The Association between Smoking and Ectopic Pregnancy: Why Nicotine Is BAD for Your Fallopian Tube
Researchers have found a connection between ectopic pregnancy and smoking, a connection that may literally prevent a woman from ever having children at all. Scientists found that women who smoked and developed an ectopic pregnancy had double the levels of the protein in their fallopian tubes. The multivariate results showed a strong relationship between smoking and ectopic pregnancy risk: Compared with women who had never.
Colin Duncan 1 Andrew W. The authors have declared that no competing interests exist. Conceived and designed the experiments: Received Dec 5; Accepted Jan This article has been cited by other articles in PMC.
Associated Data File S1: Primary antibody dilution and detection details.
Here, we set out to determine the effect of smoking on Fallopian tube gene expression. We therefore assessed the effect of smoking on cell turnover in retrospectively collected human samples. These results suggest that smoking may alter tubal epithelial cell turnover and is associated with structural, as well as functional, changes that may contribute to the development of ectopic pregnancy. In the Western world, it remains the most common life-threatening early pregnancy complication .
Nevertheless, descriptive observations support the hypothesis that tubal implantation is likely caused by embryo retention within the Fallopian tube due to impaired tubal transport and alterations in the tubal microenvironment allowing early implantation to occur. Transport of the embryo through the Fallopian tube is controlled by a combination of smooth muscle contractility and ciliary beating . The factors that regulate and maintain the normal tubal microenvironment are largely unknown.
Epidemiological studies have shown that cigarette smoking is a major risk factor for tubal ectopic pregnancy adjusted OR 1.
Despite these findings, the exact mechanism by which cigarette smoking leads to ectopic pregnancy remains uncertain. We recently reported that cotinine an active metabolite of nicotine increases the expression of prokineticin PROKR1 in the Fallopian tube, a regulator of smooth muscle contractility and a gene thought to be important for intrauterine implantation . We proposed that cigarette smoking attenuates tubal PROKR1 expression resulting in changes in Fallopian tube function, providing a possible explanation for the link between smoking and tubal ectopic pregnancy.
In this study, we take this finding forward by investigating how smoking alters global gene expression and function of tubal epithelial cells. Serum samples 10 ml and Fallopian tube biopsies 2—3 cm from the ampullary region of the Fallopian tube were collected from participants at the time of hysterectomy for benign gynaecological conditions.
Smoking link to ectopic pregnancy - BBC News
Women were between 18 and 45 years of age. All biopsies were collected in the mid-luteal phase of the menstrual cycle, and cycle phase was later confirmed by estradiol and progesterone levels measured in the serum samples as described previously .
A smoking history was obtained from all patients. ELISA data were analyzed in conjunction with the smoking history provided by the participants.
A very strong relationship was observed between serum cotinine concentrations and the self-reported smoking status of the patients . Cells were seeded atcells per well in well dishes and incubated for 24 hours. All experiments were performed in triplicate and replicates pooled. Exposure of Human Fallopian Tube Explants to Cotinine Fallopian tube explant culture was performed as previously described .Ectopic Pregnancy
RNA was extracted using Trizol Invitrogen according to the manufacturer's instructions. The odds for women who smoked most heavily or more cigarettes a day--were 3. STD history was another important factor in ectopic pregnancy risk. Women who had had an STD with a confirmed diagnosis of pelvic inflammatory disease had more than tripled odds of ectopic pregnancy odds ratio, 3. Tubal surgery, which may occur because of STD-related infection, also was associated with substantially elevated odds of ectopic pregnancy 4.
As women's age increased, the risk of ectopic pregnancy grew.
- The Association between Smoking and Ectopic Pregnancy: Why Nicotine Is BAD for Your Fallopian Tube
- Smoking link to ectopic pregnancy
The sharpest rise occurred after age In some instances, previous pregnancy terminations were associated with increased odds of ectopic pregnancy. Women who had had one or two spontaneous abortions had no greater risk of ectopic pregnancy than those who had had none; the risk was elevated, however, for those who had had three or more odds ratio, 3.
Odds of Ectopic Pregnancy Are Sharply Elevated Among Heavy Smokers
And whereas women who had had only surgical abortions were at no greater risk than those who had never had an abortion, women who had had a medical abortion had elevated odds 2. Women who had experienced any period of infertility were at increased risk; odds ratios ranged from 2.
The researchers note that the relationship between infertility and ectopic pregnancy is particularly complex because each condition may be viewed as a consequence of the other, and they emphasize the importance of identifying common risk factors for the two.
Multiple factors may contribute to any occurrence of ectopic pregnancy, and individual proportions therefore add to more than the overall figure.