Causes and Solutions Primer on Conception and Infertility

Conception is a remarkable process that initiates the journey of pregnancy. It involves a series of complex biological events, primarily the release of an egg from the ovary, fertilisation by sperm, and the implantation of the resulting embryo in the uterus. In this article, Dr Simon Nothman provides critical insights into the biology of conception and the various factors that can impact fertility, helping those navigating their reproductive journey make informed decisions.

The Biology of Conception

1. Ovulation:
   Ovulation occurs when a mature egg is released from one of the ovaries. This typically happens midway through the menstrual cycle, around day 14 of a 28-day cycle, though timing can vary. As discussed in the blog post about ovulation, predicting ovulation can sometimes be more complicated than simply counting days.
2. Fertilisation:
   Conception happens when sperm travels through the cervix and uterus to meet the egg in the fallopian tube. This union forms a single cell called a zygote, containing all the genetic information necessary to develop a new individual.
3. Implantation:
   After fertilisation, the zygote divides and forms a blastocyst as it makes its way to the uterus. Once in the uterus, the blastocyst implants itself into the uterine lining, marking the start of pregnancy.

Defining Fertility

Fertility refers to the natural ability to conceive and produce offspring. On average, a fertile couple has a 25% chance of conceiving in any given month, with cumulative success rates rising to around 85-90% over a year.

Successful conception requires several key factors:

• Regular ovulation
• Healthy sperm
• Clear fallopian tubes to facilitate the meeting of egg and sperm
• A receptive uterine environment for embryo implantation

In addition, for a healthy pregnancy, the embryo must be genetically normal and free from chromosomal abnormalities or genetic diseases. In cases where in-vitro fertilisation (IVF) is used, genetic testing can be performed on embryos before implantation to ensure chromosomal health.

Major Causes of Infertility

Infertility is typically defined as the inability to conceive after 12 months of regular, unprotected intercourse. Around 15% of couples experience subfertility. The causes of infertility are varied, and in general terms, about a quarter of cases are due to male factors, a bit over a quarter are due to female factors, one quarter is due to a combination of both, and one quarter remains unexplained after testing. The most common causes of infertility include:

1. Ovulatory Disorders:
   Conditions like polycystic ovary syndrome (PCOS) can affect regular ovulation, making it challenging to predict fertile windows.
2. Tubal Factors:
   Blockages or damage to the fallopian tubes, often caused by previous infections such as chlamydia or conditions like endometriosis, can prevent the sperm from reaching the egg or block the fertilised egg from reaching the uterus.
3. Male Factor Infertility:
   Issues such as low sperm count, poor sperm motility, or abnormal sperm morphology can hinder the fertilisation process.
4. Uterine or Cervical Abnormalities:
   Structural problems, such as fibroids or cervical issues, can impede implantation or hinder sperm movement. These problems generally don’t prevent natural conception but can increase the risk of miscarriage or reduce success rates with fertility treatments.
5. Unexplained Infertility:
   In some cases, no clear cause for infertility is identified, even after thorough evaluation. This is termed unexplained infertility and can be particularly frustrating for couples.

Common Fertility Tests

A range of tests can help diagnose the cause of subfertility. In a heterosexual couple, testing usually includes:

1. Blood Tests:
   For women, hormonal tests assess ovarian reserve and ovulation status.
2. Pelvic Ultrasound:
   This evaluates the ovaries and uterus to check for abnormalities or conditions that may affect fertility.
3. Tests for Fallopian Tube Patency:
   A HyCoSy or HSG test determines if the fallopian tubes are open and functional.
4. Semen Analysis:
   This assesses sperm count, motility, and morphology in men. Additional tests, such as sperm DNA fragmentation testing, can provide information on sperm function.
5. Karyotype Testing:
   Some specialists may request karyotype testing for both partners to assess for chromosomal abnormalities that could affect fertility.
6. Genetic Carrier Screening:
   While not part of the typical infertility workup, genetic carrier screening is recommended alongside other testing to identify potential genetic conditions that could be passed on to offspring.

Key Takeaways

1. Fertility is Complex:
   Achieving a pregnancy may seem straightforward, but many factors must align for successful conception. Numerous elements are beyond your control, and fertility requires the proper function of both partners.
2. Infertility Has Multiple Causes:
   Causes of infertility can vary significantly between couples, and sometimes, no apparent reason is identified. It’s essential to recognise that infertility may stem from male, female, or combined factors or remain unexplained.
3. You Are Not Alone:
   Infertility is more common than many people realise, and it can be overcome. Many couples facing infertility go on to successfully conceive, whether through natural means or with medical assistance.

Understanding these fundamental aspects of conception and infertility can help couples make informed decisions about when to seek medical help. If you’re concerned about your fertility or feel that a more in-depth discussion is needed, book an appointment with Dr Simon Nothman to explore your options.

Ready to Take Control of Your Fertility Journey?

If you have concerns about your fertility or would like a personalised fertility assessment, schedule a consultation with Dr Simon Nothman today. His guidance will help you understand your fertility health and navigate the best options for achieving pregnancy.