Vaginal bleeding and early pregnancy outcome in an infertile population

Early pregnancy bleeding after assisted reproductive technology: a systematic review and secondary data analysis from 320 patients undergoing hormone replacement therapy frozen embryo transfer

STUDY QUESTION

How common is bleeding in early pregnancy after Hormone Replacement Therapy (HRT) Frozen Embryo Transfer (FET) and does bleeding affect the reproductive outcome?

SUMMARY ANSWER

A total of 47% of HRT-FET patients experience bleeding before the eighth week of gestation, however, bleeding does not affect the reproductive outcome.

WHAT IS KNOWN ALREADY

Bleeding occurs in 20% of spontaneously conceived pregnancies, although most will proceed to term. However, our knowledge regarding bleeding in early pregnancy after HRT-FET and the reproductive outcome is sparse.

STUDY DESIGN, SIZE, DURATION

We performed a systematic review of the existing literature on early pregnancy bleeding after assisted reproductive technology (ART) to evaluate the bleeding prevalence and resulting reproductive outcome in this population. A random-effects proportional meta-analysis was conducted. Subsequently, we performed a prospective cohort study including 320 pregnant patients undergoing HRT-FET and a secondary analysis of the cohort study was performed to evaluate bleeding prevalence and reproductive outcome. The trial was conducted from January 2020 to November 2022 in a public fertility clinic.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A systematic literature search was performed, using MESH terms and included studies with data from ART patients and with early pregnancy bleeding as a separate outcome. The cohort study included patients with autologous vitrified blastocyst transfer treated in an HRT-FET protocol. In the event of a positive HCG-test, an early pregnancy scan was performed around 8 weeks of gestation. During this visit, patients answered a questionnaire regarding bleeding or spotting and its duration after the positive pregnancy test. The information was verified through medical files, and these were used to obtain information on reproductive outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

The review revealed a total of 12 studies of interest. The studies reported a prevalence of early pregnancy bleeding ranging from 2.1% to 36.2%. The random effects proportional meta-analysis resulted in a pooled effect estimate of the prevalence of early pregnancy bleeding in the ART population of 18.1% (95% CI (10.5; 27.1)). Four of the included studies included data on miscarriage rate following an episode of bleeding. All four studies showed a significantly increased risk of miscarriage in patients with early pregnancy bleeding as compared to patients with no history of bleeding. No studies investigated bleeding after HRT-FET specifically. In our HRT-FET cohort study, we found that a total of 47% (149/320) of patients with a positive pregnancy test experienced bleeding before 8 weeks of gestation. Generally, the bleeding was described as spotting with a median of 2 days (range 0.5-16 days). Out of 149 patients with one or several bleeding episodes, a total of 106 patients (71%) had an ongoing pregnancy at 12 weeks of gestation. In comparison, 171 patients reported no bleeding episodes and a total of 115 (67%) of these patients had an ongoing pregnancy at 12 weeks of gestation. This difference was not significant (P = 0.45). Furthermore there was no difference in the live birth rate between the two groups (P = 0.29).

LIMITATIONS, REASONS FOR CAUTION

Most studies included in the review were older and not all studies specified the type of ART. Moreover, the studies were of moderate methodological quality. The patients in the cohort study were treated in a personalized HRT-FET protocol using a rectal supplementary rescue regimen if serum progesterone levels were <35 nmol/l at embryo transfer. The results may not be applicable to other FET protocols, and the present data were based on self-reported symptoms. The systematic review revealed an increased risk of miscarriage following an episode of early pregnancy bleeding. However our cohort study found no such association. This discrepancy can partly be due to the fact, that the four studies in the review only included episodes of heavy bleeding. Also, none of the four studies included data on HRT-FET cycles making them unfit for direct comparison.

WIDER IMPLICATIONS OF THE FINDINGS

Episodes of early bleeding during pregnancy are associated with distress for the pregnant woman, especially in a cohort of infertile patients. Our cohort study showed that at least minor bleeding seems to be a common adverse event of early pregnancy after HRT-FET. From the systematic review, it seems that this prevalence is higher than what has previously been described in relation to other types of ART. However, minor bleeding during early pregnancy after HRT-FET does not seem to affect the reproductive outcome. Knowledge regarding the frequent occurrence of bleeding during early pregnancy after HRT-FET and the fact that this should not be used as a prognostic parameter will help the clinician in counselling patients.

STUDY FUNDING/COMPETING INTEREST(S)

Gedeon Richter Nordic supported this investigator-initiated study with an unrestricted grant as well as study medication (Cyclogest). B.A. has received an unrestricted grant from Gedeon Richter Nordic and Merck and honoraria for lectures from Gedeon Richter, Merck, IBSA, and Marckyrl Pharma. P.H. received honoraria for lectures from Merck, Gedeon Richter, Institut Biochimique SA (IBSA), and Besins as well as unrestricted research grants from Merck, Gedeon Richter, and Institut Biochimique SA (IBSA). The other authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

EudraCT no.: 2019-001539-29.

Fetal loss in threatened abortion after demonstration of fetal cardiac activity in a low socioeconomic population

This study was conducted to determine the incidence and risk factors of fetal loss in threatened abortion after ultrasonographic detection of fetal cardiac activity in a low socioeconomic population. A total of 202 women with singleton pregnancies who presented with vaginal bleeding in which fetal heart activity was ultrasonographically demonstrated between 5 and 14 weeks' gestation were included. Pregnancies with fetal abnormalities were excluded from the study. All cases were followed-up with respect to pregnancy outcomes. A total of 54 of 202 pregnancies (26.7%) resulted in fetal loss before 20 weeks' gestation. The mean fetal heart rate (FHR) and cervical length values were lower in spontaneous abortions than in viable pregnancies (121.2 +/- 13.3 vs 143.5 +/- 12.4 and 41 +/- 6.0 vs. 34.8 +/- 6.1, respectively; p < 0.001). A receiver operating characteristic (ROC) curve analysis revealed an area under the curve of 0.88 for FHR and 0.77 for cervical length. A FHR value <130 b.p.m. was 81.4% sensitive, 85.1% specific and a cervical length value <40 mm was 80.8% sensitive, 54.7% specific for determination of fetal loss before 20 weeks' gestation. Fetal loss was observed in about one-quarter of pregnancies admitted with threatened abortion in a low socioeconomic population. Bradycardia and short cervix were found to be significant risk factors affecting the pregnancy outcome in women presenting with vaginal bleeding, in whom fetal cardiac activity was documented.

First-trimester bleeding and pregnancy outcome in singletons after assisted reproduction

BACKGROUND

First-trimester bleeding is frequent in assisted reproductive technique (ART) pregnancies. It is unknown whether first-trimester bleeding, if not ending in a spontaneous abortion, negatively influences further pregnancy outcome in ART in singletons.

METHODS

Data were obtained from our ART database (1993-2002), with 1432 singleton ongoing pregnancies being included in this study. The outcome measures-second-trimester and third-trimester bleeding, preterm contraction rates, pregnancy duration, birthweight, Caesarean section rates, intrauterine growth retardation (IUGR), preterm prelabour rupture of membranes (P-PROM), neonatal intensive care unit (NICU) admission and perinatal mortality-were compared in the groups with and without first-trimester bleeding.

RESULTS

Significantly more singleton pregnancies resulted from a vanishing twin in the group with first-trimester bleeding (8.7%) than in the controls (4.0%). A correlation was found between the incidence of first-trimester bleeding and the number of embryos transferred. First-trimester bleeding led to increased second-trimester [odds ratio (OR)=4.56; confidence interval (CI)=2.76-7.56] and third-trimester bleeding rates (OR=2.85; CI=1.42-5.73), P-PROM (OR=2.44; CI=1.38-4.31), preterm contractions (OR=2.27; CI=1.48-3.47) and NICU admissions (OR=1.75; CI=1.21-2.54). First-trimester bleeding increased the risk for preterm birth (OR=1.64; CI=1.05-2.55) and extreme preterm birth (OR=3.05; CI=1.12-8.31).

CONCLUSIONS

First-trimester bleeding in an ongoing singleton pregnancy following ART increases the risk for pregnancy complications. The association between first-trimester bleeding, the number of embryos transferred and adverse pregnancy outcome provides a further argument in favour of single-embryo transfer.

Fetal loss in threatened abortion after embryonic/fetal heart activity

OBJECTIVES

To study the incidence of fetal loss in threatened abortion after detection of embryonic/fetal heart activity.

METHODS

A prospective study was performed on pregnant women with clinically diagnosed threatened abortion between 6 and 14 weeks of gestation. All had a good menstrual history and the calculated gestational age using crown-rump length in the first trimester ultrasound was in agreement. Embryonic/fetal heart rate measurements were obtained by a 5 MHz vaginal probe using M-mode and real-time B mode imaging. All cases were followed up with respect to pregnancy outcomes. The data were analyzed using the SPSS computer program.

RESULTS

Eighty-seven pregnant women were included in the study. There were three pregnancies (3.4%) which resulted in fetal loss before 20 weeks of gestation. In viable pregnancies, the mean embryonic/fetal heart rate increased with advancing gestational age. The individual values of embryonic/fetal heart rate for fetal losses were within the reference range.

CONCLUSIONS

The incidence of fetal loss in threatened abortion after detection of embryonic/fetal heart activity was 3.4%. There was no evident pattern of bradycardia or tachycardia that signaled the incipient of viability.