likelihood of a miscarriage
Will it happen again?
I know this is a big question. If it happened once, you worry that it will happen again. If this is your first pregnancy, you worry that it will happen every time.
It’s not very likely that you will lose every pregnancy. The stories I hear about women losing even two in a row are pretty rare. I’ve included a chart to give you some idea of what books and medical sites tend to say. Know that hardly any of them agree, as some are hard numbers, others are extrapolated from what they assume are unreported losses.
Some doctors distinguish between a “clinical pregnancy” that has been tested on the less sensitive office urine tests and ones that were done with home tests that can go positive even before you miss a period.
Most doctors are unwilling to get into statistics, as you may have discovered. I researched this issue well and am going out on a limb because I know you want to know something, even if it may not apply to you in the end.
For most normal, healthy women in their first pregnancy, the statistics look like this:
Week of Gestation |
Percentage Likelihood of Miscarriage |
| 1 (You can only know fertilization occurred if you are doing infertility treatments) |
75% It is estimated that 3 out of 4 eggs that are fertilized do not fuse their DNA correctly, and therefore either do not attempt to implant or fail at implantation. Your period will come as expected in that case.~ |
| 2 (You have not yet missed your period, but may have taken an early detection home test.) |
30% Implantation occurs about 7-10 days after ovulation. About 1 in 3 eggs will not successfully burrow into the uterus, but might generate a small amount of hCG in the attempt, and set off the early urine tests that detect levels of 25. Your period will often come as expected, even if a test was positive.~ |
| 3-6 | 10% Once you pass the day that you have missed your period, the implantation is usually established. This number applies to pregnancies where hCG levels reach 50-80.~ |
| 7-12 | 5% Once the heartbeat is heard, usually at the end of the sixth week or beginning of the seventh, the baby has crossed a major developmental milestone and the miscarriage rate drops again. Because this is the range for a missed miscarriage, only a sonogram will detect a loss after about 9 weeks, as hCG levels stop doubling naturally.~ |
| 2nd trimester | 3% The cause of a loss at this point is most often uterine abnormalities or preterm labor or rupture of membranes. These are rare. At 20 weeks, the statistics move from miscarriage to stillbirth, although babies up to 24 weeks can be considered a miscarriage at the doctor’s discretion, so labor & delivery may not be required.~ |
| 3rd trimester | 1% A loss this late is no longer considered miscarriage once fetus is beyond one pound (500 grams) around 24 weeks gestation. The majority of losses at this point are chromosomal or development problems, cord accidents, or premature birth.~ |
Statistics for repeat miscarriage
Situation |
Percentage Likelihood of Miscarriage in Your Next Pregnancy |
| If you had a miscarriage in your first pregnancy~ | 13% chance of it happening again (up from 10%) |
| One miscarriage after having one or more live births~ | 10% (no more than normal) |
| Two pregnancies and two miscarriages~ | 40% (you should already be eligible for basic testing) |
| Multiple miscarriages with one or more live births | 13% if you are under 35 If you had one healthy child early on and later have several miscarriages in a row, you should seek testing, as your odds may have changed.~ |
| Three pregnancies and three miscarriages | 60% (you should have testing done after three concurrent miscarriages to determine cause and treatment)~ |
| Four or more miscarriages with no live births | It’s time to stop trying on your own and seek the help of a qualified reproductive endocrinologist or fertility specialist. See the section on causes of miscarriage for more information on what may be causing your losses. Your odds of carrying a baby to term vary incredibly based on the findings. Many things are very easy to treat.~ |
| Maternal age over 35 | If you have healthy children or this is your first pregnancy, and are in good health yourself, there is no reason to worry about an increased risk of miscarriage. It is a fact, however, that eggs begin to deteriorate after age 35 regardless of the mother’s health, and a higher rate of miscarriage and babies born with birth defects will occur. Recommended reading if you are over 35 can be found at www.marchofdimes.com.~ |
| After your first miscarriage, your likelihood of becoming a recurrent miscarrier | 20% although I don’t like this statistic, as it doesn’t match the others. But few places will give a number for this. This one comes from Miscarriage, A Woman Doctor’s View. |
Statistics on Ectopic Pregnancy
Situation |
Percentage Likelihoodof Ectopic |
| No history of ectopics | 2% |
| Tube with ectopic removed completely | 9% |
| Tube with ectopic preserved | 12% |
Even though your rate of ectopic is a bit higher when your tube is preserved, you want to keep your tube if you can. It dramatically increases your ability to get pregnant again.