid that surrounds it sends out “love messages” to the sperm, alerting them to its presence and triggering their swim in the right direction. Perhaps these messages are selective, attracting the highly motile and vigorous sperm, rather than the very young or very old, which might be less viable.

On this journey, many of the sperm will be immobilized by the acidity in the vagina before they reach the relative safety of the alkaline cervix. Many get lost in the uterus, simply hanging around till they die, never finding the fallopian tube in which the egg is waiting.

An egg is normally released by one of the two ovaries in each cycle, usually alternately. Sperm might pick the wrong tube entrance. What starts off like a crowd at a fun-run thins out quite rapidly.

The egg will wait for a great-looking sperm for between 12 to 24 hours, but after that, it passes on. The sperm live longer, up to 3 to 5 days. Although they take 10 to 11 weeks to be produced, once released into the vaginal tract, 5 days is the most they can survive.

Before that lucky sperm can penetrate an egg, it undergoes a process whereby hormonal secretions in the female cause the release of two enzymes from the sperm, making the way clear for the final breakthrough by enabling the sperm to burrow through the egg’s two outer coatings.

The fertilized egg is then wafted down the rest of the tube, helped along by the tube’s rhythmic contractions, and by the hair-like projections that line it. This trip takes about a week, after which the egg reaches the uterus, and implants in the endometrium.

How can we help fertization happen?

  • We need to know when ovulation has taken place
  • It’s better to have sperm waiting for the egg than the other way round
  • Sperm and eggs must be “young” and strong
  • Frequent intercourse is needed during the peak fertile time

What’s also obvious is that the health of the egg and that of the sperm is fundamental to a healthy conception. There’s much focus on peri-conception (that’s the time when plans are made!) on behalf of the prospective mum, but very, very little focus on the other half of the procreative act! Peri-conception is defined as the time preceding, during and following the moment of conception.

The causes of infertility in men and women

Making a baby really does sound simple. A couple of ingredients from each partner, the correct “cooking time” and a bouncing bundle of joy should be yours about 40 weeks later.

The causes of infertility in men and women are well known.

They include:

  • hormonal disturbances
  • auto-immune diseases
  • infection
  • stress

So many factors behind these are well known, including:

  • obesity
  • a toxic lifestyle
  • poor diet
  • a person’s unique genetic tendencies.

Unfortunately, it’s now recognised that not only do these villains contribute to adverse pregnancy outcomes, they can increase a child’s risk of disease later in life.

How can nutrients increase conception?

It sounds a rather trite question, but how many prospective parents lack the essential phytonutrients and minerals that are important for optimum fertility? Less than half of Australian men and women aged between 19 and 44 don’t consume the recommended servings of fruits and vegetables (excluding potatoes). Mineral deficiencies are common, with average intakes of selenium, calcium, iodine and magnesium often below the recommended daily intakes.

The most specific nutrients which have been shown to have a positive impact on foetal programming are the methyl donors. These nutrients are folic acid, vitamin B12 and methionine. Additionally, vitamin D plays a role in foetal health. The importance of a maternal supplement is obvious.

What can men do to help fertilization?

Men, on the other hand require more consideration. After all, they are blokes! Men are half the baby, but rarely get attention, both clinically and in published studies.

Basically, not all sperm are created equal. Of that 20 million per ml we mentioned, only about 50 per cent are motile, with 25% rapidly progressive.

Sperm DNA damage is increased by lifestyle factors including:

  • inadequate nutrition
  • increased weight
  • smoking
  • substance abuse (including excessive coffee and alcohol intake).
  • nutritional factors For example, vitamin D affects calcium levels in sperm.

Some exciting news for men is that daily sex reduces sperm DNA damage. So, frequent ejaculation is another way of reducing the exposure to sperm to oxidative damage in the testicular ducts.

Use your health professionals to get the best advice about what’s safe. Many over-the-counter products need to be carefully scrutinized. For example, taking non-steroidal anti-inflammatories like ibuprofen, in mid-cycle, reduces rates of conception.

Fertility and conception

In summary, it takes two to tango. Fertility is a couple issue, not just a woman’s issue. Good reproductive outcomes require a focus on both partners.


–  by community pharmacist and herbalist Gerald Quigley

Image credit: Eraxion/123RF Stock Photo

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