Recurrent miscarriage can be an extremely wearing experience for couples, both physically and emotionally. When pregnancies that were awaited with such hope end one after another, it can create a deep sense of sorrow and helplessness. Thanks to advances in modern medicine and reproductive technology, however, the causes of this condition are now much better understood, and in many cases effective treatment approaches can be offered. As Ankara IVF Center, our aim is to support our couples through this difficult process with a scientific and compassionate approach. In this article we will examine the causes of recurrent miscarriage and current treatment approaches, drawing on the expertise of Prof. Dr. Mehmet Çınar.
Definition of Recurrent Miscarriage
Recurrent miscarriage is generally defined as two or more consecutive pregnancy losses. This condition, also known in the medical literature as "habitual abortion", is characterised by the spontaneous ending of a pregnancy before the 20th week. The great majority of pregnancy losses occur in the first trimester, that is, within the first 12 weeks. While approximately 15–20% of pregnancies in the general population end in miscarriage, the proportion of couples who experience recurrent miscarriage is around 1–2%. Although the definition usually refers to two or more miscarriages, some specialists argue that even a single pregnancy loss may warrant a detailed investigation, particularly if the mother-to-be is older or is having difficulty conceiving. Understanding the causes of recurrent miscarriage is of critical importance for determining the right diagnostic and treatment strategies.
Genetic Causes
One of the most frequently encountered causes of recurrent miscarriage is genetic factors. Approximately 50–60% of pregnancy losses result from chromosomal abnormalities that arise in the embryo. These abnormalities usually occur at random during fertilisation and prevent the healthy development of the embryo, leading to the ending of the pregnancy at an early stage.
Embryonic Chromosomal Abnormalities
Numerical (for example, trisomy or monosomy) or structural chromosomal disorders in the embryo are among the most common factors preventing a pregnancy from continuing. This situation usually arises from errors occurring during the formation of the egg or sperm cells, even though there is no problem in the couple's own genetic make-up. Advanced maternal age in particular, together with the decline in egg quality, increases the risk of chromosomal abnormality in the embryo.
Parental Chromosomal Abnormalities
In approximately 2–5% of couples experiencing recurrent miscarriage, structural chromosomal abnormalities such as a balanced translocation can be detected in the mother or the father. In this case, although the parents themselves are healthy, the sperm or egg cells they produce may carry unbalanced sets of chromosomes. This causes some of the embryos to be genetically abnormal and therefore to end in miscarriage. In such situations, Preimplantation Genetic Testing (PGT) can increase the chance of pregnancy by identifying and transferring healthy embryos. PGT allows the genetic examination of cell samples taken from embryos during IVF treatment.
Anatomical and Hormonal Causes
Abnormalities in the structure of the uterus or hormonal imbalances can also be among the important causes of recurrent miscarriage. These factors may prevent the embryo from implanting in the uterus or from developing healthily.
Anatomical Causes
- Uterine anomalies: congenital abnormalities in the shape of the uterus — for example a uterine septum, a double uterus (uterus didelphys) or a heart-shaped uterus (bicornuate uterus) — can create an environment unsuitable for the implantation and development of the embryo. The uterine septum is one of the most common anomalies and can be corrected surgically.
- Intrauterine adhesions (Asherman's syndrome): adhesions that form inside the uterus after previous curettage procedures, infections or surgical interventions can narrow the uterine cavity or impair the function of the endometrium (uterine lining), and thereby lead to miscarriage.
- Fibroids and polyps: fibroids growing towards the inner cavity of the uterus (submucosal fibroids) or intrauterine polyps can prevent the embryo from implanting or cause miscarriage in the later stages of pregnancy.
- Cervical insufficiency: this is a condition in which the cervix opens painlessly in the later weeks of pregnancy, leading to miscarriage or premature birth. It is generally seen in second-trimester losses.
These anatomical problems can usually be diagnosed by methods such as hysterosalpingography (HSG), ultrasonography, sonohysterography, or hysteroscopy and laparoscopy, which provide direct visualisation, and in most cases they can be corrected with surgical intervention.
Hormonal Causes
- Thyroid disorders: both hypothyroidism (an underactive thyroid gland) and hyperthyroidism (an overactive thyroid gland) can have adverse effects on pregnancy and increase the risk of miscarriage. Regulating thyroid hormone levels is important for a successful pregnancy.
- Polycystic ovary syndrome (PCOS): PCOS can affect egg quality by causing hormonal imbalances, and can lead to insulin resistance and raised androgen levels. These conditions can increase the risk of miscarriage.
- Luteal phase defect (LPD): this is a condition in which the uterine lining (endometrium) is not sufficiently prepared after ovulation for a pregnancy to implant. Although it is associated with insufficiency of the hormone progesterone, the scientific evidence that this condition causes recurrent miscarriage is debated, and routine treatment is not always recommended.
- Diabetes: uncontrolled diabetes, and in particular high blood sugar levels, can significantly increase the risk of miscarriage. Achieving good blood sugar control before and during pregnancy is of critical importance.
Clotting Disorders
Clotting disorders, also known as thrombophilia, are conditions that cause the blood to clot inside the vessels more easily than normal. These conditions can lead to the formation of micro-clots in the placenta, impairing blood flow to the foetus, and can be an important cause of recurrent miscarriage.
Inherited Thrombophilias
Certain genetic mutations can make a person more prone to clotting. The most frequently seen of these are:
- Factor V Leiden mutation: one of the most common causes of inherited thrombophilia.
- Prothrombin gene mutation (G20210A): leads to excessive production of the prothrombin protein, which plays a role in blood clotting.
- Methylenetetrahydrofolate reductase (MTHFR) mutations: these can affect folate metabolism, raising homocysteine levels and increasing the risk of clotting. However, the direct relationship between MTHFR mutations and miscarriage is still debated, and routine screening is not always recommended.
Acquired Thrombophilias
The best-known acquired thrombophilia syndrome is antiphospholipid syndrome (APS).
- Antiphospholipid syndrome (APS): an autoimmune disease characterised by the body producing antibodies (antiphospholipid antibodies) that attack its own tissues. These antibodies can trigger clotting in the blood vessels and lead to pregnancy complications such as miscarriage, stillbirth or premature birth. The diagnosis of APS is made by detecting specific antibodies in the blood together with a history of recurrent miscarriage.
In patients in whom a clotting disorder is suspected, specific factors and antibodies are investigated with blood tests. Once a diagnosis has been made, blood-thinning medication (for example, low molecular weight heparin) is used during pregnancy in an effort to reduce the risk of clotting. These treatments can significantly improve pregnancy success, particularly in conditions such as APS.
Treatment and Follow-up Plan
The causes of recurrent miscarriage are highly complex and varied. For this reason, a comprehensive diagnostic assessment must first be carried out in order to create an effective treatment and follow-up plan. At Ankara IVF Center, Prof. Dr. Mehmet Çınar and his team adopt an individualised approach suited to each couple's particular situation.
Diagnostic Assessment
Before treatment begins, the following tests and assessments may be carried out:
- Detailed history and physical examination: information such as previous pregnancies, medical history and family history is collected.
- Genetic tests: karyotype analysis is performed for both the mother and the father. If necessary, genetic analysis of tissue from a previous miscarriage may be requested.
- Hormonal tests: thyroid function tests, prolactin, blood sugar and insulin resistance are evaluated.
- Anatomical assessment: the uterus and pelvic organs are examined using imaging methods such as transvaginal ultrasonography, sonohysterography, hysterosalpingography (HSG) and hysteroscopy and/or laparoscopy.
- Clotting tests: antiphospholipid antibodies (lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein I antibodies) and an inherited thrombophilia panel (Factor V Leiden, prothrombin gene mutation and so on) are examined.
- Immunological tests: in some cases, factors relating to the immune system may be investigated, but treatments in this area are still at the research stage and are not routinely recommended.
Treatment Approaches
Treatment is determined according to the cause or causes identified:
- Genetic causes: when a balanced chromosomal anomaly is detected in the parents, or in situations such as advanced maternal age, Preimplantation Genetic Testing (PGT) may be applied together with IVF treatment. With PGT, genetically healthy embryos are selected and the chance of pregnancy is increased.
- Anatomical causes: conditions such as a uterine septum, adhesions or certain fibroids can be corrected with hysteroscopic or laparoscopic surgical methods. In the case of cervical insufficiency, a cervical cerclage (a stitch placed in the cervix) may be performed.
- Hormonal causes: conditions such as thyroid dysfunction, diabetes or PCOS are brought under control with appropriate medical treatment. Regulating hormone levels before and during pregnancy is important.
- Clotting disorders: when antiphospholipid syndrome or certain inherited thrombophilias are detected, blood-thinning medication (low-dose aspirin and/or low molecular weight heparin injections) may be used throughout the pregnancy. These treatments aim to reduce the risk of miscarriage by improving blood flow in the placenta.
- Lifestyle changes: lifestyle changes such as avoiding smoking and alcohol, eating healthily, maintaining an ideal weight and managing stress can have a positive effect on the success of a pregnancy.
Psychological Support and Follow-up
Recurrent miscarriage places a great psychological burden on couples. During this process, psychological support and counselling services can help couples come through this difficult period. Regular follow-up during treatment is of critical importance for the health of both mother and baby. Once pregnancy is achieved, close monitoring and, where necessary, supportive treatment help ensure that the pregnancy continues healthily. At Ankara IVF Center, our experienced team, which includes Prof. Dr. Mehmet Çınar, offers couples experiencing recurrent miscarriage a comprehensive assessment and up-to-date treatment approaches. Without giving in to despair, it is possible to reach a healthy pregnancy with the right diagnosis and treatment.
Recurrent miscarriage is a difficult process that can leave deep marks on a couple's life. Thanks to advances in modern medicine and reproductive technology, however, the causes of this condition have largely been clarified and many effective treatment methods have been developed. As Ankara IVF Center, with the expertise of Prof. Dr. Mehmet Çınar and our experienced team, our aim is to offer each couple a scientific and compassionate approach suited to their particular situation and to help their hopes flourish again. Remember that with the right diagnosis and a personalised treatment plan, you always have a chance of reaching a healthy pregnancy. You are not alone on this difficult journey.
To obtain more information about recurrent miscarriage or to have your personal situation assessed, you can contact Ankara IVF Center and arrange a free preliminary consultation appointment.