Table 1.

Study characteristics.

Authors	Study	Participants (N, age, time PP)	Parity and delivery mode	Cut off value DRA	Main outcome measure	Secondary outcome measures
Walton et al. 201630 USA	RCT	N = 9 18–45 years 3 months to 3 years PP	Parity not reported. Cesarean section and vaginal delivery (n = 1)	Not reported	•IRD measured with ultrasound and caliper 4.5 cm above, at, and 4.5 cm below umbilicus	•ODI •PFDI
Kamel & Jousif 201732 Egypt	RCT	N = 60 25–35 years 2 months PP	Primi- and multiparous. Vaginal delivery	>2.5 cm measured any place along linea alba during a curl-up	•IRD measured with ultrasound at X-U/2 and U-P/2	•Abdominal muscle strength
Bobowik & Dąbek 201831 Poland	RCT	N = 40 32.3 ± 5.9 years 0–3 days PP	Parity and delivery mode not reported	≥2 cm	•DRA measured with palpation (one finger width = 1.3 cm)
Tuttle et al. 201828 USA	Pilot RCT	N = 30 32.03 ± 4.3 years 6–12 weeks PP	Primi- and multiparous. Delivery mode not reported	≥2 finger widths during head lift	•IRD measured with ultrasound 4.5 cm above and below umbilicus during rest and head lift	•PFDI-20 •RDQ
Gluppe et al. 201825 Norway	RCT	N = 175 29.8 ± 4.1 years 6 weeks PP	Primiparous. Vaginal delivery	≥2 finger widths or a visible protrusion during a curl-up	•DRA measured with palpation 4.5 cm above, at, and 4.5 cm below umbilicus during a modified sit-up Measurements 6 and 12 months PP
Thabet & Mansour 201933 Saudi Arabia	RCT	N = 40 22–35 years 3–6 months PP	Parity and delivery mode not reported	>2 cm from umbilicus to 4.5 cm above umbilicus or a visible protrusion	•IRD measured with caliper 4.5 cm above umbilicus during a modified sit-up	•PF10
Keshwani et al. 201929 Canada	Pilot RCT	N = 32 31 ± 3 years 22 days PP	Primiparous. Vaginal delivery	>2 finger widths at, 2 cm above, 5 cm above, or 3 cm below umbilicus	•IRD measured with ultrasound at umbilicus, 3 cm above, 5 cm above, or 3 cm below umbilicus	•Abdominal muscle strength •PFDI •Body image •IFSAC

DRA, diastasis recti abdominis; IFSAC, inventory of functional status after childbirth; IRD, inter-recti distance; ODI, Oswestry Disability Index; PF10, the Physical Functioning scale; PFDI, Pelvic Floor Distress Index; PP, postpartum; RCT, randomized controlled trial; RMQ, the Roland-Morris Disability Questionnaire; X-U/2, halfway between umbilicus and xiphoid process; U-P/2, halfway between umbilicus and symphysis.