Frequency of non-hormonal contraception around conception and association with congenital malformations in offspring

A case-control study using data on deliveries in the mid-1970s at five Connecticut hospitals (cases, n = 1427; controls, n = 3001) found little relationship between delivery of a malformed infant and use by the mother of nonhormonal contraceptive methods at conception. Of particular interest was the lack of an association with use of the rhythm method (odds ratio (OR) = 1.02, 95% confidence limits (CL) = 0.73, 1.42), spermicides (OR = 1.26, 95% CL = 0.85, 1.85) at conception and a modest association for the intrauterine device (IUD) one week before conception (OR = 1.99, 95% CL = 0.98, 4.04). Continued use of the IUD after conception may further increase the risk for malformations but this observation was statistically unreliable in the present study. Mothers of newborns with cleft lip and palate (OR = 2.91) and congenital hydrocele (OR = 4.64) were more frequent rhythm users at conception, and mothers of newborns with multiple anomalies had more recent IUD exposure (OR = 9.87), but these and all other specific congenital malformation groups were not significantly related to any non-hormonal contraceptive after adjustment for multiple observations. Potentially confounding maternal risk factors were controlled.

Effects of two low-dose oral contraceptives on serum lipids and lipoproteins: differential changes in high-density lipoprotein subclasses

Oral contraceptives containing DL-norgestrel or norethindrone with ethinyl estradiol were administered by random assignment to 21 menstruating women, matched for anthropometric measurements, age, diet, alcohol consumption, smoking, and exercise habits. Pretreatment and 7-week treatment blood samples were obtained and assayed for serum cholesterol, triglyceride high-density lipoprotein cholesterol (HDL-C), and total high-density lipoprotein (HDL), HDL2a, HDL2b, and HDL3 subclasses by analytic ultracentrifugation. Subjects using the norethindrone oral contraceptive had a significant increase in HDL-C: baseline, 46 mg/dl; 7 weeks, 51 mg/dl. Values for the subjects using the norgestrel oral contraceptive were not significantly changed: 46 and 44 mg/dl, respectively. Users of the norethindrone oral contraceptive had significant elevations of total HDL and HDL3, while norgestrel oral contraceptive users demonstrated no significant changes. HDL2b increased with the norethindrone oral contraceptive and declined with the norgestrel oral contraceptive. The changes in HDL2b from baseline to treatment were not significant (p greater than 0.05), but the change with the norethindrone oral contraceptive did differ significantly from that with the norgestrel oral contraceptive (p less than 0.02). These changes may indicate oral contraceptive-induced alterations in HDL structure and metabolism that could be related to the risk of development of atherosclerosis.

Fertility regulation in nursing women: IV. Long-term influence of a low-dose combined oral contraceptive initiated at day 30 postpartum upon lactation and infant growth

The study was designed to test the long-term influence of a low-dose combined oral contraceptive upon lactation and infant growth when treatment was initiated at day 30 postpartum. The contraceptive tested contained ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg. Two control groups were formed by women who received an injectable placebo or a Copper T at day 30 postpartum. Women in the injectable placebo group received non-hormonal contraceptives at day 90 postpartum. An exacting list of requirements for admission and continuation in the study was applied to all groups. The oral contraceptive group had a significantly lower percentage of cases in full nursing from the 4th through the 10th postpartum month when compared to both control groups. The average absolute weight of infants in the oral contraceptive group was significantly lower at several ages when compared to the placebo group but not when compared to the Copper T group. No adverse side effects upon infant's health were detected. It was concluded that the oral contraceptive tested showed a moderate inhibitory influence upon lactation when treatment was initiated at the beginning of the second postpartum month.

Endometriosis and infertility: a laparoscopic study of endometriosis among fertile and infertile women

To test the widely accepted--but not well-supported--impression that endometriosis and infertility are associated, we compared the prevalence of endometriosis visualized at laparoscopy in 100 patients being evaluated for infertility and in 200 fertile control subjects (two age-matched to each patient) undergoing tubal ligation. The extent of endometriosis and adhesions noted in the operative reports was classified according to the system proposed by The American Fertility Society. Endometriosis was found in 21 of the 100 infertile patients--mild in 11, moderate in 8, severe in 2. It was found in 4 (2%) of the 200 controls and was mild in all 4. Thus, endometriosis is more often present, and more often severe, among infertile patients. The risk of infertility was estimated to be almost 20 times greater with endometriosis than without. These data support the clinical impression that an association exists.

Plasma progesterone levels during long-term treatment with levonorgestrel silastic implants

Plasma progesterone levels were measured in 113 women using a subdermal implant containing 200 mg levonorgestrel (NORPLANT) in an attempt to assess the roles of anovulation and inadequate luteal function in the contraceptive action of this method. Twenty-two women using an IUD (Copper T 200) served as a control group. Blood samples were taken twice a week for 6 consecutive weeks. This was done one to four times in each subject during the first 7 years after insertion of NORPLANT. Plasma progesterone was measured by a specific RIA and criteria based upon normal values in this laboratory were used to define each set of samples as ovulatory, uncertain or anovulatory. The rate of anovulation varied between 25 and 80% throughout the 7 years. The highest rate was observed during the first year of treatment of treatment. The rate of anovulation was significantly correlated with the plasma levels of levonorgestrel. Varying degrees of inadequate corpus luteum function were detected among NORPLANT users. All sets of samples in the control group were ovulatory and compatible with normal luteal function. These results clearly show that continuous administration of levonorgestrel by means of NORPLANT interferes with ovulation and/or luteal function in a significant proportion of cycles throughout the first 7 years of use.

[Measurements of the urban low socioeconomic level in families with malnourished infants]

Two measurements of low socioeconomic level (LSL) were compared in a group of families of low socioeconomic strata from the Metropolitan Area of Santiago, Chile. The purpose was to search for an instrument capable of discriminating the more deprived sectors. The sample included 85 families with infant, the experimental group consisted of 42 families with severely malnourished infant, and the control group was formed by 43 families with healthy infant. The modified Graffar Scale and a Specific Index to measure LSL were applied throughout a survey carried out in the mothers. The study also comprised health and sociocultural aspects. Results indicated that the modified Graffar Scale does not discriminate at the level of an apparently homogeneous group. In contrast, the Specific Index does detect significant differences between both groups, as well as correlations between the health and sociocultural variables. The Specific Index is therefore a helpful and easy to use instrument when applied to urban groups of low socioeconomic level.

The effects of ampicillin on oral contraceptive steroids in women

1 Thirteen women taking long term oral contraceptive steroids were studied while taking ampicillin (500 mg three times daily) and compared to a control cycle while not taking ampicillin. 2 There were no significant changes in the plasma concentrations of ethinyloestradiol, levonorgestrel, follicle stimulating hormone or progesterone, although lower concentrations of ethinyloestradiol were noted in two women. 3 We conclude that most patients taking oral contraceptive steroids do not need to take alternative contraceptive precautions while taking ampicillin.

Epithelial ovarian cancer and combination oral contraceptives

The risk of epithelial ovarian cancer in relation to the use of combination oral contraceptives was evaluated in a case-control study of women younger than 60 years. Combination oral contraceptives were used by 35 (26%) of 136 cases and 187 (35%) of 539 controls. The relative risk estimate for combination oral contraceptive use was 0.6 (95% confidence interval, 0.4 to 0.9). The reduction in risk appeared to persist for as long as ten years after use had ceased and to be greater for longer durations of use, but these results were not statistically significant. The findings were not explained by parity or by other identified potential confounding factors. The results suggest that the use of combination oral contraceptives protects against epithelial ovarian cancer.

No increase in arteriolosclerotic retinopathy or activity in tests for circulating immune complexes 5 years after vasectomy

On the basis of studies in monkeys, the hypothesis has been proposed that vasectomy induces the formation of circulating immune complexes (CICs), which--via activation of the complement system--may result in immune injury of the endothelium and thereby exacerbate atherosclerosis; the same mechanism has been suggested to cause retinal arteriolar changes in vasectomized men. We compared 46 men, 5 years after vasectomy, with 46 age-matched control subjects and found no difference in the distribution of arteriolosclerotic retinopathy gradings evaluated by ophthalmoscopy and fundus photography. Blood samples from the two groups were collected and handled identically, and no significant difference in activity was found in four different tests for CICs and two tests for split products of complement factor C3. Thus, the results do not support the hypothesis that changes mediated by CICs occur in vessels after human vasectomy.

Biosynthesis of platelet lipids in relation to aggregation in women using oral contraceptives

The platelet lipid biosynthesis in relation to platelet aggregation and lipemia was studied by 14C-acetate and mevalonate incorporation into platelets of seventeen women without medication and of eighteen women using a low estrogen oral contraceptive. The lipid biosynthesis was significantly increased by 59% (mevalonate) and 38% (acetate) in women on oral contraceptives. From mevalonate, lipid synthesis was increased mostly in the lanosterol-dihydrolanosterol fraction (p less than .01). From acetate, lipid synthesis was significantly enhanced in all the lipid classes. In the oral contraceptive group, the response of platelets to thrombin aggregation was only slightly higher, but HDL-cholesterol was significantly lower. However, in the women using oral contraceptives, the percentage of abnormal values in HDL-cholesterol, thrombin-aggregation and acetate incorporation into lanosterol was similar. Thus, more than 40% of the women studied here, using low estrogen oral contraceptives, presented an increase in platelet lipid biosynthesis, especially in the lanosterol-dihydrolanosterol fraction, which was significantly correlated (p less than .05) with the response of their platelets to thrombin-induced aggregation.

Oral contraceptives and prolactinomas: a case-control study

The increase in the number of newly diagnosed cases of prolactinomas seems to coincide with the use of oral contraceptives during the past two decades. The following retrospective case-control study was undertaken in an attempt to disprove a null hypothesis of relationship between oral contraceptive use and prolactinomas. Each of 70 patients operated upon for removal of a prolactinoma was closely matched for age, gravidity, and year of final diagnosis with one patient in each of three control groups. The control groups selected were constituted, respectively, of patients with secondary amenorrhea and normal prolactin levels, patients with normal ovulatory cycles consulting for infertility, and subjects without medical or gynecologic problems. No statistically significative differences were found in the exposure rates to oral contraceptives among four groups. This study thus failed to reveal a significant association between prolactinomas and oral contraceptives but, given the sample size, a relative risk lower than 3.32 cannot be demonstrated or disproved.

The role of augmented Hageman factor (factor XII) titers in the cold-promoted activation of factor VII and spontaneous shortening of the prothrombin time in women using oral contraceptives

Spontaneous shortening of the Thrombotest time and an increase in factor VII activity after cold storage of plasma in plastic vials have been described in the plasma of women using OCAs. The phenomenon if CPA is dependent on the presence of HF (factor XII) and is associated with increased plasma kallikrein activity and the disappearance of C1-INH activity. In the present study, spontaneous CPA and shortening of the prothrombin time were observed in 66% of women using OCAs. The prothrombin time was inversely related to factor VII activity and HF coagulant titer, whereas factor VII activity was strongly associated with the titer of HF. The addition of purified HF to normal plasma to a degree observed in OCA users promoted CPA generation and shortening of the prothrombin time. In contrast, reduction of the HF coagulant titer in the plasma of OCA users to a normal level prevented the rise in factor VII activity and shortening of the prothrombin time after cold storage. These data indicate that a high titer of HF, such as that observed in OCA users, is needed for the spontaneous CPA and add support to evidence linking the extrinsic and intrinsic pathways of clotting. The relationship of this in vitro phenomenon to the pathogenesis of thrombosis in women using OCAs is presently unclear. (J Lab Clin Med 99:363, 1982.)

Protection against endometrial carcinoma by combination-product oral contraceptives

Seventy-nine patients with endometrial carcinoma were compared with 203 control subjects regarding their use of combination-product oral contraceptives (OCs). Overall, 6.3% of patients and 15.3% of control subjects had used these products. The risk of endometrial cancer for users of OCs was less than half the risk for nonusers. Five years or more of use reduced the risk to a third. Recent users were strongly protected, whereas discontinuation resulted in risks returning to those of nonusers. Furthermore, OCs with predominantly progestational effects of intermediate formulations produced greater protection than those with predominantly estrogens. This pattern of results is biologically consistent with a protective effect of combination-product OCs against endometrial carcinoma.

Immunological and clinical consequences of vasectomy

Blood samples from 109 vasectomized and 100 non-vasectomized fertile men were tested for antisperm antibodies using Tray Agglutination Test (TAT) and Sperm Immobilization Test (SIT), Cell Mediated Immunity to sperm using Leukocyte Migration Inhibition Test (LMIT). Incidence of antisperm antibodies in vasectomized group was 76.2% by TAT and 13.8% by SIT whereas in control group was 11% (p less than 0.001) and 3% (P less than 0.01) respectively. Titre of TAT antibodies increased with post vasectomy period even beyond 20 years post vasectomy. High Incidence of TAT titre of greater than 1:250 was observed in vasectomized men with post operative complications. No significant incidence of positive LMIT to sperm antigens was detected in vasectomized group as compared to control group.

Effect of chronic oral contraceptive steroids on theophylline disposition

The effect of chronic oral contraceptive (OC) usage on the disposition of theophylline was examined. Aminophylline solution (4 mg/kg) was given orally to 8 healthy female non-OC users and to 8 healthy women who were chronic (greater than 6 months) OC users. The OC user group had a significantly lower total plasma clearance of theophylline than women not using OC (35.1 +/- 5.6 vs. 53.1 +/- 14.5 ml/h/kg). The t1/2 was also significantly prolonged in the OC group (9.79 +/- 1.43 vs. 7.34 +/- 1.75 h) while the volume of distribution was similar between the 2 groups. The serum ethinylestradiol (EE) concentrations after oral OC administration were measured simultaneously. The apparent clearance of EE was about 30% lower in the OC users. A significant positive correlation was found between the apparent clearance of EE and the plasma clearance of theophylline. The effects of OC are predominantly due to chronic use with decreased elimination of both theophylline and EE.

Reversal of vasectomy: the effects of sperm antibodies on subsequent fertility

Antisperm antibodies were measured in serum and seminal plasma in 130 males before and after vasectomy reversal and the occurrence of pregnancy was analysed in the partners of 77 who were followed for more than one year. Sperm-agglutinating antibodies were found in the serum of 79% of patients; seminal plasma antibodies were present in only 9.5% before reversal and this rose to 26% afterwards. Pregnancies occurred in the partners of 53% of those men who were trying to produce children. A pregnancy was significantly less likely when the pre-operative serum antisperm antibody titre was 512 or more, but no decrease in fertility was seen with titres below this. Several pregnancies were produced by patients with seminal plasma antibodies, but numbers and follow-up are too small to permit detailed analysis. A randomised controlled trial of per-operative steroids showed that they produced no benefit. The antisperm antibodies associated with vasectomy reversal appear to differ fundamentally from those occurring in naturally subfertile males.

Prophylaxis against prostaglandin-induced gastrointestinal side effects

Prostaglandin F2 alpha was administered intravenous drip in 130 patients with missed, incomplete inevitable and septic abortion, intrauterine death and vesicular mole and for therapeutic termination of midtrimester pregnancies. In 84 patients (control group), no prophylactic antiemetic or antidiarrheal drugs were administered, while in 46 patients (study group), an antiemetic (prochlorperazine) and an antidiarrheal (diphenoxylate hydrochloride with atropine sulfate) drug were administered prophylactically before and during prostaglandin infusion. The incidence in vomiting and diarrhea was statistically much less in the study group (P less than 0.0005 for vomiting and P less than 0.005 for diarrhea). There was no statistically significant difference in the success rate of prostaglandin induction in the two groups.

Exogenous estrogens and endometrial cancer: a case-control study and assessment of potential biases

Eighty-eight cases with newly diagnosed carcinoma of the endometrium and 177 age-matched neighborhood controls were interviewed to test the hypothesis that exogenous estrogens lead to an increased risk of endometrial cancer. Forth-five per cent of the cases and 22% of the controls reported a history of estrogen use which yielded an odds ratio of 2.9 (confidence interval (Cl) 1.7-5.1). Women with five or more years of estrogen use had an odds ratio of 8.6 (Cl 3.2-23.0). Approximately 80% of the estrogen users had used conjugated equine estrogens. For these women the odds ratio was 4.0 (Cl 1.9-8.4) for daily dosages of more than 1 mg of estrogen. Several sources of bias which might affect the estrogen association were investigated. These included comparability of cases and controls, selection procedures, difference between estrogen users and nonusers, exclusion of controls who had hysterectomy, source of estrogen information, and differential recall. The concept or medical surveillance was evaluated by access to medical care and prior history of dilatation and curettage. The strong association between exogenous estrogen use and endometrial cancer remained after consideration for the effects of these biases.

Cost of case-control studies

A financial review of five case-control studies concerning the relationship of birth control methods to the occurrence of disease was conducted. The review had two major objectives: first, to identify costs associated with the planning, conduct and analysis of case-control studies; second, to assess whether sample size determination based on optimal allocation would have resulted in a significant reduction in cost. The data collection phase represented about 75% of the total cost of a study, whereas the costs of planning and analysis were roughly 10% and 15% of total cost, respectively. The typical cost in mid-1970s dollars was from +100-+200 per subject. Evaluation of an optimal allocation procedure based on the relative cost of cases and controls demonstrated that such a method was likely to reduce total study cost by at most 2 per cent.