Zhou, W., Sørensen, H. T., & Olsen, J. (1999). Induced abortion and subsequent pregnancy duration. Obstetrics and gynecology, 94(6), 948-953. https://doi.org/10.1016/s0029-7844(99)00440-8
Zhou W, Sørensen HT, Olsen J. Induced abortion and subsequent pregnancy duration. Obstet Gynecol. 1999;94(6):948-953. doi:10.1016/s0029-7844(99)00440-8
Zhou, W., et al. "Induced abortion and subsequent pregnancy duration." Obstetrics and gynecology, vol. 94, no. 6, 1999, pp. 948-953.
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To examine whether induced abortion influences subsequent pregnancy duration.
Methods
Women who had their first pregnancies during 1980, 1981, and 1982 were identified in three Danish national registries. A total of 15,727 women whose pregnancies were terminated by first-trimester induced abortions were compared with 46,026 whose pregnancies were not terminated by induced abortions. All subsequent pregnancies until 1994 were identified by register linkage.
Results
Preterm and post-term singleton live births were more frequent in women with one, two, or more previous induced abortions. After adjusting for potential confounders and stratifying by gravidity, the odds ratios of preterm singleton live births in women with one, two, or more previous induced abortions were 1.89 (95% confidence interval [CI] 1.70, 2.11), 2.66 (95% CI 2.09, 3.37), and 2.03 (95% CI 1.29, 3.19), respectively. Odds ratios of post-term singleton live births in women with one, two, or more previous induced abortions were 1.34 (95% CI 1.24, 1.44), 1.50 (95% CI 1.26, 1.78), and 1.58 (95% CI 1.09, 2.28), respectively.
Conclusion
The study showed an increase in preterm and post-term pregnancies after induced abortions. The risk of post-term delivery was high regardless of the interpregnancy interval, whereas increased risk of preterm delivery was seen mainly when interpregnancy intervals were longer than 12 months.
Liu X et al., 2024·BMC pregnancy and childbirth·Free full text on PubMed Central
[BACKGROUND] Thin endometrium (TE) is a common cause of female infertility in clinical practice. Platelet-rich Plasma (PRP) therapy becomes a novel treatment for thin endometrium; however, its clinical application remains controversial. This meta-analysis aims to evaluate the therapeutic effects of intrauterine autologous PRP infusion in women with thin endometrium through relevant randomized controlled trials (RCTs). [METHODS] We systematically searched studies published in English from inception until June 2024 in databases such as PubMed, The Cochrane Library, Embase, Web of Science, and MEDLINE. Search terms included "Platelet-Rich Plasma," "thin endometrium," "endometrial thickness," "infertility," "pregnancy," "reproduction," and "adverse reactions". RCTs identified through the search were subjected to systematic review and meta-analysis, and data were analyzed using fixed-effects or random-effects models based on heterogeneity. [RESULTS] Eight RCTs involving 678 patients with thin endometrium were included. Patients receiving PRP infusion demonstrated significantly superior outcomes compared to the control group in endometrial thickness (MD: 1.23, 95%CI: 0.87 to 1.59, P = 0.000), clinical pregnancy rate (RR: 2.04, 95%CI: 1.52 to 2.76, P = 0.000), live birth rate (RR: 2.46; 95%CI: 1.57 to 3.85, P = 0.000), cycle cancellation rate (RR: 0.46, 95%CI: 0.23 to 0.93, P = 0.000), and embryo implantation rate (RR: 2.71; 95%CI: 1.91 to 3.84, P = 0.000). There were no statistically significance in spontaneous abortion rate (RR: 0.85, 95%CI: 0.40 to 1.78, P = 0.659), chemical pregnancy rate (RR: 1.84, 95%CI: 0.72 to 4.72, P = 0.204) and endometrial vascular improvement rate (RR: 1.10; 95%CI: 0.89 to 1.38, P = 0.367) between the two groups. The limitations of this study includes that, we only included single lauguage for literature research, the sample size and heterogeneity which could cause criteria bias. [CONCLUSION] Intrauterine PRP infusion may be an effective and safe treatment for women with thin endometrium. Further high-quality, large-sample, randomized controlled trials are needed to validate the reliability of our results. [TRIAL REGISTRATION] The review protocol is registered on PROSPERO with registration number CRD42023490421, and no modifications were made to the information provided at registration.
Pedersen ES et al., 2024·Paediatr Perinat Epidemiol·Free full text on PubMed Central
The use of fertility indicators to predict ovulation has largely been studied for contraceptive purposes, while less so as fertility-promoting tools. To investigate the association between fertility indicators and fecundability in Danish women trying to conceive. Web-based preconception cohort study. We analysed data from 11,328 females aged 18-49 years trying to conceive without fertility treatment for ≤6 menstrual cycles, from the Danish SnartGravid.dk and SnartForældre.dk cohorts (2007-2023). Participants reported the use of fertility indicators (counting days since the last menstrual period, cervical fluid monitoring, urinary ovulation testing, feeling ovulation, using a smartphone fertility app and measuring basal body temperature [BBT]). Time to pregnancy was measured in menstrual cycles ascertained by self-reported pregnancy status. We estimated fecundability ratios (FR) and 95% confidence intervals (CI) using proportional probabilities regression models adjusted for age, socio-economic position, health indicators, reproductive history and gynaecological factors. Fertility indicators were used by 63.3% of participants at study entry. Counting days was the most common (46.9%), while measuring BBT was the least (3.0%). Other indicators ranged from 17.0% to 23.6%, with 69.7% using more than one indicator. Compared with non-use, use of any fertility indicator was associated with greater fecundability (adjusted FR 1.14, 95% CI 1.08, 1.19). Cervical fluid monitoring showed the strongest association (aFR 1.46, 95% CI 1.03, 2.07), followed by urinary ovulation testing (aFR 1.35, 95% CI 1.16, 1.58) and counting days (aFR 1.18, 95% CI 1.09, 1.29). Feeling ovulation and fertility apps were modestly associated with fecundability, while measuring BBT was not associated. Sensitivity analysis restricting to ≤2 cycles of attempt time and two cycles of follow-up showed an aFR for any indicator use of 1.21 (95% CI 1.13, 1.31). In this Danish preconception cohort, use of fertility indicators was associated with a higher fecundability, varying by type of indicator.
Prescribing Safety · Medication Safety in Pregnancy
Bauer AZ et al., 2021·Nature reviews. Endocrinology·Free full text on PubMed Central
Paracetamol (N-acetyl-p-aminophenol (APAP), otherwise known as acetaminophen) is the active ingredient in more than 600 medications used to relieve mild to moderate pain and reduce fever. APAP is widely used by pregnant women as governmental agencies, including the FDA and EMA, have long considered APAP appropriate for use during pregnancy when used as directed. However, increasing experimental and epidemiological research suggests that prenatal exposure to APAP might alter fetal development, which could increase the risks of some neurodevelopmental, reproductive and urogenital disorders. Here we summarize this evidence and call for precautionary action through a focused research effort and by increasing awareness among health professionals and pregnant women. APAP is an important medication and alternatives for treatment of high fever and severe pain are limited. We recommend that pregnant women should be cautioned at the beginning of pregnancy to: forego APAP unless its use is medically indicated; consult with a physician or pharmacist if they are uncertain whether use is indicated and before using on a long-term basis; and minimize exposure by using the lowest effective dose for the shortest possible time. We suggest specific actions to implement these recommendations. This Consensus Statement reflects our concerns and is currently supported by 91 scientists, clinicians and public health professionals from across the globe.
Liew Z et al., 2020·Environmental health perspectives·Free full text on PubMed Central
Per- and polyfluoroalkyl substances (PFAS) are widespread persistent organic pollutants and endocrine disruptors. High doses of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) exposure can cause pregnancy loss and infant deaths in animals, but the associations between PFAS exposures and risk of miscarriage in humans are not well studied. Using a case-control study nested within the Danish National Birth Cohort (DNBC, 1996-2002), we compared 220 pregnancies ending in miscarriage during weeks 12-22 of gestation, with 218 pregnancies resulting in live births. Levels of seven types of PFAS [PFOS, PFOA, perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOSA)] were measured in maternal plasma collected in early gestation (mean gestational week 8). We estimated the odds ratios (ORs) and 95% confidence intervals (CIs) for miscarriage and each PFAS as a continuous variable or in quartiles, controlling for maternal age, parity, socio-occupational status, smoking and alcohol intake, gestational week of blood sampling, and maternal history of miscarriage. Stratification by parity and PFAS mixture analyses using weighted quantile sum (WQS) regression were also conducted. We observed a monotonic increase in odds for miscarriage associated with increasing PFOA and PFHpS levels. The ORs comparing the highest PFOA or PFHpS quartile to the lowest were 2.2 (95% CI: 1.2, 3.9) and 1.8 (95% CI: 1.0, 3.2). The ORs were also elevated for the second or third quartile of PFHxS or PFOS, but no consistent exposure-outcome pattern emerged. An interquartile range (IQR) increment in the WQS index of seven PFAS was associated with 64% higher odds for miscarriage (95% CI: 1.15, 2.34). The associations were stronger in parous women, while findings were inconsistent among nulliparous women. Maternal exposures to higher levels of PFOA, PFHpS, and PFAS mixtures were associated with the risk of miscarriage and particularly among parous women. Larger replication studies among nulliparous women are needed to allay concerns about confounding by reproductive history. https://doi.org/10.1289/EHP6202.
The likelihood of repetition of preterm birth after spontaneous onset of labour has been studied in 6572 reproductive careers after excluding stillbirths, multiple births, all careers in which any labour had been induced, and all careers in which the gestation length in any pregnancy was not certain. The analysis was controlled not only for pregnancy number, but for the nature of the reproductive outcomes. In most reproductive sequences there was a weak correlation between the gestation in one pregnancy and subsequent ones. The risk of preterm birth was tripled after one previous preterm birth with or without a preceding abortion, and increased six-fold after two previous preterm births. However, the attributable risk was low, and most multiparae with preterm births did not have a previous history.
Tessema GA et al., 2022·PLoS medicine·Free full text on PubMed Central
The World Health Organization recommends to wait at least 6 months after miscarriage and induced abortion before becoming pregnant again to avoid complications in the next pregnancy, although the evidence-based underlying this recommendation is scarce. We aimed to investigate the risk of adverse pregnancy outcomes-preterm birth (PTB), spontaneous PTB, small for gestational age (SGA) birth, large for gestational age (LGA) birth, preeclampsia, and gestational diabetes mellitus (GDM)-by interpregnancy interval (IPI) for births following a previous miscarriage or induced abortion. We conducted a cohort study using a total of 49,058 births following a previous miscarriage and 23,707 births following a previous induced abortion in Norway between 2008 and 2016. We modeled the relationship between IPI and 6 adverse pregnancy outcomes separately for births after miscarriages and births after induced abortions. We used log-binomial regression to estimate unadjusted and adjusted relative risk (aRR) and 95% confidence intervals (CIs). In the adjusted model, we included maternal age, gravidity, and year of birth measured at the time of the index (after interval) births. In a sensitivity analysis, we further adjusted for smoking during pregnancy and prepregnancy body mass index. Compared to births with an IPI of 6 to 11 months after miscarriages (10.1%), there were lower risks of SGA births among births with an IPI of <3 months (8.6%) (aRR 0.85, 95% CI: 0.79, 0.92, p < 0.01) and 3 to 5 months (9.0%) (aRR 0.90, 95% CI: 0.83, 0.97, p = 0.01). An IPI of <3 months after a miscarriage (3.3%) was also associated with lower risk of GDM (aRR 0.84, 95% CI: 0.75, 0.96, p = 0.01) as compared to an IPI of 6 to 11 months (4.5%). For births following an induced abortion, an IPI <3 months (11.5%) was associated with a nonsignificant but increased risk of SGA (aRR 1.16, 95% CI: 0.99, 1.36, p = 0.07) as compared to an IPI of 6 to 11 months (10.0%), while the risk of LGA was lower among those with an IPI 3 to 5 months (8.0%) (aRR 0.84, 95% CI: 0.72, 0.98, p = 0.03) compared to an IPI of 6 to 11 months (9.4%). There was no observed association between adverse pregnancy outcomes with an IPI >12 months after either a miscarriage or induced abortion (p > 0.05), with the exception of an increased risk of GDM among women with an IPI of 12 to 17 months (5.8%) (aRR 1.20, 95% CI: 1.02, 1.40, p = 0.02), 18 to 23 months (6.2%) (aRR 1.24, 95% CI: 1.02, 1.50, p = 0.03), and ≥24 months (6.4%) (aRR 1.14, 95% CI: 0.97, 1.34, p = 0.10) compared to an IPI of 6 to 11 months (4.5%) after a miscarriage. Inherent to retrospective registry-based studies, we did not have information on potential confounders such as pregnancy intention and health-seeking bahaviour. Furthermore, we only had information on miscarriages that resulted in contact with the healthcare system. Our study suggests that conceiving within 3 months after a miscarriage or an induced abortion is not associated with increased risks of adverse pregnancy outcomes. In combination with previous research, these results suggest that women could attempt pregnancy soon after a previous miscarriage or induced abortion without increasing perinatal health risks.
The aim of this study was to examine the separate and joint effects of previous pregnancy history, year of pregnancy outcome, maternal age, height, smoking and fertility on risk of fetal death. Data were available from a study of female radiographers. Analyses were carried out on 3053 women with a total of 6993 pregnancies. Women reporting problems with conception or previous fetal losses had an increased risk of a pregnancy ending in a fetal death. In particular, women with primary or secondary infertility had an approximately fourfold increase in risk compared with women who reported no difficulties [odds ratio (OR): 3.92; 95% confidence interval (CI): (3.02, 5.07)]. This relationship was independent of pregnancy order and pregnancy history and was more marked in older maternal ages. The effect of pregnancy history was cumulative and possibly multiplicative in effect, with a threefold increase in the risk of losing a third pregnancy following two previous losses [OR: 3.19; 95% CI: (1.60, 6.35)]. There were no consistent patterns of risk associated with year of pregnancy outcome, maternal age, height or smoking status. These results suggest that previous pregnancy outcomes and problems with conception may be the strongest determinants of fetal loss in subsequent pregnancies.
To describe the relationship between pregnancy complications and fetal outcome in first and second pregnancies, focusing on idiopathic and indicated preterm birth of singleton infants in either pregnancy. Included in the study were 13,967 women in Denmark who gave birth to their first singleton infant in 1982 and a second infant in 1982-1987. Information on pregnancy and birth was obtained by linking the National Medical Birth Register and the National Register of Hospital Discharges, based on personal identification numbers. The risk of a preterm second birth in women with idiopathic and indicated preterm first birth did not differ significantly (15.2 and 12.8%, respectively). However, women with idiopathic preterm birth in the first pregnancy tended to repeat idiopathic preterm birth twice as often as women with indicated preterm birth repeated indicated preterm birth (11.3 versus 6.4%). Adjustment by logistic regression analysis for other risk factors for preterm birth did not influence the relative risk (6.0 before 32 weeks and 4.8 for 32-36 weeks) of a second preterm birth after a first preterm birth. Women with idiopathic preterm delivery in their first and second pregnancies gave birth to infants with lower birth weight than in previous or subsequent pregnancies. Emergency cesarean delivery in a first term pregnancy was a risk factor for subsequent idiopathic preterm birth. Idiopathic preterm birth is associated with emergency cesarean delivery at term in previous pregnancies and infants with lower birth weight in previous and subsequent pregnancies.
PMID 10576181 10576181 DOI 10.1016/s0029-7844(99)00440-8 10.1016/s0029-7844(99)00440-8 Zhou et al. 1999, Zhou 1999
Cite this article
Zhou, W., Sørensen, H. T., & Olsen, J. (1999). Induced abortion and subsequent pregnancy duration. Obstetrics and gynecology, 94(6), 948-953. https://doi.org/10.1016/s0029-7844(99)00440-8
Zhou W, Sørensen HT, Olsen J. Induced abortion and subsequent pregnancy duration. Obstet Gynecol. 1999;94(6):948-953. doi:10.1016/s0029-7844(99)00440-8
Zhou, W., et al. "Induced abortion and subsequent pregnancy duration." Obstetrics and gynecology, vol. 94, no. 6, 1999, pp. 948-953.
