A heterotopic pregnancy occurs when there is both intrauterine and extra-uterine gestation – in other words, it is a multiple pregnancy, with one embryo implanted normally in the uterus and one implanted as an ectopic pregnancy. Under normal circumstances (when conception occurs naturally), the likelihood of heterotopic pregnancies is quite rare (one in 30,000 pregnancies is heterotopic).In the case of assisted reproduction, however, the rate increases to one in 100 pregnancies. Specifically, women who have undergone in vitro fertilization (IVF) in which more than five embryos are implanted are at the highest risk of developing a heterotopic pregnancy – the number then jumps to one in forty-five cases.
Diagnosing Heterotopic Pregnancy
Like ectopic pregnancies, heterotopic pregnancies can be difficult to diagnose under normal circumstances. While one way of detecting these types of pregnancies is via an hCG blood test, it can be difficult to detect because there is already a normal pregnancy that is affecting blood levels. About 85 percent of these cases go undetected until the ectopic pregnancy is ruptured. Coupling blood tests with transvaginal ultrasounds can help detect the presence of a heterotopic pregnancy, and in about half of the cases of heterotopic pregnancies, the ectopic pregnancy is discovered within two weeks of the identification of the normal intrauterine pregnancy.
Treating Heterotopic Pregnancy
The treatment of a heterotopic pregnancy must be done cautiously, especially when taking into consideration the viability of the normal pregnancy. Sometimes, lapar
oscopy (a minimally-invasive procedure that uses small incisions no more than a ½ inch long and is performed using a long, slender device, called a “laparoscope” can be performed to remove the ectopic pregnancy before it ruptures without harming the uterine pregnancy. This can be a dangerous procedure, and there may still be an increased danger of miscarriage even after the ectopic pregnancy is treated.
Although the options for treatment and research surrounding heterotopic pregnancies have been limited, reproduction specialists are beginning to focus on efforts for more solutions as the occurrence of heterotopic pregnancies rises with the ongoing use of IVF and other forms of assisted reproduction.