The original “high-tech babies” were known as test tube babies. These are babies grown from an egg and sperm that were brought together in a lab. The sperm fertilized the egg outside the body (in vitro, meaning in the lab), and the fertilized egg was allowed to grow until it was a very small embryo. The embryo was then put into the woman’s uterus. If successful, the embryo would take hold of the uterine lining and start to grow like a normal baby in the womb. In the end, a baby would be delivered the normal way.
The first in vitro fertilization (IVF) took place in 1978. This was followed by successful pregnancies using IVF. In the United States, “test-tube babies” have been around for 20 years, although the fertilization of the egg and growth of the embryo actually take place in a culture dish and not a test tube. Today, about 1% of babies delivered in the US have been conceived using IVF or other assisted reproductive technology (ART).
All babies born who have been conceived using ART are “high-tech babies” because it takes a lot of technology, knowledge, and experience for an ART procedure to result in a successful pregnancy. According to the Centers for Disease Control (CDC), the term assisted reproductive technology refers to all treatments for infertility during which both sperm and eggs are handled.
For IVF to be successful, a large number of eggs must be collected and mixed with enough sperm to fertilize multiple eggs and grow multiple embryos. Ovarian stimulation by injectable medications is done, and when multiple eggs are ready they are harvested. The ratio is usually 75,000 sperm for each egg per culture dish. The sperm have been concentrated so there are more of them and treated to make fertilization more likely, especially in cases of male infertility. A fertilized egg will then be transferred to a special solution where it can grow into a tiny embryo of only six to eight cells in about two days. In the United States and Canada, the embryo may be grown for another three days.
The reason to obtain multiple eggs for fertilization is that the best embryos can then be chosen for use. We now have the technology for some genetic screening of the embryos, but at this time, there is no way to be absolutely sure that an embryo will grow into a normal baby. Doctors use many different pieces of information to choose the best embryo. More than one embryo is usually transferred to the mother’s uterus to improve the odds that one will take. There are guidelines about how many embryos should be transferred at one time. Two to three is the number used in many places.
IVF is expensive and time consuming. As infertile couples get older, their chances of a successful pregnancy decrease. This is why multiple eggs are harvested and multiple embryos made. Unused embryos can be frozen and used for subsequent attempts, especially if time passes and the woman is not able to release more eggs.
The goal of IVF is to achieve a single pregnancy resulting in a live birth. The success rate depends on many things, including the mother’s age. The live birth rate after IVF is about 27%. However, the live birth rate for young women (under age 35) who are having IVF with their own eggs can be as high as 41% per cycle.
In addition to simple IVF, ART can produce babies that are more “high tech.” In a procedure called intracytoplasmic sperm injection (ICSI), a single sperm is injected into a single egg using a microscope to visualize the injection. This is used when the sperm quality is very poor and the sperm is unable to fertilize an egg on its own.
IVF can also be done using donor sperm and/or eggs donated from another person. To collect eggs, another woman must go through ovarian stimulation and have eggs harvested. While this could be done by a friend, practically speaking, there is often an egg donor who must be compensated for her donation. Sperm banks offer a choice of donor sperm, and as such, sperm are easier to collect and freeze.
There can be donor sperm used with a woman’s own egg, a donor egg with the father-to-be’s sperm, or both can be donated. If the woman cannot carry a pregnancy successfully due to abnormalities in her uterus or cervix or because of hormonal problems or significant medical illness, a surrogate can be used. If a woman carries an embryo with both sperm and egg from someone else, she is not biologically related to the baby she is carrying. A woman could also donate her eggs to this process, in which case she would be related to the baby.
While much of the time these arrangements are made through infertility centers, where screening takes place and through which payment can be made to donors or surrogates, infertile couples sometimes do this on their own. They may use IVF or surrogacy with a woman who is a friend and is donating her eggs or willing to carry a baby to term for the couple.
Undergoing an infertility workup, having IVF and subsequent pregnancy, or using an egg donor or surrogate is all very expensive. Much is not covered by insurance. There can also be issues surrounding the woman who is carrying the baby and may not want to give it up. This is especially a problem if the woman’s eggs were used, since she would then be the biological mother of the baby.
A baby carried by an unrelated woman using donated sperm and donated eggs is about as high tech as ART can achieve at the current time. As noted, there is some genetic testing possible, but it is extremely limited. Babies born after ART have twice the number of congenital abnormalities compared to babies conceived and born naturally. It is not know if this is because of the procedures or because the sperm and/or eggs of infertile couples have more abnormalities naturally.
Anything like babies grown completely in a laboratory or babies with all genetic traits selected is still in the realm of science fiction.