Randomized clinical trial evaluating the frequency of membrane sweeping with an unfavorable cervix at 39 weeks

Figures & data

Figure 1 Flow diagram of the randomized controlled trial of membrane sweeping frequency.

Abbreviation: n, number.

Table 1 Population demographics at baseline. Unless otherwise stated n (%) are shown

	No sweep (n = 116)	Once-weekly sweep (n = 117)	Twice-weekly sweeps (n = 117)	Pvalue
Maternal age^†	24 (21–28) [19–42]	24 (21–29) [18–40]	24 (21–28) [18–47]	0.607
< 20	8 (6.9)	9 (7.7)	10 (8.5)	0.731
20–34	101 (87.1)	98 (83.8)	102 (87.2)
35+	7 (6.0)	10 (8.5)	5 (4.3)
Maternal race
Caucasian	70 (60.3)	78 (66.7)	83 (70.9)	0.243
A-A	33 (28.4)	33 (28.2)	24 (20.5)
Other**	13 (11.2)	6 (5.1)	10 (8.5)
Gravidity^†	2 (1–3) [1–6]	2 (1–3) [1–8]	2 (1–3) [1–8]	0.890
Parity^†	0 (0–1) [0–4]	0 (0–1) [0–4]	0 (0–1) [0–4]	0.928
Nulliparous	74 (63.8)	70 (59.8)	73 (62.4)	0.806
Bishop’s score at recruitment
0–2	38 (32.8)	33 (28.2)	20 (17.1)	0.019
3–4	78 (67.2)	83 (70.9)	97 (82.9)
GA at recruitment^†	39 (38.9–39.2) [38.7–39.3]	39 (38.9–39.2) [38.7–39.3]	39 (38.9–39.2) [38.7–39.3]	0.458

Notes:

† Median, interquartile range (first–third quartile), and range [minimum–maximum] are shown;

** 10 Asian, 18 Hispanic, 1 American Indian.

Abbreviations: A-A, African-American; GA, gestational age; n, number.

Table 2 Obstetric outcomes for three randomization groups. Unless otherwise stated n (%) are shown

	No sweep (n = 116)	Once-weekly sweep (n = 117)	Twice-weekly sweeps (n = 117)	Pvalue
GA on admission^†	40.6 (39.9–41.0) [38.7–41.7]	40.4 (39.9–41.0) [38.7–41.7]	40.2 (40.7–39.7) [39.0–41.7]	0.009
Recruitment–admission interval (days)^†	11 (6–14) [0–19]	10 (6–14) [0–18]	8 (5–12) [0–19]	0.018
Bishop’s score on admission^†	7 (4–10) [1–13]	7 (6–14) [1–12]	8 (5–12) [1–13]	0.010
Bishop’s score
0–4	33 (28.4)	13 (11.1)	10 (8.5)	<0.001
5–9	54 (46.6)	77 (65.8)	77 (65.8)
10–13	29 (25.0)	27 (23.1)	30 (25.6)
Remaining undelivered at 41 weeks and admitted for labor induction	40 (34.5)	32 (27.4)	27 (23.1)	0.149
Admission to delivery interval (hours)^‡	12.2 (7.3–20.0)	11.5 (6.1–16.8)	11.0 (6.4–18.3)	0.114
Mode of delivery
Vaginal delivery**	83 (71.6)	89 (76.1)	87 (74.4)	0.730
Cesarean delivery	33 (28.4)	28 (23.9)	30 (25.6)
Reasons for cesarean delivery
Fetal labor intolerance	9 (27.3)	11 (39.3)	13 (43.3)	0.520
CPD/FTP	20 (60.6)	17 (60.7)	15 (50.0)
Failed induction	3 (9.1)	–	1 (3.3)
Malpresentation	1 (3.0)	–	1 (3.3)
Chorioamnionitis at delivery	12 (10.3)	7 (6.0)	9 (7.7)	0.466
GBS on vaginal swab	21 (18.1)	25 (21.4)	30 (25.6)	0.375
Birth weight^† (gm)
< 2,500	3,507 (3,304–3,818) [1,845–4,750]	3,578 (3,225–3,913) [2,245–4,670]	3,530 (3,263–3,825) [2,615–4,610]	0.903
Apgar score < 7
1 minute	10 (8.6)	8 (6.8)	8 (6.8)	0.836
5 minutes	–	–	2 (1.7)	0.331
Umbilical artery pH^†	7.28 (7.23–7.30) [7.06–7.41]	7.29 (7.26–7.32) [7.05–7.45]	7.29 (7.26–7.31) [7.09–7.43]	0.027
< 7.21	17 (14.7)	14 (12.0)	14 (12.0)	0.779
< 7.10	1 (0.9)	2 (1.7)	1 (0.9)	0.999
NICU admission	4 (3.4)	2 (1.7)	2 (1.7)	0.609

Notes:

† Median, interquartile range (first–third quartile), and range [minimum–maximum] are shown;

‡ interval between admission and delivery was estimated using Kaplan–Meier survival probabilities and with all cesarean deliveries censored;

** vaginal deliveries include nine assisted vaginal deliveries, n = 5, n = 3, and n = 1 for control, one sweep per week, and two sweeps per week, respectively.

Abbreviations: GA, gestational age; GBS, group B Streptococcus; CPD, cephalopelvic disproportion; FTP, failure to progress; NICU, neonatal intensive care unit; n, number.

Figure 2 Kaplan–Meier survival curves comparing the time interval between randomization and delivery. Overall and pair-wise log-rank tests were performed to assess the equality of survivor functions.

Note: The results of the survival curve indicate that there were no significant differences between the three groups (P = 0.081).