Maternal Smoking during Pregnancy and Newborn Neurobehavior: Effects at 10 to 27 Days

May combine two claims.

In adjusted analyses, moderate effects of maternal smoking during pregnancy were observed for excitability (Cohen's delta = .55) and arousal (Cohen's delta = .41), in addition to a large effect on handling (Cohen's delta = .76).

“In addition to large effects on handling (Cohen’s delta = .76), moderate effects of MDSP were observed for both excitability and arousal (Cohen’s deltas=.55 and .41, respectively).”

• AssumptionRests on an assumption: The exposed and unexposed groups are comparable on all relevant confounders after matching and adjustment.
• AssumptionRests on an assumption: The adjustment for postnatal second-hand smoke exposure and breast-feeding is sufficient to isolate the effects of maternal smoking during pregnancy from postnatal nicotine exposure.

May combine two claims.

Maternal smoking during pregnancy was associated with poorer self-regulation at 10-27 days but not at 1-2 days.

“Effects of maternal smoking during pregnancy on poorer self-regulation and increased arousal were evident at 10–27 but not 1–2 days.”

• Also stated in: § DISCUSSION · plain

  “exposure to maternal smoking during pregnancy was associated with increased need for external handling to maintain a quiet alert state, greater difficulties in self-regulation, and increased arousal and excitability at 10–27 days, past the half-life of nicotine/cotinine.”

May combine two claims.

Smoking-exposed infants show significantly worse self-regulation and greater need for handling and trended toward greater arousal and excitability than unexposed infants (Cohen's deltas = .54, .57, .45, and .52, respectively).

“Smoking-exposed infants show significantly worse self-regulation and greater need for handling and trended toward greater arousal and excitability than unexposed infants (Cohen’s deltas = .54, .57, 45, and .52, respectively).”

• Also stated in: § DISCUSSION · plain

  “We found evidence for greater need for handling and poorer self-regulation in exposed compared with unexposed infants at 10–27 days.”

• Also stated in: § DISCUSSION · hedged

  “Although effect sizes were moderate, exposed infants trended toward greater excitability and arousal.”

May combine two claims.

In adjusted analyses, maternal smoking during pregnancy was associated with a 0.18 unit increase in need for handling (95% CI = .04-.32), and handling was the only continuous NNNS scale to remain significant.

“Handling was the only continuous NNNS scale to remain significant in the adjusted analyses; maternal smoking during pregnancy was associated with a 0.18 unit increase in need for handling (95% CI= .04–.32).”

• AssumptionRests on an assumption: The exposed and unexposed groups are comparable on all relevant confounders after matching and adjustment.
• AssumptionRests on an assumption: The adjustment for postnatal second-hand smoke exposure and breast-feeding is sufficient to isolate the effects of maternal smoking during pregnancy from postnatal nicotine exposure.

May combine two claims.

No significant group differences emerged for stress/abstinence or hypertonicity scales at 10-27 days, unlike results from the immediate newborn period.

“Unlike results from the immediate newborn period,11 no significant group differences emerged for stress/abstinence or hypertonicity scales.”

• Also stated in: § DISCUSSION · plain

  “In contrast to results from the immediate newborn period,11 we found no differences between exposed and unexposed groups in signs of stress/abstinence and hypertonicity.”

• cites [11] Law, 2003, Smoking during pregnancy and newborn neurobehavior, Pediatrics sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Neither hypertonicity nor hypotonicity was significantly associated with maternal smoking during pregnancy in adjusted analyses.

“Neither scale was significantly associated with maternal smoking during pregnancy.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Mean cigarettes smoked over the pregnancy, including three months prior, was 8.6 (SD = 6.0).

“Mean cigarettes smoked over the pregnancy, including three months prior was 8.6 (SD = 6.0).”

May combine two claims.

Smoking-exposed infants weighed on average 49 grams less than unexposed infants at birth, a difference much smaller than the 200 grams typically found in prior studies.

“Notably, smoking-exposed infants, on average, weighed only 49 grams less than unexposed infants at birth, a difference much smaller than the 200-grams typically found in prior studies.34”

• cites [34] Beeghly, 1994, Effects of prenatal exposure to cocaine in early infancy: toxic effects on the process of mutual regulation, Infant Ment Health J sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Maternal smoking during pregnancy was associated with increased arousal at 10-27 days but not at 1-2 days.

“Effects of maternal smoking during pregnancy on poorer self-regulation and increased arousal were evident at 10–27 but not 1–2 days.”

• Also stated in: § DISCUSSION · plain

  “exposure to maternal smoking during pregnancy was associated with increased need for external handling to maintain a quiet alert state, greater difficulties in self-regulation, and increased arousal and excitability at 10–27 days, past the half-life of nicotine/cotinine.”

May combine two claims.

Maternal smoking during pregnancy was associated with signs of stress/withdrawal at 1-2 days but not at 10-27 days.

“In contrast, effects of maternal smoking during pregnancy on signs of stress/withdrawal, and increased muscle tension were evident 1–2 but not 10–27 days.”

• Also stated in: § DISCUSSION · hedged

  “That effects of smoking exposure on signs of stress/abstinence were no longer evident past the half-life of nicotine/cotinine in the present study, but were strong at 24–48 hours in our previous study, points to a possibility of a withdrawal process in infants exposed to maternal smoking during pregnancy.”

May combine two claims.

Maternal smoking during pregnancy was associated with increased muscle tension at 1-2 days but not at 10-27 days.

“In contrast, effects of maternal smoking during pregnancy on signs of stress/withdrawal, and increased muscle tension were evident 1–2 but not 10–27 days.”

May combine two claims.

In the current study, adjusted effect sizes were large-to-moderate for handling (.73), excitability (.55), and arousal (.41).

“Several adjusted effect sizes in the current study were of large-to-moderate level according to Cohen’s31 nomenclature (Handling=.73, Excitability=.55, Arousal=.41)”

• cites Cohen’s31Not checked yet

  Not checked in the free run.

May combine two claims.

Effects of maternal smoking during pregnancy at 10-27 days are subtle and consistent with increased need for external intervention and poorer self-regulation.

“Effects of maternal smoking during pregnancy at 10–27 days are subtle and consistent with increased need for external intervention and poorer self-regulation.”

• AssumptionRests on an assumption: Matching on socioeconomic status, maternal age, and pregnancy alcohol use adequately controls confounding by these factors for the observed associations.

Classified as probably not a substantial claim.

Due to the small sample size, emphasis was placed on effect size estimation rather than hypothesis testing.

“Due to the small sample size, emphasis was placed upon effect size estimation, rather than hypothesis testing, so that potentially clinically significant findings could be highlighted for replication in future studies.”

Probably not a substantial claim: may not pass S3 (load-bearing).

NNNS summary scales have coefficient alphas ranging from 0.56-0.85.

“NNNS items are scored and combined into summary scales (Tables I and II) with coefficient alphas ranging from 0.56–0.85.26”

• cites [26] Lester, 2004, Summary statistics of neonatal intensive care unit network neurobehavioral scale scores from the maternal lifestyle study: a quasinormative sample, Pediatrics sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Both maternal self-report and a bioassay were used to identify smoking exposure during pregnancy.

“Both maternal self-report and a bioassay were used to identify smoking exposure during pregnancy.”

Classified as probably not a substantial claim.

Exposed and unexposed infants were selected to be healthy, full-term, and normal birthweight.

“Exposed and unexposed infants were selected to be healthy, full-term, and normal birthweight.”

May combine two claims.

Maternal cotinine was used to confirm maternal self-report of smoking, and infant cotinine provided a biomarker for postnatal nicotine exposure via second-hand smoke and/or breast milk.

“Maternal cotinine was included to confirm maternal self-report of smoking; infant cotinine provided a biomarker for postnatal nicotine exposure via second-hand smoke and/or breast milk.”

May combine two claims.

Examining infants at 10-27 days is less likely to indicate acute effects of nicotine or nicotine withdrawal and may represent a neurobehavioral profile more consistent with early vulnerability to long-term behavioral deficits.

“Thus, examining infants at 10–27 days is less likely to indicate acute effects of nicotine or nicotine withdrawal and may represent a neurobehavioral profile more consistent with early vulnerability to long-term behavioral deficits.”

May combine two claims.

Cotinine is readily passed from mother to infant, with fetal concentrations reaching approximately 90% of maternal values.

“and is readily passed from mother to infant, with fetal concentrations reaching approximately 90% of maternal values.20”

• cites [20] Donnenfeld, 1993, Simultaneous fetal and maternal cotinine levels in pregnant women smokers, Am J Obstet Gynecol sourceNot checked yet

  Not checked in the free run.

May combine two claims.

The NNNS is sensitive to effects of intrauterine drug exposure but also captures the normative range of behaviors.

“The exam is sensitive to effects of intrauterine drug exposure22, 23 but also captures the normative range of behaviors.”

• cites [22] Lester, 2002, The Maternal Lifestyle Study: effects of substance exposure during pregnancy on neurodevelopmental outcome in 1-month-old infants, Pediatrics sourceNot checked yet

  Not checked in the free run.

• cites [23] Johnson, 2001, Buprenorphine treatment of pregnant opioid-dependent women: maternal and neonatal outcomes, Drug Alcohol Depend sourceNot checked yet

  Not checked in the free run.

Classified as probably not a substantial claim. May combine two claims.

Examiner blinding for home visits was assured through requests to the mother and examiner training focused on multiple sources for signs or smells of smoke.

“Examiner blind for home visits was assured through requests to mother (e.g., hide smoking paraphernalia, no discussion of smoking status with examiner, return of second-hand smoke questionnaire in sealed envelope) and examiner training focused on multiple sources for signs/smells of smoke—e.g., other smokers in the home or mother.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The NNNS was developed for the National Institutes of Health to assess effects of prenatal drug exposure in infants.

“The NNNS was developed for the National Institutes of Health to assess effects of prenatal drug exposure in infants.12, 21”

• cites [12] Lester, 2004, History and description of the Neonatal Intensive Care Unit Network Neurobehavioral Scale, Pediatrics sourceNot checked yet

  Not checked in the free run.

• cites [21] Lester, 2004, The Neonatal Intensive Care Unit Network Neurobehavioral Scale procedures, Pediatrics sourceNot checked yet

  Not checked in the free run.

May combine two claims.

The pattern of results suggests that smoking-exposed infants were more irritable and less able to self-soothe than unexposed infants.

“The pattern of results suggests that smoking-exposed infants were more irritable and less able to self-soothe than unexposed infants.”

• AssumptionRests on an assumption: The exposed and unexposed groups are comparable on all relevant confounders after matching and adjustment.
• AssumptionRests on an assumption: The adjustment for postnatal second-hand smoke exposure and breast-feeding is sufficient to isolate the effects of maternal smoking during pregnancy from postnatal nicotine exposure.

May combine two claims.

The profile of a smoking-exposed infant in the later neonatal period includes greater need for external intervention to maintain a quiet alert state, greater difficulty in self-regulation, and a tendency toward increased arousal and excitability.

“The profile of a smoking-exposed infant in the later neonatal period includes greater need for external intervention to maintain a quiet alert state (either to arouse infant from a sleeping state or calm infant from a crying state), greater difficulty in self-regulation, and a tendency toward increased arousal and excitability.”

• AssumptionRests on an assumption: The exposed and unexposed groups are comparable on all relevant confounders after matching and adjustment.
• AssumptionRests on an assumption: The adjustment for postnatal second-hand smoke exposure and breast-feeding is sufficient to isolate the effects of maternal smoking during pregnancy from postnatal nicotine exposure.

May combine two claims.

The study adjusted for potential confounds in the pre- and postnatal periods (breast-feeding, maternal and infant second-hand smoke exposure, maternal depressive symptoms) and used biomarkers for maternal and infant nicotine.

“In addition to comparability between groups, further strengths of this study include model-based adjustment for potential confounds in the pre and postnatal periods (breast-feeding, maternal and infant second-hand smoke exposure, maternal depressive symptoms), and use of biomarkers for maternal and infant nicotine.”

May combine two claims.

Smoking mothers were comparable to non-smoking mothers in gravida, parity, social class, employment, alcohol use, and caffeine consumption.

“Smoking mothers were of comparable gravida, parity, social class, and employment to non-smoking mothers, and displayed similarly low levels of alcohol use and similar caffeine consumption.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The Timeline Follow Back (TLFB) is a reliable, valid structured clinical interview for gathering detailed information on substance use.

“The calendar-based TLFB is a reliable, valid structured clinical interview designed to gather detailed information on substance use using anchor points to facilitate recall.27, 28”

• cites [27] Sobell, 1992, Timeline Followback: A technique for assessing self-reported alcohol consumptionNot checked yet

  Not checked in the free run.

• cites [28] Sobell, 1996, The reliability of the Timeline Followback (TLFB) method as applied to drug, cigarette, and the cannabis useNot checked yet

  Not checked in the free run.

May combine two claims.

No significant differences emerged between groups for infant characteristics including Apgar scores, gestational age, birthweight, breast-feeding, second-hand smoke exposure, and maternal depression.

“Notably, no significant differences emerged between groups for infant characteristics including Apgar scores, gestational age, birthweight (< 50 gram difference between groups), breast-feeding, second-hand smoke exposure, and maternal depression, providing further evidence of successful matching between exposure groups.”

Classified as probably not a substantial claim. May combine two claims.

The NNNS was administered at post-birth days 10-27 (M = 17) by a certified examiner blind to infant exposure status.

“The NNNS was administered to infants at post-birth days 10 – 27 (M = 17) by a certified examiner blind to infant exposure status.”

May combine two claims.

The pattern of effects of smoking exposure on signs of stress/abstinence (no longer evident past the half-life of nicotine/cotinine in the present study, but strong at 24-48 hours in the previous study) points to a possibility of a withdrawal process in infants exposed to maternal smoking during pregnancy.

“That effects of smoking exposure on signs of stress/abstinence were no longer evident past the half-life of nicotine/cotinine in the present study, but were strong at 24–48 hours in our previous study, points to a possibility of a withdrawal process in infants exposed to maternal smoking during pregnancy.”

• AssumptionRests on an assumption: The half-life of nicotine/cotinine in newborns is short enough that 10–27 days is past it.
• AssumptionRests on an assumption: In the previous study from our group, effects of smoking exposure on signs of stress/abstinence were strong at 24–48 hours.

Classified as probably not a substantial claim.

The effects shown at 10-27 days in this study could represent prolonged symptoms of withdrawal rather than persistent neurotoxic effects.

“we cannot rule out the possibility that effects shown at 10–27 days in this study represent prolonged symptoms of withdrawal rather than persistent neurotoxic effects.”

• AssumptionRests on an assumption: Definitive evidence for a neonatal nicotine withdrawal syndrome and its time course has not been established.

May combine two claims.

These effects are evident in the first month, suggesting the possibility of early identification of offspring who may, in combination with exposure to poor parenting and other postnatal factors, be at greater risk for later adverse neurobehavioral outcomes.

“That these effects are evident in the first month suggests the possibility of early identification of offspring who may, in combination with exposure to poor parenting and other postnatal factors, be at greater risk for later adverse neurobehavioral outcomes.”

May combine two claims.

Even greater effects may be evident in infants exposed to higher levels of smoking, low birthweight infants, and/or infants who show additional complications related to maternal smoking.

“Given that these moderate-to-large neurobehavioral effects from maternal smoking during pregnancy emerged in infants exposed to low levels of smoking and selected as healthy and normal birthweight, even greater effects may be evident in infants exposed to higher levels of smoking, low birthweight infants, and/or infants who show additional complications related to maternal smoking.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Greater levels of depressive symptoms were present in the unexposed versus smoking-exposed group.

“greater levels of depressive symptoms in the unexposed versus smoking-exposed group is puzzling and inconsistent with prior research.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Inclusion of maternal saliva cotinine to verify self-report of smoking is a strength of the study.

“although inclusion of maternal saliva cotinine to verify self-report of smoking is a strength of the study”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Differing results from prior studies may be related to the use of a control group matched on socio-economic status.

“Differing results from prior studies may be related to our use of a control group matched on socio-economic status.”

May combine two claims.

Godding et al. found evidence for withdrawal symptoms and neurological deficits in newborns exposed to maternal smoking during pregnancy.

“Results from our group are complemented by Godding et al, 13 who also found evidence for withdrawal symptoms and neurological deficits in newborns exposed to maternal smoking during pregnancy.”

• cites Godding et al, 13Not checked yet

  Not checked in the free run.