The prevalence of preterm birth varies by season of last menstrual period

The aim of this study was to assess the validity of the last menstrual period (LMP) estimate in determining pre and post-term birth rates, in a prenatal cohort from two Brazilian cities, São Luís and Ribeirão Preto. Pregnant women with a single fetus and less than 20 weeks' gestation by obstetric ultrasonography who received prenatal care in 2010 and 2011 were included. The LMP was obtained on two occasions (at 22-25 weeks gestation and after birth). The sensitivity of LMP obtained prenatally to estimate the preterm birth rate was 65.6% in São Luís and 78.7% in Ribeirão Preto and the positive predictive value was 57.3% in São Luís and 73.3% in Ribeirão Preto. LMP errors in identifying preterm birth were lower in the more developed city, Ribeirão Preto. The sensitivity and positive predictive value of LMP for the estimate of the post-term birth rate was very low and tended to overestimate it. LMP can be used with some errors to identify the preterm birth rate when obstetric ultrasonography is not available, but is not suitable for predicting post-term birth.

Download Full-text

The association between periconceptional folic acid supplementation and the risk of preterm birth: a population-based retrospective cohort study of 200,000 women in China

European Journal of Nutrition ◽

10.1007/s00394-020-02409-8 ◽

2020 ◽

Author(s):

Yu Wu ◽

Yanling Yuan ◽

Cai Kong ◽

Qiuyue Ma ◽

Hanfeng Ye ◽

...

Keyword(s):

Cohort Study ◽

Folic Acid ◽

Preterm Birth ◽

Retrospective Cohort Study ◽

Lower Risk ◽

Retrospective Cohort ◽

Chinese Women ◽

Population Based ◽

Menstrual Period ◽

Last Menstrual Period

Abstract Purpose The aim of this study was to examine the association between periconceptional folic acid (FA) supplementation and risk of preterm birth. Methods We conducted a retrospective cohort study in women aged 18–49 who participated in the NFPHEP from 2010 to 2018, and had a singleton livebirth in 129 counties in southwest China. Participants were divided into four groups according to the time period starting FA use: no use, after the last menstrual period, at least 1–2 months before the last menstrual period, at least 3 months before the last menstrual period. The outcomes were preterm birth (gestation < 37 weeks) and early preterm birth (gestation < 34 weeks). Results 201,477 women were included and 191,809 (95.2%) had taken FA during periconception. Compared with women who did not take FA, women who started taking FA 1–2 months before their last menstrual period had a 15% lower risk of preterm birth (aOR = 0.85, 95% CI 0.79–0.92), and women who started taking FA at least 3 months before their last menstrual period had a 20% lower risk of preterm birth (aOR = 0.80, 95% CI 0.75–0.87), but women who started taking FA after their last menstrual period did not appear to reduce the risk of preterm birth. Conclusions In this study of 200,000 Chinese women, periconceptional supplementation with FA was associated with a lower risk of preterm birth. Women who started taking FA at least 3 months before their last menstrual period were more likely to reduce the risk of preterm birth.

Download Full-text

Clinical Evaluations Have Low Sensitivity for Identifying Preterm Infants in a Clinical Trial in a Limited Resource Setting

Global Pediatric Health ◽

10.1177/2333794x19857402 ◽

2019 ◽

Vol 6 ◽

pp. 2333794X1985740

Author(s):

Andrea G. Buchwald ◽

Ibrahima Teguete ◽

Moussa Doumbia ◽

Fadima C. Haidara ◽

Flanon Coulibaly ◽

...

Keyword(s):

Birth Weight ◽

Preterm Birth ◽

Low Birth Weight ◽

Preterm Infants ◽

Gestational Age ◽

Limited Resource ◽

Menstrual Period ◽

Last Menstrual Period ◽

Low Birth Weight Infants ◽

Resource Setting

Preterm birth is a primary outcome of interest in maternal vaccination trials but determination of gestational age is challenging in limited-resource settings. This study compares the New Ballard Score and fundal height measurements with the current standard of early ultrasound for sensitivity of predicting preterm birth. A trial of maternal influenza vaccination was conducted in Bamako, Mali. The New Ballard Score and fundal height were collected on 4038 infants born in the trial, ultrasound data were available for 1893 of those infants. New Ballard Score and fundal height were compared, consecutively, to all ultrasound results, early ultrasound results from the first trimester, and the date of last menstrual period for estimation of gestational age. Sensitivity of the New Ballard Score for identifying preterm infants was 0.33 compared with early ultrasound and 0.1 compared with the last menstrual period based estimates of gestational age. Sensitivity of low birth weight alone was 0.43 compared with early ultrasound. New Ballard Score estimated gestational age within 1 week of ultrasound more frequently than fundal height (53% compared with 7.6%, respectively) yet New Ballard Score identified few infants as preterm (1.8% vs 5.8% by early ultrasound), and was biased toward categorizing low birth weight infants and infants requiring hospitalization as preterm. New Ballard Score is not an ideal measure for identifying preterm births in low-resource settings. Despite the time and cost of training required for correct measurement of New Ballard Score, measurement of low birth weight alone performed better than New Ballard Score for identifying preterm infants.

Download Full-text

Randomized trial of mifepristone and buccal or vaginal misoprostol for abortion through 56 days of last menstrual period

Yearbook of Obstetrics Gynecology and Women s Health ◽

10.1016/s1090-798x(08)70169-3 ◽

2007 ◽

Vol 2007 ◽

pp. 235-236

Author(s):

L.P. Shulman

Keyword(s):

Randomized Trial ◽

Menstrual Period ◽

Last Menstrual Period ◽

Vaginal Misoprostol

Download Full-text

Fetal infection resulting from maternal rubella after the first trimester of pregnancy

Journal of Hygiene ◽

10.1017/s0022172400063452 ◽

1980 ◽

Vol 85 (3) ◽

pp. 381-391 ◽

Cited By ~ 26

Author(s):

J. E. Cradock-Watson ◽

Margaret K. S. Ridehalgh ◽

Mary J. Anderson ◽

J. R. Pattison ◽

H. O. Kangro

Keyword(s):

First Trimester ◽

Menstrual Period ◽

Last Menstrual Period ◽

Igg Antibody ◽

True Rate ◽

Igm Antibody ◽

Prenatal Infection ◽

Fetal Infection ◽

First Trimester Of Pregnancy ◽

Specific Igg

SUMMARYWe have tried to measure the incidence of prenatal infection in 304 infants whose mothers had had rubella at various times after the first 12 weeks of pregnancy. Two methods of assessment were used: first, serum obtained soon after birth was tested for specific IgM antibody; secondly, serum obtained after the age of eight months was tested for specific IgG. When maternal rubella occurred 12–16 weeks after the last menstrual period specific IgM antibody was detected in 28 out of 50 infants (56%). The proportion fell progressively to 12% after maternal rubella at 24–28 weeks, rose to 19% after rubella at 28–36 weeks and then to 58% when the illness occurred during the last month of pregnancy. In all, IgM antibody was detected in 77 out of 260 infants (29%). The fetus can thus be infected at any time during the second and third trimesters of pregnancy, but the risk varies at different stages.The figures for the prevalence of IgG antibody were greater throughout, because some infants had IgG who had previously lacked specific IgM. After maternal rubella at 12–16 weeks IgG antibody persisted in 22 out of 31 infants (71%). The proportion fell to 28% after rubella at 24–28 weeks and then increased progressively to 94% after rubella during the last month. In all, IgG antibody persisted in 94 out of 190 infants (49%). The true rate of fetal infection probably lies between the rates estimated from the presence of IgM antibody and the subsequent prevalence of IgG.Infants whose mothers had rubella at any time during pregnancy should be examined regularly for possible evidence of damage.

Download Full-text