Attila Toth, M.D., * and Martin Lesser, Ph.D.**

Abstract

Background The chance of achieving a successful pregnancy through IVF is limited. This chance rapidly diminishes in subsequent cycles. The role of infections is uncertain.

Methods We performed a retrospective analysis on clinical data of 52 couples that visited our center after one or multiple previously failed IVF cycles who subsequently received broad-spectrum antibiotic therapy before returning for another IVF trial. The chance of achieving a pregnancy in subsequent IVF cycles, the course of the pregnancies, delivery events and health of the newborns were evaluated.

Results There was a significantly improved chance for the couples to achieve a successful pregnancy following antibiotic therapy when compared with historical controls in conventional repeat IVF cycles.  Except for one case of preeclampsia, there was no other pregnancy-related complication. Cesarean section was performed on an elective basis, none of the newborns suffered from IUGR. For the 19 deliveries there were 24 neonatal ICU days, all but four for the twins’ and triplets’ deliveries. For singleton pregnancies, there were no perinatal maternal or fetal complications.   

Conclusion These findings support the hypothesis that a certain number of failures during IVF cycles are due to an intrauterine infection that could affect the course of the pregnancy, the mode of delivery and cause maternal and fetal complications.

Source Information

* MacLeod Laboratory, New York Presbyterian Medical Center, 65 East 79^th Street New York NY. 10021.

**Biostatistic Unit, Feinstein Institute for Medical Research, North Shore LIJ Health System, 1129 Northern Blvd., Manhasset, NY. 11030

Address reprint request to Attila Toth, MD at 65 East 79^th Street, New York, NY 10021. E-mail address: tiltoth@aol.co


http://www.ispub.com/ostia/index.php?xmlFilePath=journals/ijgo/vol7n1/outcome.xml

While improvements in IVF technology have offered numerous infertile couples the chance to achieve a successful pregnancy the per cycle success rate in most clinics hovers around 25% (1, 2) and the chance for a successful outcome diminishes with subsequent trials. The cumulative live birth rate after seven IVF cycles is around 60% (3-8). Some of the failures are attributed to male factor (9), poor oocyte quality (10), reduced ovarian reserve (11), uterine problems (12), and chromosomal abnormalities of the embryos (13). In general, advanced maternal age is associated with a poorer outcome (14). The role of infections is also appreciated and most IVF cycles are complemented with a limited oral antibiotic regimen (15-19). In a high percentage of cases, however, the cause of failure remains unknown. In addition there are only speculative explanations why IVF pregnancies are more often complicated by premature birth, intrauterine growth retardation and chromosomal abnormalities than naturally conceived pregnancies (20-23).

Two decades of favorable experience with antibiotic therapy, initially given orally, later administered intravenously with uterine lavages, both in terms of reversing infertility and improving pregnancy outcome, prompted us to offer broad spectrum antibiotic therapy to couples who have failed one or multiple IVF cycles and were ready to return for subsequent trials (24, 25).

We report our experience here with the first 52 couples that were treated at our clinic between 01/01/2002 and 04/01/2004.

Methods

Study Design

A retrospective chart analysis and telephone follow up was carried out on 52 couples who were treated at the MacLeod Laboratory between January first 2002 and April first 2004. The Institutional Review Board of New York Presbyterian Hospital approved the study. Informed consent was obtained from the patients for data collection, analysis and publication conforming with local and national regulations. The authors had full access to the data, directed the data analysis, and were responsible for decisions regarding publication. The principal investigator (Dr. Toth) assumes full responsibility for the integrity and interpretation of the data.  

Patients

52 consecutive couples with history of primary or multiple previously failed IVF cycles that were referred to us through different infertility websites or through direct patient referral for antibiotic therapy were eligible for the study. Before initiating the antibiotic therapy both husband and wife underwent serum antisperm antibody testing using immunobead technique. Cervical and endometrial cultures on the females and seminal fluid and urethral cultures on the males were performed. Chlamydia trachomatis was tested for using the Pathfinder Direct Antigen Detection System from Bio-Rad Laboratories, A7 differential agar was used to identify Mycoplasma, and API systems were used for aerobic bacteria identification. Ramel Rapid Ana II system was used to identify anaerobic bacteria and the API 20c AUX system was used to identify yeast. The Rapid NH System identified Neisseria and Haemophilus. Trichomonas vaginalis was identified after overnight growth in a selective broth. (In Pouch TV test Kit). The result of the culture studies did not influence the recommendation of antibiotic therapy. All females were treated with a combination of ten days of intravenous Clindamycin in full therapeutic dose, typically, 900 mg every 8 hours for an individual of 150 lbs body weight, and five intrauterine lavages performed on consecutive days of the first five days of IV therapy.  The lavages applied a mixture of 6 grams ampicillin, 160 mgs gentamicin, 4 mgs fluconazole (Diflucan), and 10 mgs metronidazol delivered one-hour daily using an ambulatory pump and a Cook 5.3FR intrauterine catheter. At the end of each lavage the uterine cavity and cervical canal were filled with a 20% metronidazol containing gel prepared by a local pharmacy. Following this, a three-week oral doxicycline course, 100 mgs twice daily, completed the treatment course. Similarly, intravenous Clindamycin was offered to the males (26 patients) and for those who declined the intravenous antibiotic, Augmentin 875 mgs twice daily for fourteen days was substituted. For both groups, this regimen was followed by oral doxicycline, 100 mgs twice daily for an additional three weeks. Except for two cases of mild diarrhea, which responded promptly to oral metronidazol, no other complications were encountered with any of the antibiotic treatment modalities.

Study Procedure and End Points

Reproductive events following the completion of the antibiotic therapy were gathered through a direct telephone interview up to a successful pregnancy or if a successful pregnancy did not occur, up to a maximum of 18 months.

Statistical Methods

Using three published studies, all with large number of cases and a high order of IVF cycles Osmanagaoglu K. et al. (6), Lass A. et al (14) and Witsenburg C. et al (8), the primary statistical analyses were comparisons of the delivery rates for the antibiotic-treated patients with those of three different historical control samples of "conventional" IVF patients. This was accomplished using the Mantel-Haenszel (MH) test, stratified according to the number of previously failed cycles.  More specifically, each of the published manuscripts contained tables showing the number of patients entering a given IVF cycle and the number who delivered immediately after that cycle.  (For calculation purposes, the number of previously failed cycles was the current cycle minus one.)  Similarly, for patients treated with antibiotics prior to an IVF cycle, an outcome was counted as a “delivery” only if the patient conceived and delivered immediately after the IVF cycle corresponding to the pre-treatment with antibiotics. Based on this information, multiple 2x2 contingency tables comparing the delivery frequency of the antibiotic sample with the particular historical sample were formed, each table corresponding to (i.e., stratified for) the number of failed cycles.  For the few patients with more than 6 previously failed cycles, the corresponding data were aggregated into a table indexed as "6 or more failed cycles". For this analysis the four spontaneous pregnancies were excluded from all calculations, since the control publications counted such pregnancies as “drop outs” and were not included in their calculations.

The standard MH test was used, first checking for homogeneity of the odds ratios using the Breslow-Day (BD) test (SAS Version 9.1, SAS Institute, Cary, NC).  In all reported analyses, the BD test was non-significant (P-values ranging from 0.24 to 0.83), thus allowing for "combining" the stratified 2x2 tables according to the MH method.  Due to the sparseness of many of the tables, exact MH tests were also carried out with nearly identical results (StatXact, Version 3.0.2, Cytel Software, Cambridge, MA).  In cases where a published result was restricted to a certain age group, the antibiotic-treated group was also restricted to that age group.  Results are reported in terms of relative risk (RR) and its associated 95% confidence interval (CI).  In this report, RR represents the "risk" of a successful delivery for the antibiotic treated group relative to the particular conventional IVF control.  A result was considered statistically significant if P<0.05.

Since the distribution of "number of prior failures" differed for the antibiotic-treated group relative to each of its comparators, the crude delivery rates are not comparable.  To make the rates comparable, the delivery rates for the antibiotic group were standardized to that of each respective comparator using the so-called "direct standardization method" (26).

Description of the Antibiotic-Treated Cohort

Table 1 shows the demographic, clinical, and pregnancy outcome profiles of the antibiotic-treated group of patients.  With the exception of age, statistics for these variables were not available in the published papers used for comparison.

Comparisons of Ages

• There were 52 patients studied in the antibiotic-treated group.  The average patient's age was 38.5 (± 4.2 SD). 
• The Osmanagaoglu historical control group consisted of women over 37 years old (mean 40.1, no SD given).  When the antibiotic-treated group was restricted to over 37 years old, the mean age was 41.2 ± 2.7 years.
• The group studied in Lass was 40 years and older.
• The Witsenburg sample was more general with a mean age of 33.0 ± 4.0 years (compared to 38.5 ± 4.2 in the antibiotic sample).

Table 2

Relative Risk of Delivery with Antibiotic Treatment Relative to Three Historical Controls

	Antibiotic (Toth)		Osmanagaoglu a			Antibiotic (Toth)		Lass b			Antibiotic (Toth)		Witsenburg c
No. Prior Failures	Delivery***		Delivery			Delivery***		Delivery			Delivery***		Delivery
	Yes	No	Yes	No		Yes	No	Yes	No		Yes	No	Yes	No
1	3	3	5	98		2	3	13	181		5	6	136	357
2	1	1	4	52		1	0	5	62		1	6	64	235
3	4	5	3	24		4	2	1	23		4	8	23	128
4	1	2	2	11		1	8	0	10		4	4	11	62
5	0	2	1	5		*	*	*	*		0	2	7	32
6 or more	1	6	0	4		*	*	*	*		2	6	3	11
Totals	10	19	15	194		8	13	19	276		16	32	244	825
Crude Delivery Rate	34.4%		7.2%			38.1%		6.4%			33.3%		22.8%
Adjusted Delivery Rate**	46.1%		7.2%			54.8%		6.4%			33.8%		22.8%
MH Relative Risk	RR=4.5 95%CI: 2.1-9.5 P<0.0001					RR=12.5 95%CI: 4.5-34.8 P<0.0001					RR=1.7 95%CI: 1.1-2.6 P<0.0302

* Due to small numbers, data for "5" and "6 or more" prior failures have been aggregated with "4" to become "4 or more".
** Direct standardization with respect to "number of prior failures" distribution of comparator.
***Spontaneous pregnancies (n=4 total) excluded from all frequency counts and analyses
a: age > 37
b: age ≥ 40
c: all ages

1. Assisted reproductive technology in the United States: 1999 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology Registry. Fertil Steril 2002; 78:918-31.
2. Assiste