Haematological Profile of Pregnant Women Attending Antenatal Clinic in Bauchi, Nigeria

Introduction: Haematological profile of pregnant women provides vital information on physiological changes in pregnancy progress, outcome and possible maternal-foetal complications. The study assessed the haematological profile of pregnant women attending the antenatal clinic. Methodology: The cross-sectional study was conducted at the antenatal clinic of Abubakar Tafawa Balewa Teaching Hospital, Bauchi between July and September 2018 among pregnant women attending the antenatal clinic. Study participant was recruited on voluntary basis and study questionnaire and informed consent administered. Blood samples are collected and analysed using System x haematology autoanalyser. Result: A total of 191 study participants comprised of 141 pregnant women at different trimester stages and 50 non-pregnant. Mean haematocrit, haemgloblin, white blood count and platelet count of 35.8 ± 9.0, 11.6 ± 1.6, 7.7 ± 5.7, and 234.0 ± 74.6 respectively. Significant difference was observed between pregnant and non-pregnant women in neutrophil (0.016), mixed (eosinophil, basophil and monocyte, 0.05), lymphocyte (0.000), platelets (0.002) and RDWSD (0.025). Comparing haematological profile with trimester stages, significant association was observed with white blood cells count and mixed cell counts. Conclusion: The reduction in mean white blood cells count and increased haemocrit concentration with the trimester stages contradict patterns in other similar studies. This further highlights the need for local data for early diagnosis of pregnancy-associated clinical conditions and management approach.

Of common haematological abnormalities of pregnancy is anaemia, defined as haemglobin concentration below 11.0 g/dl or haemocrit concentration below 33% according to World Health Organization [6]. In developing countries, particularly in subsaharan Africa including Nigeria, anaemia in pregnancy prevalence is greater than 50%, which varies with geographical location and several factors like infectious disease, malaria and intestinal helminthes that affect haemglobin concentration [7] [8] [9]. Associated clinical complications include high maternal mortality rate, preter maturity, low birth weight, miscarriage and abortion [10] [11] [12]. According to the WHO/UNICEF (1999-2015) joint report on maternal mortality in Nigeria, revealed 58,000 maternal death which accounted for 19% globally, with the highest maternal mortality rate in the northeastern Nigeria with 1549 death per 100,000 live birth [13].
In pregnancy, physiological characteristics are noticeable with varied haematological levels. Hormonal secretion of oestrogen and progesterone by placenta stimulated release of renin that activates renin-angiotensin mechanism which causes increase in the plasma volume by 40% -50%, early in the pregnancy and continued till delivery and sodium retention [1] [14] [15] [16] [17]. While maternal erythropoiesis increases with red cell mass production in response to foetal demand and increased plasma volume results in haemodilutional effect, which is responsible for the decrease in the red blood cell indices [16] [17]. Manifestation of increased haemocrit and haemglobulin concentration decreases with the trimester stages, and typical drop in the second trimester due to maternal plasma volume [2] [5] [18] [19] [20] [21], dependent on factors such as geographical location, malaria, helmthitic infection, dietary and iron supplement intake [22]. While red blood cells indices (MCV, MCH and MCHC ) serve as a good indicator of iron-deficiency anaemia in pregnancy and concentration varies with studies [1] [14].
The absolute white blood cell counts increased early in pregnancy and continued throughout the trimesters stages, primarily due to physiological stress, neutrophil count and neutrophilic apoptosis [1] [14] [23] [24]. Neutrophil is a major leucocyte of differential count and contributes significantly to leucocytosis in pregnancy [25] [26] [27]. Gestational thrombocytopenia is second to anaemia of heamatological abnormalities, which occurs in 7% -8% pregnancy, a mild condition that requires no clinical attention [1] [14] [28]. But the decrease in platelets count can be attributable to platelets activation, and clearance [29] [30] [31].
Variability in haematological profile in pregnancy due to several factors as documented in most studies the need for local data derivable from pregnant women attending antenatal clinic to provide important information for clinical assessment of pregnancy, wellbeing, and early detection of pregnancy associated complication. Based on this information, we assessed the haematological profile of pregnant women attending antenatal clinic of tertiary hospital in Bauchi State.

Methodology
The cross-sectional study was conducted at the antenatal clinic of Abubakar Tafawa Balewa University Teaching Hospital, Bauchi between July and August 2018.
The 750-bed hospital in Bauchi, North-eastern provides multi medical specialties services to Nigerian and nationals of neighboring countries. The study protocol was approved by ATBUTH instutional review board. Recruitment of study participants was voluntary based on verbal briefing in English and Hausa languages. A well-structure study questionnaire and informed consent were administered by the authors [MAB, LMD, AS] on the study participants after routine antenatal clinical review. Age-matched non-pregnant study participant as control were recruited among member of staff of the hospital with no evidence of pregnancy. Information of the questionnaire includes, age, occupation, residential location, marital status, type of relationship, educational background, gestational age, parity and haematenic intake.
Five millimeter of venous blood specimen was collected aseptically into labeled EDTA bottles for haematological analysis, using Sysmex haematology analyser.
The eosinophil, basophil and monocyte were presented as mixed counts.
Haematological profile and demographic variables were analysed using SPSS version20.0, values expressed in mean, frequency and percentages. Categorical variables were compared using chi-square test with statistical significance at p < 0.05.

Result
A total of 191 study participants, comprised of 141 pregnant women at different gestational stages and 50 non pregnant as controls, mean age of 29.26 ± 5.94 years. Demographic characteristic of study participant presented in Table 1, majority of study participants were within age-group 27 -32 years (n = 76, Comparing the haematological profile of pregnant and non-pregnant women as presented in Table 2, significance difference was observed between pregnant and non-pregnant women with mean neutrophil count (0.016), mixed count  Comparsion of haematological profile and trimester stage of pregnant women (Table 3), mean haematocrit concentration increased with trimester (36.4 ± 3.2) at first trimester, a dip at the second trimester (34.7 ± 7.1), rise at the third trimester (37.1 ± 11.5), while slight decrease with heamglobulin concentration, 12.3 ± 1.2, 11.6 ± 1.4 and 11.3 ± 2.0 respectively. MCV, MCH and MCHC concentration showed a slightly stable increase from first to third trimester, MCV 83.4 ± 7.7, 86.4 ± 7.7, 87.0 ± 8.3, MCH-28.1 ± 3.3, 29.2 ± 3.0 and 29.4 ± 3.1 and MCHC-33.7 ± 2.1, 33.8 ± 3.0 and 33.8 ± 2.1. The mean RDWSD concentration showed increase from 47.6 ± 3.2 at the first trimester, drop to 46.5 ± 6.5 at second trimester, and rise to 49.0 ± 9.4 at the third trimester.  [18]. The relatively stable concentration of red blood cells indices as observed in our study could be due to the low prevalence malaria and iron-supplement intake among the pregnant women [22]. In addition, the mean RDWSD level assessed red blood cell width variation, the level increases during pregnancy, and asses iron-deficiency anaemia during pregnancy [2]. In this study, the RDWSD concentration exhibited similar pattern with haemocrit and heamglobin concentration, with increased level at first trimester, slight reduction at second trimester and later increase in the third trimester.
In pregnancy, leucocytosis increases from early stage and continued to the delivery stage, due to series of immunological activities of inflammatory response, selective immune tolerance, immunosuppression and immunomodulation of foetus [19] [23]. This contributes to the slight increase in the mean white blood cells and neutrophil counts among pregnant women compared to non-pregnant women, in contrast to high mean mixed, lymphocyte and platelet counts among non-pregnant women. But significant difference was observed with mean neutrophil (0.015), mixed (0.005) and lymphocyte (0.000) and platelet (0.000). Eosinophil, monocyte and basophil count response to allergy to intestinal parasitic infection [1]. In this study, eosinophil, basophil and monocyte were presented as mixed counts; significant difference was observed between pregnant women and non-pregnant women, while significant association was observed with the trimesters as reported in similar study conducted in Libya, which revealed relatively decreased mixed counts with the trimester [18]. Primarily, monocyte functions in preventing foetal allograft rejection. While eosinophil and basophil count seem relatively unchanged during pregnancy [1] [14].

Conclusion
The reduction in the WBC count with trimester and increase haemocrit concentration affirmed the need for more local studies on haematological profiles of pregnancy which is essential to effective monitoring and management during antenatal visits.