Circulating Cell-Free Fetal DNA Dynamics as a Predictive Biomarker for Spontaneous Preterm Birth

International Journal of Obstetrics and Gynecology | Vol. 14, No. 5, May 2026 | pp. 13–24

DOI: 10.46882/2026/IJOG/000478

Original Research Article

Title: Circulating Cell-Free Fetal DNA Dynamics as a Predictive Biomarker for Spontaneous Preterm Birth

Names of Authors: Oluwaseun A. Adebayo¹, Aminat Z. Yusuf¹

Authors’ Affiliations:
¹ Department of Obstetrics and Gynecology, College of Medicine, University of Lagos, Lagos, Nigeria

Abstract:
Spontaneous Preterm Birth (sPTB) is a complex obstetric syndrome lacking highly sensitive, non-invasive early predictive markers. This prospective longitudinal study explored whether quantified changes in maternal plasma cell-free fetal DNA (cffDNA) fractions during the early second trimester can predict sPTB prior to 34 weeks of gestation. Maternal blood samples were collected from 480 asymptomatic singleton pregnancies at two specific gestational intervals: 14 to 16 weeks and 20 to 22 weeks. Absolute cffDNA concentrations and the relative fetal fraction were quantified utilizing digital droplet polymerase chain reaction targeting Y-chromosome sequences for male fetuses and specific single-nucleotide polymorphisms for female fetuses. Patients were tracked until delivery, and the primary endpoint was defined as sPTB before 34 weeks. Forty-two women (8.8%) experienced sPTB before 34 weeks. At 20 to 22 weeks, the median cffDNA fetal fraction was significantly elevated in women who subsequently delivered preterm compared to those who delivered at term (16.4% vs. 10.2%, p < 0.001). A rate of increase in fetal fraction greater than 1.5% per week between the two sampling intervals was associated with a multi-fold increase in the risk of sPTB (Odds Ratio [OR] = 5.4; 95% Confidence Interval [CI], 2.8 to 10.3; p < 0.001). Utilizing a receiver operating characteristic curve, the combination of a high cffDNA fetal fraction at 22 weeks and a shortened cervical length (≤ 25 mm) yielded an area under the curve (AUC) of 0.91 for predicting sPTB. Accelerating maternal cffDNA dynamics in the second trimester indicate placental dysfunction or accelerated senescence, serving as a powerful, non-invasive biomarker to identify women at high risk for spontaneous preterm birth.

Keywords: Spontaneous Preterm Birth; Cell-Free Fetal DNA; Fetal Fraction; Biomarker; Placental Senescence; Liquid Biopsy.

Manuscript Timeline: Received: January 18, 2026; Revised: March 11, 2026; Accepted: April 08, 2026; Published: May 15, 2026.

Citation: Adebayo OA, Yusuf AZ. Circulating Cell-Free Fetal DNA Dynamics as a Predictive Biomarker for Spontaneous Preterm Birth. International Journal of Obstetrics and Gynecology. 2026; 14(5): 13–24.

International Journal of Obstetrics and Gynecology | Vol. 14, No. 5, May 2026 | pp. 25–36

DOI: 10.46882/2026/IJOG/000479

Original Research Article

Title: Efficacy and Safety of Single-Dose Intravenous Ferric Carboxymaltose versus Oral Ferrous Sulfate for Moderate Iron Deficiency Anemia in the Third Trimester

Names of Authors: Mariam T. Bello¹, Grace E. Effiong²

Authors’ Affiliations:
¹ Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University College Hospital, Ibadan, Nigeria
² Department of Public Health, University of Calabar, Calabar, Nigeria

Abstract:
Iron Deficiency Anemia (IDA) during the third trimester is strongly linked with low birth weight, preterm delivery, and increased maternal blood transfusion requirements. This open-label, randomized controlled trial compared the clinical efficacy, hematological response, and safety profile of a single total-dose infusion of intravenous (IV) ferric carboxymaltose against standard oral ferrous sulfate therapy. Two hundred and sixty pregnant women in their third trimester (28 to 32 weeks of gestation) presenting with a baseline hemoglobin (Hb) between 7.0 and 9.0 g/dL and serum ferritin < 15 μg/L were randomized into two equal groups (n = 130 per group). The IV group received a single 1,000 mg infusion of ferric carboxymaltose, while the oral group received oral ferrous sulfate (200 mg) twice daily for a total duration of six weeks. The primary outcome was the mean increase in Hb levels from baseline to delivery. At the 4-week post-treatment evaluation, the mean Hb increase was significantly higher in the IV group compared to the oral group (2.4 ± 0.5 g/dL vs. 1.2 ± 0.4 g/dL, p < 0.001). Similarly, target Hb levels (≥ 11.0 g/dL) at delivery were achieved by 91.5% of women in the IV group compared to only 62.3% in the oral group (p < 0.001). Serum ferritin stores were significantly more restored in the IV cohort (median 112.4 μg/L vs. 24.8 μg/L, p < 0.001). Gastrointestinal adverse effects were reported by 41.5% of women in the oral group, leading to non-compliance in 15.4% of cases, whereas transient mild injection-site reactions occurred in only 3.8% of the IV group. A single total-dose infusion of ferric carboxymaltose in the third trimester provides rapid, superior hematological correction and superior restoration of iron reserves with excellent compliance and safety compared to conventional oral iron.

Keywords: Iron Deficiency Anemia; Ferric Carboxymaltose; Ferrous Sulfate; Hemoglobin; Ferritin; Third Trimester.

Manuscript Timeline: Received: January 25, 2026; Revised: March 15, 2026; Accepted: April 14, 2026; Published: May 24, 2026.

Citation: Bello MT, Effiong GE. Efficacy and Safety of Single-Dose Intravenous Ferric Carboxymaltose versus Oral Ferrous Sulfate for Moderate Iron Deficiency Anemia in the Third Trimester. International Journal of Obstetrics and Gynecology. 2026; 14(5): 25–36.

International Journal of Obstetrics and Gynecology | Vol. 14, No. 6, June 2026 | pp. 37–48

DOI: 10.46882/2026/IJOG/000480

Original Research Article

Title: Evaluation of Single-Port vNOTES (Vaginal Natural Orifice Translumenal Endoscopic Surgery) versus Conventional Laparoscopy for Benign Adnexal Masses

Names of Authors: Olayinka O. Cole¹, Nesta C. Chuka¹

Authors’ Affiliations:
¹ Gynecologic Oncology Unit, Department of Obstetrics and Gynecology, National Hospital, Abuja, Nigeria

Abstract:
Vaginal Natural Orifice Translumenal Endoscopic Surgery (vNOTES) represents an innovative paradigm shifting the execution of minimally invasive gynecologic procedures by eliminating visible abdominal incisions. This prospective randomized controlled trial compared the perioperative outcomes, postoperative pain scores, and cosmetic satisfaction of single-port vNOTES versus conventional multi-port laparoscopy for the surgical excision of benign adnexal masses. A total of 140 women requiring surgical intervention for benign ovarian cysts or adnexal pathologies (mass diameter ≤ 8 cm) were randomized to either the vNOTES group (n = 70) or the conventional laparoscopy group (n = 70). The primary endpoints evaluated included total operative time, visual analog scale (VAS) pain scores at 12 and 24 hours postoperatively, and analgesic consumption. The mean operative time was significantly shorter in the vNOTES group compared to the laparoscopy group (42.5 ± 11.2 minutes vs. 56.8 ± 14.5 minutes, p < 0.001). Postoperative VAS pain scores were significantly lower in the vNOTES cohort at both 12 hours (2.1 ± 0.6 vs. 4.4 ± 1.1, p < 0.001) and 24 hours (1.2 ± 0.4 vs. 2.8 ± 0.8, p < 0.001), resulting in a 45.0% reduction in total postoperative opioid consumption. The median length of hospital stay was shorter for vNOTES patients (14.2 hours vs. 26.5 hours, p = 0.004). Cosmetic satisfaction scores evaluated at week 6 were significantly higher in the vNOTES group due to the complete absence of abdominal scars (9.8 ± 0.4 vs. 7.6 ± 1.2, p < 0.001). Complication rates, including pelvic infection and hematoma, did not differ significantly between the arms (p > 0.05). Single-port vNOTES for benign adnexal masses is a safe, efficient, and highly reproducible surgical technique that minimizes operative duration, reduces postoperative pain, and eliminates abdominal scarring compared to conventional laparoscopy.

Keywords: vNOTES; Laparoscopy; Adnexal Mass; Ovarian Cystectomy; Postoperative Pain; Minimally Invasive Surgery.

Manuscript Timeline: Received: February 12, 2026; Revised: April 05, 2026; Accepted: May 02, 2026; Published: June 08, 2026.

Citation: Cole OO, Chuka NC. Evaluation of Single-Port vNOTES (Vaginal Natural Orifice Translumenal Endoscopic Surgery) versus Conventional Laparoscopy for Benign Adnexal Masses. International Journal of Obstetrics and Gynecology. 2026; 14(6): 37–48.

International Journal of Obstetrics and Gynecology | Vol. 14, No. 6, June 2026 | pp. 49–60

DOI: 10.46882/2026/IJOG/000481

Original Research Article

Title: A Multi-Center Randomized Trial of Carbetocin versus Oxytocin for the Prevention of Postpartum Hemorrhage after Vaginal Delivery

Names of Authors: Emeka J. Obi¹, Funmilayo R. Adeyemi², Zainab H. Dogara¹

Authors’ Affiliations:
¹ Department of Obstetrics and Gynecology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria
² Maternal Health Division, Federal Ministry of Health, Abuja, Nigeria

Abstract:
Postpartum Hemorrhage (PPH) remains a primary contributor to avoidable maternal death. While oxytocin is widely utilized for routine prophylaxis, its short half-life necessitates continuous intravenous infusion. This multi-center, double-blind, randomized controlled trial investigated whether a single intramuscular injection of carbetocin, a long-acting oxytocin agonist, provides superior efficacy over standard oxytocin infusion for preventing PPH following singleton vaginal deliveries. A cohort of 1,800 low-risk pregnant women at term was randomized to receive either a single 100 μg intramuscular dose of carbetocin (n = 900) or a standard 10 IU intravenous oxytocin infusion administered over 4 hours (n = 900) immediately following fetal expulsion. The primary endpoint measured was the incidence of blood loss ≥ 500 mL or the requirement for additional uterotonic intervention. The incidence of PPH ≥ 500 mL was 3.8% in the carbetocin group compared to 6.2% in the oxytocin group, representing a statistically significant risk reduction (Relative Risk [RR] = 0.61; 95% CI, 0.40 to 0.93; p = 0.021). The utilization of additional therapeutic uterotonics was lower in the carbetocin cohort (2.4% vs. 5.1%, p = 0.003). Severe PPH (blood loss ≥ 1,000 mL) occurred in 0.7% of carbetocin patients versus 1.4% of oxytocin patients (p = 0.14). The safety profiles, including rates of transient nausea, headache, flushing, and maternal tachycardia, were comparable between the groups (p > 0.05). A single intramuscular injection of carbetocin offers superior clinical efficacy in reducing the incidence of postpartum hemorrhage and minimizing secondary therapeutic uterotonic interventions following vaginal delivery.

Keywords: Postpartum Hemorrhage; Carbetocin; Oxytocin; Vaginal Delivery; Uterotonics; Maternal Mortality.

Manuscript Timeline: Received: February 20, 2026; Revised: April 14, 2026; Accepted: May 10, 2026; Published: June 15, 2026.

Citation: Obi EJ, Adeyemi FR, Dogara ZH. A Multi-Center Randomized Trial of Carbetocin versus Oxytocin for the Prevention of Postpartum Hemorrhage after Vaginal Delivery. International Journal of Obstetrics and Gynecology. 2026; 14(6): 49–60.

International Journal of Obstetrics and Gynecology | Vol. 14, No. 6, June 2026 | pp. 61–72

DOI: 10.46882/2026/IJOG/000482

Original Research Article

Title: Metabolomic Profiling of Follicular Fluid to Predict Oocyte Competence and Blastocyst Development in Assisted Reproductive Technology

Names of Authors: Anita P. Nwosu¹, Samuel T. Kudoyin²

Authors’ Affiliations:
¹ Reproductive Endocrinology and Infertility Unit, Department of Obstetrics and Gynecology, Lagos State University Teaching Hospital, Ikeja, Nigeria
² Department of Radiology, College of Medicine, University of Lagos, Lagos, Nigeria

Abstract:
In Assisted Reproductive Technology (ART), selecting the highest quality embryo remains a crucial factor in minimizing the time to pregnancy. This prospective study evaluated the clinical utility of untargeted metabolomic profiling of human follicular fluid (FF) to identify metabolic biomarkers indicative of high oocyte quality, successful fertilization, and high-grade blastocyst development. Individual FF micro-environment samples were collected from 150 women undergoing controlled ovarian hyperstimulation for intracytoplasmic sperm injection (ICSI). A total of 420 individual follicular fluid samples matching specific retrieved oocytes were analyzed using liquid chromatography-mass spectrometry (LC-MS). Metabolite variations were correlated with oocyte maturity, fertilization rates, and blastocyst morphology on Day 5. Multi-variate statistical models identified significant alterations in lipid and amino acid pathways. Follicular fluid corresponding to oocytes that successfully developed into high-grade blastocysts demonstrated significantly higher relative concentrations of L-carnitine (p < 0.001), pyruvate (p = 0.004), and specific phosphatidylcholines, alongside decreased concentrations of lactic acid (p = 0.012) and valine (p = 0.022) compared to follicles resulting in poor-quality embryos or developmental arrest. A predictive biomarker panel constructed using L-carnitine and the pyruvate-to-lactate ratio demonstrated a sensitivity of 84.6% and a specificity of 79.2% (AUC = 0.88) for forecasting high-grade blastocyst transformation. Metabolomic profiling of individual follicular fluid components identifies key non-invasive biomarkers of oocyte competence, reflecting intracellular energy production mechanisms and offering an objective diagnostic layer to refine embryo selection in IVF laboratories.

Keywords: Metabolomics; Follicular Fluid; Oocyte Competence; Blastocyst Development; In Vitro Fertilization; Mass Spectrometry.

Manuscript Timeline: Received: February 25, 2026; Revised: April 18, 2026; Accepted: May 15, 2026; Published: June 26, 2026.

Citation: Nwosu AP, Kudoyin ST. Metabolomic Profiling of Follicular Fluid to Predict Oocyte Competence and Blastocyst Development in Assisted Reproductive Technology. International Journal of Obstetrics and Gynecology. 2026; 14(6): 61–72.

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