The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

Vaginal delivery in SARS-CoV-2-infected pregnant women in Northern Italy: a retrospective analysis

OBJECTIVE

To report mode of delivery and immediate neonatal outcome in women infected with COVID-19.

DESIGN

Retrospective study.

SETTING

Twelve hospitals in northern Italy.

PARTICIPANTS

Pregnant women with COVID-19-confirmed infection who delivered.

EXPOSURE

COVID 19 infection in pregnancy.

METHODS

SARS-CoV-2-infected women who were admitted and delivered from 1 to 20 March 2020 were eligible. Data were collected from the clinical records using a standardised questionnaire on maternal general characteristics, any medical or obstetric co-morbidity, course of pregnancy, clinical signs and symptoms, treatment of COVID 19 infection, mode of delivery, neonatal data and breastfeeding.

MAIN OUTCOME AND MEASURES

Data on mode of delivery and neonatal outcome.

RESULTS

In all, 42 women with COVID-19 delivered at the participating centres; 24 (57.1%, 95% CI 41.0-72.3) delivered vaginally. An elective caesarean section was performed in 18/42 (42.9%, 95% CI 27.7-59.0) cases: in eight cases the indication was unrelated to COVID-19 infection. Pneumonia was diagnosed in 19/42 (45.2%, 95% CI 29.8-61.3) cases: of these, 7/19 (36.8%, 95% CI 16.3-61.6) required oxygen support and 4/19 (21.1%, 95% CI 6.1-45.6) were admitted to a critical care unit. Two women with COVID-19 breastfed without a mask because infection was diagnosed in the postpartum period: their newborns tested positive for SARS-Cov-2 infection. In one case, a newborn had a positive test after a vaginal operative delivery.

CONCLUSIONS

Although postpartum infection cannot be excluded with 100% certainty, these findings suggest that vaginal delivery is associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn.

TWEETABLE ABSTRACT

This study suggests that vaginal delivery may be associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn.

Assisted reproductive technologies and uterine factors influencing their success

Congenital and acquired uterine factors are known to influence the success of assisted reproductive technologies (ARTs). Several studies analyzed the role of uterine septa, adenomyosis, myomas, endometrial polyps and intrauterine adhesions in female infertility. All of them might cause defective endometrial receptivity and consequently decreased embryo implantation and pregnancy rate. In particular, septate uterus represents the most frequent Müllerian anomaly leading to an increased risk of abortion. Many studies evaluated the role of hysteroscopic metroplasty on fertility outcomes, but this topic remains controversial. The role of adenomyosis in infertility is still debated and, even if different mechanisms have been described to explain implantation failure, there are still conflicting findings on the impact of adenomyosis on ART. The effects of myomas on fertility mainly depend on their type, so that submucous have a detrimental impact on fertility, subserous seem to have no effect, while there is no clear consensus regarding the effect of intramural. Consequently, the potential influence of myomectomy on fertility outcomes depends on the type, being mandatory only the hysteroscopic treatment of submucous myomas. The effect of endometrial polyps on endometrial receptivity and fertility is not clear, even if some studies identified improvement in pregnancy rates after hysteroscopic polipectomy. In presence of intrauterine adhesions, infertility represents the most common manifestation and the restoring of normal uterine cavity should be always pursued when possible.

Reproductive assistance in HIV serodiscordant couples

BACKGROUND

Three quarters of individuals infected with human immunodeficiency virus (HIV) are in their reproductive years and may consider pregnancy planning. Techniques have been developed which can minimize the risk of HIV transmission in these couples, and the current literature on this topic is reviewed here.

METHODS

We reviewed the literature for the following topics: risk of HIV transmission, effects of HIV infection on fertility, reproductive assistance in industrialized and low-income countries, pre-exposure chemoprophylaxis (PrEP) and timed intercourse in HIV-discordant couples for both male and female positivity. Relevant publications were identified through searches of the EMBASE Medline and PubMed databases, the Google-indexed scientific literature and periodic specialized magazines from the on-line Library Service of the University of Milan, Italy.

RESULTS

In serodiscordant couples in which the man is positive, the primary method used to prevent HIV transmission is 'sperm washing', followed by IUI or IVF. Data show that sperm washing in HIV-positive men has not produced seroconversion in women or their offspring; however, the evidence is limited. Recently, increasing evidence describing PrEP for HIV prevention has been published and PrEP could be an alternative to ART for fertile couples. Usually HIV-infected women undergo self-insemination around the time of ovulation. Few studies have been published on IVF outcome in HIV-infected women.

CONCLUSIONS

Assisted reproduction programmes should be integrated into global public health services against HIV. For HIV serodiscordant couples with infected men, sperm washing should be the first choice. However, timed intercourse and PrEP for HIV prevention has been reported. Recent data highlight the possible impairment of fertility in HIV-infected women. Efforts to design a multicentric study should be strengthened.

Women facing HIV. Key question on women with HIV infection: Italian consensus workshop

A panel of leading Italian specialists in infectious diseases, obstetrics and gynaecology met in a national consensus workshop on women facing HIV to review critical aspects and discuss recommendations for selected key questions on four issues: (1) women and highly active antiretroviral therapy (HAART): access to care and adherence to therapy, side effects and drug-drug interaction; (2) HIV-infected pregnant women: prevention of mother to child transmission; (3) desire for children among women living with HIV: assisted reproduction; (4) sexually transmitted diseases and genital disturbances. The method of a nominal group meeting was used, and recommendations were graded for their strength and quality of evidence using a system based on the one adopted by the Infectious Diseases Society of America. Main conclusions are summarized and critically discussed, and some of the most recent data supporting recommendations are provided.

Reproductive assistance for infected couples with bloodborne viruses

During the past 15 years Assisted Reproduction has been facing a new demand from patients requiring ART: couples at risk of partner to partner, and mother to child transmission of viral infections, mainly HIV-1, HCV and HIV-HCV co-infected partners. The general conditions and life expectancy of many patients with HIV infection are very good, and three-quarters of these individuals are in their reproductive years. For these reasons, a large number of young couples are expected to make future plans to have children. This desire is not easy to realize for serodiscordant couples, if we consider that, in order to avoid HIV virus transmission, it is necessary to encourage the condom use in vaginal and anal contacts. On the other hand infertile discordant HCV couples need to be included in protocols of controlled assisted reproduction procedures to avoid any risk of HCV transmission to the partner. In this paper we consider assisted reproduction in discordant couples for HIV or HCV-positive men.

Hepatitis B or hepatitis C coinfection in HIV-infected pregnant women in Europe

OBJECTIVES

The aim of the study was to investigate the prevalence of and risk factors for hepatitis C or B virus (HCV or HBV) coinfection among HIV-infected pregnant women, and to investigate their immunological and virological characteristics and antiretroviral therapy use.

METHODS

Information on HBV surface antigen (HBsAg) positivity and HCV antibody (anti-HCV) was collected retrospectively from the antenatal records of HIV-infected women enrolled in the European Collaborative Study and linked to prospectively collected data.

RESULTS

Of 1050 women, 4.9% [95% confidence interval (CI) 3.6-6.3] were HBsAg positive and 12.3% (95% CI 10.4-14.4) had anti-HCV antibody. Women with an injecting drug use(r) (IDU) history had the highest HCV-seropositivity prevalence (28%; 95% CI 22.8-35.7). Risk factors for HCV seropositivity included IDU history [adjusted odds ratio (AOR) 2.92; 95% CI 1.86-4.58], age (for > or =35 years vs. <25 years, AOR 3.45; 95% CI 1.66-7.20) and HBsAg carriage (AOR 5.80; 95% CI 2.78-12.1). HBsAg positivity was associated with African origin (AOR 2.74; 95% CI 1.20-6.26) and HCV seropositivity (AOR 6.44; 95% CI 3.08-13.5). Highly active antiretroviral therapy (HAART) use was less likely in HIV/HCV-seropositive than in HIV-monoinfected women (AOR 0.34; 95% CI 0.20-0.58). HCV seropositivity was associated with a higher adjusted HIV RNA level (+0.28 log(10) HIV-1 RNA copies/mL vs. HIV-monoinfected women; P=0.03). HIV/HCV-seropositive women were twice as likely to have detectable HIV in the third trimester/delivery as HIV-monoinfected women (AOR 1.95; P=0.049).

CONCLUSIONS

Although HCV serostatus impacted on HAART use, the association between HCV seropositivity and uncontrolled HIV viraemia in late pregnancy was independent of HAART.

Safety of sperm washing and ART outcome in 741 HIV-1-serodiscordant couples

BACKGROUND

To evaluate the safety of sperm washing and assisted reproduction technique (ART) outcome offered to serodiscordant couples with a human immunodeficiency virus-1 (HIV-1)-positive male.

METHODS

Sperm washing was performed and checked by RT-PCR on each semen sample before its fresh usage. Intrauterine insemination (IUI) or IFV/ICSI was offered according to fertility profile of each couple. Non-infected women underwent HIV testing 2 weeks before each procedure and for up to 6 months after.

RESULTS

Seven hundred and forty-one couples entered the study of a possible 2011 serodiscordant couples counselled over 4 years. Superovulation and IUI were performed in 581 couples, where the pregnancy rate per cycle and pregnancy rate per couple were 19 and 78%, respectively, with multiple pregnancy rate being 4%. One hundred and sixty couples were treated by IVF/ICSI, where pregnancy rate per cycle and per couple were 22 and 41%, respectively, with multiple pregnancy rate being 10%. All female partners were still HIV-1 negative at follow-up.

CONCLUSION

Sperm washing within a programme of reproductive counselling was proved to be safe in this large series of serodiscordant couples. The overall pregnancy rate (70.3%), independent of the procedure used (IUI or IVF/ICSI), justifies the effort of the medical team in setting up and implementing dedicated centres and of the individual patient in seeking a safe pregnancy.

Implantation Failure in Assisted Reproduction Technology and a Critical Approach to Treatment

In this article, we review the literature and our personal experience regarding the many factors that appear to influence implantation rate. Oocyte quality, as determined by patient age and aneuploidies, probably plays a major role in RIF. However, a panoply of other factors have been brought under investigation, quite often with contradictory results and additional intriguing questions to be studied. Infections of the vagina, cervix, and endometrium, the role of mucus aspiration and washing of the cervix on transfer, the role of catheter guidance for a correct transfer and potion of embryos, the effect of mock transfer, and the role of hysteroscopy and its timing before transfer procedures are analyzed both as a review of the literature and as opinions and data from our experience. Many of these factors are interlaced and from the apparently simple issue of trauma, to infections and immune modulation of hatching and implantation, a biological continuum can easily be identified. The impact of abnormalities of the immune system and of homeostasis abnormalities is also covered in a brief overview of reported works and our experience. These latter areas probably constitute the common biological background of all other external factors that, however, the skilled must equip themselves for improving implantation success.

The incidence of complications after caesarean section in 156 HIV-positive women

OBJECTIVE

To investigate the risks of post-operative complications in HIV-positive mothers who undergo a caesarean section (CS) because the delivery cannot be safely accomplished by the vaginal route or to protect the infant from viral infection.

DESIGN

In a multicentre study, we reviewed the incidence and type of post-operative complications in 156 HIV-positive women who underwent a CS. These results were compared with those observed in an equal number of HIV-uninfected women who matched for the indication requiring a caesarean delivery, the stage of labour, the integrity or rupture of membranes, and the use of antibiotic prophylaxis.

SETTING

Seven teaching hospitals providing obstetrical care for mothers infected with HIV.

RESULTS

We found that six HIV-infected mothers suffered a major complication (two cases of pneumonia, one pleural effusion, two severe anaemia and one sepsis) compared with only one HIV-negative woman who required blood transfusion after surgery. Minor complications like post-operative fever, endometritis, wound and urinary tract infections were significantly more frequent in HIV-positive women than controls. Multivariate analysis revealed that in HIV-infected women the only factor associated with a significant increase in the rate of complications was a CD4 lymphocyte count < 200 x 10(6)/l.

CONCLUSIONS

The results of our study indicate that HIV-positive mothers are at an increased risk of post-operative complications when delivered by CS. The risk of post-operative complications is higher in HIV-infected women who are severely immunodepressed.