Risk Factors for Preterm Birth and Low Birth Weight in a Family Medicine Residency Clinic Craig P. Griebel, M.D., Jean C. Aldag, Ph.D. University of Illinois College of Medicine at Peoria Family Medicine Residency

Objectives of the study To evaluate the prevalence of known risk factors for preterm birth and low birth weight at a family medicine residency clinic To assess whether those known risk factors place these patients at risk for preterm birth and low birth weight

Conflict of interest disclosure Craig P. Griebel, M.D.—No conflicts to disclose Jean C. Aldag, Ph.D.—No conflicts to disclose

Concern regarding preterm birth and low birth weight Increased mortality rate (primarily in infants less than 32 weeks gestation) High risk for: respiratory problems, cerebral palsy, necrotizing enterocolitis, infections, cardiovascular disorders (short-term and long- term medical morbidities)

National rates of preterm birth and low birth weight: Preterm birth rate in 2008: 12.3 per cent (peaked at 12.8 per cent in 2006, was 10.6 per cent in 1990) Rate of low birth weight in 2008: 8.18 per cent (was 6.98 per cent in 1990)

Known risk factors for preterm birth and low birth weight Low socio-economic status* African-American race* Teen or advanced age* Tobacco use* Cocaine, heroin abuse* Inadequate prenatal care*

Known risk factors for preterm birth and low birth weight, cont’d Previous preterm birth Multiple gestation Pre-existing medical conditions Pregnancy-specific medical conditions Genital infections

Cohort of 614 pregnant women (updated from 391) Data collected from prenatal and hospital records between Dec., 2004 and Feb., 2012 (extended from July, 2010) Women who delivered their baby under the care of the family medicine residency model clinic (residents and faculty) Study was approved by the local IRB

Methods Smoking status determined by patient report Maternal drug use was determined by patient report and by maternal and newborn drug screens, if performed Maternal race was obtained from the records Maternal insurance status was determined from the records

Methods, cont’d Age at the time the subject became pregnant was calculated from the prenatal records Adequacy of prenatal care was determined using the Kotelchuck Adequacy of Prenatal Care Utilization Index

Methods, cont’d Infants were categorized as term (>37 weeks) or preterm (<37 weeks) Birth weight was recorded and categorized as normal (>2,500 grams) or low birth weight (<2,500 grams)

Methods, cont’d Data were entered into an Excel spreadsheet and analyzed using SPSS software The difference between rates of preterm delivery for subjects with/without risk factors was assessed using chi-square Difference between birth weights for subjects with/without risk factors was assessed using the Student’s t test A “p” value of 0.05 or less was accepted as significant

Results Smoking rate of 24.5% (9.7%) Rate of drug use of 29.0% (5.1%) – 92.0% marijuana – 7.5% cocaine – 2.9% alcohol – 1.7% opiates – 0.6% ecstasy

Results, cont’d Maternal race: – AA—55.1 (13%) – White—31.1% (64%) – Hispanic—11.8% (16%) – Asian—0.8% (5%) – Other/Mixed—1.2% (2%) Age 18 or less at the time of becoming pregnant—24.1% (6.3%)

Results, cont’d Medicaid insurance—93.4% (40%) Inadequate prenatal care: – Adequate plus—11.2% (31.4%) – Adequate—55.4% (39.5%) – Intermediate—12.6% (20.9%) – Inadequate—20.7% (7.9%)

Results Overall rate of preterm delivery was 12.0% (12.3%) Smokers had a significantly higher (“p”=0.039) rate of preterm birth than non-smokers No significant increase in preterm birth for the other risk factors studied: – Age 18 and under (“p”=0.104) – Drug use (“p”=0.327) – AA race (“p”=0.205) – Medicaid insurance status (“p”=0.432) – Inadequate prenatal care (“p”=0.551)

Results Overall rate of low birth weight was 10.3% (8.2%) Significantly lower birth weights were found for: – Mothers who smoked (“p”<0.001; -295 gm); – Mothers who used drugs (“p”=0.007; -155 gm); – AA mothers (“p”<0.001; -274 gm) – Mothers age 18 or less (“p”=0.002; -183 gm) – No significant difference in birth weight for mothers insured with Medicaid (“p”=0.653; -48 gm), mothers with inadequate prenatal care (“p”=0.242; -64 gm)

Discussion/Conclusions This family medicine residency clinic cares for a higher risk cohort of pregnant patients when compared to national statistics Most of the risk factors studied put patients at increased risk for preterm birth or lower birth weight It is interesting that Medicaid insurance status and inadequate prenatal care did not put pregnant women at significantly increased risk for delivering a high risk newborn

Study limitations Smoking status obtained by verbal self-report Drug screens were performed at the beginning of pregnancy, often not repeated Did not include subjects with no prenatal care Did not evaluate subjects for previous preterm birth Small sample size

Plans for the future Compare this experience with those at other family medicine residency clinics Evaluate ways to reduce risk factors for preterm birth and low birth weight: – Interventions to reduce tobacco use – Use of progesterone for patients with a history of previous preterm birth – Interventions to reduce drug use – Interventions to reduce teen pregnancy

References: 1. Behrman RE, Butler AS, eds. Preterm birth: Causes, consequences, and prevention. Washington D.C.: National Academies Press Slattery MM, Morrison JJ. Preterm delivery. Lancet 2002; 360(9): Tucker J, McGuire W. ABC of preterm birth. Epidemiology of preterm birth. Br Med J 2004; 329: US Department of Health and Human Services. Births: Final data for Natl Vit Stat Rep. 2010; 59(1): Kotelchuck M. An evaluation of the Kessner adequacy of prenatal care index and a proposed adequacy of prenatal care utilization index. Am J Public Health 1994; 84(4):

References 6. Osterman MJ, Martin JA, Mathews TJ, Hamilton BE. Expanded data from the new birth certificate, Natl Vit Stat Rep 2011; 59(7): Substance Abuse and Mental Health Services Administration (2009). Results from the 2008 national survey on drug use and health: National findings (Office of Applied Studies, NSDUH Series H-36, HHS Publication Nos. SMA ). Rockville, MD. 8. US Census Bureau. State and county quickfacts Andrews, M. Pregnant women, new mothers get more protections under healthcare law. Los Angeles Times June 21, 2010.

References 10. Heaman MI, Newburn-Cook CV, Green CG, Elliott LJ, Helewa, ME. Inadequate prenatal care and its association with adverse pregnancy outcomes: A comparison of indices. BMC Preg Child 2008; 8(15):1-8

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