Evaluation and Treatment of Recurrent Pregnancy Loss
Recurrent pregnancy loss (RPL) is a serious problem for some infertile couples. After losing two pregnancies, a woman should consider seeing a fertility specialist. Traditionally, a diagnosis of RPL is done after a woman loses three pregnancies.
How common is recurrent pregnancy loss?
Overall, around 20% of pregnancies end in spontaneous abortion (miscarriage) due to a non-recurrent cause. The risk of two consecutive losses is only one-fifth of this, meaning 4% of women experience recurrent pregnancy loss.
What is the most common cause of pregnancy loss?
The most common reason for pregnancy loss is abnormal number of egg chromosomes. Chromosomal translocation is the relocation of a portion of genes from one chromosome to another, and this is seen in around 4% of couples. While the parents have normal chromosomal complement, the sperm and egg end up with ½ of the original set, but could end up missing a portion of a chromosome or extra chromosomal material.
What other conditions cause RPL?
Other causes of recurrent miscarriage include:
• Undiagnosed and untreated uterine anomalies, such as polyps or fibroid tumors.
• Congenital uterine malformations, such as a uterine septum.
• Incompetent cervix, where the cervix dilates prematurely without contractions.
• Infections, such as chlamydia or gonorrhea.
• Hormone imbalances, due to pituitary dysfunction, thyroid disease, or other problems.
• Age-related elevation of follicle stimulating hormone (FSH) or decrease in inhibin B, which increase the possibility of miscarriage.
• Abnormal blood clotting due to antibodies or phospholipids.
• Allogenic immunity, involving lack of protective blocking antibody, increased natural killer cell numbers and activity, as well as increased levels of substances that stimulate the immune system’s attack response.
What are the risk factors for recurrent pregnancy loss?
Risk factors for spontaneous abortion include:
• Advanced maternal age
• Frequent alcohol consumption
• High caffeine consumption
• Use of illicit drugs
• Overweight or underweight
What is the workup for RPL?
An evaluation for known causes is initiated after three consecutive pregnancy losses. The full evaluation involves:
• Assessment for hormonal deficiency in progesterone production (by laboratory or endometrial biopsy)
• Demonstration of a normal shaped uterus (by hysteroscopy or hystersalpingogram)
• Analysis of both paternal and maternal chromosomes (by bloodwork)
• Taking a full history of environmental exposure, toxin contact, and maternal disease states
• Laboratory evaluation for immunologic causes of miscarriage
What are the options for uterine abnormalities?
A sonohysterography (saline-ultrasound) or hysterosalpingogram (x-ray dye exam) can be used to evaluate the uterus. Surgery is used to correct abnormalities in low-risk outpatient procedures. The fertility specialist can perform a septum resection on the uterine septum to improve the chances of a successful delivery.
What can be done to prevent spontaneous miscarriages associated with fetal chromosomal abnormalities?
The fertility specialist may recommend preimplantation genetic diagnosis (PGD) before the IVF. This assesses for inherited genetic disorders, such as muscular dystrophy or cystic fibrosis.
Can immune factors be treated?
A well-established link exists between recurrent pregnancy loss and antiphospholipid antibodies, which are proteins that appear to attack the developing fetus. This can be treated by using a low dose of aspirin and a low dose of heparin during pregnancy.
How are hormone imbalances corrected?
Hormonal problems in the mother can lead to unwanted miscarriage. To prevent problems associated with diabetes, tight glucose control is recommended. The same holds true for thyroid dysfunction, with normal levels of thyroid hormone protecting against miscarriage.