Adverse birth outcomes associated with drug use in pregnancy at Kenyatta national hospital.

Abstract

Background: Drug prescribing and use during pregnancy is common and essential for either treating a pre-existing condition or a condition that develops during pregnancy. Use of various drugs during pregnancy cause possible adverse outcomes. In Kenya, there has been an increase in cases of adverse birth outcomes congenital malformations, neonatal deaths, premature labour, and stillbirths, among others. It is exceedingly difficult to assess the effect of drugs on the fetus during clinical trials due to ethical reasons. Therefore, pregnant women constitute a uniquely vulnerable population for which the risks of medication use must be separately assessed. Objective: To determine the association between adverse birth outcomes and medication used during pregnancy among mothers who delivered at Kenyatta National Hospital. Methodology: An unmatched case control study was conducted at Kenyatta National Hospital. The cases were mothers who delivered babies with adverse birth outcomes and the controls were mothers who delivered normal healthy babies. A structured, interviewer administered questionnaire was used to collect data from the mothers and also their medical records including their ANC records were reviewed. The adverse birth outcomes included preterm, birth defects and still birth. Multivariable logistic regression was conducted to assess the relationship between drug use and selected outcome variables. Results: Preterm birth was the most common adverse birth outcome at KNH with a frequency of 27.6%, followed by stillbirth (15.3%) and congenital malformations (7.14%). Majority (48.4%) of the women received drugs from Pregnancy Risk category A. A few drugs from category D were prescribed and there was a difference in their use with more women in the case group (13.9%) compared to the control group (8.7%) on these medications. The risk of developing ADBOs increased 6-fold with nifedipine (OR 6.42), 4-fold if the mother had used carbamazepine (OR3.97) and 3-fold with magnesium sulphate (OR 3.11) after adjusting for social-demographic, past obstetric history, co-morbidities, pregnancy complications, and maternal delivery outcomes. Conclusion: Preterm birth is the most common adverse birth outcome among women attending antenatal clinic at Kenyatta National Hospital. Most women are exposed to drugs during pregnancy and there was a risk of adverse birth outcomes due to medication factors. Prescribing medication to pregnant women should be carefully evaluated and measures put in place to monitor and prevent the potential known and unknown medication risks to the developing fetus.