The effects of maternal smoking on fetal cranial development. Findings from routine midtrimester sonographic anomaly screening

Figures & data

Table 1. Comparison of baseline demographic and clinical characteristics between smoking and non-smoking women.

Variable	Smokers (n: 54)	Non-smokers (n:196)	p
Age (years)	29.05 ± 4.66	29.66 ± 4.73	.4
Female fetus (%)	27 (%50)	97 (%49.5)	.535
BMI kg/m^2	26.86 ± 4.44	25.33 ± 3.83	.013
Gravida med (Q1–Q3)	2 (1–7)	1 (1–2)	.051
Parity med (Q1–Q3)	0 (1–3)	0 (0–1)	.082
CO (ppm)	7.18 ± 3.8	1.23 ± 0.6	<.001
Hematocrit (%)	35.88 ± 1.68	36.3 ± 1.61	.103
Education			.285
Uneducated or preliminary	11 (19.6)	33 (17.1)
High school	27(48.2)	89(46.1)
College	18 (32.2)	71(36.8)
Paternal smoking (Q1–Q3) (number/day)	14 (10–20)	0 (0–2)	<.001
Paternal smoking status	46 (82.1)	49(25.3)	<.001
Single motherhood	2 (3.6)	1 (0.5)	.127
ICP	0 (0)	1(0.5)	.776
Gestational diabetes	4 (7.1)	7 (3.6)	.272
Gestational hypertension	5(8.9)	2 (1)	.007
Preeclampsia	1 (1.8)	1(0.5)	.399
Preterm birth	8 (14.3)	6 (3.1)	.004
Growth restriction	3(5.4)	5(2.6)	.383

Notes: Values are expressed as n (%), mean ± standard deviation or median (min–max). p < .05, statistically significant difference. BMI: body mass index; CO: exhaled carbon monoxide concentration; ICP: intrahepatic cholestasis of pregnancy.

Table 2. Comparison of gestational age at ultrasound examination and sonographic measurements between smoking and non-smoking women.

Variable	Smokers (n: 54)	Non-smokers (n: 196)	p
Gestational age at US (days)	145.64 ± 7.72	147.34 ± 6.55	.10
BPD (mm)	49.2 ± 3.96	50.59 ± 3.84	.024
BPD (MoM)	−0.75 ± 1.6	−0.51 ± 1	.3
HC (mm)	183.38 ± 14.56	189.28 ± 12.53	.003
HC (Z-score)	0.18 ± 1.39	0.56 ± 0.92	.023
Lateral ventricle (mm)	6.18 ± 0.73	6.18 ± 0.78	.95
Cisterna magna (mm)	5.59 ± 1.02	5.66 ± 1.13	.651

Note: MoM: multiple of median. Values are expressed as mean ± standard deviation. p < .05, statistically significant difference. BPD: biparietal diameter; HC: head circumference.

Table 3. Multiple linear regression analysis of independent effect of smoking on fetal cranial measurement.

	B	Std. error	p	95.0% Confidence interval for B
				Lower bound	Upper bound
HC Z-score	−0.405	0.197	.041	−0.794	−0.016
HC score	−5.153	2.406	.033	−9.892	−0.414
BPD Z-score	−0.310	0.220	.161	−0.743	0.124
BPD score	−0.309	0.221	.162	−0.744	0.126
LV	0.049	0.146	.738	−0.238	0.336
CM	0.061	0.210	.772	−0.352	0.474

Notes: Body mass index, gravida, paternal smoking, gestational hypertension, preterm birth, hematocrit level, educational status and single motherhood were taken as independent variables. HC: head circumference; BPD: biparietal diameter; LV: lateral ventricle; CM: cisterna magna.