Is uterus involution delay more common in Lower Segment Cesarean Section (LSCS) compared to normal vaginal delivery?

Uterine Involution After LSCS vs Vaginal Delivery

Yes, uterine involution is delayed after cesarean section compared to normal vaginal delivery, though both ultimately complete involution by 6-7 weeks postpartum. 1, 2

Evidence of Delayed Involution After Cesarean Section

The most direct evidence comes from ultrasound studies measuring actual uterine dimensions:

• Cesarean section results in slower and unsteady uterine involution compared to vaginal delivery, with this delay being more pronounced in repeat cesarean sections 2

• Despite the delay, both vaginal delivery and cesarean section groups complete uterine involution by the 6th to 7th week postpartum when measured by ultrasound 1

• The rate of uterine involution after cesarean is delayed and uneven, particularly in cases of repeat cesarean sections 2

Clinical Measurement Discrepancy

An important clinical caveat exists regarding fundal height assessment:

• Daily fundus checks by palpation may not accurately reflect the true involution status after cesarean section 1

• After vaginal delivery, the uterus assumes pronounced anteversion and sits lower in the pelvis, while after cesarean section the uterus adopts a more extended position causing the fundus to appear higher on palpation despite similar actual uterine size 1

• This positional difference means that palpation findings suggesting delayed involution after cesarean may be misleading - the uterus may be involuting normally but positioned differently 1

Factors Affecting Involution Rate

Several obstetric factors influence the speed of involution:

• Primiparity and prematurity are associated with lower starting values of symphysis-fundus distance but may show different involution patterns 2

• In vaginal deliveries, prematurity and fetal macrosomia delay uterine involution rates 2

• Prolonged labor (>300 minutes) significantly increases the risk of delayed involution, with odds ratio of 13.1 for enlarged uterus 3

Clinical Implications and Risk Factors

The delayed involution after cesarean section has important clinical consequences:

• Incomplete uterine involution is significantly more common after cesarean section compared to vaginal delivery 4

• Prolonged parturition and impaired placenta expulsion increase the risk of postpartum metritis, which further delays uterine involution 3

• Manual intrauterine palpation and presence of ≥2 stillborn fetuses are additional risk factors for both delayed involution and intrauterine fluid accumulation 3

Interventions

Regarding therapeutic interventions:

• Daily intramuscular oxytocin (Syntocinon) following cesarean section has no measurable influence on the rate of involution 1

• However, exogenous oxytocin may support uterine involution in the presence of postpartum metritis 3

• Low-intensity ultrasound therapy for 30 minutes daily for 3 consecutive days starting 24 hours post-cesarean shows promise in promoting uterine contraction and involution, with lower rates of incomplete involution at 30 days 4

Monitoring Recommendations

Given these findings:

• Rely on ultrasound measurements rather than fundal height palpation alone when assessing involution after cesarean section, as palpation may be misleading due to altered uterine position 1

• Monitor for signs of metritis (intrauterine fluid accumulation, fever, uterine tenderness) as this significantly delays involution 3

• Expect completion of involution by 6-7 weeks regardless of delivery mode, but recognize the pattern may be less steady after cesarean 1, 2