Miscarriages

A friend asks about miscarriages. For what it's worth, here's my response:

1. Definitions

   a. Miscarriage is also known as spontaneous abortion. Spontaneous abortion isn't the best term because it can confuse people to think it's associated with elective abortion.

   b. Miscarriage is such a broad term. In general it refers to a pregnancy that spontaneously ends before the embryo or fetus has reached a viable gestational age. A complication is "viable gestational age" is itself a vague term susceptible to change, depending on medical science and technology. Currently that would be around the 20th week of gestation (as calculated from the date of the last menstrual period). However, it's possible future medical science and technology will alter the age of viability.

   c. Another common definition of miscarriage (such as the World Health Organization uses) is the spontaneous expulsion of an embryo or fetus weighing 500 g or less. A 500 g fetus would approximately correspond to the 20th week of gestation.

   d. Miscarriages can be subdivided into complete or incomplete miscarriages. If it's complete, then the uterus is entirely emptied, whereas if it's incomplete, then some tissue remains.

   e. One could make further distinctions such as induced (usually elective) abortions, threatened abortions, inevitable abortions, missed abortions, and tubal abortions or ectopic pregnancies.

2. Incidence

   a. It's somewhat difficult to obtain accurate numbers (e.g. it depends how miscarriages are detected).

   b. To my knowledge, most of these studies on miscarriages are based on tests measuring β-hCG. However, measuring β-hCG has its limitations. Other tests measure other factors like early pregnancy factor (EPF), but these tests have their limitations too.

   c. The popular belief is the incidence of spontaneous abortion is ~50%. To my knowledge, that's only the case when preimplantation losses are factored in. An extremely pertinent question to ask is, what is the exact nature of these preimplantations? Specifically, how many are viable zygotes/embryos? Unfortunately this is a highly politicized question to ask, but my own research suggests the majority are not viable zygotes/embryos.

   d. What then is the incidence of spontaneous abortions or miscarriages? Estimates range from 8-20% of all clinically recognized pregnancies under 20 weeks. The incidence is significantly lower at 5% among women who have previously had a child. The incidence of spontaneous abortion is higher at 13-26% if we include unrecognized or subclinical pregnancies. (Sources: here, here, here, here, here.)

   e. Finally these figures appear to be largely based on fertilized oocytes. Fertilized oocytes are not necessarily equivalent to what pro-lifers mean when they argue life begins at conception. For one thing, a fertilized oocyte is not necessarily a viable zygote/embryo. Not all fertilized oocytes are chromosomally or structurally normal.

3. Etiology

   a. The most common cause of spontaneous abortions is most likely due to genetic abnormalities in the embryo or fetus. This is thought to account for ~75% of all spontaneous abortions. The most common genetic abnormalities are autosomal trisomies (50% of all genetic abnormalities). And trisomy 16 (which is 100% lethal) is the most common of the trisomies.

   b. Other causes of spontaneous abortions (~25%) are infections, autoimmune diseases, endocrine issues, uterine issues, and drug or substance abuse.

4. Risk factors

   The biggest risk factors for spontaneous abortions are: advanced maternal age, previous spontaneous abortion, and maternal smoking (10 cigarettes per day or more).

   It may come as no surprise that Western societies have a significantly increased risk for spontaneous abortion primarily due to advanced maternal age.

5. Fertilization/conception

   a. I think it's worth noting an important distinction: fertilization is not identical to conception and vice versa. Fertilization occurs when the sperm enters or penetrates the oocyte (later ovum) or egg. Conception occurs when the sperm and egg cease to exist as sperm and egg in order to become a zygote which has its own unique genetic material and which has its own unique behavior.

   b. I think it's possible to argue human life begins either at fertilization or conception. I see merits to both. It's arguable we should play it safe and err on the side of fertilization. I'd argue conception (syngamy) is certainly the latest it could be.

   c. I realize many or most state the sperm and egg fuse, unite, or the like. That's fine as far as it goes, and I don't object to the terminology. However, at certain times it could be misleading language, scientifically speaking. More on this below.

   d. After the sperm has entered the egg, but prior to the creation of the zygote, the sperm and egg duplicate their respective genetic information in becoming paternal pronuclei and maternal pronuclei. The two pronuclei line up and move toward one another within the egg, their nucleic membranes dissolve (not fuse), and the chromosomes pair up to eventually become a new human genome.

   e. Overall it takes approximately 12-18 hours after fertilization for the zygote appear.

6. References

   Beckmann, C. Obstetrics and Gynecology (2009). (6th ed.).
   Cunnigham et al. (2014). Williams Obstetrics (24th ed.).
   Mularz, A., Dalati, S., & Pedigo, R. (eds.). (2016). OB/GYN Secrets (4th ed.).
   Tulandi, T., & Al-Forzan, H.M. (2017). "Spontaneous abortion: Risk factors, etiology, clinical manifestations, and diagnostic evaluation". In D. Levine, R. Barbieri, & K. Eckler (eds.), UpToDate. Retrieved April 28, 2017, from https://www.uptodate.com/contents/spontaneous-abortion-risk-factors-etiology-clinical-manifestations-and-diagnostic-evaluation

Ectopic pregnancy

For what it's worth, if anything, here are some of my thoughts on the topic of ectopic pregnancy:

1. Keep in mind I'm a mere med student, not a physician, let alone an OB/GYN. I'm open to correction on the medical science and other related data.

2. The vast majority of ectopic pregnancies are tubal ectopic pregnancies. Specifically, 95-98% of all ectopic pregnancies are tubal ectopic pregnancies. This simply means they're in one of the Fallopian aka uterine tubes.

   Other types of ectopic pregnancies are far less common (e.g. ovarian, cervical, abdominal).

3. My understanding is if an ectopic pregnancy occurs (e.g. the embryo implants in one of the uterine tubes), then there are basically two possibilities:

   a. The pregnancy will end in miscarriage.

   b. The baby will grow too big and rupture the uterine tube. This may in turn damage adjacent organs. Worse, the rupture could likewise cause the mother to hemorrhage to death.

4. If ectopic pregnancy is discovered early on, and doctors think (a) is most likely, then doctors will attempt what's called "expectant management." This means the doctors will closely monitor the mother and hope the pregnancy will naturally resolve itself in a miscarriage. That way, nothing much needs to be done by the medical team, and the health outcomes for the mother are probably best (e.g. she'll still likely be fertile).

   But if (b) is more likely, then medical (in the form of an abortifacient drug i.e. methotrexate) and/or surgical intervention is needed. It could be a medical emergency depending on how close to rupturing it is.

5. A few possible if currently perhaps unrealistic pro-life options:

   All these assume the baby in the ectopic pregnancy is developing normally or at least not developing too abnormally. This may be a pretty big assumption though. It's quite possible the baby won't be developing normally. Not getting enough blood and nutrients from the mother and so on since it's not implanted in the mother's womb but outside it (by definition).

   a. A potential option is to surgically transplant the embryo from the uterine tube (or wherever else it is) to the uterus aka womb.

   However, at least to my knowledge, medical science isn't advanced enough to do this let alone do this safely.

   Maybe someday in the future.

   b. Another possible option is to allow the ectopic pregnancy to grow and develop as much as possible, and then to surgically remove the baby as a preemie.

   However, this is highly unrealistic in a tubal ectopic pregnancy. The diameter of the uterine tube is approximately half an inch or thereabouts (about 1.25 cm). While the uterine tube is extensible to some degree (depending on several factors), the bottom line is if the baby grows too much bigger than the diameter of the uterine tube, then it could rupture the tube, and put the mother's life at risk. The baby would already be about half an inch at around 6 weeks. By 8 weeks or so, the baby would have doubled this size. At this point, or not too much beyond this point, it's possible the uterine tube could be at grave danger of rupturing. But to remove the baby at even 10-12 weeks would mean it'd die.

   Currently the earliest we've been able to save babies is around 20 weeks, give or take. And that's extremely rare. Most don't make it.

   But maybe future medical technology will make this a viable option.

   c. In the vast majority of ectopic pregnancies (i.e. tubal ectopic pregnancies), unfortunately it seems the best option is either to allow the ectopic pregnancy to naturally end i.e. miscarriage, or to intervene and abort. This is where some philosophers and ethicists justify the abortion by the doctrine of double effect. But in a small percentage of ectopic pregnancies, it may be possible to save the baby and/or mother. Basically, my understanding is these are in general only realistic in abdominal ectopic pregnancies, although there may be some cases where it's happened in other types of ectopic pregnancies.

   If the ectopic pregnancy is in the abdomen, then there might be more room as well as sufficient blood supply (depending on where in the abdomen the baby is) for the baby to grow and develop and with some luck make it to 20+ weeks, and thus we could hope to remove the premature baby such that neonatologists have a fighting chance to work their magic and rescue the baby. Although even 20+ week old babies are still at huge risk of dying. (A full-term pregnancy is at least about 37 weeks.)

   But even still there's absolutely no guarantee both baby and mother won't die. I think it'd be best to look at abdominal ectopic pregnancies on a case by case basis and see what, if anything, can be done to save both, or one (if not both).

   Here is a list of some successful ectopic pregnancies. But note the vast majority of them (if not all of them) are abdominal ectopic pregnancies, not tubal ectopic pregnancies (which again constitute the vast majority of all ectopic pregnancies - i.e. 95-98%).

To be or not to be

According to the JAMA:

Conclusions In this survey, a small proportion of terminally ill patients seriously considered euthanasia or PAS for themselves. Over a few months, half the patients changed their minds. Patients with depressive symptoms were more likely to change their minds about desiring euthanasia or PAS.

Partisan politics and vicious assaults

Peter Wehner writes:

First it was Alan Colmes; now it is Eugene Robinson of the Washington Post, who went on MSNBC to mock Rick Santorum for how he and his wife Karen dealt with the death of their son Gabriel. (A severe prenatal development led to his very early delivery, and Gabriel died two hours after his birth.)

Read the rest here.