In vitro fertilization, intracytoplasmic sperm injection, preimplantation genetic testing and etc are all part of what’s called assisted reproductive technology. This remarkable technology has helped many with conception issues as well as screen for those with severe genetic disorders. However, there has been some concern about the safety of these procedures on maternal health. We’ll review some of them and its supporting data.
Cancer risk
Although definitive answers are limited due to certain confounding factors and the nature of the studies, currently there is no evidence to suggest that women who underwent in vitro fertilization had an increased risk of cancer including breast, cervical or ovarian.
IVF does not seem to increase the risk of future breast cancer, even in those with BRCA mutations.
It is important to note that women who have issues with infertility by default have an increased risk of ovarian cancer compared to the general population. The studies have accounted for this and has not found increased risk with ovarian cancer with IVF beyond the risk associated with infertility.
Cardiovascular disease risk
Beyond the similar limitations of the studies discussed above, there does not seem to be an increased risk of cardiovascular disease in those who underwent IVF.
Risk of Venous Thromboembolism
Thromboembolism is when a blood clot forms in the blood vessels of organs like the lungs or the legs, causing disruption of normal blood flow.
A study had shown a small but notable increased risk of thromboembolism in women who underwent IVF. Particularly in their first trimester of their pregnancy.
Gestational Diabetes
Some women get diabetes during pregnancy due to the body’s increased need for insulin and its inability to make enough. Though in most cases this type of diabetes goes away, these individuals are at higher risk for getting diabetes after birth.
An analytical study showed that ART pregnancies increased the risk of gestational diabetes for that individual.
Gestational diabetes can cause several issues for the mother and the baby including increased baby weight (which may increase difficulty of birth and need for C section), risk of obesity for the baby later in life, and a serious condition called preeclampsia.
Preeclampsia
Preeclampsia is a serious condition during mid to late pregnancy or shortly after delivery that causes high blood pressure as well as problems with organs such as kidneys, liver, and placenta. The effect on the placenta may cause the baby to not develop well.
Pregnancies through ART has been associated with increased risk of preeclampsia.
Some studies have shown a possible link between corpus luteum (a temporary endocrine structure after an egg has been released from the ovary) and its protective effects against preeclampsia. Natural conception produces a corpus luteum and IVF cycled conception does not.
The use of donor eggs during IVF was associated with increased risk of preeclampsia.
Placenta disorders
Risk for placenta previa and placenta accreta seem to be increased in IVF treated pregnancies.
Placenta previa is when the placenta covers the opening of the cervix. This can cause issues such as bleeding and contractions.
Spontaneous or early pregnancy loss
Spontaneous loss of pregnancy is common even among naturally conceived pregnancies. It is important to note that the reproductive health of the mother correlates to the rate of loss in both natural and ART pregnancies.
So far there is no increased rate of loss in ART pregnancies compared to the rate of loss seen in natural conception.
It is interesting to note that a lower rate of ectopic pregnancies is seen in frozen embryo and blastocyst stage implantations versus fresh and earlier stage implants, respectively.
Low birth weight
Studies have shown that ART pregnancies were higher risk for low birth weight at term and preterm.
Multiple pregnancies
It is well known that IVF increases chance of multiple pregnancies, which presents with other complications. However, with changes in practice including single egg transfers and improvement in technology, single pregnancies have increased.
Outcomes are more favorable when it is a single pregnancy.
Other severe adverse outcomes
Studies have shown that pregnancies conceived through ART/IVF were more likely to have hospital admissions and longer stays during their pregnancy. Other observed increased risks included infection with sepsis, postpartum hemorrhage, and admission to the intensive care unit.
It should be noted that women who require IVF for conception, tend to be older and have pre-existing medical issues that put them at higher risk for adverse outcomes compared to women who do not require IVF for conception. These studies however have accounted for those factors.
Conclusion
Even with the growing concern with ART, there seems to be a consensus with the available data that ART is generally safe and results in similar outcomes when compared to natural conception.
Though the studies do show some increased risk in some categories, the absolute risk is small. It is also good to note that there are many confounding factors when it comes to these studies that are hard to control for. More studies are needed.
Comments