Pregnancy and delivery after traumatic brain injury: a nationwide population-based cohort study in Finland

Figures & data

Figure 1. Flowchart of the study population. Data from the MBR were combined with data on the diagnosed TBI and TBI-related surgical operations in the Care Register for Health Care.

Figure 2. (A) Incidence of traumatic brain injury hospitalization among fertile-aged (15–49 years) women during the study period. (B) Incidence of traumatic brain injury surgeries among fertile-aged (15–49 years) women during the study period.

Table 1. Background information on the deliveries and perinatal characteristics in the traumatic brain injury group and the control group.

	Traumatic brain injury group		Control group
	13 448		1 143 954
Total number	n	%	n	%	p-value
Age at birth (years, mean SD)	28.7 (5.5)		29.7 (5.4)		<.001
Nulliparous	5 963	44.3	472 966	41.3	<.001
Previous CS*	1 566	11.6	122 789	10.7	<.001
Maternal smoking during pregnancy**	3 722	27.7	165 650	14.5	<.001
LBW*** < 2500 g	515	3.8	33 991	3.0	<.001
Induction of labor	3412	25.4	216 715	18.9	<.001
Preterm****
Preterm < 37 + 0 gestational weeks	755	5.6	52 425	4.6	<.001
Very preterm 28 + 0 − 31 + 6 gestational weeks	75	0.6	4710	0.4	<.001
Extremely preterm ≤ 27 + 6 gestational weeks	37	0.3	3268	0.3	.108
Perinatal mortality*****	72	0.5	6100	0.5	.176
1 minute Apgar score ≤ 6	1948	14.5	155 601	13.6	.326
Neonatal intensive-care unit	1756	13.1	114 160	9.9	<.001
Discharged from hospital during the first week	12 458	92.6	1 075 257	94.0	<.001

*CS: Cesarean section.

** Contains women with smoking during the only first trimester and/or in later trimesters.

***LBW: low birthweight.

**** Preterm births were calculated in overall (< 37 + 0 gestational weeks), and for very preterm (28 + 0 – 31 + 6 gestational weeks) and extremely preterm (≤ 27 + 6 gestational weeks) pregnancies, which is the classification by the World Health Organization (WHO).

*****Perinatal mortality includes stillbirths and deaths before the age of seven days.

Table 2. Proportions of obstetric variables in attempted vaginal deliveries in the traumatic brain injury group and control group.

	Traumatic brain injury group		Control group
	12 409		1 068 214
Total number (without elective CS)	n	%	n	%	p-value
Mode of delivery
Spontaneous vaginal delivery	9613	77.5	865 909	81.1	<.001
Breech delivery	75	0.6	6938	0.6	.035
Vacuum or forceps delivery	1174	9.5	89 757	8.4	.060
Unplanned CS*	1547	12.5	105 610	9.9	<.001
Labor analgesia
Epidural	6306	50.8	464 117	43.4	<.001
Spinal	1962	15.8	121 256	11.4	.292
Spinal + epidural	232	1.9	13 440	1.3	.915
Paracervical block	2301	18.5	186 444	16.3	<.001
Pudendal block	1082	8.7	66 489	6.2	.044

Elective CS in the TBI group n 1039 (7.7%) and in the control group n 75 740 (6.6%) were excluded.

*CS: Cesarean section.

Table 3. Univariable and adjusted Odds ratios (OR) with 95% confidence intervals (CI) for the main variables.

	Preterm delivery	Cesarean section	Neonatal intensive care
	OR (95% CI)	OR (95% CI)	OR (95% CI)
Univariable	1.24 (1.15–1.33)	1.26 (1.21–1.32)	1.35 (1.29–1.42)
Adjusted*	1.23 (1.17–1.28)*	1.23 (1.18–1.29)**	1.30 (1.24–1.37)***

Women in the TBI group were compared with the control group consisting of all women without TBI before pregnancy.

*The model was adjusted with the socioeconomic status of the mother, maternal smoking during pregnancy and maternal diabetes during pregnancy.

**The model was adjusted with maternal smoking during pregnancy and maternal diabetes during pregnancy.

***The model was adjusted with maternal smoking during pregnancy.