Miscarriages are common and often remain unexplained, which can be very stressful for a woman who wants to fall pregnant afterwards but is concerned about another miscarriage. It may be reassuring to know that most pregnancies following a single miscarriage do continue till term with the delivery of a healthy, normal baby. In fact, investigations are normally not warranted even after two spontaneous miscarriages because a woman can still have an uneventful pregnancy. However, in the event of three consecutive spontaneous abortions (a condition known as recurrent abortion), it is advisable to undergo a number of tests and investigations to identify the cause of the miscarriages.
How soon after a miscarriage can a woman fall pregnant?
This is the question most frequently on a woman’s mind after a miscarriage. While there is no definite answer to this, it is generally advisable to wait for one or two normal periods before trying to fall pregnant. This not only gives the body time to heal but also gives a woman some time to recover emotionally so as to be prepared for another pregnancy.
However, it is possible to get pregnant soon after a miscarriage because ovulation may occur even 2 weeks after an abortion and some couples prefer not to wait before trying again for a baby.
When should miscarriage investigations and tests be done?
- For first trimester miscarriages, which are most often due to chromosomal abnormalities, investigations are usually not advised unless there is a history of recurrent abortions.
- Women over the age of 35 years may be tested for chromosomal abnormality even after one miscarriage.
- Second trimester miscarriages are more often due to other causes such as structural abnormalities of the uterus or cervix, and should be investigated sooner.
- Women suffering from systemic diseases such as diabetes, hypertension or thyroid problems should undergo investigations as soon as possible to ensure that their condition is under control and being managed appropriately.
- Women with history of infertility should undergo all the tests and investigations once the problem has been identified.
Investigations to Find the Cause of Miscarriage
For a woman who is anxious to find out the reason for the miscarriage and to identify any preventable causes, the following investigations may be advised. More than one cause may be involved in some cases. Sometimes, no cause will be found even after a thorough investigation. While this can be frustrating, it can also mean that there really is no problem and the next pregnancy will be successful.
- The blood from both parents are tested in a genetics laboratory for any chromosomal abnormality.
- In a small percentage of cases, there is a chromosomal abnormality known as balanced translocation in one or both parent, which does not cause a problem in either parent but may be passed down to the fetus.
- This can be the cause of a miscarriage.
- No treatment can be offered for chromosomal abnormality. Genetic counseling may help a couple to understand and make an informed decision regarding future pregnancies.
- Fetal Karyotype
- Fetal tissue is tested for chromosomal abnormalities.
- About 50% of miscarriages occur due to a chromosomal abnormality in the fetus which is not related to any abnormality in either parent’s genes.
- If an abnormal chromosome pattern is found in the fetus, but results are normal in the parents, it is unlikely that there will be a problem in future pregnancies.
Tests for Lupus Anticoagulant and Anticardiolipin Antibodies (Antiphospholipid Syndrome)
- High levels of these antibodies detected in a woman’s blood may be the cause of recurrent miscarriage.
- Two positive blood tests, six weeks apart, confirms the diagnosis of antiphospholipid syndrome.
- Low dose aspirin (75mg daily), starting before conception or early in pregnancy, is the treatment of choice.
- Heparin injections may also be given once pregnancy is confirmed and the fetal heartbeat is seen on scan.
Hormonal Blood tests for luteinizing hormone (LH), Progesterone and Human Chorionic Gonadotropin (hCG)
- Polycystic ovarian syndrome (PCOS) and high levels of LH could be the cause of recurrent miscarriage. No definitive treatment is available yet for either condition.
- Treatment with progesterone is often undertaken to help in continuing a pregnancy that may be threatened but efficacy of treatment is still not conclusively proven.
- Progesterone therapy (in the form of vaginal suppositories, gel and tablets) has been tried in recurrent pregnancy loss with reported success in a number of cases.
- Thyroid function test may be done to rule out thyroid hormone imbalance as a cause of miscarriage.
- Blood sugar levels are tested since uncontrolled diabetes could increase the risk of abortion.
- Structural abnormalities within the uterus may be identified by means of ultrasound, hysterosalpingogram (HSG), or a hysteroscopy. Surgery may be helpful in correcting some of these abnormalities, such as a uterine septum or a fibroid, but it will by no means guarantee a future successful pregnancy since some other factor could be responsible for the miscarriage.
- Cervical resistance test may be done if cervical incompetence is suspected from the history. Cervical cerclage is the treatment procedure, where a stitch is placed high up around the cervix around 13 or 14 weeks of pregnancy.
- TORCH screening for infections is often done while conducting investigations for miscarriage. This includes testing for toxoplasma, other viruses, rubella, cytomegalovirus, herpes virus, and sometimes HIV. Infection, however, is not thought to be a significant cause of a recurrent abortion.
- Vaginal cultures for infection such as bacterial vaginosis may be done.
Prevention of Miscarriage
Certain steps may reduce the risk of miscarriage in future pregnancies. This includes :
- Pre-pregnancy counseling.
- Early prenatal care.
- Avoiding smoking.
- Avoiding drugs and alcohol.
- Eating a healthy, balanced diet.
- Losing weight, if obese.
- Keeping diabetes (blood sugar), hypertension (blood pressure) and other systemic diseases under control.
- Avoiding exposure to x-rays and other environmental hazards.
- What is Spontaneous Abortion? Types of Miscarriage in Pregnancy
- Causes of Spontaneous Abortion (Miscarriage)
- Miscarriage Complications, Dangers of Spontaneous Abortion
- Investigation of Recurrent Miscarriages. British Medical Journal (BMJ)