Endometriosis linked to elevated risk of placenta previa in pregnancy

Association between surgically diagnosed endometriosis and adverse pregnancy outcomes

2018 Study Abstract

To examine the association between surgically diagnosed endometriosis and pregnancy outcomes in subsequent pregnancies.

Retrospective cohort study of women who delivered a singleton live birth from 2003 to 2013 in Ottawa, Ontario, Canada.

Tertiary level academic center.

Pregnant women with surgically diagnosed endometriosis were identified using International Classification of Diseases-10 codes from previous hospital admissions and were compared with pregnant women with no prior admission for endometriosis for the occurrences of adverse pregnancy outcomes.

Observational study.

Main Outcome Measure(s)
Gestational hypertension, preeclampsia, placenta previa, placental abruption, postpartum hemorrhage, preterm birth, low birth weight, small for gestational age, and neonatal intensive care unit admission.

Among the 52,202 eligible mother-infant pairs, we identified 469 mothers with surgically diagnosed endometriosis from a previous hospital encounter. Compared with women without endometriosis, women with endometriosis were on average older and were more likely to be primiparous, have lower gravidity, have a history spontaneous abortion, conceive with assisted reproductive technology, and reside in areas with higher neighborhood income and lower proportion of immigrants. Women with endometriosis were found to have an elevated risk of placenta previa (relative risk [RR], 3.30; 95% confidence interval [CI], 1.65–5.40) and cesarean delivery (RR, 1.24; 95% CI, 1.10–1.40). After adjustment for potential confounding factors, women with endometriosis were found to have a significantly elevated risk of placenta previa compared with women without endometriosis (adjusted RR, 2.54; 95% CI, 1.39–4.64).

This study identifies baseline demographic differences between women with and without endometriosis and suggests that women affected by endometriosis have an independently elevated risk of placenta previa in pregnancy.

Preterm birth associated with maternal fine particulate matter exposure

Millions of premature births could be linked to air pollution

Researchers for the Stockholm Environment Institute (SEI), the London School of Hygiene and Tropical Medicine and the University of Colorado, have concluded that as many as 3.4 million premature births across 183 countries could be associated with fine particulate matter, a common air pollutant, with sub-Saharan Africa, north Africa and south and east Asia most impacted by the issue.


  • Ambient fine particulate matter (PM2.5) exposure is a possible risk factor for preterm birth.
  • We estimate 2.7–3.4 million preterm births may be associated with PM2.5 exposure in 2010 globally.
  • South/East Asia, North Africa/Middle East and West sub-Saharan Africa had largest burdens.
  • Maternal PM2.5 exposure should be considered alongside other preterm birth risk factors.


Preterm birth associated with maternal fine particulate matter exposure: A global, regional and national assessment, sciencedirect, dx.doi.org/10.1016/j.envint.2017.01.023, 10 February 2017.

Millions of premature births could be linked to air pollution, study finds, the guardian, 16 February 2017.

Image credit Claude Robillard.

Reduction of preterm births (< 37 completed weeks of gestation) would substantially reduce neonatal and infant mortality, and deleterious health effects in survivors. Maternal fine particulate matter (PM2.5) exposure has been identified as a possible risk factor contributing to preterm birth. The aim of this study was to produce the first estimates of ambient PM2.5-associated preterm births for 183 individual countries and globally. To do this, national, population-weighted, annual average ambient PM2.5 concentration, preterm birth rate and number of livebirths were combined to calculate the number of PM2.5-associated preterm births in 2010 for 183 countries. Uncertainty was quantified using Monte-Carlo simulations, and analyses were undertaken to investigate the sensitivity of PM2.5-associated preterm birth estimates to assumptions about the shape of the concentration-response function at low and high PM2.5 exposures, inclusion of provider-initiated preterm births, and exposure to indoor air pollution.

Globally, in 2010, the number of PM2.5-associated preterm births was estimated as 2.7 million (1.8–3.5 million, 18% (12–24%) of total preterm births globally) with a low concentration cut-off (LCC) set at 10 μg m− 3, and 3.4 million (2.4–4.2 million, 23% (16–28%)) with a LCC of 4.3 μg m− 3. South and East Asia, North Africa/Middle East and West sub-Saharan Africa had the largest contribution to the global total, and the largest percentage of preterm births associated with PM2.5. Sensitivity analyses showed that PM2.5-associated preterm birth estimates were 24% lower when provider-initiated preterm births were excluded, 38–51% lower when risk was confined to the PM2.5 exposure range in the studies used to derive the effect estimate, and 56% lower when mothers who live in households that cook with solid fuels (and whose personal PM2.5 exposure is likely dominated by indoor air pollution) were excluded. The concentration-response function applied here derives from a meta-analysis of studies, most of which were conducted in the US and Europe, and its application to the areas of the world where we estimate the greatest effects on preterm births remains uncertain. Nevertheless, the substantial percentage of preterm births estimated to be associated with anthropogenic PM2.5 (18% (13%–24%) of total preterm births globally) indicates that reduction of maternal PM2.5 exposure through emission reduction strategies should be considered alongside mitigation of other risk factors associated with preterm births.

Environmental quality index low measure linked to preterm birth

Poor air quality associated with increased risk of preterm birth

Research using the Environmental Quality Index (EQI) linked increased risk of preterm birth with poor air quality, but not with overall low environmental quality. The study is one of the first to explore the relationship between preterm birth and environmental quality across a range of different environmental domains (including water, air, land, built environment and sociodemographic aspects).


The associations between environmental quality and preterm birth in the United States, 2000–2005: a cross-sectional analysis, BiomedCentral, 9 June 2015.
Salt Lake City by Augie Ray.

Many environmental factors have been independently associated with preterm birth (PTB). However, exposure is not isolated to a single environmental factor, but rather to many positive and negative factors that co-occur. The environmental quality index (EQI), a measure of cumulative environmental exposure across all US counties from 2000—2005, was used to investigate associations between ambient environment and PTB.

With 2000–2005 birth data from the National Center for Health Statistics for the United States (n = 24,483,348), we estimated the association between increasing quintiles of the EQI and county-level and individual-level PTB; we also considered environmental domain-specific (air, water, land, sociodemographic and built environment) and urban–rural stratifications.

Effect estimates for the relationship between environmental quality and PTB varied by domain and by urban–rural strata but were consistent across county- and individual-level analyses. The county-level prevalence difference (PD (95 % confidence interval) for the non-stratified EQI comparing the highest quintile (poorest environmental quality) to the lowest quintile (best environmental quality) was −0.0166 (−0.0198, −0.0134). The air and sociodemographic domains had the strongest associations with PTB; PDs were 0.0196 (0.0162, 0.0229) and −0.0262 (−0.0300, −0.0224) for the air and sociodemographic domain indices, respectively. Within the most urban strata, the PD for the sociodemographic domain index was 0.0256 (0.0205, 0.0307). Odds ratios (OR) for the individual-level analysis were congruent with PDs.

We observed both strong positive and negative associations between measures of broad environmental quality and preterm birth. Associations differed by rural–urban stratum and by the five environmental domains. Our study demonstrates the use of a large scale composite environment exposure metric with preterm birth, an important indicator of population health and shows potential for future research.

Breast feeding premature babies may improve their heart function as adults

Breastfed preterm babies may have better IQs, working memory, motor function


Preterm birth relates to long-term alterations in cardiac morphology and function. Understanding whether preterm postnatal life is a tractable period of cardiovascular development that can be positively altered by nutrition is relevant to long-term outcomes. We hypothesized that being fed human breast milk during early postnatal life is beneficial to long-term cardiac structure and function in preterm-born individuals compared with infant formulas.

Breast Milk Consumption in Preterm Neonates and Cardiac Shape in Adulthood, pediatrics, June 2016.

A total of 926 preterm-born infants originally took part in a randomized controlled trial of postnatal milk-feeding regimens between 1982 and 1985 across 5 different UK centers. Preterm-born individuals were randomly assigned to either breast milk donated by unrelated lactating women or nutrient-enriched formulas. We followed 102 individuals from this cohort: 30 of whom had been randomized to being fed exclusively human milk and 16 to being fed exclusively formula. As a comparison group, we recruited an additional 102 individuals born term to uncomplicated pregnancies. Cardiac morphology and function were assessed by MRI.

Breast feeding premature babies improves their heart function as adults, study shows, The BMJ 2016;353:i3307, 14 June 2016.

Preterm-born individuals fed exclusively human milk as infants had increased left and right ventricular end-diastolic volume index (+9.73%, P = .04 and +18.2%, P < .001) and stroke volume index (+9.79%, P = .05 and +22.1%, P = .01) compared with preterm-born individuals who were exclusively formula fed as infants.

Pediatrics / Children’s Health
Pregnancy / Obstetrics
Women’s Health / Gynecology
Breastfed preterm babies may have better IQs, working memory, motor function, medicalnewstoday, 02.08.2016.

This study provides the first evidence of a beneficial association between breast milk and cardiac morphology and function in adult life in those born preterm and supports promotion of human milk for the care of preterm infants to reduce long-term cardiovascular risk.

Infertility among Women exposed prenatally to DiEthylStilbestrol

DES-exposed women have a higher risk of infertility

2001 Study Abstract

pubmed logo
DES-exposed women have a higher risk of infertility

Although it is well established that women exposed to diethylstilbestrol in utero have an increased risk of spontaneous abortion, ectopic pregnancy, and preterm delivery, it is not known whether they also have an increased risk of infertility. The authors assessed this question in data from a collaborative follow-up study of the offspring of women who took diethylstilbestrol during pregnancy. In 1994, 1,753 diethylstilbestrol-exposed and 1,050 unexposed women from an ongoing cohort study (National Cooperative Diethylstilbestrol Adenosis Study and Dieckmann cohorts) provided data on difficulties in conceiving and reasons for the difficulty. Age-adjusted relative risks were computed for the association of diethylstilbestrol exposure with specific types of infertility. A greater proportion of exposed than unexposed women were nulligravid (relative risk (RR) = 1.3, 95% confidence interval (CI): 1.1, 1.5), and a greater proportion had tried to become pregnant for at least 12 months without success (RR = 1.8, 95% CI: 1.6, 2.1). Diethylstilbestrol exposure was significantly associated with infertility due to uterine and tubal problems, with relative risks of 7.7 (95% CI: 2.3, 25) and 2.4 (95% CI: 1.2, 4.6), respectively. The present findings indicate that diethylstilbestrol-exposed women have a higher risk of infertility than do unexposed women and that the increased risk of infertility is primarily due to uterine or tubal problems.

Sadly for many DES daughters having their own children is not possible! Many of us who have experienced miscarriages, want to have kids but are struggling or unable to…


  • Infertility among women exposed prenatally to diethylstilbestrol,NCBI, PMID: 11495854, 2001 Aug 15;154(4):316-21. Full text: Oxford Journals Medicine & Health International Journal of Epidemiology link.
  • NCI, DES Follow-up Study Published Papers.
More DES DiEthylStilbestrol Resources

Preterm Birth, Fetal Growth, Age at Menarche among Women exposed prenatally to DiEthylStilbestrol

DES exposed daughters more likely to have begun menstruating at younger age

DES Follow-up Study Summary

National Cancer Inst logo image
DES exposed daughters appeared to weigh slightly less and have a higher risk of being born prematurely than unexposed daughters. They also were somewhat more likely to have begun menstruating at age 10 or younger.

Research has suggested that early life characteristics, such as size at birth and age at menarche, may be associated with health conditions later in life. For example, some studies have suggested that low birth weight babies tend to have a higher risk of cardiovascular disease later in life. Other studies have shown that women who begin having periods at a young age have a slightly higher risk of breast cancer than those who begin menstruation later.

Although there has been a great deal of research on health of the 2nd generation (DES daughters) later in life, little attention has been paid to whether they were similar in terms of birth weight and other early life factors. Results from one of the early clinical trials of DES suggested that it might be related to lower birth weight and a higher risk of preterm birth. We conducted a systematic evaluation of DES daughters participating in the NCI DES Follow-up Study to determine whether there were any differences in birth weight, length of gestation, and the average age of first menstruation in the DES-exposed compared to unexposed daughters.

We found that there was a 2 to 3 fold increase in risk of having been born prematurely (before 37 weeks gestational age) among the DES-exposed compared to unexposed daughters. On average, DES daughters tended to weigh slightly less at birth, and there was also a 60% higher risk of being born too small, or small for gestational age (SGA), defined as less than the 10th percentile of birth weight at each gestational age. We found stronger effects for birth weight, SGA, and preterm birth among women who were participants in the original DESAD study, as compared to those who were in the Dieckmann clinical trial, suggesting that part of the effect may have been due to the higher risk pregnancies among the exposed women and not solely to DES exposure.

When we evaluated the risk of having started menstruation before age 11, we found no difference between the DES exposed and unexposed daughters. However, DES daughters did have a small increased risk (40%) of starting menarche very young-at age 10 or less-but this was based on very small numbers of participants who had very early menstruation.

In summary, DES exposed daughters appeared to weigh slightly less and have a higher risk of being born prematurely than unexposed daughters. They also were somewhat more likely to have begun menstruating at age 10 or younger. These effects may have a small impact on the risk of some diseases occurring later in life.

2011 Study Abstract:

Diethylstilbestrol (DES), a synthetic estrogen used in pregnancy during the 1950s and 1960s, provides a model for potential health effects of endocrine disrupting compounds in the environment. We evaluated prenatal exposure to DES, based on medical record review, in relation to gestational length, fetal growth, and age at menarche in 4429 exposed and 1427 unexposed daughters. DES exposure was associated with an increase in preterm birth (odds ratio (OR)=2.97; 95% CI=2.27, 3.87), and a higher risk of small for gestational age (SGA) (OR=1.61; 95% CI=1.31, 1.98). The association between DES exposure and early menarche was borderline, with stronger effects when early menarche was defined as ≤ 10 years (OR=1.41 95% CI=0.97, 2.03) than defined as ≤ 11 years (OR=1.16; 95% CI=0.97, 1.39). This study provides evidence that prenatal DES exposure was associated with fetal growth and gestational length, which may mediate associations between DES and health outcomes in later life.


  • Preterm birth, fetal growth, and age at menarche among women exposed prenatally to diethylstilbestrol (DES),NCBI, PMID: 21130156, 2011 Feb;31(2):151-7. doi: 10.1016/j.reprotox.2010.11.006. Epub 2010 Dec 2. Full text link.
  • NCI, DES Follow-up Study Published Papers.
More DES DiEthylStilbestrol Resources