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The Effect of Maternal Opioids on Labour, Delivery and the Newborn in the First Three Years of Life

Student thesis: Doctoral ThesisDoctor of Philosophy

Background: There have been few current longitudinal studies focusing on the effects of opioids on neonates born to drug users especially in the developmental period following birth. Design: The effect of prenatal opioid exposure was investigated in this thesis in order to clarify the aetiology of perinatal and developmental effects through a retrospective 10-year study and a prospective 3-year study during which time children were assessed to see if they achieved their milestones on time and if type of guardianship had any affect on their development. Methods: In the retrospective 10-year study all Maltese Substance Misusing Mothers (SMM) attending the Substance Misusing Out-Patients Unit, (SMOPU) run by Sedqa, Malta and who were pregnant and gave birth between the years 2000-2009 (n = 182) were compared with a randomized computer-generated representative sample of the general Maltese maternal population (control group) delivering during the same period (n = 329). In the prospective case series study (2012 - 2016), SMM who became pregnant were recruited to the study as well as all their new-borns: children were monitored for 3 years. The control group was comprised of alternative guardianship; namely foster parents or institutional care. The mother-child relationship was also studied to investigate whether healthy attachment bonds had any effect on the development of the child using the Parental Development Interview (PDI) and PIRAT tool. Ethical consent was obtained from the Malta Medical School Ethical Board, from the University of Malta Ethical Board and from King’s College Ethical approval committee. Results: In the retrospective study the SMM (n = 182) were significantly younger (P < 0.001), single (P < 0.001), had more children (P < 0.001), were usually unemployed and with a lower education background than the Maltese population (P = 0.007). Their new-borns (n = 182) had a significantly lower mean birth weight (P < 0.0005), head circumference (P = 0.003), and lower Apgar scores (P = 0.014 after 1 minute; P < 0.001 after 5 minutes). The SMM were significantly less likely to be breastfed (P < 0.001) and their newborns stayed in hospital significantly longer (P < 0.001) than children born to non-drug using mothers. In the longitudinal study 69 SMM were recruited and matched SMM in the retrospective study being significantly younger (P < 0.001), single (P < 0.001), multiparous (P < 0.001), unemployed and poorly educated (P < 0.001). Most were heroin dependent and prescribed methadone: mean methadone dose was 46.22 ± 28.51 mg/day. Doses in the third trimester were significantly higher than they were in the first trimester (P value 0.005). There were 69 live births, mean birth weight and mean head circumference were significantly smaller than Maltese population (P < 0.001) half (50.7%) were males, 18.8% were preterm. Of 69 children, 70% were placed (at birth) with their biological mother, 26% were fostered and 4% institutionalized: by the 30 month assessment 4% of those placed with their mother were removed (6/48 to an institution and 3/48 into foster-care). From the population of 69 children, 7 were found to have autistic traits: the SMM cohort had a significantly higher rate (10.1%) of autism than the general Maltese population (P value 0.031, Z score = 2.1649); 4 children had strabismus (squint), mainly amblyopia (lazy eye); 3 had Talipes Equino Varus (club foot); 6 received regular treatment for wheezing and 2 had cleft palate. The infants recuperated their weight 4 and height in the first year of life. At 3 years (N = 33), the children scored significantly lower in the performance (P < 0.001), hearing and language (P < 0.001), eye and hand coordination scales (P < 0.001). There was no significant difference when guardianship and gender were compared. Discussion: Opioid use in pregnancy may have contributed to several physical abnormalities and may have an intrinsic effect on the child’s development when considering hearing and language, performance and eye and hand coordination skills regardless of parenting skills and environment. Conclusion: Opioid use along with smoking and sexual promiscuity is part of a complex environment that impacts on pregnancy. It has effects on size of newborn and Apgar score. These do not persist when infant is 1 year of age. Effect on performance, hearing and language and eye-hand coordination continues until 3 years of age inspite of type of guardianship and gender.
Original languageEnglish
Awarding Institution
Award date2019

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