Are Babies from IVF Normal?

The astute reader of this blog may come to the conclusion that Dr Gordon is not normal. I mean the guy likes Monty Python, couldn’t get a date in high school, tells bad jokes and yet somehow managed to convince a PhD in Engineering to marry him and reproduce with him. Go figure. What really does it mean to be normal? I banged my head on the kitchen counter this morning when I saw that the Red Sox lead over the Yankees was down to 2 and a half games. Is that normal behavior? Well, for a Sox fan it is but that is besides the point.

So many questions arise when considering the normalcy of children after IVF. Are they normal? Will they get 2400 on the new SAT? Will they cheer for the Red Sox against the evil empire? Who knows. However, a lot of attention has been focused on the issue of birth defects after IVF so here is today’s Question of the Day from 100 Questions and Answers about Infertility.


53. Are the children born after IVF normal?


The question of the health of children born after advanced fertility treatments is one that has great importance both to the parents and to fertility physicians. In general, the data regarding the outcomes for children born after IVF, either with or without the use of ICSI, have been extremely reassuring. The problem with these studies remains the identification of an appropriate control group with which to compare the rate of problems found in the children conceived with advanced fertility techniques. Overall, most studies suggest a background risk of birth defects in naturally conceived children of approximately 4% to 5%. However, these couples tend to be younger than the couples undergoing IVF and, by definition, do not suffer from infertility. Although the vast majority of studies suggest no increased risk of anomalies in children conceived after IVF, none of these studies have looked at the rate of congenital anomalies in children conceived naturally but born to parents who suffered infertility that spontaneously resolved without treatment. This group of patients would clearly represent a more appropriate control group with which to compare with patients who seek out advanced fertility treatments.

One recent study from Australia (Hansen, M et al, Human Reproduction 20 (2):328-338, 2005) was a systematic review of all studies that had previously examined the possible increased risk to children conceived after treatment with IVF and/or ICSI. However, many of these studies compare the rate of congenital abnormalities in children conceived spontaneously with the rate in children who were born to older couples undergoing IVF and/or ICSI. In many studies the rate of congenital anomalies in the control group have been around 4%, whereas the rate of congenital anomalies in the group of couples undergoing IVF and ICSI have been 6% or greater. The difference between 4% and 6% is statistically significant and suggests that there may be an increased risk to children conceived through the use of advanced reproductive techniques. However, the question remains as to whether this is a problem related to IVF itself or to the underlying infertility that leads to the use of IVF. In any case, most patients accept an increased absolute risk of 2% as being reasonable, especially given that their options for spontaneous conception may be significantly limited. The greatest risk to the children conceived after fertility treatment is that of prematurity related to multiple pregnancy.

Several strategies are used to reduce the rate of multiple gestations (see Question 54, which deals with how many embryos to transfer in IVF). The risks of prematurity are significant and should not be discounted quickly, especially given that 50% of twins deliver a month or more before their due date. In addition, the question has been raised as to whether even
IVF singleton pregnancies are at higher risk for low birth weight and prematurity. If true, the cause of this increased risk may be difficult to determine.

Patients undergoing IVF suffer from infertility, so that any increased rate of adverse pregnancy outcome might not be so much a result of the IVF process as it is related to the couple’s underlying problem ofinfertility. Several studies have suggested that women who conceive spontaneously, but who have a preceding history of infertility, have a significantly increased rate of prematurity and pregnancy-related complications such as placenta previa, abruption, and low-birth-weight infants. Another way to look at the question of whether any risk is related to the process of IVF itself versus the patient who is undergoing IVF is to examine the pregnancy outcomes in women who undergo IVF and then use a gestational carrier (carriers usually have an excellent reproductive history). A study of these pregnancies found there was no increased risk of prematurity or low birth weight in the children conceived and carried in this way. This reassuring outcome would suggest that the problem lies not so much with the IVF process but, unfortunately, with the patients who require IVF to conceive.

The impact of new and emerging technologies on the rate of congenital anomalies in children born after fertility treatment remains a subject of ongoing debate. The potential risks inherent in micromanipulation of the embryo prior to embryo transfer—like that required for preimplantation genetic diagnosis (PGD)—remain unknown. Although more than 4 million IVF babies have been delivered worldwide to date, only a relatively small number of children have been delivered after the use of PGD or another emerging technology (such as egg freezing) or following unusual situations such as performing rescue ICSI on the day following egg collection because of unanticipated failed fertilization. When considering such novel treatments, the physician needs to inform the patient /couple of any known or suspected risks. Currently, several studies are under way in this country and throughout the world to continue to monitor the health of those children delivered following advanced fertility treatments.