Cell and Organ Transplantology. 2023; 11(2):130-135.
DOI: 10.22494/cot.v11i2.158

Sleep disorders and changes in melatonin concentrations in pregnant women with preeclampsia

Savka R., Berbets A.

• Bukovinian State Medical University, Chernivtsi, Ukraine

Abstract

Melatonin plays a significant role in the development of normal pregnancy, in particular, it contributes to the successful implantation of the fertilized egg, affects the act of childbirth, is actively produced by the trophoblast and placenta, reduces oxidative stress, in particular, with preeclampsia. In addition, melatonin is one of the essential hormones in the protection of the endothelium and stem cells from the oxidative stress.
Objective – to study the mechanisms of development, terms of manifestation, and types of sleep disorders, as well as changes in the concentrations of melatonin in the blood of pregnant women with preeclampsia.
Methods. 50 pregnant women at a mean age of 29.1 ± 3.4 years who had preeclampsia in the 3^rd pregnancy trimester were examined (experimental group). All women in the research group had a gestation term of 30-32 weeks of pregnancy. The control group consisted of 33 women with a mean age of 31.2 ± 6.6 years who had an uncomplicated pregnancy. The presence of sleep disorders was established using a questionnaire: pregnant women were asked about the term of pregnancy in which complaints of sleep disorders appeared, the nature of sleep disorders, the frequency of episodes of sleep disorders (how many times a week such a condition was noted), etc. The concentration of melatonin in the venous blood of the examined pregnant women was determined by ELISA. Blood was taken at 9:00 a.m., on an empty stomach, and all patients were analyzed at the same time of a day.
Results. The study showed that sleep disorders in pregnant women with pre-eclampsia, which complicates the pregnancy in the 3^rd trimester, occurred earlier, compared to women with an uncomplicated pregnancy: pregnant women with pre-eclampsia were more likely to notice worsening of sleep, starting from 22-30 weeks of pregnancy (in 26.0 % of cases), while in pregnant women with a physiological pregnancy, similar complaints appeared mainly after 30 weeks. In the third trimester of pregnancy women with preeclampsia were more likely to wake up 2 or more times per night (in 68.0 % of cases) compared to controls (in 23.3 % of cases, p < 0.001) and 3 or more times per night per week (in 54.0 % of cases, in controls – in 16.7 % of cases, p < 0.001), which may be a consequence of a disorder of the function of the pineal gland. Women with preeclampsia were more likely (56.0 % vs. 13.3 % in the control group, p < 0.01) to use gadgets (electronic devices, mainly smartphones) for more than 2 hours after 9:00 p.m., which also negatively affects the function of the pineal gland. In pregnant women whose pregnancy was complicated by preeclampsia in the 3^rd trimester, a significant (1.8-fold) decrease in the level of melatonin in venous blood taken at 9 a.m. was observed, compared to women with an uncomplicated pregnancy (p = 0.029).
Conclusion. Sleep disorders in pregnant women with preeclampsia occur earlier and are more expressed compared to women with an uncomplicated pregnancy. The appearance of complaints of insomnia in the second trimester of pregnancy, in our opinion, can be considered a diagnostic sign of pineal gland dysfunction in preeclampsia. A decrease in the level of melatonin in pregnant women with preeclampsia, established against the background of minimal daily activity of the pineal gland (at 9 a.m.), indicates a decrease in the melatonin-producing function of the placenta which might have an impact on the condition of stem cells of fetus and placenta.

Key words: pregnancy; placenta; preeclampsia; pineal gland; melatonin; sleep disorders

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