Tests & Investigations · 2 min
Family blood relationships and fertility, the honest conversation
Top things to know
In some communities, marriage between cousins has been common for generations; this is information, not judgement.
Children of first-cousin parents have a somewhat higher risk of certain genetic conditions, from around 2–3% to 4–6%.
If there is known consanguinity and a pregnancy is planned, you can ask about genetic counselling.
If a partner's semen analysis shows significant abnormalities, asking about genetic testing is reasonable.
Why is family consanguinity a fertility topic?
In some South Asian communities, particularly Pakistani and Bangladeshi Muslim, and some Hindu and Sikh subgroups, marriages between first cousins or closer relatives have been common for generations. This is a private family matter for most people. It is also a piece of fertility and pregnancy information that matters to have.
Children of first-cousin parents carry a somewhat higher risk of being born with certain genetic conditions. The absolute risk is usually modest, roughly double the baseline rate of serious genetic conditions, from around 2–3% to 4–6%, but it is real, and it is worth knowing.
2–3% → 4–6%
Children of first-cousin parents carry roughly double the baseline risk of serious genetic conditions, from around 2–3% to 4–6%.
Born in Bradford study, Sheridan E et al, The Lancet, 2013
What can you actually do with information about family blood relationships?
This is not a judgement on your family or your culture. It is information that helps you and your partner plan with full knowledge.
How does family consanguinity affect male fertility specifically?
In Pakistani populations specifically, rates of AZF ( factor) region abnormalities on the Y chromosome are higher than baseline. This is one contributor to male factor infertility that can be picked up on karyotype + Y microdeletion testing, tests that are part of standard work-up for low sperm count in UK andrology clinics.
If your partner has had a showing significant abnormalities, asking about genetic testing is reasonable.
Which of these sound familiar?
Tap any. Private to you; only anonymous totals are ever counted.
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Reviewed by clinicians
Authored and reviewed by clinicians from the founding team. Information only, not personalised medical advice.
From the team behind Her Holistic Health, founded by Dr Divpreet Sacha, NHS-trained GP.