The Pineal Gland and Spontaneous Abortions: Implications for Therapy with Melatonin and Magnetic Field

Abstract

Spontaneous abortion, the termination of pregnancy prior to 20 weeks of gestation, is estimated to occur in 40%-50% of all pregnancies and in 12%-15% of identified pregnancies. The causes of spontaneous abortion can be divided into two main categories: those arising from chromosomal anomalies and those arising from abnormalities in the intrauterine environment. In the following communication, we propose that deficient pineal melatonin functions in early pregnancy may be causally related to the development of spontaneous abortions in cases where chromosomal anomalies or structural abnormalities of the uterus have been excluded. This hypothesis is based on the findings that: (a) melatonin plasma levels normally increase by 200%-300% in the first 20 weeks of pregnancy; (b) melatonin decreases uterine contractility in the rat; (c) melatonin stimulates the secretion of progersterone, which decreases uterine contractility and prevents immunological rejection of the trophoblast; (d) melatonin inhibits the synthesis of prostaglandins, which are potent inducers of uterine contractility and labor, and (e) pinealectomy increases the number of spontaneous abortions in pregnant rats. In addition, since melatonin is a hormone with immunosuppressant properties, we propose that the increased melatonin production in early pregnancy may contribute to a state of "transplantation immunity" to the paternal histocompatibility antigens preventing immunological rejection of the trophoblast. If this hypothesis is correct, then plasma melatonin levels during early pregnancy could be used as an indicator for increased risk of spontneous abortions. Moreover, it is possible that in cases where plasma melatonin levels are diminished in early pregnancy administration of oral melatonin or the use of artificial bright light therapy may be useful in the treatment of threatened abortion as well as in the prevention of habitual abortions. Finally, since in experimental animals and humans external application of magnetic fields has been shown to synchronize the rhythms of circadian melatonin secretion by acting upon the pineal gland, low intensity magnetic therapy may be useful in the treatment and prevention of spontaneous abortions.

Increased brain damage after stroke or excitotoxic seizures in melatonin‐deficient rats

“…In addition, endogenous melatonin can influence the secretion of other hormones with neuroprotectiveactivity. One such hormone is progesterone;ithas been shown to be neuroprotective (37),and itssecretionmight be stimulatedby melatonin (38).Others may include the adrenal hormones (18).…”

Roles of Melatonin in Fetal Programming in Compromised Pregnancies

“…During normal pregnancy, melatonin acts as an antioxidant and appears to be essential for a successful pregnancy. Sandyk et al had found the association of melatonin and spontaneous abortion which was presumed to be due to melatonin’s role in diminishing uterine contractions by decreasing the production of prostaglandins and in prevention of the immunologic rejection of trophoblast by stimulating the progesterone production [31]. Further, Matsuzuka et al showed that alleviation of the embryo death might be achieved by administration of melatonin in mice [32].…”

Melatonin and vitamin C increase umbilical blood flow via nitric oxide‐dependent mechanisms

“…For instance, maternal plasma melatonin levels are elevated during pregnancy, reaching a maximum at term and then returning to basal levels soon after delivery. Concentrations of melatonin in maternal plasma are also higher in twin than in single pregnancies [12–15]. The expression of melatonin receptors in the human and rat placenta further suggests that melatonin plays a functional role in feto‐placental development [16–18].…”