Do patients with a short cervix, with or without an ultrasound-indicated cerclage, have an increased risk for a small for gestational age newborn?

Abstract

Introduction: Mothers with a short cervix have been shown to have increased risk of spontaneous preterm delivery (PTD) and newborn morbidity. Those who require an ultrasound-indicated cerclage experience the highest rates of morbidity. Inflammation has been linked to a short cervix, and it has been linked to pregnancies affected by small for gestational age (SGA) newborns. To date, there are no studies that have investigated an association between a short cervix, with or without an ultrasound-indicated cerclage, and a SGA newborn. Methods: This was a case-control study examining all pregnancies with a transvaginal cervical length <25 mm found at their second trimester anatomy scan. Cases were subdivided into those who received an ultrasound-indicated cerclage (Group 1, n ¼ 52) and those who did not (Group 2, n ¼ 139). Controls were defined as pregnancies with a transvaginal cervical length >25 mm with no cerclage (Group 3, n ¼ 186) whose due date was within 2 months of the case pregnancy. Each short cervix case was matched with a control from group 3 in a 1:1 ratio. The primary outcome was birthweight <10% (SGA). Unadjusted data was analyzed with simple odds ratios. A logistic regression was used to control for confounding variables and provide an adjusted odds ratios (aOR). Results: The incidence of SGA among cases overall (group 1 þ group 2) was 13.6% (26/191). In group 3, the SGA incidence was 4.3% (8/186). The adjusted odds ratio (aOR) for a SGA infant was significant, 2.8 (95% CI 1.2, 6.6). Subgroup analysis showed that Group 1 had an increased risk for an SGA infant [aOR 4.9 (95% CI 1.8, 13.7)], but Group 2 did not show a significant finding [aOR 2.3 (95% CI 0.9, 5.7)]. Conclusion: Pregnancies complicated by a short cervical length <25mm, with or without a cerclage, were associated with an increased risk for a SGA newborn. Most of this significance was due to the pregnancies which received an ultrasound-indicated cerclage for a mid-trimester short cervix.

Effects of vaginal progesterone and placebo on preterm birth and antenatal outcomes in women with singleton pregnancies and short cervix on ultrasound: a meta-analysis

“…Under normal circumstances, the cervix remains closed to keep the fetus secure within the uterus. However, in the case of a short cervix, the cervix may fail to stay effectively closed, making the fetus vulnerable to external pressure and infection, potentially leading to preterm birth or miscarriage (6). A short cervix is also known as cervical incompetence and typically refers to a cervix length of less than 25 mm, although some researchers use 3.0 cm as the critical threshold for a short cervix (7,8).…”

“…A short cervix is also known as cervical incompetence and typically refers to a cervix length of less than 25 mm, although some researchers use 3.0 cm as the critical threshold for a short cervix (7,8). Due to the cervix opening prematurely, pregnant women are more susceptible to intrauterine infections, which can result in preterm birth or endanger the life of the fetus (6). Some studies suggest that a short cervix may also lead to other antenatal complications, such as premature rupture of membranes, early membrane rupture, or malposition of the fetus and the placenta (9).…”