Miscarriages are unfortunately an all too common part of the journey towards having your baby. My patients often ask me several questions about miscarriages that I think are worth a discussion.

Why do they happen?

There are many reasons, but overwhelmingly they are due to chromosomal abnormalities in the embryo that has implanted.

Although these abnormalities can stem from either the sperm or the egg, they tend to come from the egg rather than sperm. Eggs are just much more vulnerable given the fact that they have been lying dormant but growing fragile in the ovaries for decades, while sperm is made fresh continuously.

When do miscarriages occur?

Often the abnormal pregnancies implant merely for a few hours or days and are never even seen on a sonogram. These “chemical pregnancies” are solely detectable by the fact that, ever so briefly, there was some BhCG or pregnancy hormone in your system that was detected by blood testing. Some abnormal pregnancies can last for several weeks, but most occur before 10 weeks of pregnancy.

When they are early they often self-resolve via menstrual-like bleeding, and no real treatment is needed. Later losses often require an intervention, usually a dilation and curettage (D&C) to remove all the uterine contents, although often one can use an agent like cytotec to cause uterine cramping in an effort to avoid any procedures.

What are your BhCG levels after miscarriage?  

The BhCG levels should be progressively lower each day following a miscarriage. The BhCG level does not drop to zero immediately after a loss.  It is a hormone that has a half-life of about 24 hours. Therefore your blood pregnancy test may stay positive for weeks even after the loss occurred, especially if you had a later loss with its accompanying higher BhCG levels. If the BhCG level plateaus after a loss, then it means there is some sort of pregnancy tissue still present that is eking out hormone long after the viability of the pregnancy has passed.

How long does it take to ovulate and get your period after a miscarriage?

The actual loss itself is usually accompanied by uterine bleeding, but that is not really what we call a period…just your uterus trying to clear itself out. Your first real period after a miscarriage will occur about 2 weeks after the first ovulation you experience after the pregnancy loss.  If you have a lot of BhCG in your system, your ovulation will likely be delayed significantly until it drops closer to zero. But if you have a very early loss, with very low BhCG levels, then you may not even be aware of being pregnant as you may get a period nearly on time.

Is there an ovulation test after miscarriage?

You can use a urine based ovulation predictor kit after a miscarriage certainly, but the exact time as to when you should start using these kits is not as clear cut as it normally is…around day 11 or 12 of your cycle. You may not ovulate for several weeks after a loss, so starting 2 weeks or so after it happens may be a bit early. Your fertility doctor can give you some guidance on this by doing sonograms because if a large follicle is noted on the ovary then ovulation ought to be imminent.

Could I be 5 weeks pregnant after miscarriage 2 months ago?

The short answer is yes! Women may ovulate as early as 2 weeks following a loss, and if sexually active at that time point they can become pregnant again that quickly. However, it is important to not try to get pregnant after a miscarriage until the blood pregnancy hormone in your system is back down to zero. Why do we care about this? Because it is the only real way to make sure that there is no residual pregnancy tissue left in the uterus. Sometimes small remnants can remain, and if they do remain they can lead to future issues like diminished fertility or abnormal uterine bleeding. Rarely, leftover pregnancy material can transform into a pre-cancer or cancer called gestational trophoblastic neoplasia (GTN), and it would not be discovered if one became pregnant right away after a miscarriage as the new pregnancy’s hormonal production would mask the hormonal production made by the GTN.  But having said all this, if your blood pregnancy hormone hits zero, and you feel physically well, then you need not wait any further to go ahead and try to conceive again.