Science and Reporting: What Do We Really Know About Fatherhood’s Effect on Men?

Today’s media features another story on the effects of fatherhood on men that is tied back to the earlier report about fatherhood and low testosterone levels.   But both stories also make me think about the role of science and science reporting in what we know (or think we know) about parenting.  That’s something of a perennial theme here.   I want to take the time to talk about the science (and the reporting) in a little detail.

This new story is about the relationship between fatherhood and life expectancy, and if you poke around the web, you will frequently find it reported this way:  “Fatherhood Helps You Live Longer.”  I’m sure that attracts readers.

Now that seems a particularly bad headline because if you actually read the reports of the study, it isn’t what it says at all.   Here’s another press account, one with a somewhat better headline ,and a discussion of the methodology, which is striking.  (The title of the study won’t make the headlines.)

It seems researchers really wanted to study the relationship between infertility and lifespan, but while they had a huge database, it didn’t directly tell them about infertility–it told them whether they actually had children.  Thus the childless group would include both infertile men and men who simply didn’t want children.  (It also includes men who had children but didn’t know it.)

To maximize the chances they were really comparing fertile/infertile (as opposed those thinking they had children with those thinking they did not have children) The researchers made an assumption.  Here is how its described in Time:

To increase the likelihood that all the men included in the study actually  wanted children, the researchers excluded those who had never been married; by  including only men who were married or had been married at least once, the  researchers could be reasonably sure they had the desire and opportunity to have  kids.

Now I do wonder a bit about the assumption.   There are in fact married couples who are childless by choice.   But that said, it looks to  me like 92% of the married men did have at least one child (that they knew about or believed to be theirs?)  This takes me to the next thing I wonder about though–8 married men out of a hundred didn’t have (or didn’t think they had?) children.   If one out of 100 married men is childless by choice (which seems possible to me) that one is in those 8.   That means 12% of the men now assumed to be infertile aren’t infertile.  Doesn’t that mess things up just a bit?

I’m not an expert and I cannot criticize the methodology, really, so I won’t linger here.   Instead, I’ll consider the findings of the study.  Here I’ll just quote the conclusions noted in the abstract of the study:

Married men who have no children have a higher risk of dying from cardiovascular disease contracted after the age of 50 than men with two or more children.

Points to the researchers here for their careful parsing.   You might notice that men with one child seem to have fallen out of the picture.   I think that’s because the analysis for men with one child looked a lot like the analysis for men with no children.   (The abstract says: “this elevated risk appeared to extend also to men with only one child.”  Doesn’t that knocks the infertility point rather out of the box?  Nevermind.)

It also strikes me that the conclusion may be an instance of the negative pregnant.   If you say “have a higher risk of dying from cardio vascular disease” then the negative implication is that there isn’t a higher risk of dying generally–just of dying from that cause.   Consistent with this, I cannot tell if the men presumed to be infertile actually had a higher risk of dying generally.

Finally, an important point to keep in mind:  The study doesn’t purport to make any findings about causation–it is at most about correlation.  Thus, there’s no suggestion that infertility causes heart disease or that having children wards off heart disease.   It’s quite possible that heart disease and fertility are both caused by some other factor that isn’t explored.

Now I’m not going through all this to trash the study.  I think it is interesting and I’d like to know more.  But like a great deal of science, it is limited in what it can tell us.   Reporters (and after reporters, headline writers) may not be so careful with the limits and so by the time the story reaches us on the web it can look rather different.   That’s a good reason why some caution is warranted.

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14 responses to “Science and Reporting: What Do We Really Know About Fatherhood’s Effect on Men?

  1. You are exactly right to poke holes in the logic of this study.

    In fact I have the same problem with almost all studies in the field of reproductive health and infant health. The data used to draw these conclusions gets more and more unreliable with each passing day. The margin of error skyrocketed with the advent of egg donation because genetically related parents names are not recorded for each birth.. The ability to freeze semen and embryos is causing yet another spike in genetically inaccurate birth records. for naming genetically unrelated people as parents on birth records

    The inaccurate records might work for a study on whether raising children impacts longevity – psychological experiences can certainly impact our overall physical health. There was a time when researchers were relatively sure that parents on original birth registrations were related to the children on the record – researchers could survey survey the fathers to see if there was an increased risk of birth defects in children whose fathers smoked marijuana prior to conception…stuff like that. We are one generation away from totally unreliable birth records. Genetically inaccurate birth records will have a devastating effect on research outcomes to the detriment of medical advancement and public health generally.

    • Your comment reminds me that I wondered about exactly what it was the researchers knew about the men–that they raised children? That they raised children they were genetically related to? That they had offspring they were genetically related to whether or not they raised them? I suppose if infertility indicates some general poor level of health which in turn correlates to increased risks of heart disease than the mere fact that you have genetically related offspring somewhere means you are not infertile. There’s no causation, but there’d be correleation.

  2. If birth records are only used to document social parenthood, as many such as many suggest,they then can only be relied upon as the basis for studies regarding the social aspects of parenthood. Medical research and advancements in the field of real reproductive medicine will come to a grinding halt due to a lack of reliable birth statistics. There must be ways to respect the diversity of various family structures without undermining overall public health welfare and safety. Should artificial reproductive patients have the right to more privacy than people who form their families by having intercourse?

    • I think it is true that what birth certificates reliably document is some sort of social/legal parenthood and so using them for genetic studies is inappropriate. I wonder if that is what they did? Or perhaps they wanted to study the effects of social parenthood in the first place. Cannot tell from this. If they want genetic lineage, I think you have to ask men about that specifically. You are right that you cannot rely on birth certificates.

      • The problem is the cdc does use information from the long form original birth records from each state because those are assumed to be genetically accurate for parentage, even thoug a margin of error has always been built in for falsely reported paternity. The CDC does not include information from revised certificates because the adoptive parents information would throw their findings off. My concern is original records are now falsified and the cdc has no way to weed that bunk information out of their statistics. at some point it will only be valuable for studies about the sociaal aspects of parenting and be totally unreliable for medical research. do you disagree?

        • I don’t know about how the CDC treats information on a birth certificate. If they get the original information from the time of birth than it is what it is–maybe genetically accurate, may not be, but that information, once transmitted, could be held by the CDC. I doubt the CDC updates the records each time a new certificate is issued (like when an adoption is completed.) That can be years after birth. But it is an interesting question. The key thing, it seems to me, is that everyone understands what a birth certificate does and does not actually convey and then uses the information accordingly. It may be that there is a need for better education around this and I’ll even agree that maybe we need to be keeping other sets of records. That’s a “what should be” question as opposed to a ‘what is” question, if you see what I mean.

          • You said you did not know about how the CDC treats info on a birth certificate – You can learn more about it at: http://www.cdc.gov/nchs/births.htm

            Below is text from their site. Suffice to say that collection of birth data by states is a federal mandate and the intent is as a public health record not as a certificate of title as in who will have custody and raise the child. Obviously that can change over time and the cdc is not interested in collecting revised certificate data about non-genetic parents on revised certs, it has social statistical value but is not helpful for public health.

            “Birth Data In the United States, State laws require birth certificates to be completed for all births, and Federal law mandates national collection and publication of births and other vital statistics data. The National Vital Statistics System, the Federal compilation of this data, is the result of the cooperation between the National Center for Health Statistics (NCHS) and the States to provide access to statistical information from birth certificates.

            Standard forms [PDF – 1.9 MB] for the collection of the data and model procedures for the uniform registration of the events are developed and recommended for State use through cooperative activities of the States and NCHS. Material is available to assist persons in completing the death certificate. NCHS shares the costs incurred by the States in providing vital statistics data for national use.”

            • So here’s the thing: It looks to me like the CDC collects a ton of information–some about prenatal care, some about smoking, and so on. See this form: http://www.cdc.gov/nchs/data/nvsr/nvsr59/nvsr59_07.pdf There is a box to check for infertility treatments, too, distinguishing between IVF and other assisted insemination and/or drugs. None of this information ends up on the birth certificate.

              Thisf leads to what I was wondering about. It isn’t clear to me that the CDC uses the information off the birth certificate given to parents for anything at all–they collect other information–much more detailed information–for statistical purposes. Thus, I don’t think there is any reason to worry that the issuance of new birth certificates on adoption matters or that listing legal parents as opposed to genetic parents on the birth certificate issued to parents matters.

              I have to say, it’s confusing because the CDC form is called something like “certificate of live birth” but it doesn’t look at all like what Washington state issued for my kids. There is a form on which all that information is reported to the state that does seem to track the CDC form, but the birth certificate I’ve been concerned about here–the one that reflects legal parentage–isn’t that form. Or at least, this is what it looks like to me.

  3. the long form is the basis for the short form. The parents on the long form are the same as the parents on the short form that you are use to seeing (OBC). The parents on the long form are assumed to be related to the child for health reporting. if they are not it is inaccurate and irrelevant for statistical purposes. 100,000+ birth records a year containing genetically inacurate info on parents is bound to undermine health statistics.
    I’m just saying the impact to public health is not insignificant

    • I can see that the long form is the basis for the short form. But it seems to me that for any of the serious statistical stuff the CDC does they would work off the long form, and since there are places to check for ART, etc then it would alert them to anything that might throw off the data, no?

  4. Yeah but saying a baby was created with IVF is one thing (it asks about IVF) asking point blank did you use someone elses egg is another and the long form tops short of that critical question. You know that there is probably a lot to be studied about the health of children carried in a body that did not create them, what problems might be genetic vs problems from possible incompatibilities or age or whatever. In my non medical opinion cdc needs the health histories of both women if they are going to continue to use birth data for medical research. You know the long form does not ask about sperm donation but refers to the father and his family as paternal rellative. There was probably always a margin of error built in for lying about paternity, but given the increase in use of donated sperm as massive corporate banks are evidence of the value of the information collected has got to be getting near worthless. It only has medical value iif its genetically accurate. That is not to say social parents dont have value that impacts the health of the cchild but remember this data is collected prior to any performance of caregiving duties by either of the people named on the certificate, With the exception of gestation conclusions about the childs health based on info about the parents is fully based in genetics.

    We have the lowest infant mortality rate lowest birth defects but that is changing. The research bases on birth statistics helped save my daughters life and will help her not have tons of miscarriages when she gets pregnant. We benefit when researchers can trust the accuracy of birh records as health records. Can you see where inaccuracies over the next couple of generations might make it almost pointless to to study genetic causes of health problems if obc’s don’t name genetic parents?

    We need to think about why the CDC collects that data and ask ourselves if we are undermining that goal with the current approach. I think we must find some reasonable compromise between the rights of legal parents and what I see as the social obligations of progenitors to be identified as related to their offspring

    • I see what you mean but you’d think that if folks checked the box that covers fertility drugs and AI (box 41 I think?) that the CDC could look at that and think that maybe there were third-party gametes. But maybe not. Perhaps I give them too much credit. it’s also true that I don’t know what exactly they CDC is trying to look at—do we know if they are actually making assumptions about genetic lineage? (BTW, I would oppose letting the CDC insist on universal genetic testing at birth.)

      As a general matter I feel like this is a little beside the point. If the CDC wanted to collect data for various statistical analysis, that’s mostly okay with me. I’m really concerned about what is on the birth certificate that people need to have for school registration and sports stuff. That clearly is understood to reflect legal parentage–that’s why the school wants it.

      Maybe this all demonstrates that we need different things for different reasons–a point on which I think you and I agree. For tracing medical histories, genetics is good. For legal authority to enroll a child, genetics is not so good, but legal parentage is.

  5. Well I was commenting on family scholars today and put a ton of cdc links in and I had an idea: The long form birth certificate is the standard federal form and it is a health record in relationship to the child they use that info assuming those people are biologically related because the revised birth certificates are for non bio parents – and then came ART. The short form issued by the state is based on the long form… what if federal law mandated that states include the following language (or similar) on every original short form certificate:
    The person for whom this certificate is issued may not be the genetic offspring of the people named as legal parents. This short form certificate for identification purposes only. The long form federal certificate will be provided to the persons named or the sibling of the person named on demand at the local registrars office and it contains sworn statements as to the identity of the genetic parents.

    Now I can go on and on about the various was to knuckle everyone into telling the truth on the long form without forcing them to do a dna test, but the upshot is the long form could be genetically accurate and flagged so the data about the social parent does not contaminate the data used for medical research and every short form would say those may not be the genetic parents so that the person named would get a copy of their long form with the truth if they ordered it. No yucky stigma of having a flag on the short form. Everyone’s privacy would be protected the exact same way.

    Pretty cool right? I’ve got my thinking cap on tonight. I’d like to throw some aadoption reform in ther just to liberate everyone in one fell swoop but that might be too much.

    Like my pipe dream will happen…I need to worry about minutia

    • It does seem as though the long form could be the basis for the genetic lineage record while the short form can serve as the legal parentage document. We’re part way there, I suppose. But as you suggest, it may not happen any time soon.

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