With many couples foregoing having children until later in life, there are a growing number of people who are struggling to conceive a healthy pregnancy. Fertility medicine has become one of the fastest-growing fields of health care. Although we know a great deal about how to encourage pregnancy, many couples still cannot conceive even with the best technology. New information about the role of melatonin in pregnancy and conception may help many people to become parents.
Natural Barriers to Becoming Pregnant
Although pregnancy is often viewed as a simple matter of “sperm meets egg,” it is actually much more complicated. Both egg and sperm must be high-quality, which often (but not always) is a reflection of the parents’ age and health. There is a very small window for these two components to meet. However, the complications do not stop there.
In order for implantation to occur, the uterus must be hospitable to the fertilized egg. This is more complicated than it initially sounds. Our immune system is designed not to let other living things grow and thrive in our bodies. Somehow this mechanism is overcome in successful pregnancy, but the process is not well-understood.
In addition, the egg, and later embryo, must be protected from the dangers of rapid growth and metabolism. When cells are rapidly dividing, which is certainly the case in a newly fertilized egg, radical oxygen species and other oxidizing elements can rapidly build up and damage DNA. The presence of antioxidants to protect the rapidly dividing cells of the embryo is extremely important in early pregnancy.
Most pregnancies simply occur, whether planned or not. Our bodies go through the correct motions and a healthy baby is the result. In matters of assisted reproduction and fertility treatments, however, it is crucial to understand exactly how a healthy pregnancy occurs. Doctors and scientists are discovering that we know very little about this. Nonetheless, melatonin and the circadian rhythm appear to play an important role.
Melatonin’s Role as an Antioxidant
One important role of melatonin in pregnancy may be as an antioxidant, protecting embryonic cells from oxidizing elements while they undergo extended periods of rapid growth. Melatonin is one of the body’s most powerful antioxidants, helping cells to get rid of free oxygen radicals so they can divide without DNA damage.
This role may be especially important in reproduction. Several studies have found high levels of melatonin in the follicular fluid surrounding eggs. In addition, several recent studies have found that melatonin may be important in reproductive technologies such as in-vitro fertilization. Eggs that are cultured in laboratories are healthier when melatonin is added to their environment.
In addition, women who are given melatonin during fertility cycles have significantly higher quality eggs harvested. Several reproductive endocrinologists are beginning to use melatonin in conjunction with fertility treatments to increase the quality of eggs and thus the chances of conception.
The Role of Melatonin in Pregnancy and Immune Response
Melatonin also appears to play an important role in modulating the immune system so a fertilized egg can be implanted. A fertilized egg has different DNA and cell markings than our own cells. In most cases, our tissues would recognize this forming embryo as an invader and the immune system would attack. Instead, our bodies welcome the rapidly dividing ball of cells as a welcome guest. What causes this unusual reaction?
Researchers are not sure exactly how this immune modulation happens but melatonin appears to play a crucial role. Melatonin is made by the placenta and appears to protect newly implanted pregnancies from immune attack while encouraging the growth of blood vessels and other changes needed to sustain a healthy pregnancy. In addition, melatonin made by the placenta is transferred to the fetus and may play an important role in the child’s prenatal development.
Circadian Rhythm and Pregnancy: What We Know
The role of melatonin in conception and pregnancy appears to be wide-ranging. What does this mean for women who are trying to conceive or are currently pregnant?
It appears to be crucial that women who are trying to conceive keep their circadian rhythms on track. This ensures that we release ample melatonin at the times that it is most needed. Because we do not understand a lot about the interaction of the circadian rhythm and conception, taking a supplement may not be helpful. We do not yet know the dose and timing that is ideal. Yet we can help our bodies to make enough melatonin by keeping a stable sleep-wake cycle and practicing good sleep hygiene. Researchers note that healthy biological rhythms are an important factor in fertility and reproduction.
There is one item that remains very unclear: whether women who are pregnant or trying to conceive should take melatonin supplements. Melatonin appears to be safe in pregnancy. However, it has not been formally tested for prenatal safety. For the time being, it is important for women who are of reproductive age to talk to your doctor or midwife before adding this or any other supplement.