Second-Trimester Pregnancy Loss in Multiple Gestations: A Comparison of Assisted Reproductive Technology and Spontaneous Conception

INTRODUCTION: To compare the clinical, laboratory, and obstetric characteristics of multiple pregnancies conceived through assisted reproductive technology (ART) and spontaneous conception (SC) that resulted in second-trimester abortion or stillbirth.
METHODS: This retrospective study was conducted at a tertiary research hospital between January 2019 and December 2024. Multiple pregnancies complicated by abortion or stillbirth occurring between 14 and 28 weeks of gestation were included in this study. Singleton and higher-order multiple pregnancies, as well as pregnancies complicated by pregestational diabetes mellitus or chronic hypertension, were excluded from the study. Patients were grouped according to the mode of conception (ART vs. SC). Demographic characteristics, obstetric history, clinical signs, laboratory findings, and progesterone use were compared between the groups.
RESULTS: A total of 64 women were included, comprising 30 ART-conceived and 34 spontaneously conceived multiple pregnancies. Maternal age, gestational age at pregnancy loss, history of vaginal delivery, and history of abortion were similar between the groups (all p>0.05). White blood cell counts and rates of positive vaginal cultures did not differ significantly. However, median C-reactive protein levels were significantly higher in the ART group than in the SC group (9.25 vs. 1.33 mg/dL; p=0.001). Progesterone use was significantly more frequent in ART-conceived pregnancies than ART-conceived pregnancies (90% vs. 21%, p=0.001). No significant differences were observed in the rates of vaginal bleeding, pelvic pain, membrane rupture, or cervical dilatation.
DISCUSSION AND CONCLUSION: Second-trimester abortion and stillbirth in multiple pregnancies showed largely similar clinical and obstetric characteristics, regardless of the mode of conception. Elevated inflammatory markers in ART-conceived pregnancies may indicate distinct underlying mechanisms and warrant further investigation in larger prospective studies.

Keywords: Assisted reproduction technologies, multiple pregnancies, second-trimester abortion, spontaneous conception, stillbirth.