Medication-Related Risk Factors for Preterm Birth in Kitui County, Kenya
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ABSTRACT

Introduction:

Premature infants contribute substantially to infant morbidity and mortality especially in low resource areas.  Understanding the factors that contribute to pre-mature labour in these areas would greatly influence infant morbidity, mortality and reduce paediatric healthcare costs.

Specific Objectives:

Among immediate postpartum mothers who had preterm term birth compared to their counterparts who had term birth in Kitui County, to determine and compare the difference in: Herbal remedy use in pregnancy, self-medication use in pregnancy and prescription medication use in pregnancy

Methods

Study design: Unmatched case control study with a 1:4 ratio of cases to controls.

Study setting: Mwingi District Hospital and Kitui District Hospital

Study population: Immediate postpartum mothers.  Cases had preterm birth and controls had term birth.

Sample size: 560 (107 cases and 453 controls): 107 eligible immediate postpartum mothers with preterm birth (Cases) and 453 eligible immediate postpartum mothers with term birth (Controls) were sampled

Data collection: Structured interviews using questionnaires administered to mothers and data abstraction form for retrieving data from patient records.

Results

General socio-demographic maternal status: Cases were more likely to be drawn from rural (98.1%) areas compared to the controls (89.6%) and were more likely to have had more than three previous pregnancies (13.1%) compared to controls (6.2%).  Cases were more likely to be of lowest levels three and four socio-economic status (38.3% and 6.5% respectively) compared to controls (25.2% and 4.9% respectively).  Alcohol use was higher in cases (10.3%) compared to controls (5.1%).  Preeclampsia was also more likely in the case group (9.45%) compared to control group (1.1%)

Herbal remedy use in pregnancy: On multivariate analysis, Herbal remedy risk factors for preterm birth were herbal use in the first trimester lasting two to five days (OR=11.10 [4.34-28.41], p<0.01), herbal use in the first trimester lasting six to 10 days (OR= 44.87 [4.99-403.87], p<0.01) and herbal use in the second trimester for six to 10 days (OR= 16.43 [4.53-59.57], p<0.01). Any herbal use in the first trimester was associated with higher risk (OR=7.10, [3.42-15.80], p<0.01.

Self-medication in pregnancy: On multivariate analysis, self-medication risk factors for preterm birth were use of the following medications in the first trimester for 2 to 5 days: Chlorpheniramine (OR=2.64 [1.22-19.65], p=0.012), Paracetamol (OR=1.34 [1.09-6.73], p=0.043), Amoxycillin (OR=5.72 [1.60-20.84], p=0.007) and Magnesium trisilicate (OR =7.66 [2.66-22.32], p=0.011).

Prescription medication use in pregnancy: Amoxicillin prescribed in the first trimester (OR=0.09 [0.01-0.66], p=0.043), ferrous sulphate, second trimester for more than 31 days (OR=0.22 [0.13-0.35], p<0.001), folic acid from second trimester for more than 31 days (OR=0.20 [0.12-0.34], p=0.02) and FDA category A (OR=0.27 [0.07-0.42], p=0.001) medications were associated with lower risk of preterm birth. Risk factors for preterm birth were: Omeprazole in second trimester used for 6-10 days (OR=7.92 [1.08-58.32], p=0.042), metronidazole use for two to five days in second trimester (OR=3.16 [1.23-12.06], p=0.02), Categories C (OR=3.22 [1.87-6.23], p=0.01) and D  medications OR=4.23 [2.10-8.74], p=0.02.

Conclusion and Recommendations:

Low socio-economic status, alcohol use and high fertility rates are important risk factors for preterm birth.  Use of herbal remedies and self-medication in pregnancy is common among the women in Kitui County and it is a major risk factor for preterm birth.  Prescribers should be sensitized on safe medication use in pregnancy and management of maternal infections, folic acid and ferrous sulphate supplementation throughout pregnancy should be strengthened.