INTRODUCTION

Iron is mandatory for normal foetal development, including the brain. Antenatal iron deficiency may have deleterious effects on intelligence and behavioral development of the offspring. Therefore, it is important to prevent foetal iron deficiency by preventing maternal iron deficiency. Besides, iron deficiency anemia is a risk factor for preterm birth and low birth weight (Milman 2006).

In Malaysia, routine antenatal iron supplementation is the norm but the practice is not evidence based due to lack of current data on the prevalence of iron deficiency. The most recently published data on anemia in pregnancy in Malaysia dates back 15 yrs ago and only surveyed rural areas of one of the poorer states (Zulkifli et al. 1997).

On the other hand, iron supplementation has a negative influence on absorption of other divalent metals and increases oxidative stress in pregnancy, for which reason the minimum effective iron dose should be advised in pregnancy (Milman 2006).

In many parts of Malaysia, urbanization has taken place and standards of education and living have improved. As such, the current socio-economic and health status have improved with declining prevalence of grandmultiparity and maternal mortality rates (Wong 1999). It is therefore possible that the country mayhave joined the ranks of developed nations in issues as basic as iron deficiency and anemia in pregnancy. The present study therefore aimed to assess the current antenatal iron status in Malaysia.

MATERIALS AND METHODS

A cross-sectional study was conducted over a six-month period on pregnant women who booked for antenatal care at an urban community health clinic located within a kilometer of a state hospital. A single blood sample was drawn from each subject and sent for laboratory assessment of full blood count and serum ferritin at the time of booking to assess for maternal anemia and iron status. All laboratory assays were conducted at the hematology and biochemistry laboratories of the state hospital.

Iron deficiency is defined as serum ferritin < 12 μg/l (Brittenham et al. 1981). Anemia is defined as hemoglobin < 11g/dl (World Health Organization 1968).

Based on Kish’s formula for prevalence study (Kish 1965)

where P = 0.212, D = 0.05 and Z1-α = Z0.95 = 1.96 (normal distribution table), the sample size required was 256.7, i.e. 257. Quota sampling was applied. Women with known chronic illness such as systemic lupus erythematosus, renal disease, thalassaemia or any other blood disorder, and those who refused to participate in the study, were excluded. All data obtained were analyzed using SPSS version 19.0.

RESULTS

A total of 250 pregnant mothers participated in the study, i.e. the response rate was 97.3% (250/257), of which 149 (59.6%) were Malays, 39 (15.6%) Chinese, 47 (18.8%) Indians, and 15 (6%) were of other ethnicities (Table 1). Out of the total number, 247 (98.8%) were married and 3 (1.2%) were single. Their age ranged from 20 - 49 yrs with a mean of 30.24 ± 1.16 yrs (mean ± standard deviation, SD). Most of the women (178, 71.2%) attained secondary school education, followed by 37 (14.8%) with tertiary education, 27 (10.8%) with primary education, and a minority (8, 3.2%) without any formal education. Most women (81.2%) were in the poverty bracket, with a family income of less than RM1000 per month. Majority of the women were primigravidae (33.6%), followed by gravidae 2, 3 and 4 (23.6%, 15.2% and 10.8% respectively), whilst 42 (16.8%) were grandmultiparae. Forty-two percent commenced antenatal care during the first trimester, 54.8% during the second trimester and 3.2% during the third trimester. Only 2% were multiple pregnancies and 1.6% vegetarian. Most women (77.6%) did not take vitamin supplements prior to pregnancy. Only 13.6% practiced contraception.

The overall prevalence of anaemia was 43.6% whilst the prevalence of iron deficiency was 31.6% (Table 2). The prevalence of anaemia and iron deficiency was highest among the Indians (46.8% and 42.5%, respectively), followed by the Malays (43.6% and 33.5%, respectively) and the Chinese (38.4% and 12.8%, respectively). Interestingly, overall, 19.1% of women with normal hemoglobin levels had iron deficiency (Table 2).

The overall mean hemoglobin was 11.00 ±±1.46 g/dl (mean ±±SEM) whereas the mean serum ferritin was 36.80 ±±2.26 μg/l. The mean serum ferritin was statistically significantly lower among Indians (27.17 ± 4.03 μg/l) compared to other ethnic groups (Table 1). Grandmultiparae had significantly lower serum ferritin (25.31 ±±3.99μμg/l) compared to women of lower parity. Late booking (in the third trimester) was associated with significantly lower serum ferritin (19.95 ±±6.80μμg/l) compared to earlier booking for antenatal care. Women with primary education had significantly lower serum ferritin (22.33 ±±7.85μμg/l) compared to other levels of education.

DISCUSSION

Anaemia and iron deficiency are most prevalent in Africa, the Middle East, Asia, and Western Pacific (de Benoist et al. 2008). In Africa, the prevalence of anaemia in pregnancy is about 57% (de Benoist et al. 2008). The exact prevalence of anaemia and iron deficiency varies from country to country, as does the cut-off values for hemoglobin and serum ferritin used in these countries. The contribution of iron deficiency to anaemia in each country also differs, depending on other locally prevalent causes (Berger et al. 2011). The prevalence of anaemia and iron deficiency in our population (43.6%) was similar to those found in the regions with the worst anaemia prevalence. In WHO terms, an anaemia prevalence of 40% and above, as seen in our study, is considered to be much severe public significance (World Health Organization 2012). It is obvious that the anaemia prevalence in Malaysia has not improved much for the past 15 yrs, as the prevalence amongst a rural population in Kelantan, one of the poorest states, was 47.5% in 1997 (Zulkifli et al. 1997). More recently published work on anaemia in Malaysia supports this perception, with prevalence rates ranging between 33% (Soh et al. 2015) and 57.4% (Nik Rosmawati et al. 2012). This was emphasized by Milman (2015) in his recent review on the seriousness of the situation in Malaysia and certainly calls for urgent remedial measures nationwide.

The cut-off value of serum ferritin used in our study (12 μg/l) was low compared to some other studies. This level correlates with iron-deficient erythropoiesis, just before anaemia sets in at serum ferritin <10μμg/l (Coad & Conlon 2011). The normal serum ferritin level is 40-160μμg/l, and levels below 25μμg/l indicate early negative iron balance, whereas levels below 20μμg/l indicate depletion of iron storage (Coad & Conlon 2011). Therefore, the statistics obtained in our study of 31.6% was certainly alarming.

The overall mean hemoglobin was 11.00 ±±1.46 g/dl, which means that the mean hemoglobin in this population of pregnant women just scrapes through the WHO criteria for anaemia (World Health Organization 1968). The mean serum ferritin was 36.80 ± 2.26 μg/l, which is well below the level corresponding to normal iron stores (Coad & Conlon 2011). Looking at the groups with the worst levels, the figures are much more worrying. For example, the mean values of serum ferritin among Indians and grandmultiparae almost touch the level indicative of early negative iron balance, and the serum ferritin level of women who book late in the third trimester without prior antenatal care is below the level indicative of storage iron depletion.

Is the high prevalence of antenatal anaemia a reflection of anaemia prior to marriage and embarking on child bearing? An interesting study by Chang et al. in (2009) showed that the prevalence of anaemia among apparently healthy adolescent girls in an urban Malaysian population was 28.3%, which was significantly lower than the matching prevalence among women of childbearing age within the same population, 41.7%. Nevertheless, both the figures are way above the anaemia prevalence in industrialized countries. Anaemia amongst adolescent girls is logically a strong predisposing factor for the subsequent occurrence and worsening, of anaemia in adult women of child bearing age. Correcting anaemia amongst adolescent girls is indeed vital towards reducing the magnitude of the problem amongst adult women.

Evidence from current medical literature advises caution in prescribing routine iron supplements in pregnancy because of its negative influence on gastrointestinal absorption of other divalent metals such as calcium, and increased oxidative stress (Milman 2006). Nevertheless, the existing guidelines suggest that iron supplements should not be given only if the serum ferritin exceeds 70 μg/l (Milman 2006). Therefore, the observations obtained in this study provide a strong basis in favor of routine iron supplementation in pregnancy among the urban poor in Malaysia. For serum ferritin levels of 30-70 μg/l, the recommended daily dose is 40mg ferrous iron, whereas for women with levels below 30 μg/l as in the high risk groups observed in this study, a much higher dose of 80-100 mg ferrous iron daily, is advised. A case could be made to call for routine assessment of serum ferritin amongst the group of pregnant women who are at especially high risk of having the worst iron status. Patient education on the importance of compliance to iron supplements cannot be overemphasized, as reluctance of women to consume routine iron supplements in pregnancy is common knowledge, as a result of an unwavering myth that it might lead to macrosomia and a difficult delivery. This myth must certainly be dispelled if a programme of routine antenatal iron supplementation is to succeed.

CONCLUSION

In conclusion, anaemia and iron deficiency in pregnancy are still serious issues amongst the antenatal population in Malaysia. Findings from this study calls for imperative measures to ensure continued provision of routine iron supplement in pregnancy. Routine checks on serum ferritin levels in certain high risk groups that recorded markedly low serum ferritin in this study should be considered, so that the appropriate higher daily dose of antenatal iron could be prescribed in order not to compromise the short and long term health of the mother and baby.

ACKNOWLEDGMENT

The authors would like to thank the Ministry of Health Malaysia for allowing recruitment of patients during the course of this study and for providing the laboratory services necessary for the tests that were performed.