Novel Use of Central Venous Pressure (CVP) Set With McDonald Cerclage Technique for Amnioinfusion in Preterm Premature Rupture of Membranes Improves Amniotic Fluid Index and Neonatal Outcomes

This study was conducted to evaluate a novel approach to amnioinfusion in pregnant women with preterm premature rupture of membranes (PPROM) complicated by severe oligohydramnios. The intervention used a central venous pressure (CVP) set to provide controlled and sustained transabdominal amnioinfusion through a single access site, with the aim of restoring and maintaining amniotic fluid volume while reducing the need for repeated puncture.

The study used a prospective, two-arm, non-randomized comparative interventional design. A total of 40 pregnant women with singleton pregnancies, PPROM between 24 and 26 weeks of gestation, and an amniotic fluid index (AFI) of less than 2 cm were enrolled. Participants were allocated to either the CVP-set amnioinfusion group or the conventional transabdominal amnioinfusion group according to procedural feasibility and operator availability. Both groups underwent amnioinfusion followed by cervical cerclage.

In the conventional amnioinfusion group, the procedure was performed transabdominally under sterile conditions and ultrasound guidance. In the intervention group, a CVP set was inserted into the intra-amniotic cavity to permit controlled and sustained infusion. Maternal condition, uterine activity, fetal well-being, and amniotic fluid volume were monitored during and after the procedure. Participants were subsequently followed with serial clinical and ultrasonographic assessments.

The primary outcome was the increase in AFI following the intervention. Secondary outcomes included gestational age at delivery, neonatal birth weight, Apgar scores, maternal length of hospital stay, procedural feasibility, maternal tolerance, and complications. The study was designed to determine whether CVP-set amnioinfusion could improve restoration and maintenance of amniotic fluid volume and pregnancy and neonatal outcomes compared with conventional transabdominal amnioinfusion.

Inclusion criteria

• Singleton pregnancy.
• Preterm premature rupture of membranes (PPROM) at 24-26 weeks of gestation.
• Oligohydramnios with an amniotic fluid index (AFI) <2 cm.
• Provided informed consent to participate in the study.

Exclusion criteria

• Presence of uterine contractions.
• Clinical or laboratory signs of intrauterine infection.
• Pregnancy complications requiring immediate termination of pregnancy, including hypertension, preeclampsia, HELLP syndrome, or other significant maternal conditions.