Research Article: Sickle Cell Disease in Pregnancy: Trend and Pregnancy Outcomes at a Tertiary Hospital in Tanzania

Date Published: February 13, 2013

Publisher: Public Library of Science

Author(s): Projestine S. Muganyizi, Hussein Kidanto, Francesc Palau.


SCD in pregnancy is associated with increased adverse fetal and maternal outcomes. In Tanzania where the frequency of sickle cell trait is 13% there has been scanty data on SCD in pregnancy. With progressive improvement in childhood survival the burden of SCD in pregnancy will increase. We analyzed all deliveries at Muhimbili National Hospital (MNH) from 1999 to 2011. Fetal and maternal outcomes of SCD deliveries were compared with non-SCD. Data were analyzed using IBM SPSS statistics version 19. Chi square and Fisher Exact tests were used to compare proportions and the independent t-test for continuous data. To predict risks of adverse effects, odds ratios were determined using multivariate logistic regression. A p-value<0.05 was considered significant. In total, 157,473 deliveries occurred at MNH during the study period, of which 149 were SCD (incidence of 95 SCD per 100,000 deliveries). The incidence of SCD had increased from 76 per 100,000 deliveries in the 1999–2002 period to over 100 per 100, 000 deliveries in recent years. The mean maternal age at delivery was lower in SCD (24.0±5.5 years) than in non-SCD deliveries (26.2±6.0 years), p<0.001. Compared with non-SCD (2.9±0.7 Kg), SCD deliveries had less mean birth-weight (2.6±0.6 Kg), p<0.001. SCD were more likely than non-SCD to deliver low APGAR score at 5 minutes (34.5% Vs 15.0%, OR = 3.0, 95%CI: 2.1–4.2), stillbirths (25.7% Vs 7.5%, OR = 4.0, 95%CI: 2.8–5.8). There was excessive risk of maternal deaths in SCD compared to non-SCD (11.4% Vs 0.4%, OR = 29, 95%CI: 17.3–48.1). The leading cause of deaths in SCD was infections in wholly 82% in contrast to only 32% in non-SCD. In conclusion SCD in pregnancy is an emerging problem at MNH with increased adverse fetal outcomes and excessive maternal mortality mainly due to infections.

Partial Text

Sickle cell disease (SCD) is a group of inherited single-gene autosomal recessive disorders caused by the sickle cell gene which affects hemoglobin structure [1]–[6]. SCD encompasses Sickle cell Anemia (SCA) which possesses SS genotype, some heterozygous conditions of the S gene and other clinically abnormal hemoglobins such as beta thalassemia, hemoglobin C, D, E and others. The combination of Sickle gene with any of these abnormal hemoglobins will lead to a similar clinical picture of SCD although the severity of the disease and prevalence differ. SCD is believed to originate from Sub-Saharan Africa and Middle East, hence high prevalence is found among populations in these regions and their descendants elsewhere in the world [7]. It is estimated 300,000 children are born each year with SCD with 75% of them living in Sub-Saharan Africa [8]–[9]. SCD is a major public health problem in East Africa. In Uganda a mean frequency of 20% Sickle cell trait is documented, with an expected 25,000 babies born with SCD each year [10]. Similarly high annual incidence of SCD births can be expected in Tanzania where the quoted frequency of Sickle cell trait is 13% [11].

During the study period there were 157,473 deliveries at MNH of which 151,518 were singleton. There were 149 SCD deliveries which makes the incidence of 95 SCD per 100,000 deliveries. Overall, the median age at delivery was 26(±6.0) years with a range of 12–50 years. From Table 1, most deliveries (84.9%) were to mothers in the relatively low risk age range of 18–34 years. Attendance to antenatal clinic was 99.5% of all deliveries. Around 18% of all the deliveries had low birth weight, and 7.1% were stillbirths. Overall there were 706 maternal deaths which is equivalent to 448 deaths per 100,000 deliveries at this hospital.

Sickle cell anemia is a major public health problem in Tanzania [11] but more attention has been drawn to SCD in childhood with almost none paid to SCD in pregnancy. As childhood survival continue to improve [20], the burden of SCD in pregnancy will continue to rise as proved by this study. The SCD incidence of 95 per 100, 000 deliveries and a rising trend of SCD deliveries from 76 per 100,000 deliveries in 1999–2002 to over 100 per 100, 0000 deliveries in more recent years, underscores the need for paying more attention to SCD in pregnancy.

The incidence of SCD delivery at MNH has been on a rise in the past 13 years. The disease is associated with excessive maternal deaths that are by far attributable to infections. Standard guidelines to improve care of SCD in pregnancy are urgently needed in Tanzania.