The overall rate of miscarriage is generally thought to be approximately 15 percent for women in their 20s, rising to more than 50 percent for women in their 40s. Similar rates are seen with fertility therapies.
Some women will have an elevated risk of miscarriage from other clinical conditions including diminished ovarian reserve or uterine factor. Women who have recurrent miscarriage should see their physician for specific treatment for this condition.
In the general population that conceive naturally, the rate of pregnancy located outside of the uterus – usually in the fallopian tube – is approximately 1 percent. This rises in women who have a history of tubal problems or previous tubal pregnancy. With fertility agents and/or IVF, the risk of a tubal pregnancy appears to be slightly elevated. For this reason, the hormone levels and ultrasound in early pregnancy will be carefully followed. At times, there can be a simultaneous pregnancy within the uterus and a pregnancy within the fallopian tube, known as a heterotopic pregnancy. If a pregnant woman experiences sharp pelvic pain, vaginal bleeding, dizziness or fainting, low back pain or low blood pressure, she should notify her physician immediately.
Although many couples desire multiple pregnancy, they should be aware that the risks are increased, even if there are only twin multiples. These risks include:
The goal of fertility therapy or treatment is the birth of a healthy baby and it is important to use the least aggressive therapy that is consistent with an excellent chance of fertility. This will be discussed at multiple points in therapy by the medical team.
Patients who have triplets or more are usually referred to a maternal fetal medicine specialist; reducing the multiple birth to twins or even a single fetus may be advisable because it is safer for the mother and baby in most cases.
The overall rate of significant birth defects in natural conception is approximately 3 percent to 5 percent. The overall rates of birth defects with fertility therapy appear to be similar to this overall rate, although certain kinds of treatments in certain clinical situations may increase the risk. Multiple birth is known to increase risk of birth defects whether the multiple birth is naturally conceived or as a result of fertility therapy. Clomiphene therapy may increase the risk of neural tube defect, usually spina bifida, which may be reduced by using folic acid found in daily multi-vitamins or prenatal vitamins.
ICSI appears to increase the risk of an extremely rare group of disorders known as imprinting disorders (Beckwith-Wiedemann, and Angelman syndrome) as well as hypospadias, an abnormality of the location of the urethra on the penis in male children. Sex chromosome abnormalities are increased in patients using ICSI but some of this may be the result of the man’s low sperm quality, which may also be a genetic defect. Nevertheless, if ICSI is advisable to reduce the risk of low fertilization, it should be used.