Planning a Family: The Complete Guide

What health checks are worth doing before trying for a baby?

Before trying for a baby, the genetic checks worth considering include carrier screening, which looks at whether you and your partner carry gene variants that could be passed to your child. It's done alongside the usual steps like prenatal vitamins and lifestyle changes, and it's most useful before conception, when you have the most time to understand your results and options.

→ Health Checks Before Pregnancy

What is carrier screening?

Carrier screening is a genetic test that shows whether you carry a change in your DNA that could be passed to your children. Everyone carries some genetic variations, and most are harmless, but if both parents carry a change in the same gene, their child could inherit the condition. Screening reveals this before pregnancy, so you can plan with full information. Importantly, being a carrier doesn't mean you're ill, carriers are healthy and usually have no symptoms.

→ Explore the Carrier Screening Test

How are inherited conditions passed on?

Inherited conditions are passed down through genes from both parents, and the pattern depends on the type of condition:

• Recessive conditions: Both parents must carry a change in the same gene. If they do, each child has a 1 in 4 chance of being affected, a 1 in 2 chance of being a healthy carrier, and a 1 in 4 chance of being unaffected.
• Dominant conditions: One altered gene copy is enough, so if one parent has it, each child has a 50% chance of inheriting it.
• X-linked conditions: Carried on the X chromosome, these more often affect males, while females are usually carriers.

→ How Inherited Conditions Are Passed On

Why can genetic conditions appear with no family history?

Genetic conditions often appear in families with no previous history because carriers are healthy and show no symptoms, so they pass on changes without ever knowing they carry them. This is one of the main reasons carrier screening exists, it reveals hidden information that family history alone can't.

→ Can You Carry a Genetic Condition With No Family History?

When should you have carrier screening?

The best time for carrier screening is before pregnancy. Testing before conception gives you enough time to understand your results calmly and consider all your options without time pressure. Phenome doesn't recommend carrier screening after pregnancy has begun, the purpose is to prepare and reassure you ahead of time, not to create stress later.

Why should both partners be tested?

Carrier screening works best when both partners are tested, because a condition is usually only a risk if both carry a change in the same gene. If one partner is found to be a carrier, the other can be tested for that same gene. Testing together gives the complete picture and lets healthcare professionals offer proper guidance.

What is newborn screening, and why does it matter?

Newborn screening checks a baby shortly after birth for certain genetic, metabolic, and hormonal conditions that aren't visible but can be managed far better when caught early. While carrier screening looks at risk before a baby is born, newborn screening looks at the baby after birth, so together they cover the full journey of planning and protecting a family's health.

→ Explore the Newborn Screening Test

What are the limits of genetic screening?

Carrier screening is powerful but, like any test, it has limits worth understanding:

• It checks specific known genes, so it can't detect every possible variation or brand-new mutations.
• In rare cases, results can be incomplete, even a negative result carries a small residual risk.
• Learning you're a carrier can feel worrying, which is why genetic counselling is offered to help you understand results calmly.

Screening is designed to inform and empower your choices, not to predict or alarm.

How do you make sense of your results?

The best way to understand carrier screening results is with genetic counselling, because the implications are personal and sometimes emotional. A counsellor helps you interpret what your results mean for you and your family, in a calm, supportive way, so you can make informed decisions with confidence rather than guesswork.

→ Explore genetic counselling
→ Genetic Testing for Health: The Complete Guide