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PubMed2003

Human chorionic gonadotropin in cervicovaginal secretions as a predictor of preterm delivery.

OBJECTIVES: To determine whether human chorionic gonadotropin (hCG) detected in cervicovaginal secretions of patients with symptoms suggestive of preterm labor is a predictor of preterm birth. METHODS: Women presenting to labor and delivery with symptoms of preterm labor were invited to participate. After collecting secretions with a cotton-tipped applicator from the posterior fornix and endocervical canal, we placed the swab in a test tube containing 1 ml of normal saline. From this solution, we performed qualitative and quantitative hCG measurements. Qualitative and quantitative hCG results from women who delivered at term were compared with those delivering prior to 37 weeks' gestation. RESULTS: Samples were obtained and analyzed from 86 women at a mean (+/- standard deviation) gestational age of 30.7+/-2.9 weeks. Of the 86 subjects enrolled, 28 (32.6%) delivered preterm. A positive rapid qualitative assay from cervicovaginal secretions between 24 and 34 weeks' gestation was associated with a significant increase in the incidence of preterm delivery (relative risk 2.62, 95% confidence interval (CI) 1.38, 4.98). The likelihood ratios for a positive and negative test were 2.19 (95% CI 1.35, 3.56) and 0.51 (95% CI 0.30, 0.85) respectively. Using a cut-off of 19 mIU/ml, similar diagnostic accuracy for predicting preterm birth was obtained with the quantitative test 1.93 (95% CI 1.14, 3.26) and 0.62 (95% CI 0.40, 0.98). CONCLUSIONS: Qualitative and quantitative hCG measurements from cervicovaginal secretions may be useful predictors of preterm birth in symptomatic patients. The qualitative hCG test can be used at the bedside with results obtained in minutes.

Adult↗

PubMed1997

Digital examination and transperineal ultrasonographic measurement of cervical length to assess risk of preterm delivery.

OBJECTIVE: To compare the diagnostic performance of cervical length measurement determined with transperineal ultrasonography and digital assessment of the cervix for the prediction of preterm delivery in patients with preterm labor. METHOD: 90 patients admitted to the hospital with the diagnosis of preterm labor and intact membrane underwent cervical length measurement by transperineal ultrasonography along with digital examination for cervical dilatation and effacement. The main outcome measure was delivery before 37 weeks' gestation. RESULTS: 32 patients (35.5%) delivered preterm. Receiver operative characteristic curve analysis revealed that cervical canal length < or = 28 mm measured by transperineal sonography had the highest diagnostic performance with a sensitivity of 78.1% and specificity of 82.7%. The sensitivity and specificity of digital examination were found to be 65.5%, 72.4% and 62.5%, 68.9% for the cervical dilatation > 2 cm and effacement > or = 40%, respectively. CONCLUSION: Transperineal ultrasonographic examination for cervical length is more accurate than digital examination for prediction of preterm delivery in patients presenting with preterm labor. Transperineal ultrasonographic examination of cervix is invaluable in the prediction of preterm delivery where transvaginal transducers are lacking or skilled staff are unavailable.

Adult↗

PubMed1990

Gross motor milestones in preterm infants: correction for degree of prematurity.

The age of gross motor milestone attainment and how it is affected by degree of prematurity at delivery were studied in 100 high-risk, preterm (less than 32 weeks) infants with normal motor outcome. We calculated the mean age of attainment for each milestone on the basis of chronologic age from the date of delivery and term age equivalent, correcting for degree of preterm delivery. Half of these preterm infants were male; 70% were black. The infants were compared with a population of normal infants born at term. In this very preterm population, there were no consistent sex differences, but black infants generally attained motor milestones before white infants. For each motor milestone, regardless of gender or race, the mean term age equivalents of attainment for very preterm infants closely approximated the mean ages of milestone attainment for term infants, whereas the mean chronologic ages were delayed 2 or 3 months. We conclude that very preterm infants can be expected to demonstrate sequential gross motor development at a rate expected for degree of prematurity. Chronologic age is not a valid measurement scale to use in determining motor delay in very preterm infants.

Aging↗

PubMed1990

Eight-year school performance and growth of preterm, small for gestational age infants: a comparative study with subjects matched for birth weight or for gestational age.

Eight-year school performance and growth outcome are reported for three groups of preterm infants: one group that was small for gestational age (SGA; 36 infants) and two comparison groups that were appropriate in size for gestational age, one matched for birth weight and the other for gestational age. The subjects all had white parents whose mother tongue was English and were matched for gender, mother's height, mother's education, and father's socioeconomic status (Blishen Scale). A comparison peer group of term infants was also studied. The three preterm groups did not differ in school performance or physical growth, with the exception of head circumference, which was smaller in the SGA children. All preterm groups had growth measures, intellectual and visual-motor integration scores, reading and arithmetic grade levels, and behavior rating levels significantly inferior to those of the peer group. Receptive vocabulary scores and spelling grade levels did not differ between the preterm groups and the peer group. On multivariate analyses, mother's education was the primary predictor of academic grade levels for the preterm SGA group, and the only predictor when the disabled children were excluded from analyses. Preterm SGA children without disabilities had academic scores similar to those of their term peers, but their scores indicated more hyperactivity. Intrauterine growth retardation did not appear to impose a disadvantage on the preterm children in this study.

Alberta↗

PubMed1997

Comparison between observation of spontaneous movements and neurologic examination in preterm infants.

OBJECTIVE: The Prechtl method of qualitative assessment of general movements (GMs) has been shown to be a good predictor of neurologic outcome in fetuses, preterm infants, and term infants. The aim of this study was to compare the results of this new technique with those of traditional neurologic examination and of cranial ultrasonography in preterm infants. METHODS: Serial videotape recordings (with off-line assessment of GMs), ultrasound examination of the brain, and neurologic examinations were performed from birth until about 6 months of corrected age, on a group of 66 preterm infants whose gestational age ranged from 26 to 36 weeks (mean 30.7 weeks). The agreement between the two techniques and their predictive power, with respect to the neurologic outcome at 2 years of corrected age, were evaluated for five different age groups from preterm age to 65 weeks of postmenstrual age. RESULTS: Overall agreement of the neurologic and GM findings was 80.3% and strongly age related (lower during the preterm and term periods and higher thereafter). At all ages the results of GM observation correlated highly with neurologic outcome; they showed higher sensitivity and specificity than the neurologic examination. This held true in particular before term age, when poor neurologic responses might be related to transient complications, and at term age, mainly because of infants with normal neurologic examination results but unfavorable outcome. During the preterm period the ultrasound results showed a better specificity and a lower sensitivity to outcome than GM findings. CONCLUSIONS: The results of this study indicate that quality assessment of GMs should be added to traditional neurologic assessment, neuroimaging, and other tests of preterm infants for diagnostic and prognostic purposes.

Child Development↗

PubMed2001

Vaginal clindamycin in preventing preterm birth and peripartal infections in asymptomatic women with bacterial vaginosis: a randomized, controlled trial.

OBJECTIVE: To determine whether treatment of bacterial vaginosis (BV) in early pregnancy decreases the risk of preterm delivery and peripartum infectious morbidity. METHODS: In this multicenter, randomized, double-masked, placebo-controlled intervention trial, screening for BV was performed by vaginal Gram stain obtained from 5432 healthy women with singleton pregnancies during the first antenatal clinic visit at 10--17 weeks' gestation. Bacterial vaginosis-positive women with no past history of preterm delivery were randomized to a single course of treatment with either 2% vaginal clindamycin cream or identical placebo cream for 7 days. Repeat Gram stains were taken 1 week after treatment and at 30--36 weeks' gestation. Preterm delivery was defined as spontaneous delivery before 37 gestational weeks. Peripartum infectious morbidity was defined as postpartum endometritis, postpartum sepsis, postcesarean wound infection, or episiotomy wound infection, necessitating antimicrobial therapy. According to the power analysis, 180 patients were needed for both treatment arms to show a three-fold difference in the rates of preterm births. RESULTS: The overall prevalence of BV was 10.4%. Of all BV-positive women, 375 (66%) were randomized to the treatment arms. The primary cure rate was 66% in the clindamycin group; in the placebo group, 34% spontaneously cleared BV (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.3, 2.8). The rate of preterm deliveries was 5% in the clindamycin group and 4% in the placebo group (OR 1.3, 95% CI 0.5, 3.5). The rate of peripartum infectious morbidity was 11% in the clindamycin group and 18% in the placebo group (OR 1.6, 95% CI 0.9, 2.8). Bacterial vaginosis recurred in 7% of women. The rate of preterm deliveries was 15% in this subgroup compared with 2% among women who remained BV negative (OR 9.3, 95% CI 1.6, 53.5). CONCLUSION: Vaginal clindamycin did not decrease the rate of preterm deliveries or peripartum infections, but recurrent or persistent BV increased the risk for these complications.

Administration, Intravaginal↗

PubMed2001

Recurrence of preterm birth in singleton and twin pregnancies.

OBJECTIVE: To assess recurrence of preterm birth and its impact on an obstetric population. METHODS: Women with consecutive births at our hospital beginning with their first pregnancy were identified (n = 15,945). The first pregnancy was categorized as delivered between 24 and 34 weeks' gestation or 35 weeks or beyond, singleton or twin, and spontaneous or induced. The risk of preterm delivery in these same women during subsequent pregnancies was then analyzed. RESULTS: Compared with women who delivered a singleton at or beyond 35 weeks' gestation in their first pregnancy, those who delivered a singleton before 35 weeks were at a significant increased risk for recurrence (odds ratio [OR] 5.6, 95% confidence interval [CI] 4.5, 7.0), whereas those who delivered twins were not (OR 1.9, 95% CI 0.46, 8.14). The OR for recurrent spontaneous preterm birth presenting with intact membranes was 7.9 (95% CI 5.6, 11.3) compared with 5.5 (95% CI 3.2, 9.4) with ruptured membranes. Of those women with a recurrent preterm birth, 49% delivered within 1 week of the gestational age of their first delivery and 70% delivered within 2 weeks. Among 15,863 nulliparous women with singleton births at their first delivery, a history of preterm birth in that pregnancy could predict only 10% of the preterm births that ultimately occurred in the entire obstetric population. CONCLUSION: In a population-based study at our hospital, women who initially delivered preterm and thus were identified to be at risk for recurrence ultimately accounted for only 10% of the prematurity problem in the cohort.

Adolescent↗

PubMed2002

The management of preterm labor.

Preterm birth is the leading cause of neonatal mortality and a substantial portion of all birth-related short- and long-term morbidity. Spontaneous preterm labor is responsible for more than half of preterm births. Its management is the topic of this review. Although there are many maternal characteristics associated with preterm birth, the etiology in most cases is not clear, although, for the earliest cases, the role of intrauterine infection is assuming greater importance. Most efforts to prevent preterm labor have not proven to be effective, and equally frustrating, most efforts at arresting preterm labor once started have failed. The most important components of management, therefore, are aimed at preventing neonatal complications through the use of corticosteroids and antibiotics to prevent group B streptococcal neonatal sepsis, and avoiding traumatic deliveries. Delivery in a medical center with an experienced resuscitation team and the availability of a newborn intensive care unit will ensure the best possible neonatal outcomes. Obstetric practices for which there is little evidence of effectiveness in preventing or treating preterm labor include the following: bed rest, hydration, sedation, home uterine activity monitoring, oral terbutaline after successful intravenous tocolysis, and tocolysis without the concomitant use of corticosteroids.

Female↗

PubMed2003

Prediction and early detection of preterm labor.

Studies of cervical sonography, fetal fibronectin, and uterine contraction monitoring during pregnancy have improved our understanding of how preterm labor occurs, but their use in practice remains uncertain. This article reviews the use of these tests to improve the accuracy of diagnosis of preterm labor and to estimate the likelihood of preterm birth in women with historical risk factors. Because the clinical criteria for a diagnosis of preterm labor are inaccurate until labor is well established, over-diagnosis is common. A cervical length measurement of more than 30 mm or a negative fibronectin obtained from a patient with possible preterm labor can avoid over-diagnosis and unnecessary treatment. There is no role for routine use of either cervical sonography or fibronectin to screen pregnant women for preterm birth risk, but women thought to be at increased risk may be reassured by negative test results. Uterine contraction monitoring has low sensitivity for detecting women at risk of preterm birth. Current use of cervical length and fetal fibronectin in pregnancy is limited to situations where a negative result can avoid unnecessary interventions.

Embryonic and Fetal Development↗

PubMed2003

Bacterial vaginosis, vaginal fluid neutrophil defensins, and preterm birth.

OBJECTIVE: To examine the association between bacterial vaginosis, vaginal fluid neutrophil defensins, and preterm birth. METHODS: Vaginal fluid specimens were obtained at 24-29 weeks' gestation from 242 cases with preterm birth and 507 noncases sampled using a case-cohort study design. We tested for bacterial vaginosis by Gram staining and Nugent scores and assayed for neutrophil defensins by enzyme-linked immunosorbent assay. Bacterial vaginosis was studied as a categoric variable (negative, intermediate, and positive), whereas defensins were studied as a continuous, categoric (based on percentiles), and dichotomous measure (presence versus absence). Three gestational age cut points were used to define preterm birth. Modified Cox proportional hazard models were used to evaluate the associations between bacterial vaginosis, defensins, and degree (less than 32, less than 34, and less than 37 weeks) and type (premature rupture of membranes, preterm labor) of preterm birth. RESULTS: Elevated vaginal fluid neutrophil defensins were not associated with birth before 37 weeks. Compared with women who did not have measurable vaginal fluid defensins, women with higher defensin levels (0-2.8 micro g/mL, 2.8-8.2 micro g/mL, and greater than 8.2 micro g/mL) had a greater risk of delivering before 32 weeks. Hazard ratios adjusted for maternal race and vaginal bleeding during pregnancy and 95% confidence intervals for these defensin levels were 1.7 (0.4, 6.9), 2.4 (0.7, 7.9), and 3.1 (1.0, 9.8), respectively. Bacterial vaginosis status did not influence the association between defensins and preterm birth. CONCLUSION: Elevated concentrations of vaginal fluid neutrophil defensins at 24-29 weeks' gestation might predict preterm birth before 32 weeks.

Adult↗

PubMed2003

Gestational diabetes mellitus and lesser degrees of pregnancy hyperglycemia: association with increased risk of spontaneous preterm birth.

OBJECTIVE: To investigate whether different degrees of maternal glucose intolerance are associated with the risk of spontaneous preterm birth. METHODS: We performed a cohort study of 46,230 pregnancies screened by a 50-g, 1-hour oral glucose tolerance test between 24 and 28 gestation weeks at the Northern California Kaiser Permanente Medical Care Program. Spontaneous preterm birth was defined as an infant born at less than 37 gestation weeks with at least one of the following: spontaneous labor, preterm premature rupture of membranes, or incompetent cervix. Glucose tolerance status was categorized as normal screening (1-hour plasma glucose less than 140 mg/dL), abnormal screening (1-hour plasma glucose of at least 140 mg/dL with a normal diagnostic 100-g, 3-hour oral glucose tolerance test result), Carpenter-Coustan (plasma glucose measurements during the diagnostic oral glucose tolerance test met the thresholds but were lower than the National Diabetes Data Group thresholds), and gestational diabetes mellitus (GDM) by the National Diabetes Data Group criteria. RESULTS: One thousand nine hundred fifty-six spontaneous preterm births occurred. Age-adjusted incidences of spontaneous preterm birth were 4.0% in normal screening, 5.0% in abnormal screening, 6.7% in Carpenter-Coustan, and 6.7% in GDM. In a logistic regression model adjusted for age, race-ethnicity, preeclampsia-eclampsia-pregnancy-induced hypertension, chronic hypertension, polyhydramnios, and birth weight for gestational age, pregnancies with abnormal screening, Carpenter-Coustan, and GDM had a significantly higher risk of spontaneous preterm birth than pregnancies with normal screening (relative risk [95% confidence interval]: 1.23 [1.08, 1.41], 1.53 [1.16, 2.03], and 1.42 [1.15-1.77], respectively). CONCLUSION: The risk of spontaneous preterm birth increased with increasing levels of pregnancy glycemia. This association was independent of perinatal complications that could have triggered early delivery.

Adult↗

PubMed2003

What have we learned about uterine contractions and preterm birth? The HUAM Prediction Study.

Measurement of uterine contraction frequency has been employed as a screening test to identify women with increased risk of preterm birth, and as an aid in the early diagnosis of preterm labor. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units (NICHD MFMU) Network performed a prospective, blinded observational study of uterine contraction frequency to detect and predict preterm labor and birth, respectively. The goal of the study was to assess the sensitivity, specificity, and positive and negative predictive value of various measures of uterine contraction frequency. Data collected from 306 women revealed that contraction frequency was significantly greater in women who would ultimately deliver before rather than after 35 weeks' gestation. However, both sensitivity and positive predictive value of any measure of contraction frequency to predict preterm birth were poor. Contraction frequency did not increase significantly within 1 or 2 weeks of an episode of preterm labor. These results serve to explain the absence of an association between contraction-based surveillance and preterm birth in randomized trials conducted in women at risk of preterm birth.

Female↗

PubMed1998

The preterm infant's antibody response to a combined diphtheria, tetanus, acellular pertussis and hepatitis B vaccine.

Several combined vaccines have recently been developed, in order to improve the implementation of immunization programmes and increase the coverage for each vaccine. As the response of preterm infants may vary depending on the vaccination schedule and the vaccine product, it should be evaluated specifically as new vaccines become available. In this study we have examined the antibody response to a combined diphtheria, tetanus, acellular pertussis, and hepatitis B vaccine (DTPa-HBV), given as a primary vaccination course at 3, 5 and 11 months of postnatal age, in 34 preterm infants (mean gestational age (GA) = 32.0 weeks) in comparison with 28 term infants. At the end of the primary course, preterm infants had antibody concentrations for pertussis 69 kDa antigen and diphtheria toxoid that were significantly lower than those of term infants; preterm infants with GA < or = 31 weeks had antibody concentrations for pertussis 69 kDa antigen and HBsAg that were significantly lower than those of preterm infants with higher GA; anti-HBs antibody levels correlated with GA. However, the combined DTPa-HBV vaccine elicited seroconversion to all its components in all but two infants, one term and one preterm, after the second dose and a total seroconversion after the third dose. We conclude that preterm infants may be immunized with a combined DTPa-HBV vaccine, starting at the same chronological age, as term infants.

Antibodies, Bacterial↗

PubMed1999

Hormone synthesis and storage in the thyroid of human preterm and term newborns: effect of thyroxine treatment.

Iodine and thyroglobulin concentrations, as well as iodine, T3, T4 and sialic acid contents of thyroglobulin, were measured in thyroid glands collected postmortem from 42 human premature or term newborns and infants. Three groups were considered: very preterm newborns (24-32 postmenstrual weeks, < 5 days postnatal life), preterm and term newborns (34-41 postmenstrual weeks, < 5 days postnatal life) and infants (born at term, postnatal age 1-8 months). Five very preterm and seven preterm newborns received a daily dose of 10 microg/kg L-T4 for at least 3 days. Thyroid weight and sialic acid content of thyroglobulin progressed with maturation. Intrathyroidal concentrations of iodine and thyroglobulin did not increase significantly before the 42nd week of postmenstrual age. The level of thyroglobulin iodination increased during the postnatal life, except in the very preterm neonates. T4 and T3 content of thyroglobulin was directly proportional to its degree of iodination and positively related to its sialic acid content. L-T4 treatment of preterm newborns increased thyroglobulin iodination and T4-T3 content, without increasing thyroglobulin concentration in the thyroid. It was concluded that the storage of thyroglobulin and iodine in the thyroid develops around term birth. This, associated with the resulting rapid theoretical turnover of the intrathyroidal pool of T4 in Tg, could be an important factor of increased risk of neonatal hypothyroxinemia in the premature infants. The L-T4 treatment of preterm newborns does not accelerate the maturational process of the thyroid gland.

Humans↗

PubMed2000

Immunophenotypic and functional characterization of CD33(+)CD34(+) cells in human cord blood of preterm neonates.

OBJECTIVE: To characterize CD33(+)CD34(+) cells, a major population in human cord blood (CB) CD34(+) cells of preterm neonates. MATERIALS: The proportion of CD33(+) cells was analyzed on CB CD34(+) cells from preterm and full-term neonates. CD33(+)CD34(+) cells were purified by cell sorting and analyzed on their clonogenic activity, proliferative activity in short-time liquid suspension culture, and GATA-2 mRNA expression by RT-PCR and Southern blot. RESULTS: The absolute numbers and proportion of CD34(+) cells in mononuclear cells inversely correlated with gestational age. CD33 was expressed on a majority of CB CD34(+) cells of preterm neonates but on only a minor population of them in full-term neonates. In addition, CD33 was dominantly expressed on CD38(-)CD34(+) cells or CD117(low)CD34(+) cells in CB of preterm neonates. CD33(+)CD34(+) cells of preterm cord blood had high proliferative and reproducible potentials compared with CD33(-)CD34(+) cells. CD33(+)CD34(+) cells as well as CD33(-)CD34(+) cells from preterm CB highly expressed GATA-2, in contrast to those from BM. CONCLUSIONS: These results suggest that CD33(+)CD34(+) cells, which are a major population in CB CD34(+) cells of preterm neonates, do not simply represent relatively mature myeloid lineage hematopoietic progenitor cells as those in adult BM CD34(+) cells, and may contain hematopoietic stem cells or primitive progenitor cells as in fetal liver.

Antigens, CD↗

PubMed1993

Prevention of preterm labour and delivery.

This chapter describes the French national programme for reduction of preterm births which started in 1971. Prevention of preterm labour and delivery in France was the objective of a national policy applied to all pregnant women for 10 years and more than 700,000 pregnancies every year, and which has continued since the end of the initial programme. Prevention is action that must be applied before the beginning of disease. The risk analysis was the first step, and showed that most known risk factors (young age, previous preterm birth, bleeding during pregnancy) could not be changed and could not form the basis of a prevention strategy. Other risk factors were described, particularly lifestyle and severity of work, which promoted uterine contractions. Uterine contractions can be recognized by individual women. Shortening of the cervix is also an important risk factor. The intervention strategy involved modifying lifestyle to reduce the workload of women, thereby reducing uterine contractions and/or premature maturation of the cervix. This national policy was evaluated by two techniques; one was performed on successive representative samples of all pregnant French women in 1972, 1976 and 1981, and repeated in 1988/9, and the second (from 1971 to 1982) involved a longitudinal study in a district hospital and included 16,000 women from the city of Haguenau. Preterm deliveries were significantly reduced in France from 7.9% in 1971 to 5.8% in 1981. The reduction was more significant in 1988-9, with a preterm delivery rate of 4.1%. This was associated with a major reduction in early preterm births (before 32 weeks of gestation): 1.6% of births in 1972, 0.7% of births in 1981 and 0.5% of births in 1988-9. As this intervention was intended for all pregnant women and not as a controlled trial, it was not possible to directly demonstrate a causal relationship between the intervention and the observed effects. However, it is argued that a close relationship exists between the intervention programme and the effective reduction of preterm births in France during that time.

Causality↗

PubMed1998

Prediction of preterm labour in multiple pregnancies.

Various methods of predicting preterm labour in both singleton and multiple pregnancies have been studied including risk scoring systems, home uterine activity monitoring, cervical assessment and biochemical methods. In practice, risk scoring systems for preterm delivery perform poorly. Consensus in the literature regarding the usefulness of home uterine activity monitoring is lacking and well designed randomized controlled trials are required. Transvaginal ultrasound assessment of the cervix appears to have a role to play in the prediction of preterm labour. The presence of IFN in cervicovaginal fluid in the late second and early third trimesters is an important risk factor for preterm labour in asymptomatic women with multiple pregnancies. Preterm labour may be mediated in part by inflammatory cytokines. The measurement of these inflammatory cytokines in cervical secretions may also prove helpful in the prediction of preterm labour. It is anticipated that an improved ability to predict preterm labour in both singleton and multiple pregnancies will depend on increasing understanding of the condition's pathophysiology.

Cervix Uteri↗

PubMed1997

Young maternal age and preterm labor.

PURPOSE: The relationship among young age, biologic immaturity (as indexed by low gynecologic age), and the causes of preterm delivery (idiopathic preterm labor [PTL], premature rupture of the membranes [PROM], and medical indications) were investigated among 605 primigravidas from the Camden Study. METHODS: The sample consisted of 366 young adolescents < 16 years at the time of their last menstrual period (LMP) and 239 older women, 18-29 years at LMP (controls). The young adolescents were significantly shorter, thinner, had younger ages at menarche, and over a third (36.3%) were of low gynecologic age, i.e., their chronologic age was 2 or fewer years more than their age at menarche. RESULTS: Adjusting for ethnicity, cigarettes smoked/day, weight gain rate, height, fetal sex, gestational diabetes mellitus, and pregnancy-induced hypertension, young adolescents overall had a nearly 75% increased risk of PTL (adjusted odds ratio [AOR] = 1.74, 95% confidence interval [95% CI]: 1.07-2.84), and preterm delivery with PTL (AOR = 2.08, 95% CI: 1.08-4.00). There was a modest decreased risk of preterm delivery among young gravidas attributable to other causes, such as PROM or medical indications (AOR = 0.70, 95% CI: 0.28-1.75). This increased risk of PTL and preterm delivery with PTL was principally attributable to biologic immaturity. Young age with low gynecologic age was associated with a twofold risk of PTL (AOR = 2.15, 95% CI: 1.19-3.89) and preterm delivery with PTL (AOR = 2.64, 95% CI: 1.23-5.65), while the risk associated with young age and higher gynecologic age was only increased moderately. CONCLUSIONS: Young adolescents, and especially those of low gynecologic age, appear prone to PTL and are at increased risk for preterm delivery through this pathway.

Adolescent↗