The Relationship of Maternal Serum Calcium Level and the Risk of Preeclampsia

Abstract

Background: Preeclamsia is one of the most common complications during  pregnancy and the leading cause of both maternal and perinatal morbidity and mortality worldwide. Several epidemiological studies conducted in developing nations suggest an association between reduced calcium intake and preeclampsia.

Objective: We aimed to assess the effect of maternal serum calcium levels at less than 20 wk   on the risk of preeclampsia.

Materials and methods: We conducted a nested case-control study of nulliparous  pregnant women less than 20 wk gestation at Maternity Hospital-damascus university within the period from 1/1/2013 to 31/12/2016 and the concentration of total serum calcium was measured in all participants.

All the participants were followed every 4 weeks from the first visit until the 36th weeks, each week up to delivery, and until 2 days after the delivery to monitor those who have had preeclamsia.

The study was limited to 1198 of the total number of 1961  participants (61%), and the rest were excluded.

There were 67 cases of preeclamsia among all participants(5.6%),of whom 55 studied, the remaining 12 were dropped.

We chose 220 women who did not have preeclamsia among the total number of participants ( who were selected from healthy pregnant women, similar to age, gestational age and body mass ) to be used for comparison.

Results :Preeclampsia was shown in 5.6% (67 women) of 1169 participants.

There were no significant differences between the group of preeclamsia and the control group  regarding maternal age, anthropometric indices, family history of preeclampsia, diabetes, hypertension, smoking and the use of oral contraceptives.

We found a significant difference between the women with normal pregnancy and the women who developed preeclamsia  concerning the mean time of delivery(39.5±1.2 vs.32.6±1.4 w),and significant lack of total serum calcium levels  (P=0.001)  in the group  who developed preeclamsia.

we found a strong inverse relationship between  serum calcium levels at less than 20 wk   and the risk of preeclamsia(P=0.02).All the neonates survived in both groups. Moreover, the results revealed a significant difference(P<0.05) between the two groups with regards to gestational age, birth weight, birth length, head circumference, and Apgar score in the first minute of birth.

Conclusion: Unavailability of this element (calcium) due to deficiency or decreased concentration may be a predisposing factor in the development of preeclampsia or a contributory factor in its pathogenesis.