Background

Cleft conditions, commonly referred to as orofacial clefts, includes all cleft lip and cleft palate birth defects [1]. Orofacial clefts occur when a baby’s lip and/or palate do not form properly during early pregnancy. Cleft lip occurs when the lip does not come together during development, separating the lip either on one side (unilateral) or on both sides (bilateral) [2]. Cleft palate occurs when the roof of the mouth fails to join together resulting in an opening in either the front of the palate, the back of the palate, or both [1]. The lip and palate develop separately during pregnancy, therefore, a baby can have either cleft lip, cleft palate, or both cleft lip and cleft palate [2]. Orofacial clefts are one of the most common birth defects in the United States [2, 3]. While the exact cause for most cases of orofacial clefts is unknown. It is believed that a combination of environmental factors, mothers behaviors during early pregnancy (what she eats/drinks and medicine consumed), and genetic factors may contribute to orofacial clefts [1, 2].

Methodology

The Alaska Birth Defects Registry (ABDR) registers birth defects as reported from health care providers using International Classification of Disease (ICD) billing codes. The use of these ICD codes can lead to misclassification of diagnosed conditions. Prior to this report, all prevalence estimates were based on the number of unique children reported to ABDR with an ICD code representing a specified condition regardless of case confirmation status.

The estimates in this report were derived by conducting medical record review and case confirmation of a random sample of cases of the condition reported to ABDR. The confirmation probability from the sample was used to develop informed estimates of the actual diagnosed defect prevalence. See defect prevalence calculation for a complete explanation of the methodology used for generating estimates.

While this report provides the most precise estimates, caution should be used in interpreting prevalence estimates based on conditions with <30 annual reports, as they are potentially vulnerable to large year-to-year variation.

For explanations of table columns see column descriptions.

All Oral Facial Clefts

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of all orofacial clefts for 29 U.S. States from 2007-2011 was 14.5 per 10,000 live births.[3]

In Alaska, during 2007-2014, the prevalence of all orofacial clefts was 31.4 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 346 281.3 89471 31.4 (27.9, 35.3)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip

Cleft Lip Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft lip was for 29 U.S. States from 2007-2011 was 3.1 per 10,000 live births.[3]

In Alaska, during 2007-2014, the prevalence of cleft lip was 4.7 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 92 42.1 89471 4.7 (3.5, 6.3)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip Trend

Prevalence per 10,000 births of Cleft Lip during 2007-2014 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.

The p-value test for trend detected no significant increase or decrease in the number of live births with cleft lip during 2007-2014. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.01872 0.02064 0.90661 0.41589

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 10.7 5.7 11143.0 5.1 (2.2, 10.9) 4.6
2008-2010 9.7 5.2 11277.0 4.6 (1.9, 9.9) 4.7
2009-2011 9.3 4.9 11281.0 4.3 (1.7, 9.5) 4.8
2010-2012 11.0 5.1 11229.7 4.6 (1.8, 9.9) 4.9
2011-2013 13.3 5.9 11218.7 5.3 (2.3, 11.2) 5.0
2012-2014 13.3 5.8 11128.7 5.2 (2.2, 10.9) 5.1
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Lip Regional Distribution

Distribution of cleft lip in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can be found here. Data suppressed for # of reports < 6.

Reports Defects Births Prevalence (95% CI)
Anchorage - - 37067 2.9 (1.5, 5)
Gulf Coast 9 3.7 5563 6.6 (2, 15.8)
Interior 19 7.9 16343 4.8 (2.1, 8.8)
Mat-Su 10 4.2 10489 4 (1.5, 9.8)
Northern 7 2.9 6185 4.7 (1, 11.7)
Southeast - - 5328 -
Southwest 17 6.9 8496 8.1 (3.3, 15.4)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip Demographics

Some subgroups may be more at risk for having a baby with a cleft lip. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.
Reports Defects Births Prevalence (95% CI)
Sex
  Female 34 14.5 43366 3.4 (1.9, 5.4)
  Male 58 24.0 46105 5.2 (3.3, 7.5)
Birth weight (grams)
  <2500 10 4.1 5077 8.0 (3.2, 20.2)
  2500+ 82 34.4 84269 4.1 (2.9, 5.6)
Maternal age
  12-19 - - 7345 5.1 (1.5, 11.9)
  20-24 37 15.2 25062 6.0 (3.6, 9.9)
  25-29 17 7.4 26953 2.8 (1.3, 5.3)
  30-34 18 7.6 19246 3.9 (1.8, 7.5)
  35-39 9 3.8 8613 4.4 (1.3, 10.2)
  40+ - - 2242 -
Maternal race
  Alaska Native/American Indian 41 16.7 22754 7.3 (4.3, 11.4)
  Asian/Pacific Islander - - 8134 -
  Black - - 3654 -
  White 42 17.9 53865 3.3 (2.0, 5.0)
Maternal education (years)
  <12 11 4.5 8660 5.2 (1.9, 11.8)
  12 46 18.9 32967 5.7 (3.5, 8.6)
  12+ 34 14.6 45079 3.2 (1.9, 5.2)
Marital status
  Married 43 18.4 56506 3.3 (2.0, 5.0)
  Unmarried 49 20.1 32845 6.1 (4.0, 9.4)
Maternal smoking use
  Reported smoking 23 9.4 13021 7.2 (3.7, 13.1)
  Reported not smoking 68 28.7 75425 3.8 (2.6, 5.4)
Medicaid (mother or child)
  Medicaid 72 29.4 45769 6.4 (4.4, 9.1)
  non-Medicaid 20 9.0 43686 2.1 (1.1, 3.9)
Father on birth certificate
  None - - 4732 -
  Present - - 84739 4.3 (3.1, 5.9)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Palate

Cleft Palate Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft palate for 29 U.S. States from 2007-2011 was 5.9 per 10,000 live births.[3]

In Alaska, during 2007-2014, the prevalence of cleft palate was 13.3 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 175 119.3 89471 13.3 (11.1, 15.9)
Notes: 95% CI = 95% Confidence Interval

Cleft Palate Trend

Prevalence per 10,000 births of cleft palate during 2007-2014 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.
The p-value test for trend detected no significant increase or decrease in the number of live births with cleft palate during 2007-2014. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.00783 0.00591 1.32378 0.25616

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 19.0 14.3 11143.0 12.9 (7.3, 20.7) 13.3
2008-2010 21.7 15.4 11277.0 13.7 (7.9, 21.6) 13.4
2009-2011 22.3 15.4 11281.0 13.7 (7.9, 21.6) 13.5
2010-2012 23.3 15.5 11229.7 13.7 (7.9, 21.6) 13.6
2011-2013 22.0 15.0 11218.7 13.3 (7.7, 21.3) 13.7
2012-2014 23.0 15.3 11128.7 13.8 (8.2, 22.2) 13.8
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Palate Regional Distribution

Distribution of cleft palate in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can be found here. Data suppressed for # of reports < 6.

Reports Defects Births Prevalence (95% CI)
Anchorage 60 41.8 37067 11.3 (8.2, 15)
Gulf Coast 18 11.3 5563 20.3 (11.1, 35.4)
Interior 33 22.1 16343 13.5 (8.9, 20.4)
Mat-Su 11 8.5 10489 8.1 (3.9, 15)
Northern 18 11.4 6185 18.5 (10, 31.8)
Southeast 11 7.3 5328 13.8 (6.5, 27.1)
Southwest 24 15.3 8496 18 (10.8, 29.1)
Notes:Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Palate Demographics

Some subgroups may be more at risk for having a baby with a cleft palate. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

Reports Defects Births Prevalence (95% CI)
Sex
  Female 81 54.9 43366 12.7 (9.6, 16.2)
  Male 94 62.8 46105 13.6 (10.5, 17.2)
Birth weight (grams)
  <2500 26 15.7 5077 30.9 (18.0, 48.7)
  2500+ 149 102.0 84269 12.1 (10.0, 14.7)
Maternal age
  12-19 - - 7345 19.0 (10.4, 30.3)
  20-24 46 31.3 25062 12.5 (8.7, 17.6)
  25-29 48 32.8 26953 12.2 (8.4, 16.8)
  30-34 35 23.8 19246 12.4 (8.0, 17.9)
  35-39 20 13.1 8613 15.2 (8.9, 25.8)
  40+ - - 2242 -
Maternal race
  Alaska Native/American Indian 78 48.7 22754 21.4 (15.9, 28.0)
  Asian/Pacific Islander 11 7.9 8134 9.8 (4.2, 17.7)
  Black 6 4.2 3654 11.4 (4.4, 28.0)
  White 79 56.1 53865 10.4 (8.0, 13.5)
Maternal education (years)
  <12 26 16.5 8660 19.0 (11.4, 30.0)
  12 82 53.2 32967 16.1 (12.3, 21.0)
  12+ 62 44.6 45079 9.9 (7.3, 13.1)
Marital status
  Married 84 59.5 56506 10.5 (8.1, 13.5)
  Unmarried 91 58.2 32845 17.7 (13.7, 22.8)
Maternal smoking use
  Reported smoking 49 30.3 13021 23.3 (16.2, 32.9)
  Reported not smoking 121 84.4 75425 11.2 (9.0, 13.8)
Medicaid (mother or child)
  Medicaid 125 80.1 45769 17.5 (14.1, 21.8)
  non-Medicaid 50 37.6 43686 8.6 (6.2, 11.7)
Father on birth certificate
  None 15 9.4 4732 20.0 (10.1, 36.1)
  Present 160 108.3 84739 12.8 (10.6, 15.4)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate

Cleft Lip with Cleft Palate Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft lip with cleft palate for 29 U.S. States from 2007-2011 was 5.6 per 10,000 live births.[3]

In Alaska, during 2007-2014, the prevalence of cleft lip with cleft palate was 13.4 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 79 119.9 89471 13.4 (11.1, 15.9)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate Trend

Prevalence per 10,000 births of cleft lip with cleft palate during 2007-2014 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.

The p-value test for trend detected a significant increase in the number of live births with cleft lip with cleft palate during 2007-2014. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.06337 0.01910 3.31816 0.02943

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 6.7 13.7 11143.0 12.3 (6.9, 19.9) 11.3
2008-2010 7.3 13.6 11277.0 12.1 (6.8, 19.7) 12.0
2009-2011 7.3 13.2 11281.0 11.7 (6.6, 19.3) 12.8
2010-2012 8.3 14.0 11229.7 12.5 (7.0, 20.2) 13.6
2011-2013 12.3 16.9 11218.7 15.0 (8.8, 23.1) 14.5
2012-2014 15.0 18.1 11128.7 16.2 (9.8, 24.8) 15.5
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Lip with Cleft Palate Regional Distribution

Distribution of cleft lip with cleft palate in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can found here. Data suppressed for # of reports < 6.
Reports Defects Births Prevalence (95% CI)
Anchorage 25 16.9 37067 4.6 (2.7, 7)
Gulf Coast 10 6.7 5563 12 (5.1, 23.5)
Interior 20 13.4 16343 8.2 (4.7, 13.6)
Mat-Su - - 10489 -
Northern 6 4.0 6185 6.5 (2.6, 16.6)
Southeast - - 5328 -
Southwest 12 8.0 8496 9.4 (4.8, 18.6)
Notes:Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate Demographics

Some subgroups may be more at risk for having a baby with a cleft lip with cleft palate. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

Reports Defects Births Prevalence (95% CI)
Sex
  Female 29 19.6 43366 4.5 (2.8, 6.8)
  Male 50 33.5 46105 7.3 (5.1, 10.1)
Birth weight (grams)
  <2500 14 9.3 5077 18.3 (9.4, 33.6)
  2500+ 65 43.9 84269 5.2 (3.8, 6.9)
Maternal age
  12-19 - - 7345 7.3 (3.0, 15.9)
  20-24 30 20.1 25062 8.0 (5.2, 12.3)
  25-29 12 8.2 26953 3.1 (1.5, 5.8)
  30-34 14 9.5 19246 4.9 (2.5, 8.9)
  35-39 12 8.0 8613 9.3 (4.8, 18.3)
  40+ - - 2242 -
Maternal race
  Alaska Native/American Indian 33 22.0 22754 9.7 (6.4, 14.6)
  Asian/Pacific Islander - - 8134 -
  Black - - 3654 -
  White 39 26.4 53865 4.9 (3.3, 7.1)
Maternal education (years)
  <12 12 8.0 8660 9.3 (4.8, 18.2)
  12 35 23.5 32967 7.1 (4.7, 10.5)
  12+ 29 19.7 45079 4.4 (2.7, 6.6)
Marital status
  Married 41 27.7 56506 4.9 (3.3, 7.0)
  Unmarried 38 25.5 32845 7.8 (5.2, 11.2)
Maternal smoking use
  Reported smoking 16 10.7 13021 8.2 (4.2, 14.1)
  Reported not smoking 62 41.8 75425 5.5 (4.0, 7.4)
Medicaid (mother or child)
  Medicaid 59 39.5 45769 8.6 (6.2, 11.7)
  non-Medicaid 20 13.7 43686 3.1 (1.8, 5.1)
Father on birth certificate
  None - - 4732 -
  Present - - 84739 5.9 (4.4, 7.6)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Technical notes

Column descriptions

# Reports: Unless otherwise noted, the number of unique reports of the defect received by ABDR during the specified birth year(s). Each report represents a unique child with the specified defect.

# Defects: The estimated true number of reports that are diagnosed defects based on medical record review and case confirmation.

# Births: The number of live births among Alaskan residents that occurred in Alaska during the specified birth year(s).

Prevalence (95% CI): The estimated diagnosed prevalence of the condition and corresponding 95% Confidence Interval. (For information on how the defect prevalence was estimated see below).

Defect prevalence calculation

The estimated defect prevalence was calculated using a Bayesian approach based on the reported prevalence, PPV and 1-NPV (see formula below).

Through medical records review and case confirmation of a random sample of reported cases, the defect prevalence is calculated as:

\[PPV (Positive Predictive Value) = p(defect|report)\] \[NPV (Negative Predictive Value) = p(\overline{defect}|\overline{report})\]

\[p(defect) \approx [p(report)\cdot PPV]+[p(\overline{report})\cdot (1-NPV)]\]

For cleft conditions, many cases were determined to be a different cleft defect than what was reported. Therefore, an additional intra-conditional probability was calculated and applied to the prevalence estimates. This probability accounts for the misclassified cleft conditions that were reported. In addition, a number of individuals were reported for more than one, or all three possible cleft conditions. For these individuals a separate PPV and NPV was calculated and applied.

Defect prevalence estimates are a more accurate estimation of the actual diagnosed prevalance of birth defects compared to the reported prevalance estimates in Alaska. ABDR obtains reports from medical providers using International Classification of Disease (ICD) codes that are extracted from individual systems which when aggregated may not reflect true diagnostics. Caution should be used when interpreting and comparing the reported prevalence estimates with national estimates.

See Data analysis methods for more information.

P-value estimate

To evaluate the trend over time and account for under/over-dispersion we constructed a quasi-Poisson regression model. This model assumes the variance is a linear function of the mean, and models the estimated number of annual defects by year with a natural log (ln) offset of the annual births. P-values < 0.05 are considered significant, which indicates that the predicted slope is significantly different from a slope of zero.

Data suppression

For region and demographic data tables, values are suppressed based on the number of reports received during the observation period. Counts less than 6 are suppressed (as indicated by ‘-’ in the table). For regions or demographics with only one cell count suppressed a second is suppressed to eliminate the ability to back-calculate the estimate.

References

[1] Facts about Cleft Lip and Cleft Palate | CDC. (2017). Centers for Disease Control and Prevention. Retrieved 22 March 2019, from https://www.cdc.gov/ncbddd/birthdefects/cleftlip.html

[2] Introduction to Cleft & Craniofacial Conditions - ACPA Family Services. (2019). Cleftline.org. Retrieved 22 March 2019, from https://cleftline.org/family-resources/introduction-to-cleft-craniofacial-conditions/

[3] Mai, C. T., Cassell, C. H., Meyer, R. E., Isenburg, J., Canfield, M. A., Rickard, R., … & Cho, S. J. (2014). Birth defects data from population-based birth defects surveillance programs in the United States, 2007 to 2011: Highlighting orofacial clefts. Birth Defects Research Part A: Clinical and Molecular Teratology, 100(11), 895-904.

Suggested Citation

State of Alaska Department of Health and Social Services, Division of Public Health, Section of Women’s, Children’s, and Family Health. Alaska Birth Defects Registry Condition Report: Cleft Conditions, Alaska, 2007-2014. Updated May 30, 2019. Available at: http://rpubs.com/AK_ABDR/cleft_Conds.

Contact

Alaska Birth Defects Registry (ABDR)
3601 C Street, Suite 358
Anchorage, AK 99503
(907) 269-3400 phone
(907) 754-3529 fax

Updated: July 12, 2019
Code source: R:\ABDR\Analysis_New\ABDR_CASECONF\cond_reports\Published_reports\cleft_conds.Rmd