Instrumento para la autoevaluación del Director o Rector

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Secondary Tertiary

4(4.5) 37(41.6)

15(13.5) 46(41.4) Type of

Marriage Monogamous Polygamous

86(96.6) 3(3.4)

104(93.7) 7(6.3)

0.896 0.344

Presumed social status Low

Medium High

51(57.3) 26(29.2) 12(13.5)

60(54.1) 31(27.9) 20(18.0)

0.757 0.685

Table 9: Serum magnesium as predictor of preeclampsia DEPENDENT

VARIABLE

B OR p-Value CI

Preeclamptic Control

3.054 Constant

21.192 0.001 10.09-44.50

OR – Odds Ratio, CI – Confidence Interval

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Preeclampsia, which is a syndrome that is characterized by the onset of hypertension and proteinuria in the second half of pregnancy has been and still is a major cause of maternal and perinatal morbidity and mortality especially in low and middle income countries with an estimated fifty thousand maternal deaths annually²⁷. Pregnant women in these developing countries have been reported to consume diets with lesser amounts of essential minerals and vitamins⁷⁵.

The precise aetiology of preeclampsia is still not known with certainty despite

intensive research worldwide¹⁸. The pathogenesis of placenta dysfunction, the initiation of systemic vasospasm, ischaemia and thrombosis that ultimately progresses to fetal and or maternal morbidity and mortality is still not fully understood^3,11.

Although several screening tests have been proposed over time for preeclampsia, no test has so far been able to appropriately screen for preeclampsia and no well established measurement for initial prevention has been designed²⁴.

The major finding in this study is that of a significantly lower level of serum magnesium in preeclamptic patients (0.63±0.07mmol/L) as compared to normotensive pregnant women (0.89±0.12mmol/L). This is also a similar observation in other studies18,19,24,34,62,63,64. The aetiology of reduced levels of serum magnesium in women with preeclampsia is not yet fully understood. Is this a cause or effect of preeclampsia? The findings in this study however revealed that, low serum magnesium in preeclampsia is more than just a coincidental finding and that magnesium assay may be a marker for preeclampsia, therefore adding to the

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armamentarium of screening tools available to the clinician in predicting this disease. In this study, further analysis also showed that hypomagnesemia was 21-times more likely to contribute to the occurrence of preeclampsia. This is in keeping with the study by Enaruna²⁵ and colleagues in Nigeria where it was espoused that, hypomagnesemia was 22 and 47 times more likely to contribute to preeclampsia than age and body mass index respectively.

Proposed explanations for the pathophysiologic effect of magnesium in hypertensive disease have been espoused to include intracellular imbalance between calcium and

magnesium due to relatively low magnesium which thus, results in increased vascular tone in the smooth muscles of the arteries and therefore increased blood pressure. Also magnesium deficiency causes a dysregulation of the Na-Mg exchanger, resulting in higher intracellular sodium and higher blood pressure⁵⁷.

Lending credence to the strong association between hypomagnesemia and

preeclampsia as found in this study is the success of magnesium sulphate in the treatment and prophylaxis of eclampsia and preeclampsia³⁴ and also a detectable dose dependent blood pressure reduction from magnesium supplementation⁷².

Furthermore this study also reveals that serum magnesium level was statistically lower in women with severe preeclampsia when compared with those with mild preeclampsia (0.59±0.05mmol/L VS 0.69±0.07mmol/L). This shows that, there is a further dip in serum magnesium level as the patient’s clinical condition worsens. This was also found in a study by Jafrin and associates in Bangladesh²¹. Seeing that preeclampsia is a progressively worsening disease and that serum magnesium reduces concomitantly, a case may then be made for the

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use of serum magnesium in the array of tests necessary for monitoring the severity of this disease of theories.

Despite the multiplicity of studies showing a significant reduction in serum magnesium in preclamptics, some studies however have a contrary view22,51,65,68.

Golmohammed et al⁵¹ in India and Idogun⁶⁸ in Nigeria reported no significant difference in the magnesium levels among normal pregnant women, pregnancy-induced hypertension and preeclampsia. Same conclusion was also reached by Adewolu³⁵ also in Nigeria who carried out a pilot study of 20 patients apiece. Would the methodology, such as the study done by Idogun et al that utilized only 11 cases to reach this conclusion have a role to play in this contrasting opinion? Could poor dietary consumption of magnesium rich diet as seen in the study from southern India have a bearing on the failure to elicit a significant difference? This contrasting finding may however be slightly contentious as magnesium use during prevention and treatment of eclampsia has been shown to oppose calcium-dependent arterial constriction leading to vasodilatation and blood pressure reduction. This is supported by a meta-analysis of randomized clinical trials on the effect of magnesium sulphate supplementation on blood pressure which concluded that, there was a detectable dose dependent blood pressure reduction from magnesium supplementation⁷².

Magnesium deficiency may contribute towards uterine artery vasospasm and

ultimately placental insufficiency and then release of antiangiogenic substances leading to the clinical picture of preeclampsia. In Nigeria, where morbidity and mortality from this disease is unacceptably high²⁷, further wide multicentre research over a reasonable duration may not be out of place.

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In this study, the booking status of patient’s revealed that the unbooked patients with preeclampsia was 59% which shows that the health seeking behavior of women in developing countries is generally poor which further contributes to adverse effects for mother and the baby. This finding is similar with other studies⁷⁶ where most pregnancy complications are seen in women who are unbooked.

This study reveals that, there were more women with low socioeconomic status who had hypomagnesemia but this was not statistically significant when compared with women with normal serum magnesium levels (p= 0.685) thus showing that there is no association between hypomagnesemia and socioeconomic status. This is supported by studies by

Okunade⁷⁷ and colleagues in Nigeria and Kumar⁷⁸ in Mauritius. This is not surprising in this study because most of the food items available to our pregnant women are rich in magnesium and are affordable to those with low, medium and high socioeconomic status in the society.

Food rich in magnesium include green leafy vegetables, cereal, grains, nuts, banana and legumes. Intermediate sources of magnesium include fruits, meat, fish and chocolates while poor sources of magnesium intake include dairy products⁴². That being said, dietary patterns of parturients may need to be further elucidated in further studies to assess the role of food consumption on serum magnesium levels. Some reports however, differ in this submission and assert that there is a significant difference in serum magnesium between women of

different socioeconomic status^79,80. Of note however, is the observation that these studies were carried out in a clime where there may have been a wide gulf in diet as compared to Nigeria and thus comparison cannot be justifiably made.

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The association of birth weight and serum magnesium is evident in this study. There was a significant difference in serum magnesium levels between women who delivered low birth weight babies and women who delivered normal weight babies (p=0.001). This is consistent with findings from other studies^81,82 where it was found that maternal

hypomagnesemia led to fetal loss and caused fetal and postnatal growth restriction. The probable reason for this may be the change in placental morphology with decreased spongiotrophoblast area and increasing glycogen cell area⁸² thus impairing placental development and function thereby leading to low birth weight babies. Parizadeh et al⁸³ in India and Enaruna²⁵ in Nigeria reached a different conclusion and did not find any

relationship between a lack of magnesium and rates of low birth weight. The provision of multivitamins and mineral supplements to all pregnant women in the study from India as a mandate from the ministry of health may have led to this conclusion.

Magnesium supplementation during pregnancy has been associated with a reduction in preterm delivery and less frequent referral of the newborn to the neonatal intensive care unit⁸³. The results of this study may suggest a role for magnesium supplementation in view of the significant number of women with hypomagnesemia who had babies admitted into the neonatal intensive care unit (p=0.004).

This present study indicates a need for further longitudinal studies with larger sample sizes to be undertaken in different parts of the country to further assess the enormity of mineral deficiencies amongst pregnant women.

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