One in seven couples will seek the help of a fertility specialist. Many people associate fertility treatments with pregnancy complications. Some of them are a preterm birth, premature birth or low birth weight, etc. Multiple births are one of the common causes of preterm births.
A large proportion of multiple births is due to fertility treatments. This usually occurs when the specialist replaces more than one embryo during embryo transfer. Transferring more than one embryo increases the risk of multiple pregnancies by almost 20-50%. This depends on whether the specialist transfers the embryos at the cleaved stage or at day -5 (Blastocyst).
There are other issues that may increase the risk of preterm birth. Such as, the age of the women at treatment, the number of embryos the specialist replaces, and any co-existing medical conditions.
It is important that your fertility specialist is aware of all this information. It helps your specialist to assess the risks and complications involved. This may influence some of the decisions about your IVF or ICSI treatment (such as the number of embryos that the specialist replaces at embryo transfer). Hence, it is important that your obstetrician or gynaecologist assesses any other risks of preterm birth. Your specialist should incorporate them into your treatment plan.
The study published in the British Medical Journal ( BMJ ) reports that just having an abnormal smear, even without any treatment, may increase the risk of premature or preterm birth. There are different treatments for abnormal cervical cells. In some treatments, the specialist destroys the cells (ablative) and in others removes them. The name of the latter is loop excision or knife cone excision. While the ablative treatment is associated with less increase in the risk compared to the loop excision or knife cone excision.
Women who had 10-15 mm of the cervical tissue removed have a two-fold increase in the risk of premature or preterm birth. If the specialist removes around 15—17 mm of the cervical tissue then your risk of preterm or premature birth increases by three-fold.
Finally, removing more than 20mm of the cervical tissue increases the risk fivefold. This usually occurs with multiple procedures. It can also occur with knife cone excision for cervical intraepithelial neoplasia or CIN 3.
Taking into consideration these risks, your fertility specialist may suggest single embryo transfer. This will decrease the risk of multiple pregnancies and thus preterm or premature birth. They may also attempt to transfer the embryos at the blastocyst or day-5 stage. This will give you better IVF or ICSI success rates even with single embryo transfer.
Besides influencing the decisions about fertility treatment, I advise you to see your obstetrician or gynaecologist for regular measurements of the length of the cervix in early pregnancy. Shortening of the cervical length during pregnancy could be one of the early indicators of the preterm birth. Early detection will give your obstetrician or gynaecologist a chance to consider putting a cervical stitch or cervical cerclage. This may help in preventing or stopping the process of preterm birth.
So, a detailed assessment at the initial visit to a fertility specialist is important in planning treatment. This will help on working towards achieving the best possible IVF success rate. It will also contribute to putting in place treatment plans that are safer for you.