Ninth Annual Maternal and Child Health Epidemiology Conference / December 10-12, 2003
Codes for Alcohol Use/Abuse: A Description of of the Women and Babies
DEBORAH FOX: For the past six years, I’ve been the Project Director for the Fetal Alcohol Syndrome Surveillance Network, coined “FASSNet,” and it was a CDC-funded cooperative agreement that began in 1997 and just ended in September of this year. And the other participating states were Alaska, Arizona, Colorado, and Wisconsin. Can everybody hear me?
UNIDENTIFIED SPEAKER: Barely.
DEBORAH FOX: I’ll speak closer to the mic. One of our goals was to develop a system and a methodology that could be adopted by other states to estimate the prevalence of FAS nationally. I’d also like to introduce my coauthor, Charlotte Druschel. She’s the Medical Director of the Congenital Malformations Registry in New York State. While I was preparing my presentation last week, I thought it would be nice to show you what the weather was like where I came from. I live north of Albany, New York, and this was the weather last Thursday; but these photos are actually old news because we had a major storm front come through over the weekend and got two feet of snow. But unfortunately, I wasn’t able to take some pictures of that snowfall because I was too busy rearranging my travel schedules to try to get to Tucson by Monday. So anyway, you can understand that I really appreciate the warm weather here in Arizona.
Prenatal alcohol exposure has been associated with a spectrum of negative birth outcomes, including fetal death, growth deficiency in preterm birth, birth defects, and fetal alcohol syndrome. This analysis was planned to look at these associations while also looking at maternal enrollment in programs that might represent opportunities to improve birth outcomes. For this descriptive study, we compared pregnant women who drank heavily to a population of pregnant women residing that represented the general population. The mothers resided in the eight-county region that I’ve circled on the map up here, and they had singleton births for the 27-month time period from October, 1997 to December, 1999. Group one was identified by the FASSNet project. For FASSNet, we used many different sources of referral to find children suspected of having fetal alcohol syndrome or suspected of prenatal alcohol exposure. Some of these sources included genetics clinics, developmental clinics, and early intervention programs. The hospital discharge database was another source for FASSNet. And using codes, we identified 144 pregnant women who had abused alcohol. Group two, the population controls were from the National Birth Defects Prevention Study, a case control study to look at the etiologies of birth defects. This is also a CDC-funded cooperative agreement that began in 1997 and is still in existence. The controls for this study are a random sample of births without birth defects.
The eight-county region and 27-month time period were selected for this analysis because we had complete overlap between the two studies. We looked at several maternal characteristics, infant birth outcomes, and maternal participation in certain programs. To select the mothers for the FASSNet study, we used a combination of ICD-9 codes indicating maternal mental disorder complicating pregnancy with one of the codes indicating heavy alcohol use or abuse of alcohol. And I’ve indicated the descriptions here. For FASSNet, we did use the child’s ICD-9 code of 76071, which is noxious influences of alcohol infecting the fetus, but this code was not used selection criteria for this analysis. Our first maternal characteristic we looked at was age, where we found no significant difference between the two groups. You can see in the FASSNet group that age is slightly older, 28 years, compared to 27½ years in the controls. And I’m going to be presenting a lot of numbers in tables, so I’ve highlighted the most noticed and notable findings to make it easier for you to follow the discussion. In just about all of our comparisons we made in our two cohort groups, we found the differences to be statistically significant.
Here, you see about 50 percent of the FASSNet mothers did not complete high school compared to 14 percent of the controls, and only one percent of the mothers graduated from college in the FASSNet group compared to 25 percent in the controls. We did see a difference with maternal race distribution. We’ve got about 40 percent of the mothers in the FASSNet group were White compared to 80 percent in the controls. All of the newborn growth measurements were significantly different between the two cohort groups, and you would expect the growth measurements and gestational age to co-vary together. We plan to look more closely at these relationships in the future before we right up our findings for publication. We may run into problems with small sample size, but we’ll have to see how we do. So here you can see we’ve got about a 500-gram difference with the crude birth weight between the two populations, and that difference continues when we stratify by race. We have about a 500-gram difference for Whites and about a 400-gram difference for African-Americans. You can also see from this slide that the average birth weight for African-Americans is less than Whites in both of our cohort groups. If we control for both race and gestational age, we still found difference in birth weights to be statistically significant now that the difference is about 280 grams.
Looking at birth weight by categories, we found that about 24 percent of the FASSNet births were low birth weight and very low birth weight compared to about eight percent of the controls. And to evaluate whether a child was small for gestational age, a methodology was published by Greg Alexander in the “Journal of Obstetrics and Gynecology” in 1996. So we applied his methods to the New York State births for the time period of October, ’97 to December, 1999 and calculated the 10th-centile cutoffs. And it was reassuring to see that our control group had a 10th-centile for small for gestational age; and in the FASSNet group, we had about two and a half times more children with small for gestational age in birth weight than would be expected. Looking at gestational age, we found a difference for the mean gestational age of about a week and a half between the FASSNet group and the control group. And again, this difference we continue to see when we stratify by race. The difference is about a week and a half for White and about a week for African-Americans. Looking at gestational age by categories, we see similar proportions than what we saw for the birth weight categories.
We’ve got about 23 percent of the infants in the FASSNet group were preterm and very preterm compared to nine percent in the controls. In the FASSNet group, birth length is almost two and a half centimeters shorter than in the controls. It’s actually 2.3 centimeters. And the cohort status was significantly related to the child’s length, even when we controlled for the gestational age. That’s this value here. After we adjusted for gestational age, we found 1.3-centimter difference between the two groups. To determine the small for gestational age status for length as well as for head circumference, which I’ll show you in the next slide, we used cutoff measurements provided in a study by *Luchenko in the “Journal of Pediatrics” in 1966. We had used this method to determine growth deficiency for the FASSNet study. It’s of concern that we only had two percent of our controls that were small for gestational age. This may reflect the age of the study or different study populations, or it may have occurred because of our relatively small sample size. And in the FASSNet group, three and a half times more children were small for gestational age and birth length.
Looking at birth head circumference, the cohort status was significantly related to the child’s head circumference, but the difference was not significant when we controlled for gestational age. In the unadjusted measurements, we found a difference of about one centimeter. And controlling for gestational age, the difference is about a half a centimeter. Twice as many children were small for gestational age in a birth head circumference measurement as would be suspected. In addition to looking at growth and gestational age, we thought it would be valuable to see how many children had birth defects. We had to use only our FASSNet group for this analysis as our control group, by definition, did not have birth defects. The number of expected cases here is based on the prevalence data from our birth defects registry. We found a much higher percentage of children with major malformations in the FASSNet group. Generally, three to four percent of births have birth defects, so we would have expected to find only about six children with major malformations, and we found 23. We would have expected only about one and a half children to have a heart defect but found 13 children with heart defects. And we also would have found a larger number of oral clefts, eight versus .2. Probably not surprising is the percentage of the number of children with FAS, almost 10 percent. This is actually a high estimate as the prevalence is generally one per thousand births.
Finally, we looked at maternal participation in programs or services because they indicate opportunities for intervention. During pregnancy, women can also be highly motivated to stop drinking for the sake of their unborn child. Here we see that 73 percent of our FASSNet group did receive prenatal care. It’s less than what we found in the controls, 96 percent; but unfortunately, only 33 percent of the prenatal care began in the first trimester, thus reducing the amount of time or visits where intervention might be conducted. Looking at enrollment in special programs, we found that 77 percent of the FASSNet mothers were enrolled in special programs serving women and children compared to 35 percent in the controls. And most notably, 72 percent of the women were enrolled in WIC. Looking at the primary payer for birth, we found that 80 percent of our FASSNet group received Medicaid assistance to pay for the group compared to about 30 percent in the controls.
So to bring this talk to an end, I wanted to leave you with the following points. First, we found a significantly poor outcome in the FASSNet group--poor birth outcome. Excuse me. Several factors contribute to these findings. Alcohol use is one factor, but poor birth outcomes may also reflect socioeconomic status, smoking use, use of other illicit drugs, and other factors. We have begun to look at alcohol use in these two groups, but the information was collected in a different format between the two groups, and alcohol use is often not reported accurately. So any data we get from that will have to be taken with a grain of salt. We did find that in the FASSNet group, 52 percent of the mothers drank during two or more trimesters during the pregnancy compared to only 11 percent of the mothers in the control group, although the sample size was much smaller for that analysis.
The second point is that opportunities for intervention do exist. We’ve documented an easily recognizable population of women that can be targeted for intervention. Alcohol use was documented to be coded. Seventy-three percent received prenatal care, and while about two-thirds did not start care until the second or third trimester, studies indicate that intervention even late in pregnancy can improve birth outcomes. It’s also important to remember that these women may have additional pregnancies, so intervention may have a positive effect on future births. Seventy-seven percent of our women did receive support services, seventy-two percent received WIC, and 80 percent were enrolled in Medicaid for birth. While some of the women may have enrolled in Medicaid may just have qualified at the birth, that’s still important. These findings are useful because it tells us where it would be most efficient to offer interventions and prevention services, as well as where to screen and do follow-up for children. Medical providers, clinics, and various programs such as WIC that provide services to a large proportion of Medicaid-eligible women should be involved first. Let me tell you some of the doable steps that I see that we can take in the field of maternal and child health.
To improve poor birth outcomes resulting from prenatal alcohol exposure, we need to focus efforts in three areas. First, we need to overcome barriers to primary intervention. Professional education and training is one key element. Health care providers and community service professionals like those in the WIC programs must understand the negative outcomes of alcohol use during pregnancy and want to act on that information. They need to learn how to ask women about alcohol use in a non-threatening way. They need to screen all women of childbearing age regularly. Brief interventions and motivational interviewing have been shown to be effective at reducing or eliminating risky drinking for women of childbearing age. Brief interventions also represent a cost-effective means to reach the general population.
Service providers need to incorporate screening and intervention methods into their health care and service programs so they become standards of care. Referral networks need to be strengthened between service providers and substance abuse treatment programs so women who have significant issues with alcohol addiction get the professional assistance they may require. We also need to expand the availability of treatment programs tailored specifically for women where they can bring their children, if they need to, and they’ll address other issues such as domestic violence or vocational training. These other issues might prevent a woman from changing her drinking habits if they’re not addressed.
Secondly, providers that care for infants and children need to become more aware of the consequences of prenatal alcohol exposure so that children are screened and followed more closely. One very important step is to help providers ask the question, “Was the child exposed to alcohol in utero, and if so, how much?” If providers and educators are aware that a child had prenatal alcohol exposure, they’ll be much more successful at supporting the child and putting the child in an environment where that child will be successful for the remainder of his or her lifetime. Finally, the importance of interagency coordination cannot be overemphasized. Activities involving pregnancy and women’s health, substance abuse treatment, and coordination of services for children with FAS and their families cross all normal service delivery channels. I’d like to acknowledge our statistician, *Lenora *Ginsburg, who spent many hours with me working on this analysis; and also our abstractor, *Christina *Westfield, who worked many hours collecting this data to make the analysis possible. Thank you.