what operations research has taught me about having a baby

After having my third baby last week, I am writing a post on how OR has helped me navigate pregnancy, labor, and birth.  Here is a few ways that OR has enhanced my experiences with having babies.

A solid OR background gave me the necessary knowledge about statistics to wade through all of the pregnancy advice out there and keep my perspective.  Much of the advice is silly and not evidence-based (like keeping your heart rate < 140 bpm, not lying on your back in a low-risk pregnancy, omitting all caffeine, avoiding certain foods, etc.).  Yet some of the best pregnancy advice (like eating your vegetables and staying active) is rarely verbalized.

A solid OR background also means that my educational background alone makes me a likely candidate to avoid most pregnancy complications (education of the mother is almost always a statistically significant factor that is negatively correlated with most adverse pregnancy outcomes).

I know that pregnancy statistics based on aggregate data are almost useless when on my third pregnancy. It’s all about correlation at this point.

After having two labors shorter than average, my midwife told me not to necessarily expect an even shorter labor.  After some discussion, I realized she was explaining that anecdotally, she has observed that most women experience regression to the mean after very short labors.  That makes sense.  If I had a good draw the last time, the odds are, I won’t get as good of a draw this time.  In general, buying into the Flaw of Averages is a bad idea for preparing for labor.  Few labors are “average.” However, I don’t have a good approach for managing the anxiety that comes along with having to prepare for a myriad of labor realizations. (I ended up having my shortest labor this time).

I have found Bayes rule to be extremely helpful for managing prenatal anxiety.  Many screening tests are performed during pregnancy.  The one that perhaps causes the most anxiety in expectant moms is the quad screening test, which attempts to screen for Downs syndrome and spina bifida.  Given that the test comes back positive, for example, a baby has about a 3% chance of having Downs Syndrome (although I recently learned that these odds vary according to the age of the mother).  My quad screen tests came back negative for all three pregnancies, but I was prepared not to panic just in case.  A similar screening test is done for gestational diabetes.  I had a false positive once and took the dreaded three hour glucose test.  That was no fun, but again, I knew not to worry.

My last two deliveries took place at the tail end of a brief surge in births at the hospital (births should be a Poisson process–see my post on the exponential distribution).  This meant that all of the recovery rooms in the hospital were occupied by the time I needed one (!)   Luckily, I was able to get into a room both times, although this time, I am indebted to two kind nurses who pulled a few strings for me.  My hospital stay illustrates that hospitals still need lots of OR for planning hospital beds.  (My hospital stay also suggests that OR could be used to schedule meal deliveries, schedule infant inspections, and organize hospital discharges).

With regard to hospital discharges, the bottleneck in the process is waiting for someone with a wheelchair to take me and baby to the car after discharge.  This was also true three years ago after my last birth.  I would have thought that the bottleneck would be scheduling the “important” stuff, like the pediatrician’s checkup of the baby and the nurse’s checkup of me.  Despite being tired after having a baby, I couldn’t help but start to model the hospital system and mentally note where they need to make improvements.

I have avoided amniocentesis for all of my pregnancies, but if I was offered amniocentesis, I would use a decision tree with my personalized economic model to make the decision.

And most importantly, decision analysis methods confirm that it was a good idea for me to be fruitful and multiply.

    11 responses to “what operations research has taught me about having a baby

    • iamreddave

      Great post. I have heard most doctors do not understand this FP/TP issue with testing. Which is pretty scarey.

      I hope everything is going well

    • Francisco Marco-Serrano

      In our case (I wasn’t the one delivering) I thanked for my statistical knowledge in two cases:

      1) While expecting the baby at the hospital, being able to read the monitoring output. The midwife tried to tells us we were going to wait for a long time (the graph didn’t said so…).

      2) Once the baby is here, understanding the growth graphs. I’m surprised how many people are not able to understand what a percentile is.

      By the way, thanks for including me in your blogroll, although the right url is http://www.kproductivity.com/fmwaves. 😉

    • Diana

      Very interesting post! And congrats on baby # 3 🙂

    • Jen

      Did you opt for painkillers during labor and why or why not?

    • Felicitász

      Very interesting and entertaining post. Congrats on your new baby. 🙂

    • Laura McLay

      Francisco, thanks for the additional tidbits! I know what you mean about the growth charts. In our case, we needed to first find the right growth chart to “prove” that our child was growing normally. It was reassuring.

      Dave, I have also heard that most doctors do not understand FP/TP. The doctor I had with my first *did* understand, but I have talked to others who had a false positive and a doctor who conveyed the wrong idea )-:

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    • Dawen @ ThinkOR

      Hi Laura,

      Great post – as always, and congratulations!

      I shared your post on Google Reader. My friend, Andrew, who is a trained doctor, but once upon a time in his former computer science years was also involved in OR somewhat, had some interesting comments. Thought I’d share with you here.

      “As someone with a loose OR background who has been spending the last three weeks catching babies, this is interesting. 🙂 One comment I’ll make is that one shouldn’t be so quick to say what the distribution of a random variable “should” be (in this case, births). That might be close, but I’d reserve judgment because I can also easily imagine that women might be more likely to get pregnant at certain times of year, and that any social and environmental factors that influence the timing of labour (and such factors definitely exist) would tend to affect multiple women in a community at once, producing more “clusters” than one would expect from Poisson. Also — there may be a small component of regression to the mean in labour duration, but in my experience (and in what I’ve been taught) the random component is small relative to the trend towards faster labour with additional pregnancies, and the persistence of physical maternal factors that give her an intrinsic tendency to have shorter or longer labour.”

    • MarianelaP

      Hi Laura, I read this post back when you wrote it and thought that some day these words would be useful. Now that I’m 33 weeks pregnant I decided to revisit your motherhood/parenthood/family posts I find this post to be absolutely true.
      I have learned that my doctor has a good understanding of statistics and was very clear about what all the test results meant. I imagine both my husband and I will be thinking of ways to optimize hospital operations during our stay at the hospital, specially him who’s research is actually OR health care applications. I am looking forward to what we will learn through the whole labor experience.
      Thanks for this post!

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