What are the chances of us conceiving?

It is impossible to give an accurate prognosis. Some couples who seem to have everything going against them succeed whereas others who seem to have a good prognosis do not. Several specialists have suggested formulae to provide some assistance in answering this central question. We have devised the following formula:

Prognostic Fertility Index =  [50- Female Partner Age] x Male Factor x Tubal Factor

/ Years of Infertility

The Male factor is the number of millions of actively motile sperm per ml of semen

 (Maximum = 5)

The Tubal Factor is assessed as follows:


5 - No known tubal disease.

4 - History of pelvic inflammatory disease both tubes patent.

3 - One tube patent and one blocked.

2 - One tube removed (e.g. For ectopic pregnancy) and

    the other tube patent.

1 - Both tubes blocked.

0 - Both tubes have been removed.

The number of years is calculated counting the current year as one. For examples:

 trying for less than one year = 1.

 trying for two years and six months = 3.

Our index does not include ovulation as ovulation induction treatment can usually overcome most ovulatory problems.

Examples of calculating the Prognostic Fertility Index are provided in Table 9.2.

Table 9.2 Examples of calculations of the Prognostic Fertility Index.

Age (Female)

Male Factor (Q9.21)

Tubal Factor

Years of Infertility

Prognostic Fertility Index




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This is the personal website of David A Viniker MD FRCOG, retired Consultant Obstetrician and Gynaecologist - Specialist Interests - Reproductive Medicine including Infertility, PCOS, PMS, Menopause and HRT.
I do hope that you find the answers to your women's health questions in the patient information and medical advice provided.

I do hope that you find the answers to your women's health questions in the patient information and medical advice provided.

The aim of this web site is to provide a general guide and it is not intended as a substitute for a consultation with an appropriate specialist in respect of individual care and treatment.

David Viniker retired from active clinical practice in 2012.
In 1999, he setup this website - www.2womenshealth.com - to provide detailed
information many of his patients requested. The website attracts thousands of visitors every day from around the world.
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