Consent Where a Second Interest Is Affected

Part of Consent and Vulnerable Populations: Pregnancy, Breastfeeding and the Evidence Gap.

About 5 minutes. Free, in your language, no account needed.

Why this matters

In almost all clinical research, the person consenting is the person affected.

In research involving a pregnant participant, a second interest is affected and has no voice, now or ever in the relevant sense. In research involving a breastfeeding participant, an infant is affected who cannot consent. In some genetic research, relatives who were never approached are affected.

The consent process has to account for an interest that cannot speak, and it does so through the consenting person, which is the only available route and is not the same as that interest being represented.

Who consents

The pregnant woman consents for herself and, in effect, for the pregnancy. There is no separate consent from or for the fetus, and no jurisdiction provides one.

Whether the partner has a role varies. Some frameworks and some ethics committees require or expect the partner's involvement where a trial may affect the pregnancy. The arguments each way are substantial: a partner has an interest in a future child, and requiring their consent makes a woman's participation contingent on another adult's agreement, which conflicts with her autonomy over her own body and her own medical decisions.

The practical position is that this is determined by the applicable framework and the ethics committee, must be settled before enrollment, and must never be resolved at the bedside by whoever is taking consent.

What the information must cover

Beyond the ordinary content, a consent process here must address:

What is known and not known about effects on the pregnancy, stated honestly including where the honest answer is that it is not known, which it frequently is.

What follow-up of the pregnancy outcome involves, and for how long. Follow-up may extend well beyond the trial's own duration, potentially years into the child's life.

Who will hold information about the child, and what the child's own rights will be when they are old enough to have them. A child followed up from birth has data about them collected under their mother's consent, and at some point that becomes their own information.

What happens if the participant withdraws, and whether the pregnancy outcome follow-up continues, which requires its own agreement rather than riding on the trial's consent.

What happens if the pregnancy does not continue, addressed with care and addressed, because the follow-up arrangements differ and a participant should not learn this at the worst moment.

The breastfeeding case

The exposed party is an infant who is present, identifiable, and will grow into a person with their own view.

The information must cover what is known about transfer into milk, what the infant's exposure is likely to be, whether any monitoring of the infant is proposed, and what happens to any data about the infant.

The infant's own consent is not available and their future interest in data about them is real, which argues for the same discipline applied to children generally: a plan for what happens when they are old enough to be asked.

In practice

A pregnancy outcome follow-up is added to a trial where participants may become pregnant.

The consent is drafted as a separate document rather than a paragraph in the main form, because it concerns a different set of questions and a different duration.

It covers: what information will be collected about the pregnancy and the birth, that follow-up of the child is proposed for two years, what will be recorded, that the participant may withdraw the child's follow-up at any time while continuing her own participation or having already ended it, who will hold the information, and that when the child is old enough the sponsor will seek their own consent for any continued retention.

The last provision is unusual and it is the one an ethics committee comments on favorably, because it is the only part of the document that treats the child as a future person rather than as an outcome.

What this looks like when it goes wrong

A participant becomes pregnant during a trial and consents to pregnancy outcome follow-up, described in a single paragraph of the main consent form as "follow-up of the pregnancy outcome."

Her baby is born and is healthy. The sponsor's follow-up continues, collecting developmental information at six months, twelve months and two years.

At eighteen months she asks what the information is being used for and how long it will be kept.

Nobody can give her a clear answer, because the paragraph she consented to said "follow-up of the pregnancy outcome" and the activity has become a two year developmental follow-up of a child.

She did not object to it and was never told what she was agreeing to with any precision, and the information being held is about a person who was not born when she consented.

The follow-up was valuable and well conducted. The consent was for something smaller and vaguer than what happened.

Key takeaways