What is a missed miscarriage?

Missed miscarriage can come as a big shock. For my first missed miscarriage, I was having some spotting but still thought everything was fine. My morning sickness was awful, even on the day of my appointment to check on the spotting. That’s when I found out that the baby had stopped growing 3 weeks prior.

A missed miscarriage, also known as a silent miscarriage or delayed miscarriage, is when the baby has stopped developing but the body has not physically miscarried. There are often no signs at all that a missed miscarriage has occurred, until it is found on a routine ultrasound. Some people may experience a decrease in pregnancy symptoms. For others, symptoms may continue without any noticeable change. Some people may have spotting, but no cramping or bleeding that would lead them to believe they were miscarrying. Often there is no bleeding or spotting at all.

This post may contain affiliate links, which means I’ll receive a commission if you purchase through my links, at no extra cost to you. Please read full disclosure for more information.

Experiencing a missed miscarriage

If you have just found out about a missed miscarriage, I am so sorry you are going through this. Grief hits in a variety of ways, and while trying to process the bad news, your provider will be asking for decisions about how you want to proceed. How can you decide and process what they are trying to tell you when you can’t even think straight? Find support, talk to a trusted person, and take your time with your decision if needed. Unless your doctor has told you it’s an emergency, you can wait a few days to decide. When you are ready for information, read or reread this page and have a chat with your provider.

You can also read about my miscarriage experiences (D&C, expectant management, and medical management) and about what to expect for recovery after miscarriage.

What causes a missed miscarriage?

The causes of missed miscarriage are the same as those for all miscarriages: chromosomal abnormalities in the baby, maternal factors like disease, paternal factors like sperm quality, or environmental factors like exposure to toxins. 

The frequency of chromosomal abnormalities in spontaneous miscarriage is 4%. But for missed miscarriages, nearly ⅔ are due to chromosomal abnormalities in the baby. Statistically, if you are experiencing a missed miscarriage, it is likely due to chromosomal abnormalities. It is important to remember that a miscarriage is not due to something that you did. Missed miscarriages don’t occur because you were too stressed, or because you had a hard workout, or because you drank 2 cups of coffee. What you are going through is difficult, and it’s unfair, and it is definitely not your fault.

How common are missed miscarriages?

Overall, 10% to 20% of clinically recognized pregnancies will end in miscarriage. Only 10-20% of those miscarriages are missed miscarriages. Missed miscarriages are becoming more common over time. My feeling is that this is because  testing and scans in early pregnancy are becoming more common, leading to more missed miscarriages being found prior to any onset of miscarriage symptoms. It’s also possible that the increase could be tied in part to women having babies at older ages and increased use of assisted reproductive techniques.

How is a missed miscarriage diagnosed?

Missed miscarriage is diagnosed via ultrasound. Depending on the size of the fetus or the gestational age, a transvaginal ultrasound may be needed. On the ultrasound, an empty gestational sac may be seen, or maybe not even a sac. In this case, development may have stopped very early or the products of conception may have been reabsorbed.

A miscarriage can also be diagnosed if an embryo is seen, but no heartbeat. The embryo may be behind in development. Depending on the developmental age, a follow up ultrasound in 1-2 weeks may be needed. This is because there is some variability in the dating of pregnancy, even when the date of the last menstrual period (LMP) is known. If you are 7 weeks pregnant and the baby is measuring small without a heartbeat, that could be a miscarriage or it might not. For example, if you ad irregular cycles, ovulated later, or implantation took longer, the baby may actually only be 5 or 6 weeks. The only way to know is to wait and do a repeat ultrasound. To learn more about this variability, read this article.

The diagnostic criteria for a type of missed miscarriage called anembyronic gestation would include seeing on ultrasound a gestational sac >13 mm without yolk sac or seeing a gestational sac >18 mm without embryonic pole. Also, missed miscarriage can be diagnosed past 38 days gestation (5 weeks 3 days) when no interval growth is seen between ultrasounds 1 week apart.

The diagnostic criteria for a type of missed miscarriage called embryonic or fetal demise would include an ultrasound showing an embryonic pole (baby) >5 mm with no fetal cardiac activity (heart beat). Also, missed miscarriage can be diagnosed if an embryonic pole <5 mm is seen and no growth between ultrasounds 1 week apart.

Treatment for a missed miscarriage

There are essentially 3 options for treatment for a missed miscarriage. Expectant management, medical treatment, or surgical management. In general, there is no right or wrong choice. The best choice is whatever makes you feel most comfortable physically and/or mentally as you go through this difficult process. To help you as you decide, here’s what each type of treatment entails and the success rates for each.

Expectant management

Expectant management is more or less a wait and see approach. Your provider will check in with you from time to time, as you wait to see if miscarriage will occur naturally. There will likely be a time frame specified by your provider, a number of days or weeks, after which a medical treatment or surgical management should be considered.

The success rate of expectant management is 53%-71% over 2 weeks in two studies I read. Those with symptoms of miscarriage are more likely to have success with expectant management. These success rates are lower than medical treatment and surgical management, but still a decent success rate considering no intervention is used. I have chosen expectant management for myself when I just wanted to go through my pain and grief at home, in comfort, with my loved ones. I also feel that I have recovered emotionally and mentally more quickly when miscarrying at home, but that is purely anecdotal and my own opinion.

Evening primrose oil

Evening primrose oil can be used as a part of expectant management or even medical treatment. My provider instructed me to use evening primrose oil for my missed miscarriages, so I have had some experience and some success with this one. Evening primrose oil is an over-the-counter supplement. It is relatively cheap and easy to get, with little risk involved.

Evidence shows that 2000 mg evening primrose oil administered vaginally the night before receiving misoprostol improved the success rate. In this study, 5 women in the test group began miscarrying before ever receiving misoprostol. This did not happen in the control group who did not use evening primrose oil, so this shows that evening primrose oil can be of benefit all on its own. The study found that in missed miscarriage, evening primrose oil led to faster time to “discharge uterine contents”, less bleeding, and a lower chance of retained products of conception. To learn more about evening primrose oil for missed miscarriage, click here.

Medical treatment

Medical treatment involves the use of medication to cause the miscarriage to begin. Misoprostol is usually the medication that is used. It is administered vaginally, with the timing and dosage determined by your provider. If success does not occur with the first dose, your provider may recommend another dose.

Sometimes mifepristone may be prescribed to be taken orally before the misoprotol is used. This can result in higher success rates without any increase in risk.

Success rates for medical treatment that I found in the literature ranged from 75-95%. These success rates are better than the rates for expectant management. Some people report increased pain with medical treatment, which is validated in the available research. Personally, my experience was similar both with natural miscarriage and medicated miscarriage. One benefit of medical treatment is that you have some control over when the miscarriage will occur, and you can prepare with pain medication.

Surgical management

Surgical management consists of uterine aspiration or dilation and suction curettage (D&C), with sharp curettage. For these procedures, you will be sedated and the doctor will remove the products of conception. This can happen in the operating room or in a clinic, and is usually an outpatient procedure.

Surgical management may be your first choice, or you may need surgical management after medical management or expectant management fails.  In some circumstances, such as heavy bleeding or infection, you may not have a choice as your provider may feel surgical management is needed for safety.

The success rate of surgical management is 97-98%. In the literature, the duration of bleeding and the amount of pain were both less with surgical management than medical or expectant management. This was also my personal experience – I had no pain at all after D&C. The risk for complications from surgical management is very rare. However, the pelvic infection rate is about twice as much for surgical management than in expectant and medical management. This rate is still low with only 6.7% of women who undergo D&C experiencing pelvic inflammatory disease, sepsis or endometritis.

Asherman’s syndrome

You may have heard about Asherman’s syndrome, or scarring in the uterus, that could occur after D&C. You may have also heard that this scarring could cause infertility in the future. But it’s not as scary as some people make it sound. Let’s look at the facts. 

Asherman’s syndrome is less likely during D&C for a first trimester loss, only affecting 13% of women. For D&C procedures in the second trimester, it could affect as many as 30% of women. Asherman’s syndrome can cause light periods, no periods, pain, and infertility. However, it can also be treated and scar tissue removed from the uterus during a hysteroscopy. The risk of Asherman’s syndrome is one that you should carefully consider, especially if you would like to try to conceive again. However, make sure the information that you are looking at is truthful and accurate. The resources I used are listed as citations 10 and 11. 

Missed miscarriage is also known as missed abortion

The word abortion is tied to such strong feelings and emotions due to the political and cultural climate. But in medical terms, a loss of pregnancy is called an abortion. This includes miscarriage. A miscarriage is called a spontaneous abortion, and a missed miscarriage is called a missed abortion. These should not be confused with elective abortion or induced abortion, when a mother has made a choice to terminate pregnancy.

Even knowing this, it can still be hard to hear the word abortion or read it in a medical note, especially because our little ones are very much wanted. Try to separate the political/cultural meaning from the medical meaning, because missed abortion is just medical jargon. And if you think that reading those words will be difficult, I recommend that you do not read your medical reports or notes at all. If you really need something verified in those notes, you could always ask a family member to read them for you.

If you have any concerns of questions I didn’t address here, please let me know. I will do what I can to find the information and help as best I can.

Citations:

  1. Prine LW, MacNaughton H. Office management of early pregnancy loss. Am Fam Physician. 2011 Jul 1;84(1):75-82. PMID: 21766758.
  2. Li X, Kang H, Yin H, Liu T, Hou Q, Yu X, Guo Y, Shen W, Ge H, Zeng X, Lu K, Xiong Y. How many missed abortions are caused by embryonic chromosomal abnormalities and what are their risk factors? Front Genet. 2023 Jan 4;13:1058261. doi: 10.3389/fgene.2022.1058261. PMID: 36685814; PMCID: PMC9846508.
  3. Alves C, Jenkins SM, Rapp A. Early Pregnancy Loss (Spontaneous Abortion) [Updated 2023 Oct 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560521/
  4. Musik T, Grimm J, Juhasz-Böss I, Bäz E. Treatment Options After a Diagnosis of Early Miscarriage: Expectant, Medical, and Surgical. Dtsch Arztebl Int. 2021 Nov 19;118(46):789-794. doi: 10.3238/arztebl.m2021.0346. PMID: 34696822; PMCID: PMC8864670.
  5. Mahmoodinasab M, Loripoor M, Vazirinejad R, Aminzadeh F. Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortion. Avicenna J Phytomed. 2023 Sep-Oct;13(5):454-462. doi: 10.22038/AJP.2023.22179. PMID: 38089421; PMCID: PMC10711576.
  6. Casikar I, Bignardi T, Riemke J, Alhamdan D, Condous G. Expectant management of spontaneous first-trimester miscarriage: prospective validation of the ‘2-week rule’. Ultrasound Obstet Gynecol. 2010 Feb;35(2):223-7. doi: 10.1002/uog.7486. PMID: 20049981.
  7. Rafi J, Khalil H. Expectant management of miscarriage in view of NICE Guideline 154. J Pregnancy. 2014;2014:824527. doi: 10.1155/2014/824527. Epub 2014 Apr 27. PMID: 24868466; PMCID: PMC4020214.
  8. Sotiriadis A, Makrydimas G, Papatheodorou S, Ioannidis JP. Expectant, medical, or surgical management of first-trimester miscarriage: a meta-analysis. Obstet Gynecol. 2005 May;105(5 Pt 1):1104-13. doi: 10.1097/01.AOG.0000158857.44046.a4. PMID: 15863551.
  9. Al-Ma’ani W, Solomayer EF, Hammadeh M. Expectant versus surgical management of first-trimester miscarriage: a randomised controlled study. Arch Gynecol Obstet. 2014 May;289(5):1011-5. doi: 10.1007/s00404-013-3088-1. Epub 2013 Nov 16. PMID: 24240972.
  10. Smikle C, Yarrarapu SNS, Khetarpal S. Asherman Syndrome. [Updated 2023 Jul 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448088/
  11. Conforti A, Alviggi C, Mollo A, De Placido G, Magos A. The management of Asherman syndrome: a review of literature. Reprod Biol Endocrinol. 2013 Dec 27;11:118. doi: 10.1186/1477-7827-11-118. PMID: 24373209; PMCID: PMC3880005.